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Ondersoek: Erdwurm - Biologie

Ondersoek: Erdwurm - Biologie


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In hierdie ondersoek gaan jy die kenmerke van 'n lewende erdwurm (Lumbricus terrestris) ondersoek. Hanteer ook die wurms sagkens, die doel is om inligting in te samel sonder om die monster te benadeel.

Kan 'n erdwurm van onder af vertel?

Kyk na die erdwurm terwyl dit beweeg. Erdwurms het nie aanhangsels (soos arms of bene), maar hulle het bilaterale simmetrie. Dit beteken hulle het 'n linker- en 'n regterkant, 'n voor- en 'n agterkant, en 'n bo- en onderkant. Die wetenskaplike name vir hierdie streke is:

Bo = Dorsale Onder = Ventrale Voor = Anterior Agter = Posterior

1. Hoe kan jy die dorsale van ventrale kant onderskei?

2. Hoe kan jy die anterior van posterior kant onderskei?

3. Benoem die kante van erdwurm deur die wetenskaplike name te gebruik:

4. Geotaksis is die beweging van 'n organisme in reaksie op swaartekrag. Hou die gesondheid en veiligheid van jou monster in gedagte, beskryf hoe dit reageer op omgedraai word asook hoe dit reageer op gekantel in die skinkbord.

Deel alle erdwurms dieselfde kenmerke?

Baie organismes het verskillende morfotipes, of variasies binne 'n spesie. Byvoorbeeld, kleur in swart bere kan wissel van bruin tot grys tot swart. Sommige organismes vertoon ook seksuele dimorfisme, waar die wyfies van die spesie anders lyk as die mannetjies. Byvoorbeeld, 'n leeumannetjie sal 'n groot maanhare hê, maar
wyfies nie.


Plaas jou erdwurm langs die erdwurm van die groep langs jou. Neem hul kenmerke noukeurig waar, fokus op dinge soos grootte, kleur, aantal segmente en ander eksterne kenmerke.


1. Wat het hulle in gemeen?

2. Wat is die verskille wat jy tussen die wurms kan waarneem?

3. Erdwurms is hermafrodiete, wat beteken dat hulle beide manlike en vroulike geslagsorgane (testes en eierstokke) het. Die verdikking van die liggaam by ongeveer segment 30 word die klitellum genoem. Uitruiling van sperm vind in hierdie streek plaas, met elke wurm wat sy maat se eiers bevrug. Vind die klitellum op jou erdwurm en vergelyk dit met ander wurms. Oorweeg die volgende:
Is die klitellum op alle erdwurms sigbaar?
Is die klitellum op dieselfde plek op alle wurms?
Is dit dieselfde grootte?
Hoe kan jy enige waargenome verskille verduidelik?

Watter sintuie het die erdwurm?

Soos alle lede van die diereryk, is erdwurms heterotrofe, wat beteken dat hulle kos moet bekom. 'n Plant is 'n outotroof, dit kan sy eie kos van maak
sonlig. Diere gebruik hul sintuie om kos te vind en gevaar te vermy. In hierdie afdeling sal jy bepaal wat die erdwurm in sy omgewing kan aanvoel. Gedrag vind plaas in reaksie op 'n stimulus, soos lig of temperatuur.

Reaksie op vog

Plaas 'n droë papierhanddoek aan die een kant van die skinkbord, hou 'n klam handdoek aan die teenoorgestelde kant. Let op die erdwurm. Beweeg dit een of ander kant toe? Spandeer dit meer tyd aan die een kant? Beskryf jou waarnemings.

Reaksie op Lig

Maak 'n area van die skinkbord donkerder of gebruik 'n flitslig om 'n helder area te maak. Beskryf hoe die wurm op die lig en die donker reageer.

Reaksie op Reuk

Doop 'n q-punt in vryf alkohol en plaas dit naby die kopstreek. Let op: moenie aan die vel raak nie, dit sal die wurm verbrand! Reageer die erdwurm op hierdie stimulus? Is hierdie toets voldoende genoeg om te bepaal of die wurm 'n reuksintuig het? Hoekom of hoekom nie?

Reaksie op temperatuur

Gebruik 'n koue pak of ys om 'n eksperiment te ontwerp om die erdwurm se reaksie op temperatuur te toets. Beskryf jou waarnemings:

Finale Analise - CER

Eksperimentele vraag: Watter sintuie het die erdwurm?


EIS (beantwoord die eksperimentele vraag deur 'n volledige sin te gebruik)

BEWYSE (som op uit jou waarnemings)

REDE: (koppel die eis aan die bewyse of aan wetenskaplike beginsels, antwoord HOEKOM dit die geval sal wees)

WOORDESKATPRAKTYK

Skryf 'n kort definisie vir elk van die volgende terme:
1. Bylaes ________________________________________________________________
2. Bilaterale simmetrie __________________________________________________________________
3. Geotaksis __________________________________________________________________
4. Hermafrodiet __________________________________________________________________
5. Heterotroof ________________________________________________________________
6. Morfotipe ________________________________________________________________
7. Seksuele dimorfisme ________________________________________________________________
8. Stimulus _________________________________________________________________


Praktiese werk vir leer

Klas prakties

Om studente bekend te stel aan aktiwiteite wat noukeurige studie van dieregedrag behels, is op sigself die moeite werd. Dit verg duidelik tyd en moeite om te verseker dat studente die diere gepas hanteer, goeie waarnemings maak en daardie waarnemings aanteken.

As jy wurms versamel as deel van die OPAL-opname, kan jy dit as 'n uitbreidingsaktiwiteit vir sommige studente gebruik. (Sien skakel hieronder: die eerste erdwurm opname data is aan die einde van Mei 2009 versamel, en data-insameling duur tot 2012.) As jy nog nooit die geraas gehoor het wat 'n wurm maak wanneer dit op 'n stuk papier beweeg nie, is 'n verrassende nuwe ervaring wag vir jou!

Les organisasie

Dit sal afhang van of jy kies om 'n paar wurms vooraf te versamel, of wurmversameling as deel van die les in te sluit. As jy die ondersteuning van 'n assistent het, kan 'n klein groepie dalk wurms gaan haal terwyl die res voorberei om hulle waar te neem.

As jy genoeg wurms het vir studente om in pare te werk, is dit die moeite werd om 15 minute te spandeer om die wurms se beweging waar te neem (en luister na die geluid van wurmhare op papier) en 'n verdere 15 minute om diagramme te teken om te wys hoe die wurm beweeg. Gebruik die volgorde van stilbeelde wat hieronder verskaf word om studente te lei wat dit moeilik vind om op die stadiums van voortbeweging te fokus.

Apparaat en chemikalieë

Vir elke groep studente:

Glasplaat (Nota 2)
Erdwurms

Vir die klas – opgestel deur tegnikus/onderwyser:

Graaf (Nota 1)

Mosterdpoeier (opsioneel – sien Voorbereiding)

Plastiekbad (1 liter plus) plastiekbad met klein luggate in deksel en kante wat potkompos bevat

Gesondheid en veiligheid en tegniese notas

Wees versigtig met glasplate
Tref higiëne voorsorgmaatreëls nadat jy grond opgegrawe het – was hande deeglik met seep en warm water.

1 By die keuse van 'n plek om te grawe, wees bewus van die risiko om infeksies van diere-ontlasting op te tel, en die risiko's van skerp begrawe voorwerpe. As jy gebreekte glas- of metaalvoorwerpe blootstel, kies dadelik 'n ander plek. Maak seker dat almal wat die grond hanteer het, hul hande met seep en warm water was wanneer hulle terugkom na die laboratorium en voordat hulle die les verlaat.

2 As jy 'n glasplaat gebruik, moet dit gemaalde of geplakte rande hê. Studente moet dit versigtig hanteer. Wees bewus van jou laboratoriumprosedures om veilig met gebreekte glas om te gaan in geval van ongeluk.

3 Hanteer wurms veilig (vanuit die wurms se perspektief): hou die wurms in 'n vogtige, donker houer, met 'n bietjie sphagnummos (nie sphagnummos turf nie).

Etiese kwessies

Onderwysers moet versigtig wees om hierdie diere bekend te stel op 'n manier wat 'n goeie etiese houding teenoor hulle bevorder en nie bloot 'n instrumentele een nie. Alhoewel hulle eenvoudige organismes is wat dalk nie op dieselfde manier as hoër diere 'ly' nie, verdien hulle steeds respek. Diere moet na die ondersoek onmiddellik na hul oorspronklike omgewing terugbesorg word. Dit ondersteun etiese benaderings vir veldwerk, waar versamelde diere na hul habitat terugbesorg word nadat waarnemings gemaak is.

Prosedure

VEILIGHEID:
Hanteer velle glas versigtig. Ruim enige breekskade veilig op.
Na hantering van grond, was hande met seep en warm water.

Voorbereiding

a Versamel wurms deur in die grond in 'n deel van jou skoolterrein of 'n huishoudelike tuin te grawe. As jy net 'n paar wurms vind, kan die volgende twee metodes meer aanmoedig om na vore te kom.

Metode 1 Ritmiese rocking
Versamel 'n groep van 8-20 studente in 'n sirkel in die area waar jy wurms wil versamel. Vra hulle om saggies heen en weer op die sole van hul skoene te wieg, van hak tot tone en weer terug. Dit is nie nodig om te stamp of kragtige bewegings te maak nie, wieg net bestendig vir 'n paar minute. Wurms sal opduik.

Metode 2 Gebruik mosterd
Die OPAL-wurmopname stel die volgende tegniek voor om wurms te versamel. Grawe 'n put van 10 cm diep en 20 cm x 20 cm breed. Versamel die wurms uit die grond wat jy onttrek. Voeg dan die inhoud van 'n sakkie mosterd (soos in restaurante verskaf) by 750 cm 3 water en gooi dit in die put. Dit moedig diepliggende wurms aan om na die oppervlak te kom. Dit is nie giftig nie en vernietig nie gras of ander plante nie. Die mosterd is effens irriterend vir die wurms, maar verkies bo ander chemikalieë (insluitend opwasmiddel) wat meer skadelik is.

Ondersoek

b Sit 'n wurm in die middel van 'n groot vel papier. Neem sy bewegings waar en probeer om dit te beskryf. Luister mooi na die geluide wat die wurm op papier maak.

c Plaas die wurm oor na 'n glasplaat. Let op hoe dit nou beweeg. Probeer om enige verskille te beskryf.

Onderrignotas

Daar is duidelike diagramme van die stadiums van wurmbeweging in die meeste tradisionele biologietekste.

Hieronder is 'n paar foto's, en ingesluit in hierdie eenvoudige Worm locomotin skyfie-aanbieding (194 KB).

As daar geen agtergrondgeraas is nie, kan jy wurms op papier hoor beweeg – 'n dowwe krapgeluid soos hul hare (genoem chaetae, chetae of setae) betrokke raak by die vraestel. Wurms kan nie 'n greep op glas kry nie en kan dus nie daaroor beweeg nie.

Die volgorde van beweging – om die chetae in een segment te betrek, gevolg deur spiersametrekking om die res van die liggaam na daardie punt te trek – is fassinerend om waar te neem. Hieronder is 'n kort video.

Die materiaal op die OPAL-webwerf help jou om dit verder te neem, en doen 'n uitgebreide ondersoek na erdwurms – wat verskillende spesies identifiseer – en hul omgewing – om grondtipes en sleutelkenmerke van grond te identifiseer.

Gesondheid en veiligheid nagegaan, Mei 2009

Webskakels

www.opalexplorenature.org
OPAL is 'n Groot Lotery-befondsde projek wat daarop gemik is om 'n nuwe generasie natuurliefhebbers te skep en te inspireer deur mense te kry om hul plaaslike omgewing te verken, te studeer, te geniet en te beskerm. Hulle doen vyf opnames regoor Engeland om meer oor ons omgewing te wete te kom, en wil graag hê dat almal betrokke moet wees. Data-insameling strek tot 2012.

Die opnamepakket bevat rekordblaaie en besonderhede van hoe om vir wurms te grawe. Dit bevat ook 'n gedetailleerde sleutel om ongeveer 13 algemene spesies wurm te identifiseer. Dit verhoog leerlinge se bewustheid van biodiversiteit en moedig hulle aan om nader na wurms te kyk.

(Webwerf besoek Oktober 2011)

Verwysing

CLAPSS-materiaal: CLAPSS-gids L275: 'Wetenskap met minibeeste: erdwurms'
Hierdie is 'n omvattende gids met besonderhede oor hoe om wurms veilig te versamel en te hou (uit jou oogpunt sowel as die wurms s'n) en voorstelle vir 'n verskeidenheid waarnemings en ondersoeke van wurmaktiwiteit.

© 2019, Royal Society of Biology, Naorojistraat 1, Londen WC1X 0GB Geregistreerde liefdadigheidsorganisasie No. 277981, Ingelyf deur Royal Charter


Erdwurm fibrinolitiese ensieme

Naam en Geskiedenis

Die erdwurm word al duisende jare in tradisionele Chinese medisyne gebruik. Vyfhonderd jaar gelede is die erdwurm in die bekende mediese boek as 'n 'aarddraak' beskryf Kompendium van materiale, waarin dit voorgeskryf is as 'n koorswerende en diuretikum sowel as vir geelsug. Hierdie middel word steeds as 'n tradisionele volksmiddel in China, Japan, Korea en ander lande gebruik.

Aan die einde van die negentiende eeu het Frédéricq [1] ontdek dat 'n ensiem wat uit die spysverteringskanaal van erdwurms afgeskei word, proteolitiese aktiwiteit het, en verskeie proteases wat kaseïen, gelatien en albumien kan verteer, is later in 1920 uit die erdwurm geïsoleer [2] . Grootskaalse studie van erdwurm-ensieme het in 1980 begin. Mihara et al. [3] het 'n groep erdwurmproteases van erdwurm geïsoleer Lumbricus rubellus, dan is meer isosime gevind van verskillende erdwurmspesies insluitend ses proteases van erdwurm L. rubellus en agt geglikosileerde tripsienagtige proteases van erdwurm Eisenia fetida [4] .

Erdwurmproteases is multikomponent, wat lei tot verskillende isosime wat uit verskillende spesies erdwurms geïsoleer is. Die proteases word onafhanklik in navorsingsgroepe bestudeer [3,5]. As gevolg van die gebrek aan standaard nomenklatuur, is verskeie name deur verskillende laboratoriums gebruik om dieselfde ensiem te beskryf [3,5]. Gerieflikheidshalwe noem ons die proteases in ons laboratorium volgens hul genus, spesie en funksie, byvoorbeeld 'n protease van E. fetida is genoem E. fetida protease (EfP).


Erdwurmgroep-eksperiment

Watter werklike wêreldprobleem kan verband hou met die doen van 'n eksperiment op erdwurms? Hoe kan dit verband hou?

Om te weet dat wurms 'n baie groot deel is van hoe plante en groente groei en 'n manier is wat diere kan help om te oorleef, as ons van hulle ontslae sou raak, sou dit binnekort baie probleme veroorsaak. Wat dan verband hou met aardverwarming. Die rede waarom aardverwarming verband hou met 'n eksperiment soos hierdie, is omdat dit wys dat as die omgewing te koud of te warm was, die wurms in elk geval geneig sal wees om uit te sterf en gou later sal uitsterf. Jy weet dit dalk nog nie maar wurms speel 'n groot rol in ons omgewing. Sonder hierdie wurms sou organiese materiaal nie ontbind word nie, die voedingstowwe in plante en groente sou nie toeneem nie en sal in werklikheid verminder, en die grond wat gestruktureer is, sal binnekort beskadig word wat die tempo van waterinfiltrasie sal beïnvloed, en laaste maar nie ten minste sonder wurms sal die voedselketting 'n ramp word en nog baie meer. Soos gesien kan word, sal ons omgewing sonder erdwurms die omgewing beïnvloed.

Vraag: Watter onderwerpe gaan jy aan jou navorsing koppel?

Antwoord: Onderwerpe wat ons aan ons navorsing gaan koppel, is die algemene gedrag van erdwurms, die temperatuur ondergronds, en feite oor aardverwarming en wat aardverwarming werklik is.

Vraag: Wat is jou werklike wêreld probleem?

Antwoord: Die werklike wêreldprobleem is hoe aardverwarming in werklikheid erdwurminteraksies teenoor mekaar en die omgewing beïnvloed.

Vraag: Watter data het jy om aan te dui dat dit eintlik 'n probleem is?

Antwoord: Data wat ons moet voorstel dat dit 'n werklike probleem is, want as dit warm word, sal die wurms te versprei wees en die grond sal nie genoeg voedingstowwe kry wat die groei van plante, groente en ens beïnvloed nie.

As die erdwurms in 'n kouer omgewing is, sal hulle saamgroepeer om warmte te bewaar.

Onafhanklike veranderlike:

Afhanklike veranderlike:

Aantal wurms in 'n groep

  1. Dieselfde aantal wurms in 'n groep
  2. Dieselfde tipe grond
  3. Dieselfde tipe basis
  4. Dieselfde wurms gebruik

Item Prys # items Totale koste per item Groeplid in beheer van die verskaffing van item
Skoendoos 1 Eren
Kleefplastiek 1 Yaritza
Potgrond 1 Aaron
Termometer 1 Maria

(Papier, potlode/penne en internetgebruik ook. Almal het dit en gratis.)

  1. Dra altyd handskoene wanneer die wurms hanteer word.
  2. Wees versigtig wanneer jy die graaf hanteer en wees versigtig om nie jouself seer te maak as jy die wurms opgrawe nie.
  3. Wees versigtig wanneer jy gate deur die deursigtige omhulsel steek, jy kan jouself steek.
  4. Geen perdespel rondom die eksperiment nie en versigtig met al die toerusting.
  5. Maak agter jouself skoon wanneer jy die eksperiment doen en hou 'n skoon werkspasie.
  6. Was altyd jou hande nadat jy aan vuil stowwe geraak het.
  7. Vra altyd toestemming of vrae van volwassenes en/of onderwyser(s).
  1. Versamel drie gesonde wurms, hetsy in die winkel of van ondergronds af, of dié wat jou biologie-onderwyser vir jou gee.
  2. Kry 'n skoenboks sonder 'n deksel van 31" lengte en 17" breedte.
  3. Plaas ’n dun lagie potvuil wat ½” hoog word op die onderkant van die skoenboks.
  4. Plaas die wurms versigtig op die grond.
  5. Plaas dan 'n termometer om die temperatuur van die grond te meet, om dit as die beheer te hou.
  6. Kry plastiek wrap met ten minste ses gate en bedek die bokant van die skoenboks. Nadat u temperatuurmetings sowel as waarnemings gekry het, teken data in grafiekvorm aan.
  7. Plaas skoenboks in 'n kamertemperatuur-omgewing vir een dag en teken elke uur vir drie uur aan en teken temperatuurmetings sowel as waarnemings in grafiekvorm aan.
  8. Herhaal stap sewe maar plaas boks buite in die sonlig.
  9. Herhaal stap sewe weer, maar plaas die boks hierdie keer in 'n donker en koue omgewing.

Koue omgewing (F) Warm omgewing (F) Kamer Temp (beheer) (F)
Temp voor die eksperiment 59 grade 80 grade 70 grade
1 uur 57 grade 81 grade 71 grade
2 uur 58 grade 80 grade 71 grade
3 uur 49 grade 80 grade 69 grade
Waarnemings in 'n koue omgewing Waarnemings in 'n warm omgewing Waarneming in 'n kamertemp omgewing
1 uur= Tot dusver het die wurms geen interaksies met mekaar gemaak nie, en dit lyk of elkeen van die wurms in hul eie klein hoekies is. 1 uur= Teen die eerste uur lyk hul optrede heeltemal normaal, behalwe dat hul vel 'n bietjie droër lyk as gewoonlik, is hulle steeds in orde. Geen interaksies met mekaar tot dusver nie. 1 uur= Gedurende die eerste uur het die wurms soms met mekaar saamgedrom, maar buiten dit is hul optrede weer normaal.
2 uur = Soos dit begin kouer word het die wurms (wel 2 van hulle) met mekaar begin meng. 2 uur= Wat die tweede uur betref, het dit gelyk asof hulle almal apart van mekaar was. Weereens nee

Die wurms in 'n koue omgewing van 57 ° F vir die eerste uur van die eksperiment was normaal. Daar was geen oorsaaklike interaksie per sê nie maar elke wurm was in hul hoek besig om hul eie ding te doen. In die derde uur toe die temperatuur 49 ° F gedaal het, was dit egter maklik om af te lei dat hul gedrag in die derde uur heeltemal anders was as hul optrede in die eerste uur. In die derde uur was al die wurms opgekrul en vermeng met mekaar op soek na warmte. Aanvanklik was die wurms almal apart van mekaar, maar nou is hulle almal saamgedrom.

Nou is die wurms in 'n warm omgewing van 81° F geplaas. Teen die eerste uur het die wurms weer geen interaksies met mekaar gemaak nie, en alles het heel normaal gelyk. Toe in die tweede uur was daar steeds geen interaksies nie, maar hierdie keer in plaas daarvan dat hulle teruggaan na hul hoeke, het hulle onder die grond ingekruip. Teen die derde uur, toe die temperatuur tot 80°F gedaal het, was die wurms steeds onder die grond begrawe.

Laastens is die wurms in 'n kamertemperatuur omgewing van 70 ° F geplaas. Anders as die wurms in 'n koue of warm omgewing waar hulle in die eerste uur geen interaksie met mekaar gehad het nie, sou die wurms in die eerste uur wat in kamertemperatuur geplaas is, eintlik vir die meeste van die tyd langs mekaar saamdrom. Sodra die tweede uur egter getref het, het die wurms hierdie keer teruggegaan na hul eie uithoeke, soos in die eerste uur toe hulle in 'n koue omgewing was. Toe die derde uur aanbreek, het twee van die wurms onder die grond gelê, maar het toe na 'n rukkie teruggekom na die oppervlak. Al met al was die wurm se interaksies toevallig.

Al hierdie interaksies kan ons vertel wat met ander spesies kan gebeur as die aarde aanhou om aardverwarming te verduur.

Aaron Alfaro:

Die doel van die laboratorium was om uit te vind hoe wurms op mekaar reageer afhangende van die temperatuur. Die probleem kan met die werklike lewe verband hou, want as die temperature verander as gevolg van aardverwarming, kan dieregedrag ook verander. Daar is aan hierdie probleem gedink nadat gesien is dat die wurms saamgeklomp is nadat hulle uit 'n vrieskas gekom het, en nadat dit in warmer temperature geplaas is, het hulle meer versprei. As gevolg van hierdie waarneming was die hipotese vir hierdie eksperiment “As erdwurms in 'n koue omgewing is dan sal hulle saam groepeer.” Na voltooiing van die eksperiment, is uitgevind dat die hipotese korrek was.

Die gedrag van die wurms het verander soos die temperatuur verander het, soos die hipotese gestel het. In temperature rondom 49 grade Fahrenheit het die wurms gegroepeer vir warmte. In temperature hoër as of gelyk aan 70 grade Fahrenheit, het die wurms na hul eie hoek gegaan en ondergronds gegaan. Die wurms het ondergronds gegaan in 'n poging om af te koel. Die eksperimente het sonder enige probleme verloop. Daar is geen oënskynlike rede om hierdie resultate nie te glo nie, aangesien daar min of geen eksterne veranderlikes was wat die eksperiment kon deurmekaar krap nie.

Die eksperimente het getoon dat wurms wel hul gedrag en interaksies met elkeen verander op grond van die temperatuur. Daarmee saam is gevind dat die hipotese korrek was en dat wurms wel in koue omgewings saamdrom. Die manier waarop die eksperiment verbeter kan word, is op verskeie maniere. Eerstens kan die boks groter wees en daar moet 'n groter hoeveelheid wurms wees, so inligting oor gedrag kan meer akkuraat wees. Ook, as daar 'n manier was om die temperatuur meer effektief te beheer, kan dit ook meer akkurate resultate gee. Van die data wat ingesamel is lyk daar’t enige ruimte vir 'n opvolg eksperiment te wees.

Daar blyk nie meer vrae te wees wat gevra kan word wat nie deur die eksperiment beantwoord word nie. Die enigste vrae wat by my opkom, is temperature waarin wurms kan oorleef. Dit kan maklik gevind word deur na artikels oor wurms deur 'n soekenjin te soek. Hierdie inligting kan belangrik wees, want as die Aarde’ se oppervlak te warm word vir wurms, kan dit 'n groot probleem veroorsaak. Dit is as gevolg van hoe wurms voedingstowwe in die grond versprei. Hulle eet grond nader aan die rots, en bring dan die voedingsryke grond op om die bogrond te vervang, en dan

Bring die bogrond onder af. As die oppervlak is te warm vir die warm vir die wurms om op te staan, dan plante sou’t in staat wees om die ryk grond van onder af te kry, en dus sou daar minder plante wees, of glad nie. Dit is die enigste vrae wat nagevors moet word om beantwoord te word.

Nayeli Alvarado:

Die doel van hierdie laboratorium was om 'n probleem te vind wat verband hou met die wurms wat ons gegee is en hulle in verband te bring met 'n werklike wêreld probleem (en 'n eksperiment daarmee te doen). Die vraag waarmee ek vorendag gekom het, is as ons wurms in verskillende omgewings met verskillende temperature plaas, hoe sal hulle met mekaar omgaan. Die hipotese was “As die erdwurms in 'n koue omgewing is, dan sal hulle saam groepeer om warmte te bewaar.” Hierdie eksperiment kan verband hou met aardverwarming, wat soos almal weet 'n geleidelike toename in die gemiddelde temperatuur van die Aarde maak’ 8217s atmosfeer, en wys vir ons dier (en selfs menslike) interaksies gebaseer op die klimaatsverandering. Nadat ons ons eksperiment getoets het, is ons hipotese reg bewys.

As ons na die datatabel kyk, is getoon dat die wurms se gedrag teenoor ander eet verander het wanneer die temperature verander het, wat verder ooreenstem met die hipotese hierbo gestel. Wanneer die temperatuur onder 60 grade Fahrenheit was, het die wurms saamgegroepeer en probeer om warmte te bespaar. Hulle het saamgedrom en inmekaar gekyk met mekaar. Tydens kamertemperature (70 grade) het die wurms anders opgetree, sommige het saamgegroepeer terwyl ander net ondergronds sou gaan en/of alleen sou bly. As die temperatuur bo 75 grade Fahrenheit sou styg, sou die wurms so ver as moontlik van mekaar af bly en selfs ondergronds gaan om hulself af te koel. Nie net dit nie, maar hul vel het ook gelyk of hulle droog en grof lyk. Daar was amper geen probleme met die doen van hierdie eksperiment nie, want ons het basies net die wurms na verskillende plekke geskuif en hulle dan waargeneem. Die enigste moeilikheid was om net te maak dat die wurms nie dood is van oormatige hitte en/of koue nie. Daar is net een rede waarom ek enige ongeloof in my data kan hê en dit is omdat wurms nie buite in werklike sonlig gesit is nie, in plaas daarvan was dit net 'n warm kamer.

Deur hierdie eksperiment het ek geleer dat wurms hul gedrag in verskillende omgewings verander. Basies as dit te warm is, sal die wurms iewers soek om hulself af te koel en in koue omgewings sal hulle probeer om hitte te bewaar. Dit is egter net vaagweg wat dit my geleer het, want die wurms was net 'n deel van die werklike eksperiment. Wat ek bedoel is dat dit nie net die wurms is wat gedrag en interaksies met mekaar verander nie, maar dit kan in werklikheid 'n voorbeeld wees van wat ander soorte spesies in hierdie situasie kan doen. Mense, plante en diere sal moet verander hoe hulle op verskillende omgewings reageer om te oorleef met aardverwarming wat plaasvind. Alhoewel hierdie eksperiment suksesvol was om my probleem te beantwoord en my hipotese korrek te bewys, is daar baie dinge wat ons kon gedoen het om ons eksperiment te verbeter. Eerstens kon ons die eksperiment vir langer sowel as vir meer dae laat loop het, sodat ons meer data kon bekom. Ons kon ook die boks groter en meer realisties gemaak het vir 'n wurm se natuurlike habitat. Sommige foute kon gewees het dat die vuiligheid nie klam genoeg, of diep genoeg was nie. Om die wurms buite en in verskillende gebiede te plaas, kon ons ook meer akkurate data gegee het. Om meer wurms by te voeg, sou ons eksperiment gehelp het en ons selfs meer bewyse gewys het dat ons hipotese reg was (of miskien kon dit selfs verkeerd bewys het). Al hierdie foute en geringe foute kan daartoe lei dat ons opvolgeksperimente maak. Selfs verskillende maar nou verwante eksperimente wat te doen het met aanpassing en bevolking kan gebeur.

Wat is volgende? In die wetenskap is dit altyd die vraag. Wat kom hierna? Daar is 'n paar vrae wat ek oor hierdie onderwerp het. Is dit byvoorbeeld net wurms wat so reageer? Beïnvloed die struktuur en anatomie die manier waarop 'n dier op omgewingsveranderinge reageer? Wat sal gebeur as aardverwarming aanhou gebeur? Wat sal gebeur as dit ophou? Al hierdie vrae kan slegs deur navorsing en my eie gevolgtrekkings/gedagtes beantwoord word. Ek sou dieregedrag, aardverwarming, diereaanpassing, evolusie en nog baie meer moes opsoek. Dit sal my egter help om 'n beter en slimmer mens te word. Nadat ek hierdie eksperiment gedoen het, het my kennis oor spesie-interaksies en aardverwarming verbreed. Dit het my gedagtes oopgemaak vir die nuwe moontlikhede wat in die wêreld kan gebeur met aardverwarming aanpassing, en nog baie meer. Dit het begin met net 'n klein eksperiment op wurms, maar het geëindig met kennis wat gesoek moes word. Maar hey, dit is wat die wetenskap doen.

Erendira Benyo:

Temperatuur affekteer alle lewende organismes in die wêreld, maak nie saak hoe onbeduidend 'n gemiddelde mens mag dink nie. Spesifiek, erdwurms is voortdurend onder verskillende temperatuur, aangesien hulle die ondergrondse bewoon. Erdwurms moet die ontberinge van die versengende hitte en dowwe koue verduur, selfs in die ondergrond. Iemand wat nie met erdwurms vertroud is nie, sal dalk wonder hoe die insekte oorleef tydens lang periodes van koue, sowel as hitte, in hul natuurlike habitat. Wat sou hulle met mekaar optree? 'n Hipotese: As erdwurms in 'n koue omgewing is, sal hulle saamgroepeer om warmte te bewaar.

Deur op hierdie hipotese te reageer, moet 'n eksperiment uitgevoer word, en die veranderlikes en konstantes is almal duidelik. Die onafhanklike veranderlike is die temperatuur, gemeet in grade Fahrenheit. Die afhanklike veranderlike sou dan weer die erdwurminteraksie wees, en dit sou gemeet word met 'n groep erdwurms in 'n ingeslote area. Die konstantes vir hierdie eksperimente sou dieselfde aantal wurms, grond, basis en soort wurm wees. Om die eksperiment suksesvol te laat verloop, moet 'n skoon kartondoos gebruik word, die boonste deel gesny en bedek met deursigtige plastiekwrap. Die plastiekwrap het klein gaatjies wat die bokant bemors, met inagneming dat die wurms suurstof nodig het om te lewe. Sodra dit klaar is, is die wurms op drie verskillende dae in drie verskillende omgewings geplaas. Een dag sou die wurms in 'n kamertemperatuur omgewing wees, die tweede dag in 'n koue, en die derde dag vir drie uur in 'n warm omgewing. Vir die eerste uur van die kamertemperatuur-omgewing het die wurms soms saamgedrom, maar het uiteindelik tipies opgetree. Die tweede uur het die wurms in hul eie klein hoekies gegaan en het soms opgetree soos in die eerste uur. Die derde uur was twee wurms onder die grond terwyl een op die oppervlak was. Na 'n rukkie het die twee wurms weer opgeduik, maar nooit weer werklik interaksie gehad nie. Op die volgende dag met die eerste uur van die wurms in 'n warm omgewing, was hul optrede normaal, maar hul vel het effens droog gelyk. Die tweede uur het twee wurms onder die grond ingekruip. Op die derde uur het al die wurms geweier om op die oppervlak te bly. Die laaste dag het die wurms in 'n koue omgewing gebly. In die eerste uur het die wurms geen interaksie onder mekaar gemaak nie en in hul onderskeie hoeke gebly. Die tweede uur het bestaan ​​uit die wurms wat met mekaar begin vleg het. Die derde uur was al die wurms in 'n knoop opgekrul. Daar was geen probleme binne hierdie eksperiment nie, en dit was alles eg, aangesien die veranderlikes en konstantes dieselfde gebly het.

Deur voort te gaan, leer hierdie eksperiment dat erdwurms in die koue aanmekaar knoop, en in die hitte grawe hulle ondergronds. Deur ons kennis te gebruik, moet erdwurms saam brei om hul liggaamshitte te bewaar. As hulle in hul hoeke gebly het, dan sou hulle heel waarskynlik gesterf het. As die wurms tydens intense hitte op die oppervlak gebly het, sou hulle gedehidreer het en uiteindelik weens hitte-uitputting doodgegaan het. Ten spyte van hierdie bevindinge, kan hierdie eksperiment verbeter word. Die wurms kon aan dieselfde intense hitte blootgestel gewees het, maar oor die verloop van langer ure, om te sien of hul gedrag staties is met die bevindings, of as dit beperk bly tot wat tydens die proewe gebeur het. Daar kon ook 'n paar foute tydens die eksperiment gewees het. Die hoeveelheid hitte kon te intens vir die wurms gewees het, en te veel direkte blootstelling kon as bedreigend vir die wurms ingehou het. Meer eksperimente kan gedoen word deur hierdie moontlike foute in gedagte te hou, om die erdwurms vir ses uur in plaas van drie in die omgewing te hê, ens.

Ten slotte, die hipotese hierbo was korrek. Dit is waar bewys deur die eksperimentering van drie proewe met tipiese erdwurms in die agterplaas. Dit is in die loop van drie dae gedoen en die resultate was akkuraat. Meer navorsing kan egter gedoen word. Hierdie erdwurmlaboratorium kan nuttig wees om 'n groter prentjie te sien. Aardverwarming is 'n baie omstrede kwessie, en hierdie laboratorium kan gesien word om te bepaal of aardverwarming tans plaasvind. Veranderinge is egter nodig om die erdwurmlaboratorium te laat verband hou met aardverwarming. Meer wurms en langer tydperke kan gebruik word om te bepaal of aardverwarming die erdwurms beïnvloed. Aardverwarming kan die wurm’ se eetgewoontes, manier om homeostase, voortplanting, en algehele ewewig van sy omgewing beïnvloed. Erdwurms lyk dalk onbeduidend, maar hulle is insiggewend wanneer dit kom by wêreldbesorgdheid. Hulle kan die samelewing wys hoe aardverwarming 'n werklike probleem is, en hoe mense die mag het om dit te voorkom.

Yaritza Criollo:

Wat ek in my laboratorium gedoen het, was om te eksperimenteer oor hoe 3 verskillende tipes wurms met mekaar sou reageer op grond van die temperatuur van die omgewing. Ek het die wurms in 'n warm omgewing van ongeveer 81 ° F, 'n koue omgewing van 50 ° F en 'n kamertemperatuur area van 70 ° F geplaas. Die doel van hierdie eksperiment was om te sien hoe die wurms met mekaar verbind het en om 'n voorbeeld te gee hoe Aardverwarming selfs die kleinste diere kan beïnvloed. Met die eksperiment het ek en my groep 'n hipotese gemaak dat as die erdwurms in 'n kouer omgewing is as hulle saam sal groepeer vir warmte. This hypothesis that we created proven to be true throughout the experiment.

The data from the experiment technically states that if the worms were to be in a chilly environment then they would huddle around each other looking for warmth, and that worms in a warm environment would want to be separate from one another and lay underneath the dirt. However, if the earthworms were placed in a room temperature environment then their interactions with each other will be “casual”. The experimental and control group of this experiment is that the room temperature room is the control room and the cold/hot room is the experimental group. The reason why the worms had grouped together for warmth in a cold environment is because since they have no exoskeleton they are very sensitive to the temperature. For example, an earthworm in a 50°F environment will feel like a worm that’s in about a 47°F room. The only difficulty with this experiment, to believe or not is, that I had to make sure that the worms wouldn’t die of overheating or too long of an exposure to the cold. The only reason to disbelief my results is that if you actually did an experiment outside where the worms were in their natural habitat them have to adapt to the temperature in my house.

What I’ve learned from this experiment is that animal’s interaction with one another can actually be affected by temperature. Before this experiment I really didn’t believe that the way animals acted towards each other can change based off temperature, especially from small animals such as worms. However, after doing this experiment it proved to me that these small animals can do just that and interact differently depending on the change of temperature. Ways I could have improved my experiment was by actually testing the worms in their natural habitat and adjusting the box where I kept to resemble more of their natural habitat. Experimental errors that could have possibly occurred is that the dirt that I used wasn’t moist enough, and or if I have let the worms under a certain temperature for a too long. These results can create questions like, can earthworms quickly adapt to habitats that aren’t similar to their natural habitat? Also questions like, how long can earthworms withstand severe heat or cold?

Research that can be done to answer my remaining questions is more research about global warming and how too much exposure to hot and cold weather can really affect animals. Also to answer what is next I would have to respond by saying that what is next is now figuring out how and why exposure to too much heat of to the coldness will really affect the animals of all around. For instance, many animals have already suffered from severe heat and or severe coldness. Like amphibians such as frogs, toads, salamanders, and etc. However, some implications to this problem is suggesting things like climate control or having people to start using less gas, start saving energy and much more. All in all, from this experiment I have learned many new information about earthworms and have experienced something new.

Maria Gudino:

In this lab we tested the effect of temperature change on earthworm interaction to see if the earthworms are in a cold environment then they will group together to preserve warmth. The hypothesis was correct b cause in the cold environment the worms were all curled together to preserve worm just like all living things do to preserve warmth.

The data says the control group that was the room temperature experience showed that by the during the experience the worms had some interaction but very little because the worms have some body heat already. Unlike in the experimental groups which was the cold temperature and warm temperature the worms had to interact with each other to preserve warmth in the cold temperature because like all things living we find ways to preserve heat and in the warm temperature the worms were just under the dirt not wanting to come back up to the hot surface because it was too hot for the worms. But there was one difficulty in this experience which was keeping the worms alive. There is no reason to disbelieve the results.

In this experience I learned that worms interact with each other very little in room temperature and interact with each other in cold temperatures. We could improve the experience by having more hours recorded to find the how the worms would interact with each other with for a week in cold, warm and room temperature environments. The follow-up experiment that these results can lead to is if the worm’s interaction would be affected by the changes of the cold temperature.

The research that is next would be how different worms would react to the room temperature and warm, cold temperatures because this in this experiment we are only testing it with earthworms and if we tested it with different worms we might get different results. Another thing that can be researched is the type of soil and how different types of effect the result of the interaction with the worms.


The role of observation in science

Observation became a key part. Our first experience of truly observing earthworms was in Nicole’s lab. She had a number of species, and we were able to see them side by side and watch their movements. Nicole pointed out differences in their appearances and showed us the native O. multiporus, a large bioluminescent specimen. Our observation skills were further honed when Ross Gray posted us 10 different species of earthworms. (They lived in Angela’s fridge until the video crew arrived!)

Next to observe the earthworms was the Worm Team – a year 4 class in charge of the compost system at a local primary school. The students spent a morning learning about earthworm characteristics and observing how the various species looked and moved. Their comments and questions formed the basis of our teaching and learning activities. The earthworms were then set free in Angela’s garden and patch of backyard bush. We still see each other on occasion!


Basic Research Tools for Earthworm Ecology

Earthworms are responsible for soil development, recycling organic matter and form a vital component within many food webs. For these and other reasons earthworms are worthy of investigation. Many technologically-enhanced approaches have been used within earthworm-focused research. These have their place, may be a development of existing practices or bring techniques from other fields. Nevertheless, let us not overlook the fact that much can still be learned through utilisation of more basic approaches which have been used for some time. New does not always equate to better. Information on community composition within an area and specific population densities can be learned using simple collection techniques, and burrowing behaviour can be determined from pits, resin-insertion or simple mesocosms. Life history studies can be achieved through maintenance of relatively simple cultures. Behavioural observations can be undertaken by direct observation or with low cost webcam usage. Applied aspects of earthworm research can also be achieved through use of simple techniques to enhance population development and even population dynamics can be directly addressed with use of relatively inexpensive, effective marking techniques. This paper seeks to demonstrate that good quality research in this sphere can result from appropriate application of relatively simple research tools.

1. Inleiding

There is no need to make a case for studying earthworms, as their role within the soil has been recognized for more than a century [1]. Collectively, these organisms are able to pass vast quantities of soil through their guts and by doing so bring about the creation of an improved crumb structure which incorporates mineral and organic elements and can become a seedbed for plant growth [2]. In addition, earthworms may aerate soils and increase water infiltration, hence reducing soil erosion, by burrow creation [3]. On top of all this some species are more highly regarded as they are attributed with ecosystem engineering capabilities that is, they are able to directly influence the environment around themselves and the availability of resources to other organisms [4].

Many avenues of research are available and this article could very easily seek to review and critique some of the more advanced techniques currently in use within the sphere of earthworm ecology. These might include DNA-related work examining the genome of selected species [12] ecotoxicology, following the accumulation of, for example, heavy metals in the tissues of earthworms on contaminated land [13] or, for example, isotopic work, looking at the transfer of radio-labelled elements through earthworm-linked food chains [14]. However, such relatively high-tech methods will not be the focus of this work, which seeks to generally avoid reliance upon potentially costly and high-maintenance equipment. This article actually aims at doing one thing it seeks to show that the use of low-technology methods is still able to gain insights into fundamental questions relating to earthworms. Much is still to be fully understood about this group, and although many advances have recently been made using sophisticated, expensive equipment/techniques, there is still room for the under-resourced professional or educated amateur to make a serious contribution. To demonstrate this, the article focuses on the following: a description of simple collection techniques, which can assist in revealing a great deal of earthworm community structure, followed by investigation of a major earthworm activity—burrowing and then a close inspection of earthworm life history and behaviours. Each aspect will hopefully show that basic techniques exist within earthworm ecology that can reveal previously unknown information and assist in building a more comprehensive picture of this important animal group.

2. Collection Techniques (First Catch Your Earthworm)

It is often desirable to quantify earthworm number or biomass in a given habitat and/or seek to collect them. A few species show their presence by surface casting (e.g., Aporrectodea longa) or creation of middens (e.g., Lumbricus terrestris) but most require some form of intervention to locate them, due to their totally subterranean existence. To this end, various techniques have been developed to enable earthworm collection. Digging is the simplest, as it requires only a spade and perhaps a quadrat for density calculations but may detect only near surface (epigeic) earthworms and horizontal burrowing (endogeic) species. Adults of deeper burrowing (anecic) species may be missed unless the researcher is prepared to dig a hole to a depth of several metres!

An alternative to digging is the application of a vermifuge (expellent), which when poured on to the soil drives earthworms to the surface as it acts as a skin irritant when contacted in their burrows (direct application, e.g., via a syringe to L. terrestris burrows may be very effective). Various chemicals have been used, with a dilute solution of formaldehyde (formalin) currently recognized as a standard [15], but as this has been reported as carcinogenic, further options have been sought. It is also suggested [16] that there are severe negative effects to other soil fauna, soil respiration, and vegetation cover if formaldehyde is applied. A suspension of table mustard in water has been used [17], but tests [10] have shown that a suspension of mustard powder (e.g., 50 g in 10 litres water) is both cheaper and more effective. More recently use of “hot” mustard has been used to give a more consistent index of earthworm abundance across a range of soil types [18]. As the type of mustard may also affect results, an extract derived from mustard seed Allyl isothiocyanate (AITC) has been used for earthworm collection [19]. AITC has recently been shown as a reliable and promising chemical expellant whether or not used in combination with hand-sorting [20]. Many researchers now advocate that the most effective collection technique is indeed a combination of digging and hand-sorting of soil (deposited e.g., on a plastic sheet in the field) followed by application of a vermifuge to the hole created [10, 20]. Different techniques have in the past given rise to differential collection of species and provided results which are not directly comparable. By contrast, Table 1 provides recent examples of data relating to earthworm density, biomass, and community structure from a variety of British habitats using the same combination of digging and mustard application for collection.

Another collection method is application of an electrical current to the soil. This method is attractive as little or no damage is done to the area sampled and only fallen leaves and overgrown vegetation need be removed prior to sampling to assist earthworm detection. To date only limited work has been undertaken with this method, specifically in agricultural soils [21] possibly because equipment is expensive as an extraction unit to sample 0.2

at a time will cost (at 2009 prices) in excess of $3000.

Having determined which earthworms are present in a given habitat, if desired, it is then possible to experimentally manipulate the earthworms themselves or resources, such as food, in the habitat. Several studies have used field enclosures to investigate the effects of earthworms on soil properties and plants [22, 23]. Such enclosures can be formed with PVC walls, buried in slit trenches to a depth of up to 45 cm and a height of 15 cm above the soil surface. These have been shown to act as effective barriers to lateral earthworm movements. Results have suggested that both earthworm removal and addition of field-collected earthworms within enclosures can be an effective and useful approach for assessing the influence of earthworms on ecosystem processes (see Figure 1).


Associated with earthworm enclosures is a novel method (“tunnel” trapping) that can be used to observe and record emigration of earthworms. Trap units can be combined with earthworm fencing in the field [24], or with mesocosms in laboratory experiments allowing examination of emigration rates, while manipulating biotic and abiotic factors (e.g., population density, community structure, predation, resources availability, temperature, precipitation).

Tunnel traps can be prepared using 1 litre plastic pots with mounted needle-perforated lids. Holes (

mm) drilled in these smaller “capture pots” just below the lid allow insertion of PVC tubing (10 mm ID, 5 cm long) to connect to either earthworm fencing in field enclosures or larger soil-filled mesocosms. Surface migrating species can move from enclosures/mesocosms into traps via the tubing that is aligned at the soil surface (Figure 2). Movement of captured individuals back into containers is prevented by filling capture pots with soil or other suitable medium to half of their total volume. Providing acceptable conditions (e.g., soil and food) in capture pots can allow earthworms to survive for long periods therefore permitting relatively infrequent examination. Tunnel traps have been successfully used in both field and laboratory experiments which aimed to examine dispersal of the anecic L. terrestris as affected by population density and resources availability [24].


Plan view of a tunnel trap showing a mature L. terrestris exiting a 20-litre mesocosm into the attached 1-litre capture pot (lids removed). Insert shows a lateral view of the whole setup.

The types of simple investigation associated with earthworm sampling should allow some of the following questions to be answered.

(i) Which species of earthworms are present within the community in the given habitat

(ii) At what densities (number m -2 ) and biomasses (gm -2 ) are these animals present (iii) What proves to be the most efficient method for collection of given earthworm species (iv) Can populations be experimentally manipulated to test density-related hypotheses (using addition/removal, fencing, and trapping)

3. Burrowing and Burrow Morphology

As with unearthing which species are present, as previously described, working out which species are active and at what depths is not so simple. Again, it usually requires some form of intervention as many earthworms are relatively small and generally live below the surface of the soil. However, some species do proclaim their presence by depositing their casts (faeces) on the soil surface. This is particularly true of larger species which may be digging burrows and have relatively large amounts of earth to dispose of and others which are almost constantly “head down” and “bottom up” producing surface casts. In temperate soils a good example of this is Aporrectodea longa (the black-headed or long worm). When present at high densities, this species is capable of almost totally covering the grass surface of a pasture with casts. It has been suggested that the amount of casting could even be used as a proxy for the density of (known casting) species present in an area [25]. Where the spread of A. longa was being followed, after introduction to an unpopulated site, casting activity was used to follow dispersal of this species through the soil over many years [26, 27]. Another deep burrowing earthworm which provides signs of its presence on the soil surface is L. terrestris. This species constructs “middens” and these structures are normally engineered above the opening of the near vertical burrow used by this animal. Scientists have been aware of such structures since Darwin’s day, but the precise function is still uncertain. Middens consist of organic (e.g., leaf) and inorganic (e.g., pebble) materials gathered together by the resident earthworm and often cemented together with casts. Regulation of burrow temperature and moisture content may be an obvious function, but protection from predators and provision of a food store (a minicompost heap) may be others [28]. Whichever way, the midden and associated burrow forms an integral part of the life of this relatively sedentary earthworm. Recent work [29] has also revealed that many other earthworm species are associated with L. terrestris middens compared with adjacent nonmidden soil so middens may play a major part in determining distribution of other earthworms at a microscale.

Nevertheless, most earthworms are mainly active below the soil surface so most investigations need to proceed within the soil. Using burrows that open at the surface, such as those of L. terrestris, is one way. Observations have shown that large burrows (often referred to as macropores diameter 8–10 mm) may have the capacity to accept relatively large volumes of rainwater and assist with prevention of surface soil erosion. Testing of this type of water entry into the soil is easily undertaken. The simplest method is to create a water-tight, isolated area at the soil surface (an infiltration “ring”) covering a known surface area and then add a known volume of water to that area and record the time taken for all water to enter the soil. Comparing different areas within a given habitat/field can be very revealing, particularly when coupled with earthworm collection from the same areas. A slight elaboration on this technique is to use a vertical column of water (Marriot device) which can be fed directly into a single burrow. Such work investigated the burrow systems of L. terrestris in agricultural systems [30]. Infiltration of water into burrows was examined with the resident earthworm present or after its removal (with a vermifuge)—the earthworm itself forming something of a plug. To further quantify and equate water ingress with burrow morphology, efforts were made to assess the volume of individual burrows. This was finally achieved by the use of a polyurethane resin, poured down the burrow and allowed to set hard [30]. Subsequently the solid representation of the burrow void was dug out by excavation of a pit alongside. Use of coloured pigment within the resin makes visual inspection in situ and after extraction much easier [31] (see Figure 3). A simpler technique than use of resin is use of coloured dyes. Dyes such as methylene blue in water can be poured into burrows or cracks in the soil [3] and then the area around excavated to see the extent of burrow systems present.


A burrow of Lumbricus terrestris filled with white-coloured resin and exposed in the soil profile to its terminal depth at 1 m.

If access to a large digging machine is possible, then excavation of a pit in any soil can be very revealing. As mentioned “resin-cast” burrows can be revealed, but unadulterated burrows, if large enough, may also be seen. For example, during an investigation undertaken during a period of frost depth to 0.5 m, [32] it was possible to follow burrows down to a depth of 1 m by “picking away” at the exposed soil profile with knives. This investigation, more interestingly, revealed much on the behaviour of L. terrestris and the (usually) shallow working Aporrectodea caliginosa during relatively cold periods. However, should it prove impossible to create a large soil pit, then it is possible to consider the activities of earthworms under more controlled conditions in a nonfield setting.

A soil pit exposes a cut surface through the soil profile, which is in essence a 2-dimensional view. This can be recreated by production of what might be viewed as a “wormery”—a structure comprising 2 sheets of glass separated by a very small distance, for example, 5–8 mm. Such structures not only have in the past been sold for domestic use (by children) to observe earthworms but also have a more research-focussed application. Early work [33] allowed use of such structures to observe the burrow formation of earthworms, and more recently these “Evans’ boxes”—also referred to as 2D mesocosms—have been used [34] for similar aims but more specific objectives (see Figure 4). These workers examined the burrowing of L. terrestris but were specifically interested in the interactions between the various life stages of this species and found, until then, previously unrecorded aspects of cocoon deposition in side chambers and encasement of these cocoons with castings (see Figure 5). Such findings clearly demonstrate that observations of this type can reveal burrow-related behaviours which may have some significance in the life of these animals and not have been recognised before, even though this is a very well-studied species [28]. Table 2 shows some of the experimental data also gathered from this investigation.

SD) produced under a number of adult manipulations in Evans’ boxes, kept at

in darkness (CTRL: no manipulation CLtRm: earthworm removed and reintroduced LtRp: earthworm removed and replaced by another LtRm: earthworm removed—adapted from [34]).


Upper 30 cm showing view through the glass side of an 80 cm deep Evans’ box used to examine burrowing behaviour of a single mature L. terrestris (the adult can be seen across the centre).


Detail of a side burrow with L. terrestris cocoon encased in parental casting seen in an Evans’ box with one glass side removed (to permit better photography).

Other ways of tracking earthworm burrows and assessing burrowing behaviours under controlled conditions are available and might be thought more appropriate as they do not occur in two dimensions. Soil cores can be extracted from the field (within suitable housing such as plastic cylinders), for example, by driving these into the soil from above and then maintaining them for the desired purpose. This may be to examine earthworm communities within and how they may assist other ecosystem process, for example, by comparing intact cores with those frozen to remove earthworms. Relatively recently, use of X-ray tomography [35] has been used to determine burrow configurations in such cores. Whilst this may be a useful tool it is one which required access to hospital-grade equipment so it cannot be considered basic. However soil cores can be utilised to study relatively simple “ecosystems” with earthworms as a component. These may allow examination of different animal species present and also plants growing at the soil surface, if kept in glasshouses. Inputs and out flows could also then be measured in simple terms. Taken to extreme lengths, researchers have developed systems such as the “Ecotron” [36] which has incorporated earthworms into its experimental systems but this facility was produced at a cost of $1.5 million. Despite this cost and sophisticated equipment for measuring in and out flows of gases and liquids, the choice of earthworm species, as a part of a biodiversity and ecosystem behaviour experiment [37], may not have been appropriate to the given mesocosms. Once again, a situation, where most expensive and modern, does not necessarily mean most appropriate and insightful. Much more simple investigations in sealed mesocosms (pots) may not give rise to the bigger ecosystem “picture” but may provide good data on earthworm life histories (see below).

Surface-related and burrow-associated investigations might enable some of the following questions to be addressed.

(i) Which species are present at which horizons/depth in the soil profile (ii) What can be learned from earthworm activities at the soil surface (iii) Do burrows assist water infiltration (iv) How can earthworm burrow extent and volume be measured (v) Can the field (cores) be brought into and utilised in a controlled setting (vi) Can mesocosms be used to observe earthworms burrowing behaviour more closely

4. Life History Studies

Many species have been well documented and much is known of their life history, but for example, ask any researcher to tell you what age an earthworm can live to, or which life stage is responsible for dispersal and you may find that no simple answer is forthcoming (even for L. terrestris). Great scope exists for gathering fundamental information on aspects of the life histories of most earthworm species. In Britain, where earthworms are reasonably well documented and a synopsis of species has been available in a number of revised forms for over 60 years [38, 39], information is still lacking in a number of quarters. Byvoorbeeld, Dendrobaena attemsi is described from a single British record from Cumbria yet we have collected this species easily from wooded areas on the Isle of Rum in Scotland. Equally for the same species, and more importantly with respect to life history, entries such as “presumably biparental” and “capsules unrecorded” [39] show that much is still to be learned—and perhaps this can be achieved relatively simply.

Wherever a researcher is based, there will be opportunities to collect local species of earthworm, as previously described. Providing that identification is not a problem, there are then chances to answer basic questions on the life history of the species. Using the soil from where the animals were collected, it should be possible to maintain them in containers of a chosen size, appropriate for the given species and its ecological group. The situation is to then ask relevant questions and seek to answer these through segregation of life stages and sampling at given time intervals. An initial question might relate to the mode of reproduction shown by the given species is it amphimictic (requiring sexual reproduction) or parthenogenetic? To solve this, in the least amount of time, immature individuals need to be isolated and kept thus until they mature. This will naturally require consideration of their requirements in terms of, for example, soil, food, moisture, temperature, and space [40]. Inspection at appropriate time periods, monthly, weekly, or more frequently for rapidly maturing animals will determine when maturity (possession of a swollen clitellum) is reached. At this point the animals might usefully be subdivided into two groups 1 : 2. The smaller third should be left in isolation and the larger two-thirds put into groups of two to give an equal number of singletons and pairs. These labelled containers can then be monitored for cocoon production over the following weeks.

Sampling for cocoons can be straightforward and require a water supply and a mesh of appropriate size—depending on cocoon size—which is a function of clitellum diameter. Contents of containers in which adults have been kept can be sieved to obtain cocoons. These can then be incubated in Petri dishes, or equivalent, on moistened filter paper or similar at an appropriate temperature for the given species [40] (Figure 6). If animals have been kept, for example, in soil columns, then the depth at which cocoons are deposited might be considered by sieving away different levels from the column (more easily achieved if the cylinder in which they are housed is presplit (and taped together) along its length [41]). Incubation of cocoons can then occur and time to develop and hatch can be monitored. To obtain cocoons more rapidly for any species, mature animals which are field-collected can be employed directly in cocoon production studies and number produced per individual per time can be recorded from the given conditions under which they are maintained. Cocoons may be kept in groups or individually (depending on space available). The advantage of individual incubation is that the number of hatchlings can more easily be assessed, as many epigeic species produce more than one hatchling per cocoon. To complete life cycle records, growth of hatchlings to maturity can be assessed. This requires the type of conditions previously described but with periodic monitoring (and mass determination) until maturity is reached (see Figure 7 for typical results). Manipulation of biotic and abiotic factors influencing the growth and reproduction of the earthworms, such as population density [42], food quality [40], interspecific interactions [43], temperature [44], and a host of others and combinations thereof, can be considered. Finally to ascertain the age to which earthworms can live, animals might need to be kept for some time.


Potent harm to woodland plants

Among the invasives the students may find are Asian jumping worms, a robust species that has shown up more frequently at local sites over the past decade. BW Summer Scholar Agrima Pradhan ’17 investigated how these more recent invaders may impact seeds stored in the soil. Nidia Arguedos, Ph.D., a Cleveland Metroparks conservation planner, calls the Asian species, “fantastic,” “incredible,” “muscular” and “very damaging.”

Dr. Arguedos says research like the BW student projects should help scientists understand the role of earthworms in the decline of woodland plants, like spring flowering trillium, which require a slowly decomposing collection of leaves to germinate. Plant ecologists suspect invasive earthworms are speeding up the decomposition, helping to create an inhospitable environment for these tender native plants.


Investigating Phenomena: How Do Earthworms Move?

Phenomena-driven science! Phenomena are observable, naturally occurring events that are everywhere and spark student questions and investigations. Ask students to observe the DCI-linked phenomenon in the video and complete the attached student sheet prior to remote learning discussions.

Waarnemings: Carefully watch the earthworm movement video. Gather all the evidence you can from the video, and write down everything you observe.

Generate Questions: Is there a pattern in the earthworm's body segments? Is there a relationship between segment contractions and direction of movement? Where does the movement start? Does the earthworm pull or push itself? How does the earthworm's body structure relate to how it moves?

Research (include sources):

Final Explanation: Use a written explanation, graphic, or flow chart to present your final explanation for an earthworm's movement.


Teaching Notes and Tips

This activity is intended for students who are ready to start exploring the use of inquiry on a regular basis. In my classroom that is generally the way that things will go for the year, so this is a non-essential lab that helps them to learn the process.

Students may be frustrated at not being given a procedure to follow, so it is helpful to be ready to ask lots of questions to focus their attention back on what they know and what they might want to know.

Additionally, grouping can be a factor in more open-inquiry type labs like this, as students at very different levels may experience a lot of frustration and lack of positive experiences if they are working together. These may be activities where student ability is considered and more closely matched so that each student gets the most from the experience.


Earthworm Biology

The earthworm biology basically consists of an elongated, cylindrical body that is metamerically segmented. A thin cuticle, epidermis and musculature makes up the body wall. The body cavity is a true coelom, as it is lined by the coelomic epithelium. There are four types of cells present in the coelomic fluid: phagocytes, mucocytes, round nucleated cells and the chloragogen cells.

The circulatory system of earthworm is closed type that is made up of blood vessels and capillaries that are fork out all over the body. The plasma and corpuscles make up the blood and it has multiple hearts. The earthworm is a hermaphrodite and reproduction is strictly sexual. The nephridia is distinguished into three types namely, pharyngeal, integumentary and the septal nephridia. The earthworm has a very well-developed nervous system that consist of a simple brain and nerve cord. In this article on earthworm digestive system we will understand the earthworm digestive system in order.


The evolution of earthworms

The humble earthworm might not seem the most exciting of animals. However, as Aristotle and Darwin stressed, their importance to the natural world is immense. New research, published this week in BMC Evolutionary Biology, provides the most comprehensive evolutionary history yet of the origins of the 6000+ species of earthworm. Lead authors Frank Anderson and Samuel James tell us more.

The plough is one of the most ancient and most valuable of man’s inventions but long before he existed the land was in fact regularly ploughed, and still continues to be thus ploughed by earth-worms. It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures.

Charles Darwin, The formation of vegetable mould through the actions of worms, with observations on their habits, bl. 313

The earthworms digging about in your back yard are members of a large, ubiquitous group with a deep evolutionary history. There are over 6000 earthworm species, found on all continents except Antarctica. Most earthworms dwell in soil, but many live in leaf litter, decaying logs and riverbanks, while some live in trees and even along the seashore.

Earthworms are major terrestrial ecosystem engineers and their economic impact is immense—earthworms turn over, aerate and drain soils, providing crucial assistance to farmers and gardeners, and compost-dwelling species are used to process food waste and animal manures. Aristotle recognized their importance as the “Intestines of the Earth”, and their reputation was burnished by Charles Darwin in The Formation of Vegetable Mould through the Action of Worms. On the other hand, a Chinese sage said “watch the earthworm, miss the eclipse”, implying that there are better things to observe. We might disagree, especially in the cases of bioluminescent earthworms, one of which (Avelona ligra) was sampled for this project, wildly colored earthworms (e.g., Archipheretima spp.), and those capable of remarkable feats of climbing, some found 40 meters up in French Guyana rainforests.

Despite their value, earthworms are generally ignored until they are needed for bait or become a problem. Approximately one-third of the earthworm species in North America have been introduced from Europe or Asia. Some have been introduced into northern forests, which have been free from earthworms since the end of the last ice age

11,000 years ago. Many other species in these forests rely on a deep layer of decaying leaf material, and earthworms are uniquely adapted to disturb this material.

Although earthworms are among the most familiar and economically important groups of large invertebrates, their evolutionary history is not well understood. As part of a collaborative effort funded by the US National Science Foundation to study annelid phylogeny, we harnessed high-throughput DNA sequencing to generate transcriptomes for representatives of nearly all of the eighteen living earthworm families as well as several groups thought to be closely related to them and used these data to infer phylogenetic relationships.

We found that the earthworm tree of life consists of two major branches, both with subgroups in the Northern and Southern Hemispheres. One of these branches includes at least three families, two found in eastern North America and one in Madagascar. The other branch contains the vast majority of earthworm species—the northern subgroup includes Lumbricidae, comprising nearly all familiar European species, and the southern subgroup includes Megascolecoidea (a group represented on all southern landmasses plus much of North America), two large Neotropical families and a tropical African family.

One long-standing question is whether the broad geographic distribution of earthworms is due to dispersal between continents (e.g., by rafting) or vicariance—riding the continents as they’ve drifted over several hundred million years—or a combination of these processes. We can use our phylogeny to assess the relative importance of these competing mechanisms, but to do so, we had to calibrate our phylogeny to the geological time scale.

Earthworms have left an impressive record of trace fossils, but it is difficult to determine which species made a particular set of fossilized burrows, since body fossils are extremely rare. However, earthworms and their relatives lay their eggs in cocoons, and sometimes these cocoons fossilize. Leech cocoon fossils are known from the late Triassic, 201 million years ago, which tells us not only the minimum age of leeches, but also the minimum age of the common ancestor of leeches and earthworms. We were able to use these fossils to calibrate our phylogeny and infer divergence dates.

Our analyses reveal that the ancestor of all living earthworms probably lived over 209 million years ago, making earthworms about as old as mammals and dinosaurs. Our date estimates for the divergences between the Northern and Southern Hemisphere subgroups of the two major branches of earthworms fall between 178-186 million years ago, coinciding with the breakup of the supercontinent Pangaea 180-200 million years ago and corroborating the hypothesis that continental breakup influenced early earthworm diversification. This also implies that earthworms likely inhabited Antarctica before the continent’s southward drift made it inimical to most terrestrial animal life.

Our phylogeny also provides a robust framework for investigating several questions about earthworm evolution. At several points in the phylogeny, earthworms have transitioned from terrestrial to aquatic habitats and vice versa. Most species in Clitellata (the group that includes earthworms) are aquatic, so earthworm genomes may retain ancestral genes that enable transitions between habitats. Alternatively, certain features may have been reinvented at each habitat transition. We have begun to explore this question, and hope to investigate other aspects of earthworm gene and genome evolution in our future work.


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