2. EarthwormsEarthworms
Free-living, beneficialFree-living, beneficial
Non - Parasitic!Non - Parasitic!
ImproveImprove soil structuresoil structure andand fertilityfertility
Enhance microbial activity that promotes plantEnhance microbial activity that promotes plant
growth and healthgrowth and health
Serve as natural food for fish, birds andServe as natural food for fish, birds and
mammalsmammals
3. ““Intestines of the Earth”Intestines of the Earth”
- Aristotle- Aristotle
“Ecosystem Engineer”“Ecosystem Engineer”
- Lavelle et al.- Lavelle et al.
“Angel in the Backyard”“Angel in the Backyard”
- Chinese- Chinese
(Source: Cuendet and Bieri, 1999)
5. Biology ofBiology of EarthwormsEarthworms
Number of Earthworm SpeciesNumber of Earthworm Species
±4,000 in the world±4,000 in the world
400 > in the Philippines400 > in the Philippines
CharacteristicsCharacteristics
Breathe through their skinBreathe through their skin
Hermaphroditic (have both sex organs)Hermaphroditic (have both sex organs)
Feed on microorganisms (fungi and bacteria) in the soilFeed on microorganisms (fungi and bacteria) in the soil
Active at nightActive at night
Many are migratoryMany are migratory
6. Biology ofBiology of EarthwormsEarthworms
Life CycleLife Cycle
Eudrilus eugeniaeEudrilus eugeniae (“African nighcrawler”) comes from(“African nighcrawler”) comes from
West AfricaWest Africa
Introduced in the Philippines in 1982 by Dr. Otto GraffIntroduced in the Philippines in 1982 by Dr. Otto Graff
Most extensively cultured species in the tropicsMost extensively cultured species in the tropics
CocoonsCocoons
(Eggs)(Eggs)
JuvenilesJuveniles
(Young)(Young)
2 wks2 wks
AdultAdult
(Breeder)(Breeder)
2 wks2 wks
7.
8. Biology ofBiology of EarthwormsEarthworms
Life SpanLife Span
1-2 years in nature1-2 years in nature
More than 10 years in captivityMore than 10 years in captivity
Growth RateGrowth Rate
the “African nightcrawler” can grow to more than 30 cmthe “African nightcrawler” can grow to more than 30 cm
in length and 3 grams eachin length and 3 grams each
9. Ecology ofEcology of EarthwormsEarthworms
Depending on their feeding pattern,Depending on their feeding pattern,
earthworms are classified into:earthworms are classified into:
Epigeic – feed on litter at the surface without burrowingEpigeic – feed on litter at the surface without burrowing
in the soilin the soil
Ex.Ex. Eudrilus eugeniaeEudrilus eugeniae
Anecic – feed on litter at the surface and burrow intoAnecic – feed on litter at the surface and burrow into
the soilthe soil
Ex.Ex. Lumbricus terrestrisLumbricus terrestris
Endogeic – feed on soil in permanent burrowsEndogeic – feed on soil in permanent burrows
Ex.Ex. Pontoscolex corethrurusPontoscolex corethrurus
10. Cultural Requirements ofCultural Requirements of
EarthwormsEarthworms Aeration (porous soil)Aeration (porous soil)
Not water-loggedNot water-logged
Oxygen needed for respirationOxygen needed for respiration
Moisture (40-80%)Moisture (40-80%)
For maintenance of body fluids (80% > of body weight)For maintenance of body fluids (80% > of body weight)
TemperatureTemperature
““Cold blooded”Cold blooded”
Tropical species will die at temperatures below 12Tropical species will die at temperatures below 12oo
CC
Organic Matter (decomposed plants and animal matter)Organic Matter (decomposed plants and animal matter)
At least 2% to provide substrate for microorganismsAt least 2% to provide substrate for microorganisms
C:N Ratio (proportions of carbon and nitrogen)C:N Ratio (proportions of carbon and nitrogen)