Wonderful World Wonderful World ofof

Welcome to theWelcome to the

EarthwormsEarthworms Free-living, beneficialFree-living, beneficial

Non - Parasitic!Non - Parasitic! Improve Improve soil structuresoil structure and and fertility fertility Enhance microbial activity that promotes plant Enhance microbial activity that promotes plant

growth and healthgrowth and health Serve as natural food for fish, birds and Serve as natural food for fish, birds and

mammalsmammals

““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)

Biology of Biology of EarthwormsEarthworms ClassificationClassification

Annelida (segmented worms)Annelida (segmented worms) Oligochaeta (few bristles)Oligochaeta (few bristles)

(Source: Gaddie and Douglas, 1975)

Biology of Biology 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

Biology of Biology 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 wksAdultAdult(Breeder)(Breeder)

2 wks2 wks

Biology of Biology of EarthwormsEarthworms Life SpanLife Span

1-2 years in nature1-2 years in nature More than 10 years in captivity More than 10 years in captivity

Growth RateGrowth Rate the “African nightcrawler” can grow to more than 30 cm the “African nightcrawler” can grow to more than 30 cm

in length and 3 grams eachin length and 3 grams each

Ecology of Ecology 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 burrowing Epigeic – 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 into Anecic – 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

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)

Temperature Temperature ““Cold blooded”Cold blooded” Tropical species will die at temperatures below 12Tropical species will die at temperatures below 12ooCC

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)