Worms

Welcome to the

Wonderful World of

Earthworms 

Free-living, beneficial  Non - Parasitic!  Improve soil structure and fertility  Enhance microbial activity that promotes plant growth and health  Serve as natural food for fish, birds and mammals

(Source: Cuendet and Bieri, 1999)

“Intestines of the Earth” - Aristotle “Ecosystem Engineer” - Lavelle et al. “Angel in the Backyard”

Biology of Earthworms 

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

(Source: Gaddie and Douglas, 1975)

Biology of Earthworms 

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Number of Earthworm Species ±4,000 in the world 400 > in the Philippines

Characteristics   

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Breathe through their skin Hermaphroditic (have both sex organs) Feed on microorganisms (fungi and bacteria) in the soil Active at night Many are migratory

Biology of Earthworms 

Life Cycle Eudrilus eugeniae (“African nighcrawler”) comes from West Africa  Introduced in the Philippines in 1982 by Dr. Otto Graff  Most extensively cultured species in the tropics 

Cocoons (Eggs)

2 wks

Juveniles 2 wks (Young)

Adult (Breeder)

Biology of Earthworms 

Life Span 1-2 years in nature  More than 10 years in captivity 

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Growth Rate 

the “African nightcrawler” can grow to more than 30 cm in length and 3 grams each

Ecology of Earthworms 

Depending on their feeding pattern, earthworms are classified into:  Epigeic – feed on litter at the surface without burrowing in the soil Ex. Eudrilus eugeniae  Anecic – feed on litter at the surface and burrow into the soil Ex. Lumbricus terrestris  Endogeic – feed on soil in permanent burrows Ex. Pontoscolex corethrurus

Cultural Requirements of

Earthworms 

Aeration (porous soil)  

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Moisture (40-80%) 

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For maintenance of body fluids (80% > of body weight)

Temperature  

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Not water-logged Oxygen needed for respiration

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

Organic Matter (decomposed plants and animal matter)

The African Night Crawler 

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Hermaphrodite, having both male testis and female ovary but can not impregnate itself. When two mature worms come together, both worms secrete mucous covering each other with a slime tube from segment 9 to the rear of the clitellum. Both get pregnant.

The African Night Crawler 

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Sexually mature worms breed every week and produce 2-10 worms per cocoon capsule. Adult worm produces about 1 egg capsule per earthworm weekly or 2-3 hatchlings after 3 weeks Hatchlings are tiny white threads about half an inch long but they grow fast reaching sexual maturity in 3-7 weeks. Three months later, they are grandparents!

The African Night Crawler 

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Propagate effectively in culture units that are shaded and well drained Grows up to about 1 gram for mature worm, just about the size of a drinking straw. Segmented worm with a flat belly and appears reddish-pink in color. Eats compost material including manure, live in the upper layer of the soil about 3-6 inches deep from surface

The African Night Crawler  

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More prolific in a controlled environment One kilo of worms may contain 1,0004,000 worms Each worm is divided by two, and the part that contains the vital organs (4 hearts, a gizzard, intestines, male and female sex organs) is the only part that regenerates in time. The other half of it dies.