Ref ID : 5901
V. Bouguenec and N. Giani; Biological studies upon Enchytraeus variatus Bouguenec & Giani, 1987 in breeding cultures. Hydrobiologia 180:151-165, 1989
Reprint
In File
Notes
The life history of an enchytraeid worm, Enchytraeus variatus, was studied under laboratory conditions at 18-22 degrees C. This species can reproduce simultaneously by asexual (architomy) or sexual reproduction. The number of ova per cocoon varies from 5 to 20 (average 10.9). The generation period (from cocoon to next cocoon) varies from 14 to 39 days (average 26.1) according to the period of the year. The number of generations per year is between 7.3 and 26.1 (average 14). A mature worm can lay between 23.7 and 25.8 cocoons during its life (254 days as maximum observed) at a mean rate of 0.12 cocoon worm-1 day-1. Experimental cultures were carried out to determine the structure, density and biomass of the populations. A maximal density of 1396314 worms was recorded after 85 days of culture. Net production reached 21.48 g m-2 day-1 after 26 days in a culture initiated from cocoons.