Open AccessSampling Shrimp Populations in Hatcheries
Author(s) -
Juarez Lorenzo M.,
Luxem Allan H.,
Rouse David B.
Publication year - 1996
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.1996.tb00273.x
Subject(s) - shrimp , biology , hatchery , sampling (signal processing) , larva , fishery , coefficient of variation , population , population density , ecology , statistics , fish <actinopterygii> , mathematics , demography , filter (signal processing) , sociology , computer science , computer vision
.– Shrimp populations were estimated with volumetric sampling techniques during different phases of hatchery operations. Factors considered which might effect precision of estimates included stage age, density and temperature. Estimates of nauplii were obtained with coefficient of variation values smaller than 3% when nauplii were concentrated in 20‐L buckets and smaller than 8% when released in 13,000 L of water in larval rearing tanks. In both cases estimates were of sufficient precision to make management decisions for routine hatchery work. A technique was developed for estimating shrimp populations in larval rearing tanks with coefficient of variation values smaller than 15%. Volumetric sampling of postlarvae older than PL 4 , in larval rearing tanks was highly variable due to the tendency of shrimp to congregate and attach to tank walls and bottoms. A direct relationship was observed between postlarval density and the precision of population estimates in harvest buckets. Water temperature and postlarval age did not affect precision at the densities and ages studied. These findings have important implications for commercial transactions. Industry standards utilizing coefficient of variation are recommended for larvae and postlarvae population estimates.