Polyculture of the shrimp Litopenaeus vannamei and the sea urchinLytechinus variegatus

摘要

Polycultures potential has been researched for many species as it represents a potential cost savings to aquaculturists. This study examines the feasibility of L vannamei and L. variegatus poly-culture. Ninety-six 19-L tanks connected to a semi-closed recircu-lating seawater system were stocked with one L. vannamei. Each tank contained two elevated mesh cages to which 0, 2, or four sea urchins/tank were added. Sea urchins were fed ca. 0.3 grams of a 27% protein research feed per day per urchin. Treatments (N = 16) were: 1) two urchins per tank plus 0.2 grams per day of a supplemental commercial 45% protein shrimp feed, 2) two urchins per tank with no supplemental shrimp feeding, 3) four urchins per tank with no supplemental shrimp feeding, 4) zero urchins per tank with 0.2 grams per day shrimp feed, 5) zero urchins per tank with 0.4 grams per day shrimp feed and 6) zero urchins per tank and no supplemental shrimp feeding. Weight gain was similar in shrimp who consumed fecal material from 4 sea urchins to those fed 0.2 grams per day shrimp feed (P > 0.05). Weight gain was higher in shrimp who consumed fecal material from two urchins plus 0.2 grams per day of supplemental shrimp feed, and was equivalent to shrimp fed 0.4 grams per day shrimp feed (P > 0.05). Fecal material alone from two urchins was not able to sustain shrimp growth. Data indicates L. vannamei is able to utilize sea urchin fecal material which enhances the likelihood of successful commercial polyculture.