Studies on the larval culture of Varuna litterata
Abstract (Summary)Thesis abstract The body weight, carapace width, carapace length and body depth of both male and female Varuna litterata caught from Kao-ping river increase gradually from March to June. During the same period, the features of ovaries change from brown and inseparable to black and disperse, the diameter increase from 0.2mm to 0.32mm. Matured female can spawn at least three times. However the fecundity decreases gradually. The highest record of larvae release from a single spawn is 145,600. Antibiotic increase larvae survival rate. Larvae survival rate are the best in the groups of 30, 35 and 40 ppt. All larvae die on the 17th day in the groups of 15, 20 and 25 ppt. Larval survival rate is highest.if larvae fed with 10 Artemia per cc. or with 50 rotifer per cc, For zoea fed with Artemia addition of rotifer within the first 20 days enhance their survival. Zoeae fed with rotifer and then Artemia nauplii added as supplement with 8 days after hatching can increases their survival. The survival of zoeae is significantly related to the time of feeding after hatching. Survival desease if zoeae were not fed on the first day. All zoeae die within 5 days if not fed over 4 days after hatching. The zoeae of V. litterata can roughly divided into 7 stages. The first zoea successfully metamorphosed to megalopa on 36 days after hatching.This result is the first time to document the whole zoeal development of V. litterata.
Advisor:none; none; none
School Location:China - Taiwan
Source Type:Master's Thesis
Date of Publication:07/29/2002