Effects of photoperiod, shelter types and canopy openness on the growth of the juveniles and optimal operational sex ratio of the adult Amano shrimp, Caridina multidentata

• Main Author: 詹闓慬
• Other Authors: 賴弘智
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/s5ydgt

碩士 === 國立嘉義大學 === 水生生物科學系研究所 === 106 === Amano shrimp (Caridina multidentata) is an indigenous species from Taiwan which is a vulnerable ornamental shrimp and also the highest live-exported aquarium species of crustaceans. But these shrimps are deeply threated in the wild and short of supply for the aquarium market due to the illegal over-fishing. The researcher tried to build stable mass production techniques in order to supply increasing demands. Due to lack of studies on this shrimp worldwide, the researcher focused on solving problems on juvenile shrimp's incubation and sex ratio of the brood-stocks of shrimps. Consequently, the study was divided into two categories, in terms of the juvenile shrimp growth , this study were choose three environment factors (photoperiod、shelter materials and canopy openness of the shelters materials) to test the effect of these factors on juvenile shrimp's body lengths、body weights and survival rates. In brood-stocks, this study focused on testing different sex ratios on brooding female shrimp's proportion、insemination period and the number of success hatched larvae. Through the results，the researcher try to understand the suitable environment for juvenile shrimp culturing and the operational sex ratio of brood-stocks which provide ground knowledge for farming in the future. The results of this study showed that, juvenile shrimp's total length、weight in long photoperiod group (14L:10D) grow better than short photoperiod group (7L:17D), but the photoperiod was no significant differently affected their survival rate . Among the different kind of shelters, the survival rates of juvenile shrimps was highest in blank group (90.000±7.091%), following with screen net group (90.000±6.047%). Garlic net group has the lowest survival rate (53.750±31.936%).Canopy openness of the materials did no significantly affect shrimp's body length、weight and survival rate. Following this result, breeders should keep the juvenile shrimp under long photoperiod environment, and the shelters can absent or just simply use screen nets. On the other hand, according to second parts results of this study, brood stocks were divided into four groups male/female ratio such as 2:1、1:1、1:3、1:5. The results indicated that the brooding female shrimp's proportion and insemination period was no significant effect between the different sex ratio groups. Among these groups, sex ratio 1:1 group has the highest success hatching larvae, and the larvae numbers also significant higher than 2:1 groups. Filially, quadratic regression was applied to analysis the number of the success hatching larvae and suggested that the operational sex ratio for Caridina multidentata under artificial environments was supposed to be female:male=1:3 has best performance.