Effect of temperature on reproductive quality of captive male Litopenaeus vannamei broodstock was investigated by measuring sperm count and percentage of abnormal sperm per compound spermatophore. Variability in these responses among and within experimental units also was evaluated. Male shrimp with an initial average weight of 48.0 g were maintained in 3.7-m diameter circular tanks with recirculating seawater, and exposed to constant temperatures of 26°C, 29°C, and 32°C for 42 days. Significantly higher mean sperm count (18.6 million cells) and lower percentage of sperm abnormalities (36.7%) were observed in shrimp held at 26°C, as compared to broodstock at 29°C (mean sperm count = 0.1 million cells; percentage of sperm abnormalities = 99.7%) or 32°C (no sperm cells) (P < 0.05). Results indicate that adequate sperm count and percentage of abnormal sperm of L. vannamei broodstock can be maintained at water temperature of 26°C, but not at 29°C or 32°C, at least within the time span of 42 days. The importance of treatment replication and sampling sufficient numbers of shrimp from culture tanks in experiments concerning male reproductive quality is discussed.
Bibliographical noteFunding Information:
This research was funded in part by Project H-8158 of the Texas Agricultural Experiment Station, United States Department of Commerce Marine Shrimp Farming Program CSREES Grant No. 95-38808-1424, to Dr. Addison Lee Lawrence, Principal Investigator.
- Reproductive quality