水産養殖研究開発ジャーナル

概要

Effect of Decreasing Water Levels on the Spawning Rate and Egg Count of Female Crayfish Procambarus (Austrocambarus) llamasi (Villalobos, 1955)

Carmona-Osalde Claudia, Puerto-Novelo Enrique and Miguel Rodriguez- Serna

Three different water levels were assessed to establish their role in Procambarus llamasi spawning synchronization. A total of 132 crayfish were used for this assay, 120 were female and 12 were male FI (reproductive male stage), with an average initial size of 45 mm total length and 2.5 g in weight. P. llamasi were produced under controlled conditions at CINVESTAV-Merida, Yucatan, Mexico. The experimental system consisted of 12 plastic tanks of 0.60×0.34×0.28 m, equipped with water recirculation, biological filters, individual PVC shelters, a constant water temperature of 26ºC and total darkness. Decreasing water levels in the crayfish tanks showed an important negative effect of this factor on most of the biological parameters measured, including the spawning rate and the number of eggs spawned by females. Spawning female sizes in low water levels were smaller and with fewer eggs than in the other levels. These results revealed an important relationship between water level and spawning rate for P. llamasi.