MALE VIABILITY DETERMINATIONS IN PENAEUS-VANNAMEI - EVALUATION OF SHORT-TERM STORAGE OF SPERMATOPHORES UP TO 36 H AND COMPARISON OF CA-FREESALINE AND SEAWATER AS SPERM HOMOGENATE MEDIA

Short term storage up to 36 h was evaluated for male gonad tissue of t he marine shrimp, Penaeus vannamei, for use in sperm gross morphology evaluations. Additionally, seawater was compared with Ca-free saline s olution as the medium for tissue storage and for sperm homogenization. A baseline sample of P. vannamei males (48.3 g +/- 2.75 s.d., It = 9) was taken with freshly ejaculated spermatophores and evaluated for sp erm counts and percent morphologically abnormal sperm, Baseline values of mean sperm of 52.00 X 10(6) +/- 8.24 s.e. and mean abnormal sperm of 32.09% +/- 9.93 were obtained, Thirty additional males were sacrifi ced and their carapace sections (without hepatopancreas and tail secti on) were placed into either seawater or a Ca-free saline solution in a n incubator at 15 degrees C for 3, 6, 12, 24 and 36 h. There were no s ignificant differences in either sperm counts or percent abnormal sper m observed at each time period (alpha = 0.05) indicating that either s eawater or Ca-free saline can be used as the homogenate medium and as the storage medium for gonadal tissue to be used in gross morphology d eterminations. In addition, samples taken at each time interval were c ompared with the baseline sample. There were no significant difference s between the freshly ejaculated spermatophores and spermatophores sto red up to 36 h at 15 degrees C for tither total sperm counts ol percen t abnormal determinations. (C) 1998 Elsevier Science B.V.