Fertilizability of cryopreserved and cadaveric fish spermatozoa of freshwater catfishPangasius sutchi(Fowler, 1937)

Abstract

Fertilizability of cryopreserved and cadaveric fish spermatozoa was attempted in the freshwater catfish Pangasius sutchi. Cryopreservation of spermatozoa was done with three cryoprotectants for short time storage (30 days). Whereas the spermatozoa obtained from the cadaveric fish were stored at À20°C (30 days) without any cryoprotectants. Cryoprotectant toxicity assay showed maximum motility of 88.53 AE 2.01% and viability of spermatozoa (96.19 AE 4.92%) with 15% of Dimethyl acetamide (DMA) at 15 min equilibration time. Whereas Dimethyl sulfoxide (DMSO) (15%) registered moderate level of motility and viability 79.23 AE 2.02% and 80.89 AE 2.1%, respectively. However, the methanol (MeOH) (20%) resulted in low percentage of motility (58.6 AE 0.9%) and viability (68.6 AE 0.9%). Scanning electron micrographs further showed no significant deformity on the surface topography of spermatozoa of cadaveric fish as well as cryopreserved with DMA (15%). The results indicated that 15% of DMA with hanks balanced salt solution (HBSS) extender at a dilution ratio of 1:10 at À80°C proved to be suitable for cryopreservation of spermatozoa in P. sutchi. This may be due to the osmolality of HBSS similar to seminal plasma of P. sutchi. Further studies on motility, viability and fertility potential of spermatozoa revealed 73.62 AE 1.61%, 88.34 AE 1.05% and 54 AE 2.2%, respectively, with DMA (15%). On the other hand, cadaveric fish sperm registered 57.12 AE 2.32%, 63.45 AE 0.94% and 25.33 AE 1.53% of motility, viability and fertilizability respectively. Thus, this study augments the feasibility of using cryopreserved as well as cadaveric fish spermatozoa for the seedling production in the fresh water catfish P. sutchi.

Evaluación de Dos Crioprotectores y Tres Curvas de Congelación Programable en la Criopreservación de Semen de Brycon henni (Pisces: Characidae)

“…En una investigación con semen de Pangasius sutchi se empleó una velocidad de descenso de temperatura de -10 °C/min y el crioprotector permeable DMSO con resultados de MT posdescongelación de 79.2 ± 2.0% (Rani et al, 2016). En otro estudio con semen de carpa plateada (Hypophthalmichthys molitrix) se utilizó una velocidad de descenso de temperatura de -10 °C/min entre -4 °C y -80 °C, con lo cual se logró una Lo anterior muestra el uso común del DMSO y su efectividad en los procesos de criopreservación de semen de especies piscícolas; no obstante, en el presente estudio se demuestra la superioridad del EG en la conservación de la vitalidad del semen de Brycon henni.…”

Understanding rigor mortis impacts on fish gamete viability

“…Studies conducted with Heteropneustes fossilis [11], Pangasius sutchi [12], and Puntius conchonius [13], stored at -20°C, where milt collection from these animals took place over several days after death, and cryopreservation was carried out, demonstrated sperm cell viability. However, the viability parameters were limited to assessing motility, staining with eosin-nigrosin, scanning electron microscopy, and attempts at fertilization.…”