Sperm cryopreservation of an endangered freshwater spiny eel, Mastacembelus armatus (Lacepede, 1800) for biodiversity conservation in Bangladesh

Journal of the World Aquaculture Society, 2004

Current Frontiers in Cryopreservation, 2012

Acta Biologica Hungarica, 2005

Cryobiology, 2006

HAL (Le Centre pour la Communication Scientifique Directe), 2014

International Journal of Fisheries and Aquatic Studies, 2015

This research dealt with standardization of sperm cryopreservation techniques of Labeo rohita. The concentration of sperm ranged from 8.55×109 to 8.57×109cells ml-1. Activation of sperm motility was decreased with increasing concentration of the extending media and motility was severely inhibited at 1% NaCl. The toxicity of cryoprotectant (DMSO and methanol) to sperm was tested at different concentrations (5%, 10%, 15%) and incubation time (5-35 min). Cryoprotectants with 5 and 10% concentrations produced better motility during 5 and 10 min incubation. Two extenders, Alsever’s solution and egg-yolk citrate, and two cryoprotectants, DMSO and methanol were used for cryopreservation of sperm. Alsever’s solution with 10% DMSO showed best performance producing 82.5±1.44% and 75.0±2.04% equilibration and post-thaw motility respectively. The fertilization and hatching rates were 62.0±0.80% and 45.5±1.78% for Alsever’s solution plus DMSO while those of 50.9±0.73% and 16±5.10% for egg-yolk c...

2018

The study was focused on the development of suitable sperm cryopreservation protocolfor minor carp, bata (Labeo bata). Sperms were collected from hormone induced males bystripping. Sperm motility activation was assessed in different concentrations of activation solution(NaCl) and observed that sperm motility diminished with increasing concentration of NaCl andfully inhibited at 1.10% NaCl. Toxic effects of cryoprotectants to sperm was assessed using twocryoprotectants- DMSO and methanol along with two extenders (Alsever’s solution and egg-yolkcitrate) at 5, 10 and 15% concentrations for 5 to 45 min. Alsever’s solution along with 10%DMSO resulted in the best equilibration (86.66±3.33%) as well as post-thaw motility(70.0±2.88%) while egg-yolk citrate with DMSO produced similar equilibration motility(68.33±4.41%). In breeding trials, sperm preserved with Alsever’s solution and DMSO showedhighest fertilization rate (87.5±2.5%) and hatching rate (18.4±6.8%) while sperm preservedwith egg-...

Catrina: The International Journal Of Environmental Sciences

Cryopreservation of fish sperm is a valuable method for restoration of endangered species as well as a technique for manipulation of reproduction for genetic improvement in fish. The objective of this study was to determine the effect of equilibration time, vapour temperature and exposure time on postthawed sperm motility characteristics in red tilapia. Semen was collected from matured male, diluted using TCAYE extender in French straws (0.25 ml) and stored in liquid nitrogen tank. This research involved a 3 x 4 x 4 factorial experiment consisting of 3 equilibration times (30, 45 or 60 minutes), 4 vapour temperatures (-70,-80,-90 or-100°C) and 4 exposure times (5, 7, 9 or 10 minutes). Sperm movement and velocity distribution after frozen-thawed were evaluated using Automated Semen Analyzer (IVOS, Hamilton-Thorne). The highest percent motility was obtained significantly (P ≤0.05) when red tilapia fish sperm were equilibrated for 60 minutes (63.2±1.9%), vapourized at-80°C (61.2±2.1%) and exposed for 10 minutes (57.6±2.0%). The results from this study on red tilapia fish sperm diluted with TCAYE extender suggested that the optimal percent motilities of sperm could be obtained from combination of 60 minutes equilibration time,-80°C of vapour temperature and 10 minutes of exposure time.

Reproduction in Domestic Animals, 2007

The main objective of the present work was to study the effect of cryopreservation of European eel sperm both on the sperm viability and the spermatozoa head morphology. Spermatozoa morphology was evaluated with computer-assisted morphology analysis after collection in fresh samples, after adding the freezing medium containing dimethyl sulfoxide as cryoprotectant and, finally, after the cryopreservation process and thawing. Cell viability was assessed, in both fresh and thawed samples, by Hoechst 33258 staining. Computer-assisted sperm analysis (CASA) was used to determine the percentage of motile cells and to measure motility parameters in sperm samples. A significant decrease of head perimeter (12.56%) and area (17.90%) was detected from spermatozoa in fresh to thawed samples, indicating that cells do not recover the original size after the cryopreservation process. CASA was used to measure the percentage of motile cells (51.9%) and spermatozoa motility parameters such as curvilinear, straight line and angular path velocities, as well as beating cross frequency. This technique was employed in the fresh sperm samples but proteins present at the freezing medium (L-α-phosphatidylcholine) made impossible to use this last technique in thawed samples. When sperm viability was assessed by Hoechst staining, a significant decrease of approximately 15% (73.10 vs 58.26%) of alive spermatozoa was registered from fresh to thawed samples. The percentage of motile cells measured by CASA in fresh samples (51.9%) was lower than the percentage of alive cells determined by Hoechst stainning, suggesting the existence of different batches of spermatozoa in different stages of development, even during the eight to tenth weeks of treatment, when the highest sperm quality was found.