Cryopreservation of striped catfish, pangasius hypophthalmus sperm | |
| Author | Samorn Kwantong |
| Call Number | AIT Diss. no.AQ-03-01 |
| Subject(s) | Cryopreservation of organs, tissues, etc. Fishes--Germplasm resources--Cryopreservation Catfishes Spermatozoa |
| Note | A dissertation submitted in partial fulfillment of the requirement for the degree of Doctoral of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. AQ-03-01 |
| Abstract | This present study examined the feasibility of cryopreservation of striped catfish, Pangasius hypophthalmus sperm. Five studies were carried out: (1) the effects of extenders, cryoprotectants and freezing rates on fertilization, motility and viability of Pangasius hypophthalmus sperm, (2) the use of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) to evaluate the cryodamage, (3) efficiency of fresh and cryopreserved sperm on fertilization rate, (4) performance of frozen-thawed sperm and subsequent hatch and survival rates of eggs and larvae, and (5) application of the methods developed for P. hypophthalmus sperm to cryopreserve sperm form closely related species black eared catfish. P. larnaudii. Effects of four cryoprotectants (methanol-MeOH, dimethyl sulfoxide-DMSO, dimethyl acetamide-DMA, and ethylene glycol-EG), three extenders (Calcium- Free Hanks' Balanced Salt Solution-C-F HBSS, Hanks' Balanced Salt Solution-HBSS and Sodium Chloride-NaCl), and two different freezing procedures (one-step and two-step) on the cryopreservation of striped catfish (P. hypophthalmus) sperm were investigated. Sperm were frozen using a controlled-rate freezer in 250 mL straws and stored for two weeks in a liquid nitrogen container. They were then airthawed at room temperature, and fertilization, motility and viability were assessed. The highest fertilization rate 41% (81% of control) was achieved with the combination of 12% DMSO and 0.9% NaCl using a one-step freezing procedure (10 ฺC min-1). Dimethyl acetamide (DMA) resulted in a higher fertilization rate (30% or 51% of the control) than MeOH (18% or 38% of the control) or EG (8% or 12% of the control). In addition, the three extenders used did not affect fertilization rates after cryopreservation with each cryop0rotectant. Fertilization, motility and viability rates were not significantly different among the three cryoprotectant concentrations and between one-step and two-step freezing procedures. However, fertilization rates of cryopreserved sperm were significantly lower than those of the controls. There was no correlation among fertilization, motility and viability rates. The results of this study indicted that high fertilization rates of striped catfish eggs can be achieved using cryopreserved sperm when frozen at 10 ฺC min-1 in DMSO or DMA with either 0.9% NaCl or C-F HBSS. The frozen sperm samples from the highest and the lowest fertilization rates from each cryoprotectant in the first study was used to assess the physical and ultrastructure damage using SEM and TEM. Sperm samples from 2 successive steps pre-freezing (fresh sperm) and post-freezing (frozen sperm) were evaluated. Ruptured plasma membranes and the loss of flagellum were commonly found in thawed sperm. Frequency of physically damaged spermatozoa diluted with the combination of 0.9% NaCl and 10% EG, at two-step freezing procedures appeared to be higher than the other treatments. More membrane damages also observed when using two-step freezing produces than one-step freezing procedure with the similar cryoprotectants. The optimum sperm: egg ratio of fresh and cryopreserved sperm were investigated. Various concentrations (1.89 x 107, 1.89 x 108, 1.89 x 109 and 1.89 x 1010) of the fresh sperm were used to fertilize 100 eggs batch-1. There was no significant difference among the three sperm: egg ratios (1.89 x 105, 1.89 x 106 and 1.89 x 107). |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. AQ-03-01 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Aquaculture and Aquatic Resources Management (AQ) |
| Chairperson(s) | Bart, Amrit N.,; |
| Examination Committee(s) | Stevens, Willem F.;Yi, Yang;Dunham, Rex A.; |
| Scholarship Donor(s) | Suranaree University of Technology;IT Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2003 |