Enhanced grouper (Epinephelus spp.) seed production using cryopreserved sperm from hormone sex-reversed males | |
| Author | Taweesin Peatpisut |
| Call Number | AIT Diss. no.AQ-11-02 |
| Subject(s) | Seed technology Epinephelus |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Aquaculture and Aquatic Resources Management |
| Publisher | Asian Institute of Technology |
| Abstract | The shortage of males and/or sperm has been an impediment in the aquaculture of orange spotted grouper (Epinephelus coioides). This study reversed orange-spotted grouper females into males using hormone implants. First, a cryopreservation protocol for sperm was developed using normal males. Then, using similar procedures cryopreservation of sperm from sex-reversed males was compared. Immature, young and mature female fish were injected with 4 mg kg-1 BW 17α methyltestosterone implants. The gonad development stages were monitored over a 120 day period. All treated females converted into functional males within 120 days. Younger females (2 year old) were converted to all males within 30 days, although not all were capable of fertilizing fresh ova until day 60. The time after injection to sex reversal in immature fish was 50% shorter than in older females.Post-thaw fertilization (81, 82%) and hatching (45, 47%) of cryopreserved sperm from natural males was highest using trehalose as a cryoprotectant 15 or 20% and 150 mMol NaCl treatment; however, less than the control (89% fertilization and 69% hatching). There was no difference in the post-thaw fertilization and the hatching between sex reversed male sperm (64% and 46%, respectively) compared to natural male sperm (59% and 49%). The findings of this study suggest the potential use of sex-reversed males and cryopreserved sperm for commercial production of orange-spotted grouper seed for aquaculture. |
| Year | 2011 |
| 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) | Athapol Noomborm;Gallardo, Wenresti;Samorn Ponchunchoovong |
| Scholarship Donor(s) | RTG Partial Scholarship |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2010 |