 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Embryonic Development of Saddleback Anemonefish, Amphiprion polymnus, Linnaeus (1758)) ผู้เขียน: Sukjai Rattanayuvakorn,  นายพิสุทธิ์ มังกรกาญจน์, ผู้ช่วยศาสตราจารย์ , นางอมรา ทองปาน, รองศาสตราจารย์, นางกรรณิกา ชัชวาลวานิช, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThe breeding pairs of saddleback anemonefish, Amphiprion polymnus Linnaeus (1758) were brought from the Gulf of Thailand and reared in the laboratory to observe their spawning behavior, eggs and embryonic development. The spawning was found to be all-year-round with the reproductive cycle between 14-21 days. The eggs were single and adhesive type, capsule shape, and light orange in color, measuring 1.9-2 mm in length and 0.9-1 mm in width containing both large and small fat globules. The process of embryonic development could be divided into 26 stages based on morphological characteristics of the developing embryo. The time elapsed of each embryonic developmental stage was recorded. Hatching took place 148?8 hours after fertilization. This report is the first published record on the morphological development of saddleback anemonefish embryo. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Gonadal Development and Sex Inversion in Saddleback Anemonefish Amphiprion polymnus Linnaeus (1758)) ผู้เขียน:Sukjai Rattanayuvakorn, นายพิสุทธิ์ มังกรกาญจน์, ผู้ช่วยศาสตราจารย์, นางอมรา ทองปาน, รองศาสตราจารย์, นางกรรณิกา ชัชวาลวานิช, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractGonadal development and sex inversion of saddleback anemonefish, Amphiprion polymnus were described. One-month juveniles had sexually undifferentiated gonads with primordial germ cells aggregated in groups, while two- to three-month juveniles displayed immature hermaphroditic gonads containing early developmental stages of both male and female germ cells, namely spermatogonia, primary spermatocytes, oogonia, and primary oocytes in chromatin-nucleolus stage. Spermatogenesis began at 4 months having testicular tissue comprising of spermatogenic cells in all developmental stages but ovarian cavity was first seen later at 5 months. The male region of ovotestis was peripheral, whereas the female region was more centrally located. There was no connective tissue between ovarian and testicular areas. Six-to 11-month fish had slightly larger ovotestes than those at previous age. Protandric sex inversion first occurred at 12 months. Sex change was characterized by degeneration of male germ cells, deposition of yellow-brown pigment and the formation of vitellogenic oocytes. Before spawning activity began, their gonads contained female germ cells in all stages with numerous vitellogenic oocytes, whereas functional males had both ovarian and testicular tissues. Most females of breeding pairs had mature oocytes in their gonads and began to spawn when their ages reached 14 months. |