title: Plasma sex steroid hormonal profile and gonad histology during the annual reproductive cycle of river catfish Hemibagrus nemurus (Valenciennes, 1840) in captivity.
abstract: Plasma sex steroid hormonal profile and gonad histology were correlated to study the annual reproductive cycle of Hemibagrus nemurus. Hormones were measured by Enzyme Linked Immunosorbent Assay. Gonad tissues were observed by using light microscopy. The highest testosterone (T) value for male was observed in November and that of female was in October. 11-ketotestosterone (11-KT) and 17β-estradiol (E2) levels were highest in June and November, respectively. Hormonal profiles of T, 11-KT and E2 showed several peaks which indicated a non-seasonal pattern. There were significant differences (p < 0.05) in the monthly levels of T, 11-KT and E2. Gonadosomatic index of H. nemurus ranged from 1.14 ± 0.02 % to 7.06 ± 1.40 %, and high gonadosomatic indices were recorded in May, August and November. Gonad histology revealed that spermatozoa were always present in the testes which implied continuous spermatogenesis and asynchronous ovarian development pattern was observed in the ovaries. The annual reproductive cycle of H. nemurus did not show a seasonal pattern and this indicate that H. nemurus is a non-seasonal breeder with several spawning cycles and can be referred to as indeterminate batch spawner. The major significances of this study are annual sex steroid hormonal profile and asynchronous ovarian development of H. nemurus. This information will contribute to our knowledge of reproductive biology of H. nemurus.
authors.affiliation: Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. adebiyi_fatima@yahoo.com
authors.forename: Fatimat Adenike
authors.initials: FA
authors.lastname: Adebiyi
authors.forename: Siti Shapor
authors.initials: SS
authors.lastname: Siraj
authors.forename: Sharr Azni
authors.initials: SA
authors.lastname: Harmin
authors.forename: Annie
authors.initials: A
authors.lastname: Christianus
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002397:Catfishes / Q000033:anatomy & histology / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000097:blood; D005260:Female; D005718:Gametogenesis / Q000502:physiology*; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006066:Gonads / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D008853:Microscopy; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D013739:Testosterone / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D012739:Gonadal Steroid Hormones; D013739:Testosterone; D004958:Estradiol; C003600:11-ketotestosterone