 ที่มา:KASETSART UNIVERSITY FISHERIES RESEARCH BULLETINหัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Microsatellite Variation among Domesticated Populations of Channel Catfish {Ictalurus punctatus) and Blue Catfish {I.furcatus)) ผู้เขียน: ธนาทิพย์ แหลมคม, Huseyin Kucuktas, Zhanjiang Liu, Ping Li,  ดร.อุทัยรัตน์ ณ นคร, ศาสตราจารย์ , Sirawut Klinbunga, Alison Hutson, Atra Chaimongkol, Joseph Ballenger, Gloria Umali, Rex A. Dunham สื่อสิ่งพิมพ์:pdf AbstractGenetic variability between and within 15 and 5 domesticated lines and strains of channel catfish Ictalurus punctatus and blue catfish, I.furcatus respectively was examined utilizing eight microsatellite loci. The channel catfish populations were more variable than blue catfish populations. Pairwise comparisons revealed significant genetic differentiation in all population pairs. Substantial genetic differentiation over all population of channel catfish and blue catfish was observed (FST = 0.2043 and 0.2371 respectively). Among channel catfish populations, there were five main clusters: 1) GK, AS and GKal, 2) SI, S2 and MR, 3) MS, TA and ARMK, 4) T, AF and AR1, and, 5) KR, MK and KS. Among blue catfish, there were two clusters: 1) ARR and DxR, and 2) D, R and AR2. The analysis of molecular variance (AMOVA) indicated slight genetic variability at the group level, channel catfish and blue catfish group (15.05%), population level of channel catfish (20.42%) and blue catfish (23.71%), and individual level of channel catfish (14.16%) and blue catfish (2.13%). Knowledge of the genetic composition of domesticated populations can be applied to maintain and monitor genetic variation, genetic conservation, and be incorporated into breeding programs. |
 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of 17 Alpha-Methyltestosterone on Growth, Survival and Sex Reversal of Thai Walking Catfish, Clarias macrocephalus ) ผู้เขียน:ดร.อุทัยรัตน์ ณ นคร, ศาสตราจารย์, Rex A. Dunham, ประทักษ์ ตาบทิพย์วรรณ สื่อสิ่งพิมพ์:pdf AbstractFry of Clarias macrocephalus were fed at first feeding with water fleas (Moina sp.) immersed for 20 minutes in 200 ppm or 400 ppm MT for 15 days. The groups fed water flea (200 ppm MT) were fed a diet containing 30 mg MT and the groups fed water flea (400 ppm MT) were fed 60 mg MT, for the additional 15 or 45 days. Results indicated that administration of MT did not affect growth (P>0.05) at 33 days but retarded growth at 63 days of all treated groups. Growth of treated groups was increasingly suppressed with increased dose and duration of treatment. Administration of MT lowered survival rate at 33 days (P<0.05). Survival from day 33-63 was unaffected by the hormone application. Ovotestes were found in the groups treated with 30 and 60 mg MT for 60 days. In general, sex reversal to maleness was not accomplished, and with increasing dose and duration there appeared to be paradoxical feminization. Alternatively, MT may have prevented gonads of genetic males from differentiation or caused the formation of ovotestes in genetic females. |