 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 : Evaluation of Channel Catfish Feeds in Long-Term Pond studies and Short term Aquarium Studies) ผู้เขียน:วิมล จันทรโรทัย, Richard T. Lovell สื่อสิ่งพิมพ์:pdf AbstractResponses of two sizes; 3 g and 60 g channel catfish (Ictalurus punctatus) to five commercial feeds (1, 2, 3, 4 and 5) and a negative control (contained low quality plant protein) were evaluated in earthen ponds and in glass aquaria, respectively. The commercial feeds were prepared from closed formulas but estimated to contain 32% crude protein, approximately 2.5 Kcal/g of digestible energy. Growth rate of fish fed feed 1, 2 and 3 were higher than those of fish fed feeds 4, 5 and the negative control in both ponds and aquaria (P<0.05). There were no significant differences in weight gains among fish fed feed 1, 2 and 3 or among fish fed feeds 4, 5 and the negative control in the ponds (P>0.05). However, in the aquaria, fish fed feed 2 gained more weight than fish fed the other feeds, and fish fed feed 5 and the negative control grew less than those fed feed 4 (P<0.05). Feed conversion ratios for fish fed in ponds were higher than those for fish fed in the aquaria except for the negative control. The correlation in weight gain between fish fed feeds in ponds and aquaria was 0.73 (P<0.05). The agreement in weight gain between ponds and aquarium was high for the good quality feeds but poor for the low quality feeds. There was no correlation in feed conversion ratio between fish fed in ponds and aquaria (P>0.05). The results indicate that aquarium studies are more sensitive than pond studies for evaluating nutritional qualities among practical diets. However, natural food from the pond can improve productivity of poor quality feeds. |
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