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 ที่มา:KASETSART UNIVERSITY FISHERIES RESEARCH BULLETINหัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Fecundity Relationship, Maturity Size and Spawning Season of Shark Catfish Helicophagus waandersii Bleeker, 1858 in the Mun River, Thailand) สื่อสิ่งพิมพ์:pdf AbstractA 48 shark catfish Helicophagus waandersii from the Mun River, Thailand was monthly sampled in 19 consecutive months (June 2003 - December 2004) for studying in fecundity relationship, maturity size and spawning season. The fecundity ranged from 21,547 to 191,539 eggs which the average was 85,174?43,206 eggs fish" . The maximum fecundity belonged to a fish with 54.2 cm in total length (TL) and 1,067 g in body weight (BW) whereas the minimum fecundity belonged to a fish with 36.0 cm and 290 g. Fecundity increased with the increase of length and weight. The regression equations of fecundity (F) on total length (TL) and body weight (BW) were log F = 0.8445+2.4518 log TL (r=0.67) and log F = 2.8492+0.7308 log BW (r=0.7), respectively. The length at 50% maturity was estimated using frequency of occurrence of matured female was 42.01 cm which gave the expected fecundity as 66,933 eggs. Maximum GS1 was in June and the minimum GSI was in November. Shark catfish was a group-synchronous spawner with a short spawning season during the rainy season from May to July. Shark catfish started moving from the Mekong mainstream since January and developed the eggs in the Mun River. After spawning, parental stock moved back to deep pools in the Mekong mainstream whereas the juvenile moved farther to the upstream floodplain for nursing and feeding purposes. Then it moved backward and joins with adult stock in September. |
 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Shark Catfish (Helicophagus waandersii Bleeker, 1858) Gillnetting in the Mun River, Thailand) ผู้เขียน: ดร.ธนิษฐา ทรรพนันทน์, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThree mesh sizes, 4.5, 5.5 and 6.5 cm, for shark catfish gillnetting in the Mun River, Thailand were compared to length at first maturity and length at 50% maturity. In case of single mesh consideration, all meshes caught the fish at the smaller size than maturity stage. In multi-meshes management, it was found that the minimum recommended mesh size should be over 5.5 cm. Shark catfish will have an opportunity to spawn at least once before being exploited. During the closed season, fishermen can be accepted to use other types of fishing gear or the use of > 5.5 cm gillnet in the open water zone apart from the spawning and nursing ground along the Mun River which covered from Kang Tana rapid through Sawang Veerawong sub-District (flood plain area). |
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ที่มา:การประชุมทางวิชาการของมหาวิทยาลัยเกษตรศาสตร์ ครั้งที่ 45หัวเรื่อง:คุณลักษณะของเอนไซม์ย่อยอาหารในปลาสวายหนู |
ที่มา:การประชุมวิชาการประมง ครั้งที่ 1 เพื่อความมั่นคงด้านการประมงและทรัพยากรทางน้ำ ม. แม่โจ้หัวเรื่อง:คุณลักษณะของเอนไซม์ย่อยอาหารในปลาสวายหนูระยะวัยอ่อน |
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