Morphological Obserations on the Larval Development of Macrobrachium Formosense

• DOI: 10.29822/jfst.199003.0003
• Publication Date: 1990-03-01
• Authors: Jhy-Yun Shy; Yueh-Er Tsou; Hsiang-Ping Yu
• Keywords: China sea; Net (polyhedron)

In order to estimate the amount of fish passing through opening ofnet while trawling,it needs find out relationship between catch andscanned area by net recorder.A self-designed,spherical recorder wasinstalled on experimental trawl-net,during two cruises performed byR.V.Fishing Trainner Ⅰ and Ocean Researcher Ⅰ,respectively.A total 26hauls were conducted in southern part East China Sea,northwesternTaiwan Strait coastal waters along southwestern Taiwan.The resultswere summerized as follows:The height mouth was 3.0-3.5m at tow speed 3.0 knots.Most pass middle layer opening.The ofcatch varied with fishing grounds,being nearly 100 Kg average,which isvery low when converted CPUE.A high correlation intergrated fishtrace types found,with coefficient 0.85 and0.78 for 34 mm 56 mesh sizes,respectively.Larger allowsthe escape more easily.When comparing efficiency typesof sizes detection echo traces,the mmtrawl-net has 24-41% higher than that mm.