东海南部海域蟹类种类组成及其数量分布

Species composition and quantitative distribution of crabs in south East China Sea

主要根据1998-1999年和2008-2009年在东海南部海域（26°00′-28°00′N、120°00′-125°30′E）开展的各季度月蟹类资源调查资料及1989-1990年在福建东北外海渔业资源调查等相关资料,研究分析该海区蟹类的种类组成、数量分布及主要渔获种类的变化特点。结果表明,该海区蟹类有66种,隶属于15科,39属;2008-2009年东海南部海域蟹类数量明显比1998-1999年减少,蟹类占总渔获量的比重下降9.8个百分点,平均资源密度指数减少36.2%;两次调查蟹类数量均以春季和夏季为高,但主要渔获种类不同,1998-1999年细点圆趾蟹渔获量占绝对优势,而2008-2009年细点圆趾蟹数量降幅最大,资源密度很低,光掌蟳、双斑蟳数量明显增多,取代了细点圆趾蟹成为最主要的渔获种类,其余种类如卷折馒头蟹、银光梭子蟹、武士蟳等所占比例变化不大;2008-2009年蟹类主要分布区域与1998-1999年不同,在海区内侧水深60 m以内海域数量分布较多,这与主要渔获种类双斑蟳分布海域范围关系密切;细点圆趾蟹资源量明显减少的原因有待以进一步调查和研究。

According to the four seasonal months investigation data of crab resources in south East China Sea （26000＇ -28°00＇N,120°00＇- 125°30＇E）from 1998 to 1999 and 2008 to 2009, and combining with relevant data of fishery resources investigation in the northeast Fujian outer-sea from 1989 to 1990, this paper studied and analyzed the species composition, quantitative distribution and main species change of crabs in the area. The results showed that 66 species were identified, which belonged to 15 families and 39 genuses. The biomass of crabs in 1998 and 1999 reduced considerably compared with that of 2008 and 2009, the total catch declined 9.8% and the CPUE declined 36.2%. The crab biomass of two investigations both showed the highest in Spring and Summer, but their main species were different, the catch of Ovalipes punctatus was absolute dominant from 1998 to 1999 and was lower from 2008 to 2009, it was replaced by Charybdisferiatus and Charybdis bimaculata, the catch percent of other species such as Calappa lophos, Portunus argentatus and Charybdis miles didn＇t change obviously. The biomass was higher in water depth within 60 m from 2005 to 2009, which was closely related to the distribution area of Charybdis bimaculata, but this was different from 1998 to 1999. The reason for the considerable biomass reduction of Ovalipes punctatus still needs further research and investigation.