Spatiotemporal distribution of dominant species of cephalopod assemblages in coastal waters off southwestern Taiwan

• Main Authors: Yi-Wen Hsu, 徐顗雯
• Other Authors: Meng–Hsien, Chen
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/b2z979

碩士 === 國立中山大學 === 生物科學系研究所 === 107 === The aims of this study are to (1) establish the baseline information of the species composition and spatial and temporal distribution of the cephalopod in the southwestern coastal area of Taiwan, (2) exploring the effects of environmental factors act on the distribution of cephalopods, (3) realize the biological information of the dominant species, and investigate their utilization of habitats. Cephalopod samples were collected from June 2007 to December 2017, with a beam trawl operated by R/V Ocean Researcher No. 3 at depth of 15–109 m, 9 stations, Wanggong, Taisi, Cigu, Jiading, Zouying, Linyuan, Dapeng, Linbian, and Fangliao. in the southwestern waters off Taiwan. Water temperature, salinity and dissolved oxygen were recorded by CTD. I also collected samples from February 2017 to September 2017, the otter trawl operated by fishing boats in Fuxing coastal area for supplementing the information of species from the middle coastal water of Taiwan. A total of 1,526 individual cephalopods of 15 families, 11 genera, and 26 species were obtained. The top six dominant species in Wanggong to Fangliao were Sepia pharaonis (31.4%), Sepia esculenta (14.5%), Loliolus beka (7.7%), and Sepia vietnamica (7.6%), Inioteuthis japonica (5.4%), and Euprymna berryi (4.4%), contributing 80.3% of the total catches. It is significant in spatial distribution in the waters off western Taiwan. There were north and the south group separated between Cigu and Jiading station. It might result in the influence of the current flow and the water mass seasonal oscillation in the Taiwan Strait. The north group dominant by Loliolus beka and Inioteuthis japonica. The sea area may be the feeding ground of L. beka which were mainly distributed at 30 m, and the abundance was high in July. The I. japonica which may complete their life history in this habitat, were distributed at 40 m and the abundance was high in March, June and October. The dominant species of the southern group are the Sepia pharaonis and Sepia esculenta. Southwest coast of Taiwan may be the feeding ground of the two dominant species. Both of their abundances were high in winter to spring. The S. pharaonis is distributed at 40 m high abundance in and the S. esculenta is distributed at 60-80 m. In addition to completing the list of the cephalopods in the southwestern coastal areas, this study also found that the coastal areas are the nursing ground of juvenile cephalopods, which can be used as an important reference for the management of cephalopod resources.