Species Composition and Sizes of Fish in the Lagoon of Dongsha Island (Pratas Island), Dongsha Atoll of the South China Sea

南中國海東沙環礁東沙島潟湖之魚種組成與體型

張至維(Chih-Wei Chang) ； 黃朝生(Chao-Sheng Huang) ； 王劭頤(Shao-I Wang)

《Platax》 2012卷 (2012/12) Pp. 25-32

https://doi.org/10.29926/PLATAX.201212.0002

摘要

東沙島為位於南中國海東沙環礁中之珊瑚島，島內之潟湖主要為海草床棲地。本研究利用三重刺網採集及潛水目視調查，進行島內潟湖之魚種組成、時空分布與體型之研究。2010年兩次的調查共記錄到20科31個魚種。鄰近潟湖出口之水域，呈現較高的魚類多樣性及豐度。前6優勢魚種佔全部採獲數量之83.3%，依序為龍占魚科（Lethrinidae）的青嘴龍占（Lethrinus nebulosus）及單斑龍占（L. harak）、白眼鲛科（Carcharhinidae）之犁鰭檸檬鮫（Negaprion acutidens）、鯔科 （Mugilidae）之大鱗鮻（Chelon macrolepis）、四齒魨科（Tetraodontidae） 之紋腹叉鼻魨（Arothron hispidus），以及鸚哥魚科（Scaridae）之纖鸚鯉（Leptoscarus vaigiensis）。潟湖內出現魚類的全長介於角蝶魚科（Zanclidae）角鐮魚（Zanclus cornutus）之最小值7.3 cm，與犁鰭檸檬鮫之最大值69.5 cm。各魚種之生活史階段為稚魚或成魚，顯示東沙島潟湖之海草床提供一個適合魚類哺育、避敵與覓食之棲地。

關鍵字

魚類相 ； 體型組成 ； 海草床

並列摘要

The Dongsha Island is a coralline island within the Dongsha Atoll located in the South China Sea. Seagrass beds dominate the lagoon surrounding the island. Species composition, spatio-temporal distribution, and sizes of fish in the Dongsha Island lagoon were documented via trammel net surveys and visual censuses in July and September 2010. A total of 20 families and 31 species of fish were recorded during the two surveys. A higher diversity and abundance of fish was found near the exit of lagoon. The top six dominant species, accounting for 83.3% of total number of fish collected, were ranked by Lethrinus nebulosus and L. harak (Lethrinidae), Negaprion acutidens (Carcharhinidae), Chelon macrolepis (Mugilidae), Arothron hispidus (Tetraodontidae), and Leptoscarus vaigiensis (Scaridae). Total lengths of the fish ranged from 7.3-cm TL for Zanclus cornutus (Zanclidae) to 69.5-cm TL for N. acutidens. Life-history stages of the fish were determined to be juvenile and adult, indicating that the seagrass beds in the Dongsha Island lagoon served as suitable habitat for nursery habitat for young fishes in terms of refuge from predation and increased foraging opportunities.

並列關鍵字

fish fauna ； size composition ； seagrass beds