Life history and instream distribution of the endangered estuarine goby Acanthogobius insularis from Okinawa-jima Island, Japan.
Life history and instream distribution of the endangered estuarine goby Acanthogobius insularis from Okinawa-jima Island, Japan.
复制标题
日本冲绳岛濒危河口虾虎鱼 Acanthogobius insularis 的生活史和河内分布。
DOI：
10.1017/s0025315417002053
复制
发表时间：
2018
影响因子：
1.2
通讯作者：
M. Iida and K. Tachihara
中科院分区：
文献类型：
--
作者：
Kunishima;T.;R. Iwamoto;M. Iida and K. Tachihara
棘虎鱼属（Acanthogobius）在东亚地区有6种，分布于河口和沿海沃茨。岛棘虎鱼（Acanthogobius insularis）是日本南部奄美大岛和冲绳岛的一种濒危和特有的虎鱼，其分布范围仅限于少数河流流域的最下游。关于这个物种的基本知识是稀缺的，尽管其脆弱的保护地位。本研究的目的是阐明A.岛状的从2014年11月到2015年11月，在冲绳本岛的大鹏川的五个站点进行了每月采样。除4月份外，各月标准体长分布均为单峰分布，表明A. insularis为一年生种。性腺指数和卵巢的组织学观察分析表明，该物种产卵从1月至5月。产卵季节的开始似乎与12月水温的下降有关。4月至12月的增长率似乎较低，冬季则较高。从每月收集的数据中，A.研究发现，在繁殖季节，岛水母随生长向上游移动，并聚集在产卵场。气候变化导致的水温升高可能会对岛屿刺虎鱼造成威胁，因为低水温对它们的繁殖和生长至关重要。此外，栖息地的多样性，从潮滩的招聘理由与鹅卵石产卵上游网站，需要完成其生命周期，并应加以保护。
The genus Acanthogobius of gobiioid fish has been reported for six species from East Asia, and inhabits estuarine and coastal waters. Within this genus, Acanthogobius insularis is an endangered and endemic goby in the Amami-oshima and Okinawa-jima Islands, southern Japan, and its range is restricted to the lowermost course of a few river basins. Basic knowledge on this species is scarce in spite of its vulnerable conservation status. The purpose of this study was to elucidate the life history of A. insularis. Monthly sampling was conducted at five stations in the Taiho River, Okinawa-jima Island, from November 2014 to November 2015. Monthly standard length (SL) distributions were unimodal except in April during the recruiting period, suggesting that A. insularis is an annual species. Analysis of the gonadosomatic index and histological observations of the ovaries revealed that this species spawns from January to May. The beginning of the spawning season seems to be related to a decline in water temperature in December. Growth rates appeared to be lower from April to December and higher in winter months. From monthly collections, A. insularis was found to move upstream with growth, and gather at spawning grounds during the reproductive season. Acanthogobius insularis might be threatened by increasing water temperature due to climate change, since low water temperatures appear to be important for their reproduction and growth. Moreover, habitat diversity, from tidal flats for recruiting grounds to upstream sites with cobbles for spawning, is needed to complete their life cycle, and should be conserved.