Adaptability and Conservation of Freshwater Elasmobranchs

淡水软骨鱼的适应性和保护

基本信息

批准号：
08041156
负责人：
TANAK Sho
金额：
$ 6.98万
依托单位：
Tokai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08041156/
关键词：
FRESHWATER STINGRAYS MEKONG RIVER CHAOPPHRAYA RIVER GANGES RIVER PHYLONGENETIC SYSTEMATICS ADAPTABILITY FOR FRESHWATER OSMOLITES AGE AND GROWTH 繁殖チャオプラヤ川系統類縁分布生態保護

项目摘要

1) Eight species of freshwater stingrays were collected in Thailand and Laos : Himantura signifer and H. chaophraya from the Chao Phraya River ; H. gerrardii, H. bleekeri and unidentified Himnantura sp., from the Nan River ; Dasyatis laosensis from the Mekong River ; H krempfi and Pastinachus sephen from the Banpakong River.2) Four species of freshwater stingrays were collected from the Ganges River System : Himanantura bleekeri H. gerrardii and Pastinachus sephen.3) The molecular phylogenetic analyses by the parsimony and neighbor-joining methods based on DNA nucleotide sequences of the cytochrome b gene showed the general topology of the trees remained mostly unaltered. While species belonging to the genus Himantura formed one group, Dasyatis laosensis and Dasyatis sp. From Thailand formed the other group. The data failed to show clear phylogenetic relationships of the genus Pastlhachus with the genera Dasyatis and Himantura.4) Analytical data of blood serum composition, rectal gland weight / body weight ratio, and rectal gland morphology in freshwater stingrays suggested that each species did not fully adapt for freshwater environment. Statoconium Sr : Ca ratios of freshwater stingrays were much lower than those of the stingrays from estuary and sea. The ratio might represent the integrated environmental history of individual freshwater stingrays.5) Analysis of the free amino acids contents in the muscles of freshwater and brakish stingrays indicated that Tau and Urea play an important role as organic osmolites.6) Himantura signifer is the most common freshwater stingray in Thailand. The male seems to be mature between 210 and 230 mmDW, while the female is between 250 and 260 mmDW. Mostly species become mature by 5 years old, though the giant species, Himantura chaophraya, did not attain to mature at 7 years old.

1）在泰国和老挝收集了八种淡水黄貂鱼：乔·菲拉亚河的Himantura emprifer和H. Chaophraya； H. Gerrardii，H。Bleekeri和来自Nan River的身份不明的Himnantura sp。来自湄公河的Dasyatis Laosensis； 2）从恒河系统中收集了四种淡水黄霉菌：Himanantura bleekeri H. gerrardii和overtinachus sephen.3）基于Parsim and nehilch cyre cyer cyer niuce nucter in Nucter niuce niuce niuce niuce niuce niuce niuce niuce niucter center in Nucto nucto niquers cy nique cyrots center niucty niuce nucto nicty niucty niucty niucty center niuce nique nique。树木的一般拓扑主要是没有改变的。属于Himantura属的物种组成了一组，而Dasyatis Laosensis和Dasyatis sp。从泰国组成了另一组。该数据未能显示出Pastlhachus属与dasyatis属和Himantura属的明显系统发育关系。4）血清组成的分析数据，直肠腺体体重 /体重 /体重比以及淡水刺痛的直肠腺形态的分析数据表明，每种物种都没有完全适应淡水环境。 Statoconium sr：淡水黄貂鱼的CA比远低于河口和海的黄貂鱼的比率。该比率可能代表了单个淡水黄貂鱼的综合环境历史。5）分析淡水和棕os骨肌肉中游离氨基酸含量的分析表明，Tau和Urea作为有机渗透岩起着重要作用。6）Himantura Signifer是Thailandailand的最常见的淡水STINGRAIRERARE。雄性似乎在210至230 mmdw之间成熟，而女性在250至260 mmdw之间。尽管巨大的物种Himantura Chaophraya并没有在7岁时成熟，但种类大部分时间就成熟了。