英文摘要 |
The white-spotted bamboo shark, Chiloscyllium plagiosum, was surveyed by using the complete sequence of the control region of the mtDNA(1085 bp in length), which yielded a total of 8 haplotypes with a mean haplotype diversity (h) of 0.254 and nucleotide diversity (π) of 0.0004. The genetic distance is between 0 and 0.0056, which means genetic distance is 0.0004. No significant population subdivisions were detected by AMOVA (Analysis of Molecular Variance; ?IST= 0.108, p>0.05). FST (Fixation index) and Nm indicate that white-spotted bamboo sharks around Taiwan waters are highly exchanging status. According to the results of this study, we could preliminarily determine that white-spotted bamboo sharks around Taiwan waters are the same stock.
The major fishing methods for catching small shark species in Jiayi and Tainan areas were bottom trawl, shrimp beam trawl, bull trawl and drift gill net which were known from the results of pervious studies. The major fishing ground was between 119.55°E-120.05°E in longitude and 23.5°N-23.05°N in latitude. And the operation depth for catching these sharks was about from 10 m to 100m. Recently, the main elasmobranch which caught in these areas were skate and rays while some small shark species have been captured occasionally. The major skate and ray species were thornback ray, sharpnose stingray, blackish stingray, red stingray and Japanese eagle ray for these areas The main small shark species were white-spotted bamboo shark and Japanese spurdog shark. Also some large landed shark species were found in these areas, they were blacktip reef shark, dusky shark, bronze whaler shark, scalloped hammerhead shark, great hammerhead shark and sandbar shark. The main fishing seasons for southwestern waters were summer and autumn, |