广西北海金海湾红树林湿地海洋线虫群落研究初探

STUDY ON MARINE NEMATODES COMMUNITY IN JINHAI BAY MANGROVE WETLAND,BEIHAI,GUANGXI

2019年夏季在广西北海市金海湾红树林湿地,设置7个断面,分别采集红树林和光滩小型底栖动物沉积物样品,进行海洋线虫群落结构的研究。分析结果共鉴定出7个小型底栖动物类群,分别为自由生活海洋线虫、桡足类、多毛类、寡毛类、双壳类、有孔虫以及少许未鉴定类群,其中海洋线虫是优势类群,占总丰度的91.79%。小型底栖动物的丰度介于(6.07±1.23)—(200.25±31.75)ind./10cm2之间,海洋线虫的丰度介于(4.16±1.7)—(195.23±30.80)ind./10cm2之间。各个断面,红树林区小型底栖动物的数量都大于相同断面光滩上的。共鉴定出6个海洋线虫优势属,分别为Terschellingia、Promonhystera、Paralongicyatholaimus、Dorylaimopsis、Halichoanolaimus和Metachromadora,其中Terschellingia为最优势属,优势度为19.35%,在各个断面广泛分布。文中比较分析了该属出现的3个相近种的尾长、化感器直径和化感器距体前端的距离等形态学特征。

To understand the community structure of free-living marine nematodes,seven sections were set up in the mangrove wetland of Beihai city,Guangxi in summer of 2019.Seven meiofanua groups were recognized,including free-living marine nematodes,copepods,polychaetes,oligochaetes,bivalves,foraminiforas,and a few unidentified individuals.Marine nematodes were the dominant group,accounting for 91.79%of the total abundance.The abundance of meiofanua ranged from(6.07±1.23)to(200.25±31.75)ind./10 cm2.The abundance of marine nematodes ranged from(4.16±1.7)to(195.23±30.80)ind./10 cm2.In all sections,the abundance of meiofanua in mangrove forests were greater than those in the beach area in the same section.Six dominant genera of marine nematodes were Terschellingia,Promonhystera,Paralongicyatholaimus,Dorylaimopsis,Halichoanolaimus and Metachromadora.Terschellingia was the most dominant genus with a dominance of 19.35%,and three similar species appeared in this genus.The morphological characteristics including the length of the tail,amphidial fovea diameter and the distance of amphidial fovea to anterior end of body were compared.