Epizoic Invertebrate Communities on Upper Mississippi River Unionid Bivalves
Epizoic Invertebrate Communities on Upper Mississippi River Unionid Bivalves
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密西西比河上游的生代无脊椎动物群落 Unionid 双壳类
DOI：
10.2307/2426876
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发表时间：
1996
影响因子：
0.6
通讯作者：
A. Miller
中科院分区：
文献类型：
--
作者：
D. C. Beckett;B. Green;S. Thomas;A. Miller
- 根据五大湖对Dreissena polymorpha的经验，很明显，如果出现高斑马贻贝密度，本地淡水贻贝（蚌科）动物群将是受影响最严重的河流群落之一。对珠蚌类的负面影响也会影响到生活在珠蚌类外壳上的表生无脊椎动物群落。在1991年和1992年（前斑马贻贝侵扰），我们确定了个别unionids从上游密西西比河的epizoic无脊椎动物的组成和密度。1991年的样本来自一个强海流的地点;在这个地点，数量上占优势的表生无脊椎动物是三种水足石蛾和摇蚊幼虫：Polypedilum convictum，P scalaenum group，Rheotanytarsus sp.，Microtendipes pedellus组和Thienemannimyia组。个体蚌类的有效表面积（ESA）（沉积物-水界面以上的壳表面积）与以下参数之间存在较强的相关性：（1）表生摇蚊幼虫的数量（r = 0.81）;（2）水生石蛾的数量（r = 0.73）;（3）表生无脊椎动物的总数（r = 0.78）。1992年在流速较慢的地区取样，发现与1991年观察到的不同的epizoic成分。Glyptotendipes nr Lobiferus是最丰富的寄生幼虫摇蚊，虽然石蛾幼虫很常见，但它们大多属于水蛾科以外的科。再次，强烈的相关性之间存在的ESA的unionids和：（1）总数量的epizoic无脊椎动物（r = 0.64）和（2）的epizoic摇蚊幼虫（r = 0.57）。一个很强的相关性也存在于unionids的大小和epizoic类群的数量（1991年：r = 0.78; 1992年：r = 0.77）。从蚌类中收集了53个无脊椎动物分类群;平均表生密度约为100。9600和6400无脊椎动物/平方米的欧空局在1991年和1992年分别。这些结果表明，蚌类是重要的底栖无脊椎动物的基板，特别是在河流中，其他大型清洁基板供应短缺。
-Based on the Great Lakes experience with Dreissena polymorpha, it is clear that the native freshwater mussel (family Unionidae) fauna will be one of the riverine communities most severely impacted if high zebra mussel densities occur. Negative impacts on unionids will also affect the epizoic invertebrate communities that live on the shells of the unionids. In 1991 and 1992 (prezebra mussel infestation) we determined the composition and density of epizoic invertebrates on individual unionids from the upper Mississippi River. The 1991 samples were from a location with a strong current; the numerically dominant epizoic invertebrates at this location were three species of hydropsychid caddisflies and the chironomid larvae: Polypedilum convictum, P scalaenum group, Rheotanytarsus sp., Microtendipes pedellus group and Thienemannimyia group. Strong correlations existed between effective surface area (ESA) (amount of shell surface area above the sediment-water interface) of the individual unionids and: (1) number of epizoic chironomid larvae (r = 0.81); (2) number of hydropsychid caddisflies (r = 0.73), and (3) total number of epizoic invertebrates (r 0.78). Sampling in a slower current area in 1992 revealed an epizoic composition dissimilar from that observed in 1991. Glyptotendipes nr. lobiferus was the most abundant epizoic larval chironomid, and, although caddisfly larvae were common, they mostly belonged to families other than the Hydropsychidae. Again, strong correlations existed between ESA of the unionids and: (1) total number of epizoic invertebrates (r = 0.64) and (2) number of epizoic chironomid larvae (r = 0.57). A strong correlation also existed between the size of the unionids and the number of epizoic taxa present (1991: r = 0.78; 1992: r = 0.77). Fiftythree invertebrate taxa were collected from the unionids; mean epizoic densities were ca. 9600 and 6400 invertebrates/M2 of ESA in 1991 and 1992, respectively. These results indicate that unionids are important substrates for epibenthic invertebrates, especially in rivers in which other large clean substrates are in short supply.