Vankara Anu Prasanna, Chikkam Vijayalakshmi
Pak J Biol Sci. 2017;20(9):465-477. doi: 10.3923/pjbs.2017.465.477.
Fishes of the genus Mystus are the members of Bagridae family which occupy an important place in Godavari fishery. Two commonly available species, Mystus vittatus Bloch, 1800 and Mystus cavasius Hamilton, 1822 of River Godavari, Rajahmundry Andhra Pradesh serve as significant hosts for metazoa\n parasites. The present study was aimed to ascertain the population dynamics, community characteristics and the faunal similarity of the two bagridae fishes, Mystus vittatus (n = 116) and Mystus cavasius (n = 94) at both infra and component community level during the 2008-2009.
Standard statistical analyses were conducted to study the parasitic communities of both the fishes. Jaccard's similarity coefficient was used to observe the faunal similarity of both the fishes. Various parameters such as Shannon-wiener index (H'), evenness (E) and Simpson's diversity indices were applied to the fully sampled metazoan infracommunities of both fishes. Mean-variance ratio described the distribution patterns of the parasites within the host. The correlation coefficient (R) explained the correlation between the standard length of host and parasitic abundance for all parasites. The Mann-Whitney U-test was applied to both the fishes to observe the influence of host sex on the overall parasitic abundance. Jaccard's interspecific association was used to find out the interspecific association between each pair of parasite species within a same host.
A total of nine metazoan parasites were obtained from both the fishes during the research study. The present investigation includes five species, i.e., Haplorchoides macrones, Bifurcohaptor indicus, Thaparocleidus tengra, Raosentis podderi and Raosentis thapari that are common to both the species. On the other hand, Metacercaria Isoparorchis hypselobagri, Raosentis godavarensis and Argulus striatus occurred specifically in Mystus vittatus and Lamproglena hospetensis occur exclusively from Mystus cavasius. There were no core and secondary species in the parasitic communities of both the fishes. Host length and rate of parasitisation showed very less correlation. There was no influence of sex on the parasitisation. Over-dispersed distribution is the generalized pattern of distribution of macroparasites and all the parasites showed over-dispersed distribution patterns except Argulus striatus, which displayed a random distribution pattern. The higher JI values indicate that there is very less competition among species as they occupy different niches within the same host.
Though, the faunal similarity of both the fishes was high but the parasitic communities of these fishes are less diverse, depauperate and non-interactive.
芒鲶属鱼类是鲿科的成员，在戈达瓦里河渔业中占据重要地位。印度安得拉邦拉贾蒙德里戈达瓦里河的两种常见芒鲶属鱼类，即1800年命名的细纹芒鲶（Mystus vittatus Bloch）和1822年命名的卡氏芒鲶（Mystus cavasius Hamilton），是后生动物寄生虫的重要宿主。本研究旨在确定2008 - 2009年期间，这两种鲿科鱼类，即细纹芒鲶（n = 116）和卡氏芒鲶（n = 94）在亚群落和组成群落水平上的种群动态、群落特征及动物区系相似性。
采用标准统计分析方法研究这两种鱼类的寄生虫群落。利用杰卡德相似系数观察这两种鱼类的动物区系相似性。将香农 - 威纳指数（H'）、均匀度（E）和辛普森多样性指数等各种参数应用于这两种鱼类完全采样的后生动物亚群落。平均方差比描述了寄生虫在宿主体内的分布模式。相关系数（R）解释了宿主标准长度与所有寄生虫寄生丰度之间的相关性。对这两种鱼类均应用曼 - 惠特尼U检验，以观察宿主性别对总体寄生丰度的影响。利用杰卡德种间关联来找出同一宿主体内每对寄生虫物种之间的种间关联。
在研究过程中，从这两种鱼类中总共获得了9种后生动物寄生虫。本调查包括5种两种鱼类共有的寄生虫，即大型单睾吸虫（Haplorchoides macrones）、印度双叉吸铗虫（Bifurcohaptor indicus）、滕氏塔帕吸虫（Thaparocleidus tengra）、波氏饶氏线虫（Raosentis podderi）和塔氏饶氏线虫（Raosentis thapari）。另一方面，异双睾吸虫后尾蚴（Metacercaria Isoparorchis hypselobagri）、戈氏饶氏线虫（Raosentis godavarensis）和条纹鱼虱（Argulus striatus）仅出现在细纹芒鲶中，而霍氏灯鱼虱（Lamproglena hospetensis）仅出现在卡氏芒鲶中。这两种鱼类的寄生虫群落中没有核心种和次要种。宿主长度与寄生率的相关性非常低。性别对寄生情况没有影响。超分散分布是大型寄生虫分布的普遍模式，除条纹鱼虱呈随机分布模式外，所有寄生虫均表现出超分散分布模式。较高的JI值表明，由于物种在同一宿主体内占据不同生态位，它们之间的竞争非常少。
虽然这两种鱼类的动物区系相似性较高，但这些鱼类的寄生虫群落多样性较低、物种匮乏且缺乏相互作用。
