Zara Fernando José, Diogo Reigada Alvaro Luiz, Domingues Passero Luiz Felipe, Toyama Marcos Hikari
Universidade Estadual Paulista, Unidade de São Vicente, Praça Infante D. Henrique, São Vicente, SP Brazil.
J Parasitol. 2009 Feb;95(1):124-8. doi: 10.1645/GE-1616.1.
Leeches exhibit a marked scope of diversity, including different kinds of symbiosis. The aim of the present study was to demonstrate through biochemical and histological analysis that a species of piscicolid leech, Myzobdella platensis, is a true parasite of blue crabs, feeding on their hemolymph and using them as a site for cocoon deposition. In a total of 48 blue crabs collected on October 2007 at 3 sites of the São Vicente Estuary, 12 specimens were infested with leeches. Callinectes bocourti (n = 7) was the most infested species with leeches and cocoons; it was chosen for biochemical and histological assays. The immunoblotting assays showed a positive reaction of the proteins in the intestinal samples of leeches collected from crabs using antihemocyanin polyclonal antibody of Ampullaria canaliculata. In addition, leech intestinal samples were recognized by antihemolymph polyclonal antibody of nonparasitized blue crabs. Histological sections of leech gut showed hemocytes and a granular matrix similar to those found in crab blood vessels. Collectively, this evidence strongly suggests a parasitic interaction between the leech M. platensis and the blue crab C. bocourti, in which the former utilizes the latter as a site for cocoon deposition and possibly for dispersal similar to that proposed for Myzobdella lugubris in Callinectes sapidus in North America.
水蛭表现出显著的多样性，包括不同种类的共生关系。本研究的目的是通过生化和组织学分析证明，一种鱼蛭科水蛭——普拉滕斯米氏蛭，是蓝蟹的真正寄生虫，以蓝蟹的血淋巴为食，并将蓝蟹作为茧的沉积场所。2007年10月在圣维森特河口的3个地点共采集了48只蓝蟹，其中12只被水蛭寄生。博氏美青蟹（n = 7）是被水蛭和茧寄生最多的物种；它被选用于生化和组织学分析。免疫印迹分析显示，使用福寿螺抗血蓝蛋白多克隆抗体，从蟹体采集的水蛭肠道样本中的蛋白质有阳性反应。此外，水蛭肠道样本被未被寄生的蓝蟹的抗血淋巴多克隆抗体识别。水蛭肠道的组织切片显示有血细胞和类似于在蟹血管中发现的颗粒状基质。总体而言，这些证据有力地表明普拉滕斯米氏蛭与博氏美青蟹之间存在寄生关系，其中前者利用后者作为茧的沉积场所，并且可能用于扩散，这与北美拟穴青蟹中黑蛭的情况类似。
