Bennett Jerusha, Jorge Fátima, Poulin Robert, Randhawa Haseeb
Zoology Department, Otago University, PO Box 56, Dunedin, 9054, New Zealand.
Ecology Degree Programme, Otago University, PO Box 56, Dunedin, 9054, New Zealand.
Parasitol Res. 2019 May;118(5):1435-1444. doi: 10.1007/s00436-019-06264-3. Epub 2019 Mar 15.
Parasites are important components of natural systems, and among their various roles, parasites strongly influence the flow of energy between and within food webs. Over 1000 tapeworm species are known to parasitise elasmobranchs, although full life cycles are resolved for fewer than 10 of them. The lack in resolution stems from the inability to distinguish larval from adult stages using morphology alone. Molecular elucidation of trophic transmission pathways is the next step in understanding the role of hosts and parasites within food webs. We investigated the parasite assemblage of New Zealand's rough skate, Zearaja nasuta. Skates and their prey items (obtained from the skates' stomachs) were dissected for the recovery of adult and larval tapeworms, respectively. A fragment of the 28S rDNA region was amplified for worm specimens with the aim to confirm species identity of parasites within rough skates and to uncover trophic transmission pathways that exploit the predation links between rough skates and their prey. We identified seven species of tapeworms from four tapeworm orders. Four trophic transmission pathways were resolved between three prey items from skates stomachs and skates, and one pathway between larval tapeworm sequence from a New Zealand sole and skate, i.e. a genetic match was found between larval tapeworms in prey and adult worms in skates. We report the first case of an adult trypanorhynch parasitising rough skate. These findings contribute to our limited understanding of cestode life cycles as well as providing insights into the importance of predator-prey relationships for parasite transmission.
寄生虫是自然系统的重要组成部分，在其众多作用中，寄生虫对食物网内部和之间的能量流动有强烈影响。已知有超过1000种绦虫寄生于板鳃亚纲鱼类，尽管其中只有不到10种的完整生命周期已被解析。解析的不足源于仅靠形态学无法区分幼虫和成虫阶段。对营养传递途径进行分子阐释是理解宿主和寄生虫在食物网中作用的下一步。我们调查了新西兰粗鳐（Zearaja nasuta）的寄生虫群落。分别解剖鳐及其猎物（从鳐的胃中获取）以回收成虫和幼虫绦虫。对蠕虫标本的28S rDNA区域的一个片段进行扩增，目的是确认粗鳐体内寄生虫的物种身份，并揭示利用粗鳐与其猎物之间捕食联系的营养传递途径。我们从四个绦虫目中鉴定出了七种绦虫。在来自鳐胃的三种猎物与鳐之间解析出了四条营养传递途径，在一条来自新西兰鳎的幼虫绦虫序列与鳐之间解析出了一条途径，即猎物中的幼虫绦虫与鳐体内的成虫之间存在基因匹配。我们报道了首例成年四吻绦虫寄生于粗鳐的情况。这些发现有助于我们对绦虫生命周期的有限理解，同时也为捕食者 - 猎物关系对寄生虫传播的重要性提供了见解。
