Garcia-Vedrenne Ana E, Quintana Anastasia C E, DeRogatis Andrea M, Dover Christina M, Lopez Maribel, Kuris Armand M, Hechinger Ryan F
Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA.
College of Creative Studies, University of California, Santa Barbara, CA 93106, USA; Department of Marine Science and Conservation, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
Int J Parasitol. 2017 Jan;47(1):41-50. doi: 10.1016/j.ijpara.2016.10.003. Epub 2016 Nov 30.
Recent findings have extended the documentation of complex sociality to the Platyhelminthes, describing the existence of a reproductive division of labour involving a soldier caste among the parthenitae of trematode parasites. However, all species examined to date occupy high positions in trematode interspecific dominance hierarchies and belong to two closely related families, the Echinostomatidae and the Philophthalmidae (Superfamily Echinostomatoidea). Further, the two species documented as lacking soldiers also belong to the Echinostomatidae. Here, we examine four species of intermediate dominance, all belonging to the family Heterophyidae (Superfamily Opisthorchioidea): Euhaplorchis californiensis, Phocitremoides ovale, Pygidiopsoides spindalis and Stictodora hancocki, all of which infect the California horn snail, Cerithideopsis californica (=Cerithidea californica). We quantify morphology, distribution and behaviour of rediae from fully developed colonies. We also provide information on colony structure for three developing heterophyid colonies to better understand colony development. We discuss the implications of our findings, particularly with respect to how they suggest alternatives to the conclusions of other researchers concerning the nature of trematode sociality. Our analyses of morphological, distributional and behavioural patterns of developed colonies indicate that these heterophyid trematodes have a non-reproductive caste whose function is defence of the colony from invading trematodes. Hence, a soldier caste occurs for species lower in dominance hierarchies than previously known, and is present in at least two superfamilies of digenean trematodes, suggesting that selection for a soldier caste may be much more common among the Trematoda than previously recognised.
最近的研究发现已将复杂社会性的记录扩展至扁形动物门，描述了吸虫寄生虫单性生殖体中存在一种涉及兵虫等级的生殖分工。然而，迄今为止所研究的所有物种在吸虫种间优势等级中都处于高位，且都属于两个亲缘关系密切的科，棘口科和嗜眼吸虫科（棘口超科）。此外，记录显示缺乏兵虫的两个物种也属于棘口科。在此，我们研究了四个处于中等优势地位的物种，它们均属于异形科（后睾超科）：加利福尼亚真杯口吸虫、卵形海豹吸虫、纺锤形矮杯吸虫和汉考克窄体吸虫，所有这些物种都寄生于加利福尼亚角螺（=加利福尼亚蟹守螺）。我们对发育完全的群体中的雷蚴的形态、分布和行为进行了量化。我们还提供了三个发育中的异形吸虫群体的群体结构信息，以便更好地了解群体发育情况。我们讨论了研究结果的意义，特别是关于这些结果如何为其他研究人员有关吸虫社会性本质的结论提供了不同观点。我们对发育完全的群体的形态、分布和行为模式的分析表明，这些异形吸虫有一个非生殖等级，其功能是保护群体免受入侵吸虫的侵害。因此，兵虫等级出现在优势等级比先前已知情况更低的物种中，并且存在于复殖吸虫的至少两个超科中，这表明在吸虫纲中对兵虫等级的选择可能比先前认为的更为普遍。
