ABSTRACT

Robinione overstreeti is a bopyrid isopod endemic to the Gulf of Mexico that inhabits the branchial chamber of the ghost shrimp Callichirus islagrande. Information on this host–parasite association is scant. This study describes population and reproductive features of R. overstreeti and its host. A total of 90 (9.97%) out of 903 individuals of C. islagrande collected from Tamiahua lagoon, Veracruz, Mexico, between April 2012 and October 2013, were parasitized by R. overstreeti. Parasite prevalence in male and female ghost shrimps was similar. However, no parasitized ovigerous females of C. islagrande were recorded, suggesting that R. overstreeti is a parasitic castrator. Host and parasite body sizes were positively correlated suggesting early host infestation by parasites and simultaneous growth of the host and parasite. Parasitic isopods frequently inhabited the same branchial chamber (n = 77) of ghost shrimps as adult male-female pairs. Females were occasionally found with supernumerary juveniles and cryptoniscus larvae in the same host individual, and rarely solitarily. Furthermore, the body size of paired adult male and female parasites was tightly correlated suggesting long-term ‘social’ monogamy in R. overstreeti. Fecundity in R. overstreeti varied between 1668 and 9884 embryos female⁻¹ and increased with female body size.

摘要

Robinione overstreeti是墨西哥湾特有的一种等足类动物，栖息在鬼虾Callichirus islagrande的鳃室中。关于这种宿主-寄生虫关联的信息很少。本研究描述了R 的种群和繁殖特征。overstreeti和它的主人。2012 年 4 月至 2013 年 10 月期间，在墨西哥韦拉克鲁斯州塔米亚瓦泻湖收集的 903 只C. islagrande 中，共有 90 只 (9.97%)被R. overstreeti寄生。雄性和雌性鬼虾的寄生虫患病率相似。然而，没有记录到C. islagrande 的寄生产卵雌性，这表明R .overstreeti是一种寄生性阉割者。宿主和寄生虫的体型呈正相关，表明早期宿主被寄生虫侵染并且宿主和寄生虫同时生长。寄生等足类动物经常 与成年雄性-雌性成对栖息在鬼虾的同一个鳃室（n = 77）中。雌性偶尔会在同一宿主个体中发现多余的幼虫和隐窝幼虫，很少单独存在。此外，成对的成年雄性和雌性寄生虫的体型密切相关，表明R. overstreeti 中存在长期的“社会”一夫一妻制。R. overstreeti 的繁殖力在1668 和 9884 胚胎雌性^-1之间变化，并且随着雌性体型的增大而增加。