Abstract:
Neoergasilus japonicus, a fish ectoparasite indigenous to eastern and southern Asia, has been introduced to various regions, including Europe and North and South America, where it spreads at an alarming rate. The parasite is not host-specific. It was also collected from the Vaal-Orange and Limpopo river systems in South Africa. This report describes the morphology of the wound-inflecting structures in N. japonicus and relates their morphology to the pathological effect on Tilapia sparrmanii. Host tissue with parasites attached was imbedded in resin for histological sectioning and stained with haematoxylin and eosin. Additional specimens were prepared for scanning electron microscopy. Adult female parasites attach by inserting the hooked tips of the antennae into the epidermis. The maxillulae are minute but have sharp tips. The maxillae have sharp tips on the endopod and brush-like setae on the exopod. The mandibles are armed with sharp tips. These structures are used to remove the epidermis of the host and brush it into the buccal cavity. Host tissue in the intestine confirms that adult females consume host tissue leaving the dermis exposed to opportunistic diseases. The microscopic size of the parasite prevents casual observation, and its occurrence in Africa is, therefore, probably underreported.
摘要:
新日本菜,一种原产于东亚和南亚的鱼类体外寄生虫,已经被介绍到各个地区,包括欧洲、北美和南美,它以惊人的速度传播。寄生虫不是宿主特异性的。它也是从南非的Vaal-Orange和Limpopo河系统中收集的。该报告描述了日本猪笼草的伤口变形结构的形态,并将其形态与对罗非鱼的病理作用联系起来。将附着有寄生虫的宿主组织嵌入树脂中进行组织学切片,并用苏木精和伊红染色。制备另外的样品用于扫描电子显微镜。成年雌性寄生虫通过将触角的钩状尖端插入表皮而附着。上颌是微小的,但有尖锐的尖端。上颌骨在内足上有锋利的尖端,在外足上有刷状刚毛。下颌骨有锋利的尖端。这些结构用于去除宿主的表皮并将其刷入口腔。肠道中的宿主组织证实,成年雌性消耗宿主组织,使真皮暴露于机会性疾病。寄生虫的微观大小阻止了随意观察,它发生在非洲,因此,可能被低估了。