Liu Yang, Yuan Junfa, Jia Luo, Huang Mingjun, Zhou Zhigang, Gu Zemao
Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, People's Republic of China; Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070, People's Republic of China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, People's Republic of China.
Key Lab for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
Parasitol Int. 2014 Jun;63(3):489-91. doi: 10.1016/j.parint.2014.01.003. Epub 2014 Jan 25.
Thelohanellus wuhanensis Xiao & Chen, 1993 infects allogynogenetic gibel carp Carassius auratus gibelio (Bloch) forming numerous plasmodia in the skin, resulting in high mortality of juvenile host fish. Within this paper we supplement the identification of this pathogenic species with information on its ultrastructural and histological characteristics. Measurements of the spores corresponded to the original description, but asymmetry in the spore shape was recorded. Scanning electron microscopy revealed that the spore surface was smooth and the sutural ridge of the anterior end was asymmetric as one side was thinner. In addition, the sutural line was either straight or "S" like. Transmission electron microscopy showed that most spores were surrounded by a membranous sheath, while some sheaths were difficult to observe under light microscopy as the closeness of the sheath to the valves. The small electron-dense granules in the sporoplasm ranged from 0.66 to 1.14 μm in diameter, but their function was unknown. Histology showed that the plasmodia of T. wuhanensis developed in the stratum spongiosum of skin dermis. The presence of melanocytes around the plasmodia was responsible for the black spots on T. wuhanensis cyst. The plasmodia were curved, perhaps to expand the surface area in contact with adjacent host tissue, facilitating the attainment of nutrients from the host.
武汉泰勒虫（Thelohanellus wuhanensis Xiao & Chen，1993）感染异育银鲫（Carassius auratus gibelio (Bloch)），在鱼皮肤中形成大量的孢质团，导致宿主幼鱼的高死亡率。在本文中，我们补充了该致病物种的鉴定信息，包括其超微结构和组织学特征。孢子的测量结果与原始描述相符，但记录到孢子形状存在不对称性。扫描电子显微镜显示，孢子表面光滑，前端的缝线嵴不对称，一侧较薄。此外，缝线要么是直的，要么呈“S”形。透射电子显微镜显示，大多数孢子被一层膜状鞘包围，而在光学显微镜下，由于鞘与瓣膜紧密相连，一些鞘难以观察到。孢质中的小电子致密颗粒直径在0.66至1.14μm之间，但其功能尚不清楚。组织学显示，武汉泰勒虫的孢质团在皮肤真皮的海绵层中发育。孢质团周围黑素细胞的存在导致了武汉泰勒虫囊肿上的黑点。孢质团呈弯曲状，可能是为了扩大与相邻宿主组织接触的表面积，便于从宿主获取营养。
