Sheena P, Janardanan K P
Department of Zoology, University of Calicut, Kerala - 673 635, India.
J Helminthol. 2007 Sep;81(3):301-6. doi: 10.1017/S0022149X07818529.
The life cycle of a new haploporid digenean, Hapladena gymnocephali sp. nov., infecting the bald glassy perchlet Ambassis gymnocephalus from the Chaliyar and Kadalundi rivers of Kozhikode district, Kerala, India, is elucidated. The new species is described in detail, its systematic position discussed and compared with related species, H. acanthuri Siddiqi & Cable, 1960 and H. spinosa Manter & Pritchard, 1961. Hapladena gymnocephali is distinctly different from the two latter species in the shape and size of body, nature of testis, extent of vitelline field and excretory bladder. Hapladena gymnocephali has a typical haploporid, two-host life cycle: the gymnocephalous, bi-ocellate, distome cercariae released by the snail Gabbia travancorica are ingested by the fish and develop directly into adults without undergoing a metacercarial stage of development. This is the first report of the genus Hapladena from India, and also the first report of the life cycle of the genus.
一种新的单殖吸虫——裸头单殖吸虫（Hapladena gymnocephali sp. nov.）的生活史得以阐明，该吸虫寄生于印度喀拉拉邦科泽科德区查利耶尔河和卡达伦迪河中秃头玻璃银鲈（Ambassis gymnocephalus）体内。详细描述了该新物种，讨论了其系统位置，并与相关物种——1960年的棘鳍单殖吸虫（H. acanthuri Siddiqi & Cable）和1961年的多棘单殖吸虫（H. spinosa Manter & Pritchard）进行了比较。裸头单殖吸虫在身体形状和大小、睾丸特征、卵黄腺范围和排泄囊方面与后两个物种明显不同。裸头单殖吸虫具有典型的单殖吸虫双宿主生活史：蜗牛特拉凡科尔湾小蟹（Gabbia travancorica）释放出的裸头双眼双盘尾蚴被鱼类摄入后直接发育为成虫，不经历后尾蚴阶段。这是印度首次报道单殖吸虫属，也是该属生活史的首次报道。
