Blair D
J Helminthol. 1976 Jun;50(2):125-32. doi: 10.1017/s0022149x00027607.
The life-cycle of Apatemon (A.) gracilis was completed in the laboratory. The snail host is Lymnaea peregra (Muller). The cercaria is redescribed from a wide range of material. Metacercariae were found in naturally infected rainbow trout (Salmo gairdneri Richardson), three-spined sticklebacks (Gasterosteus aculeatus L.) and stone loach (Nemacheilus barbatulus (L.)) from Scotland and in three-spined sticklebacks from Iceland. In trout, most metacercariae were found in the pericardial cavity, in sticklebacks, the eye, and in loach, the body cavity. In infection experiments, cercariae from naturally infected Scottish snails developed in three-spined sticklebacks, rainbow trout and brown trout (Salmo trutta L.). Under experimental conditions cercariae did not penetrate stone loach, although this species is naturally infected with A. gracilis. The phenomenon of fish host specificity is briefly discussed. Development of the metacercaria is described. Excystation of metacercarial cysts with pepsin and trypsin solutions is unlike that reported for any other digenean; the contents of the cyst appear to be under pressure. In pepsin, layers of the cyst wall peel back from one end. When transferred to trypsin, one pole of the cyst ruptures and the worm is forcibly expelled.
纤细艾氏吸虫（Apatemon (A.) gracilis）的生活史在实验室中得以完成。蜗牛宿主为截口土蜗（Lymnaea peregra (Muller)）。根据大量材料对尾蚴进行了重新描述。在来自苏格兰的自然感染虹鳟（Salmo gairdneri Richardson）、三刺鱼（Gasterosteus aculeatus L.）和石纹鳅（Nemacheilus barbatulus (L.)）以及来自冰岛的三刺鱼体内发现了囊蚴。在鳟鱼中，大多数囊蚴发现于心包腔；在三刺鱼中，发现于眼部；在石纹鳅中，发现于体腔。在感染实验中，来自自然感染的苏格兰蜗牛的尾蚴在三刺鱼、虹鳟和褐鳟（Salmo trutta L.）体内发育。在实验条件下，尾蚴无法穿透石纹鳅，尽管该物种自然感染了纤细艾氏吸虫。简要讨论了鱼类宿主特异性现象。描述了囊蚴的发育过程。用胃蛋白酶和胰蛋白酶溶液使囊蚴囊肿脱囊的过程与报道的任何其他复殖吸虫不同；囊肿内容物似乎处于压力之下。在胃蛋白酶中，囊肿壁的各层从一端向后剥落。当转移到胰蛋白酶中时，囊肿的一端破裂，虫体被强行排出。
