Читать книгу Clinical Guide to Fish Medicine - Группа авторов - Страница 57

The bowfin (Amia calva) is the only extant species of this order. They are freshwater predatory fish with long, sharp teeth, and two protruding tube‐like nares. They have spiracle remnants and their skeleton is predominantly cartilaginous. They are physostomous and the swim bladder can function as a lung. There is a rudimentary spiral valvular intestine. Scales are cycloid rather than the ganoid scales typical of similar “primitive” fish. Kidney tubules open directly into the coelomic cavity. They are often mistaken for burbot (Lota lota) or snakeheads (Channidae) (Helfman et al. 2009; Nelson et al. 2016).