The caudal peduncle is the tapered region behind the dorsal and anal fins where the caudal fin attaches to the body. The depth of the caudal peduncle, which is measured at its narrowest point, gives some indication of the power of a fish and the speed at which it can swim. For example, ambush predators, … [Read more…]
Teleosts are the most diverse group of fishes (over 26,500 extant species). Over half of all living vertebrate species are teleosts. Teleosts are characterized by a protrusible jaw (musculature gives them the ability to move their maxilla and premaxilla) and a symmetrical tail (their spine that ends at the caudal peduncle unlike, for example, sharks). Teleosts … [Read more…]
Finlets are highly specialized fins located on the dorsal and ventral sides of the body between the dorsal fin and/or the anal fin and the caudal fin. They are only found on certain fish including those in the Scombrid family (mackerels, tunas, and bonitos), Scomberesocid family (sauries), snake mackerels (family Gempylidae), and Bichirs (family Polypteridae). For Bichirs, the finlets are … [Read more…]
The caudal fin, or tail, of a fish is the only fin to be connected to the vertebral column. It is the primary means of locomotion for most fish. Unlike many marine mammals with tails that use an up-and-down motion, fish generally use a side-to-side thrust of their caudal fin for propulsion. The shape of the … [Read more…]