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The anal/cloacal fin is located on the ventral surface behind the anus/cloaca. The bones that support the anal fin are called pterygiophores. There are up to two series, a proximal series (axonosts) and a distal series (baseosts) Most fish use their anal fin to stabilize while swimming; Knifefish use their anal fins for thrust (gymnotiform ...
The tail fin can be rounded at the end, truncated (almost vertical edge, as in salmon), forked (ending in two prongs), emarginate (with a slight inward curve), or continuous (dorsal, caudal, and anal fins attached, as in eels). Anal fins: Located on the ventral surface behind the anus, this fin is used to stabilize the fish while swimming ...
Dorsal fin diagram with landmarks labeled. Fins allow the sharks to be able to guide and lift themselves. Most sharks have eight fins: a pair of pectoral fins, a pair of pelvic fins, two dorsal fins, an anal fin, and a caudal fin. Pectoral fins are stiff, which enables downward movement, lift, and guidance.
The main purpose of the dorsal fin is usually to stabilize the animal against rolling and to assist in sudden turns. Some species have further adapted their dorsal fins to other uses. The sunfish uses the dorsal fin (and the anal fin ) for propulsion.
Fins first evolved on fish as a means of locomotion. Fish fins are used to generate thrust and control the subsequent motion. Fish and other aquatic animals, such as cetaceans, actively propel and steer themselves with pectoral and tail fins. As they swim, they use other fins, such as dorsal and anal fins, to achieve stability and refine their ...
Caudal fin: Heterocercal: Heterocercal or diphycercal: Pelvic fins: Usually posterior. Mostly anterior, occasionally posterior. Intromittent organ: Males use pelvic fins as claspers for transferring sperm to a female Do not use claspers, though some species use their anal fins as gonopodium for the same purpose Mouth
The dorsal fin, which is set far back near the tail, has no spines and five to seven soft rays, and the anal fin has no spines and four soft rays. The pectoral fins are robust and held at right angles to the body; they are limb-like and are used to "walk" over the seabed, and the more slender pelvic fins serve the same purpose. [9]
The anal fin of the black bullhead also has a gray base, and its tail has a pale bar. Also, the brown bullhead generally has 21 to 24 soft rays through its anal fin as opposed to the black bullhead's 17 to 21. The brown bullhead is also typically mottled brown and green on top instead of the darker black.