Search results
Results from the WOW.Com Content Network
The shape, size, position and colour of the dorsal fin varies with the type of billfish, and can be a simple way to identify a billfish species. For example, the white marlin has a dorsal fin with a curved front edge and is covered with black spots. [4] The huge dorsal fin, or sail, of the sailfish is kept retracted most of the time. Sailfish ...
A fish can have up to three dorsal fins. The dorsal fins serve to protect the fish against rolling, and assist it in sudden turns and stops. In anglerfish, the anterior of the dorsal fin is modified into an illicium and esca, a biological equivalent to a fishing rod and lure; The bones that support the dorsal fin are called pterygiophores.
Dogfish likewise have two dorsal fins, each with smooth spines, but no anal fin, and their skin is generally rough to the touch. [1] As the species reaches adulthood, males usually measure a maximum of 100 cm (39 inches), while females typically measure 125 cm (49 inches) long. The species therefore exhibits female-dominant sexual dimorphism.
Dorsal fins: Located on the back of the fish, dorsal fins serve to prevent the fish from rolling and assist in sudden turns and stops. Most fishes have one dorsal fin, but some fishes have two or three. In anglerfish, the anterior of the dorsal fin is modified into an illicium and esca, a biological equivalent to a fishing rod and lure.
The dorsal fin usually is composed of three or four long dorsal spines followed by a series of shorter dorsal spines. Hogfish reach a maximum of 90 centimetres (35 inches) in total length and a weight of about 11 kilograms (24 pounds).
The caudal fin has asymmetrical lobes, forming a heterocercal tail. The species name acanthias refers to the shark's two spines. These are used defensively. If captured, the shark can arch its back to pierce its captor with spines near the dorsal fins that secrete a mild venom into its predator. [7]
The fin spines of reef-dwelling horn sharks are shorter than those living in algal habitats, as their spines become worn down on rocks from the sharks' movements. [3] The first dorsal fin originates over the bases of the large pectoral fins, while the second dorsal fin originates slightly anterior to the free rear tips of the pelvic fins.
The dorsal fin has 10 spines and 14-15 soft rays while the anal fin contains 3 spines and 8 soft rays. [2] The long perctoral fin extends as far as the anus and contains16-17 rays. [7] This fish attains a maximum total length of 128 cm (50 in), although 60 cm (24 in) is more typical, and the maximum published weight is 28.6 kg (63 lb). [2]