Four-horned sea scorpion

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Four-horned sea scorpion
Triglopsis quadricornis (Pieni) .jpg

Four-horned sea scorpion ( Myoxocephalus quadricornis )

Systematics
Order : Perch-like (Perciformes)
Subordination : Cottoidei
Partial order : Bull relatives (Cottales)
Family : Dickkopf bullheads (Psychrolutidae)
Genre : Myoxocephalus
Type : Four-horned sea scorpion
Scientific name
Myoxocephalus quadricornis
Linnaeus , 1758

The four-horned sea scorpion ( Myoxocephalus quadricornis ) is a fish from the family of the thick-headed bullheads (Psychrolutidae), which is found in coastal waters of Eastern Europe, North Asia and North America.

distribution

The four-horned sea scorpion lives on the coast of the Arctic Ocean in northern North America, on the coast of the White Sea , the Barents Sea and Siberia to the mouth of the Anadyr , as well as in the northern and eastern Baltic Sea. In Swedish, Finnish and Karelian cold and deep lakes, there are relic populations that were trapped in these fresh waters at the end of the last Ice Age .

features

The four-horned sea scorpion is of very variable length. While the freshwater forms only reach lengths of 10 to 25 cm, the marine populations of the species can become much longer, up to 60 cm in the Bering Sea . Like all bullheads, it has a tadpole-shaped body with a flattened, broad, thick head. A characteristic and eponymous feature of the species are four spongy bony outgrowths on the top of the head, two between the eyes and two more on the back of the head. These "horns" are smaller in juvenile fish and females and can also be missing in freshwater forms. The gill trap rays are reduced to rounded, prickly outgrowths. The palatine bone is toothless. The Vorkiemendeckel carries four spines, the uppermost of which is the longest, the gill cover has two thorns. The fish are scaleless. Only between the sideline and the two dorsal fins run one or more rows of bone humps.

The pectoral fins are fan-shaped, the pelvic fins on the chest. The second, smooth dorsal fin is larger than the first, especially in adult males. The caudal fin is spade-shaped or slightly rounded.

Young four-horned sea scorpions are gray-brown on top and show three to four dark, saddle-like spots below the dorsal fins and another spot on the caudal fin stalk. The sides are yellowish, the belly whitish. The fins have rows of dark spots. Adult fish become darker.

Way of life

Four-horned sea scorpions live on the bottom at depths of up to 100 meters, always near the coast, in brackish water and cold lakes, more rarely in river underflows up to more than 150 km inland. They feed on small fish, worms, crustaceans and mollusks and are diurnal from November to April, and nocturnal the rest of the year. During the spawning season from December to January, the male builds a pit under stones, where mating takes place and where the eggs laid in clumps are guarded by him until the young fish hatch after five weeks.

literature

  • Bent J. Muus, Jørgen G. Nielsen: The marine fish of Europe in the North Sea, Baltic Sea and Atlantic. Kosmos, Stuttgart 1999, ISBN 3-440-07804-3 .
  • Fritz Terofal: Steinbach's natural guide, freshwater fish. Ulmer, Stuttgart 2003, ISBN 3-80014-296-1 .

Web links

Commons : Myoxocephalus quadricornis  - Collection of images, videos and audio files