Ocean sunfish
Sunfish, North Sea Oceanarium, Hirtshals (2009)
The ocean sunfish ( Mola mola, from Latin mola, " millstone" ) is considered the heaviest bony fish in the world. The moon fish can reach a length of 3.30 meters and a weight of 2.3 tons, but usually remains small. Some other teleost species, such as the European Hausen ( Huso huso ) or the belt fish Regalecus glesne be much longer.
Dissemination
The pelagic sunfish occurs mainly in warm seas. In the eastern Pacific, he was found from British Columbia to Chile, in the eastern Atlantic from Scandinavia to South Africa, in the western Atlantic from Newfoundland to Argentina. It also occurs in the Mediterranean, is frequently in the autumn in the North Sea, floating up in the Skagerrak and Kattegat.
Features
The body is short, disc- shaped, and scarcely longer than high. A normal, seated at a caudal peduncle caudal fin is missing, it is re-formed in the course of ontogenesis. Instead, it is replaced by a Clavus said corrugated cutaneous rim that closes the rear bluff body and extends almost from the back - up to the anal fin. This gephyrocerk called tail fin shape is just the sunfish own and exists in no other bony fish family.
The scaleless body of the moon fish is of a very thick (7.5 cm), leather-like and elastic skin covers ( Linnaeus named the genus therefore Orthagoriscus, " pig "). Dorsal and anal fin have the same high, triangular - pointed shape. They sit far back, symmetrically opposite each other, are the main driving element and be beaten synchronously side for propulsion. Both fins have a narrow base and are stiff. They can not be folded. The dorsal fin is supported 15-18 cartilaginous fin rays, the anal fin 14 to 17 The pectoral fins are up and are round and small ventral fins are missing. The mouth is very small and is mostly open, the teeth are fused into a parrot -like beak. The gill opening is reduced to a small hole above the base of the pectoral fins ( by extrusion of water can be produced recoil ). The skeleton of adult animals consists almost entirely of cartilage, a swim bladder is absent. The back of the sunfish is brownish, gray or greenish, the edges and the bottom bright
Way of life
Sunfish live in the open ocean from the water surface to a depth of 480 meters. They often stay near the surface, either vertically floating, with the dorsal fin, like a shark, can rise out of the water, or in a lateral position, horizontally on the water surface floating ( " basking ").
Food
Their diet consists mainly of gelatinous organisms such as jellyfish and salps. In addition, plankton, small fish, especially eel larvae, but also herring, small pelagic cephalopods, pteropods, crustaceans, brittle stars and other marine animals are eaten.
Reproduction
Sunfish are extremely fertile. A female can lay per spawning up to 300 million eggs, the highest number of all fish species. The eggs having a diameter of one millimeter. The larvae are hatching 3 mm long and still have a normal tail fin. For five long spines they are supposed to protect them from predators. Through various larval stages, of which resemble the first two for the related sphere and box fish, they are transformed to the adult animal. The spines are regressed in the course of development, but remain as bony remains in the skin.
Sunfish and humans
Moon fish are rarely caught targeted for human consumption. In Taiwan, however, the rubbery meat is appreciated. This may include sunfish, such as suitcases and puffer fish, the neurotoxin tetrodotoxin. Some parts of the fish are used in traditional Chinese medicine.
Sunfish are held in some large public aquariums in captivity, such as in the Oceanarium de Lisboa, in the L' Oceanographic in Valencia, in Aquàrium de Barcelona, at the National Aquarium of Ireland in Galway, in the Monterey Bay Aquarium and in the North Sea Oceanarium in Hirtshals.