Grenadier fish

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Grenadier fish
Coryphaenoides leptolepis

Coryphaenoides leptolepis

Systematics
Sub-cohort : Neoteleostei
Acanthomorphata
Paracanthopterygii
Order : Cod-like (Gadiformes)
Subordination : Macrouroidei
Family : Grenadier fish
Scientific name
Macrouridae
Gilbert & Hubbs , 1916

The grenadier fish (Macrouridae ( Gr .: "Macros" means big and "oura" means tail )), also called rat tails , are fish from the order of the cod-like (Gadiformes). They live in all oceans at depths of 200 to 6000 meters, mostly pelagic , but close to the ground. Grenadiers make up 15% of all deep-sea fish.

features

Grenadier fish

Grenadier fish have a stocky, laterally slightly flattened body that ends in a long, pointed tail. The head is large, the snout pointed or blunt, the mouth terminal or below. The tip of the snout is often covered by shield-like scales that continue in a row below the large eyes. Usually a goatee is present. The sensory channels on the head are well developed and lie in open, bony furrows, some of which are separated by skin membranes. The number of Branchiostegal rays is six to eight, that of the trunk vertebrae is 10 to 16.

The first dorsal fin is small, high and pointed. The first fin ray of the dorsal fin can be designed as a spine, which is the exception in cod-like fish. The second dorsal and anal fin meet at the tail. A caudal fin and the accompanying skeleton are not present. Only Trachyrincus has a caudal fin. The pectoral fins are set high, the pelvic fins sit far in front, in front of, under or just behind the base of the pectoral fin. They are supported by five to 17 fin rays and are only absent in Macrouroides . The scales are small and usually prickly. Both round and comb scales occur in the family. Some species have luminous organs along the midline of the abdomen, in front of the anus . The sideline is well developed. Some species can make sounds with the help of their swim bladders.

Most species grow to be around 80 centimeters long. The smallest grenadier, Hymenocephalus papyraceus , is ten centimeters long, while the largest representative, the giant grenadier ( Albatrossia pectoralis ) reaches a length of 1.5 meters.

The larger species such as Albatrossia pectoralis and the round-nosed grenadier ( Coryphaenoides rupestris ) are fished commercially.

ecology

Grenadier fish live alone or in small schools. They often gather in deep-sea oases such as hydrothermal springs or shipwrecks. She was also photographed on the wreck of the Titanic . The animals eat smaller fish, such as lantern fish, pelagic crabs, small cephalopods and other animals.

Reproduction

Grenadier fish lay up to 100,000 eggs 1–2 millimeters in diameter in open water. The eggs contain a droplet of oil and float in the water. After hatching, the larvae stay in shallow water and only later migrate to greater depths. In the species Coryphaenoides armatus , the adults die after spawning.

Internal system

Round-nosed grenadier ( Coryphaenoides rupestris )

The grenadier fish comprise four subfamilies, 38 genera and almost 400 species. This makes them the most species-rich family of cod-like and make up more than half of the species:

In a study published in 2009 on a phylogenetic systematics of cod-like species, the Bathygadinae were given family status, Macrouroidinae and Trachyrincinae were placed as sister groups in a newly established family Trachyrincidae and the grenadier fish were thus limited to the Macrourinae.

literature

  • Joseph S. Nelson : Fishes of the World , John Wiley & Sons, 2006, ISBN 0-471-25031-7 .
  • Cohen, DM; Inada.T .; Iwamoto, T .; Scialabba, N. FAO species catalog. Vol. 10: Gadiform fishes of the world (Order Gadiformes). An annotated and illustrated catalog of cods, hakes, grenadiers and other gadiform fishes known to date. FAO Fisheries Synopsis. No. 125, Vol. 10. Rome, FAO. 1990. 442 p. on-line

Individual evidence

  1. Adela Roa-Varón, Guillermo Ortí: Phylogenetic relationships among families of Gadiformes (Teleostei, Paracanthopterygii) based on nuclear and mitochondrial data. Molecular Phylogenetics and Evolution 52 (2009) 688-704, doi : 10.1016 / j.ympev.2009.03.020

Web links

Commons : Grenadiers  - Collection of images, videos and audio files