Grenadiers (fish)

Coryphaenoides leptolepis

The Grenadiers ( Macrouridae ( Gr. " macros " is big and " oura " means tail) ), also called rat-tails, are fishes from the order of the cod -like ( gadiformes ). They live in all oceans at depths of 200-6000 meters, mostly pelagic, but close to the ground. From their number represent the Grenadiers 15% of deep-sea fish.

Features

Grenadiers have a stocky, somewhat laterally flattened body, terminating in a long, pointed tail. The head is large, the muzzle pointed or blunt, the mouth terminal or inferior. The tip of the snout is often covered by signs like scales that go on in a row below the large eyes. In most cases a chin Bartel is available. The sensory channels at the head are highly developed and are partially separated by skin membranes, in open bony groove. The number of Branchiostegalstrahlen is six to eight, that of the trunk vertebrae 10 to 16

The first dorsal fin is small, high and pointed. The first fin ray of the dorsal fin may be formed as a sting, what is the exception in cod -like fish. The second dorsal and anal fins meet at the tail. A tail fin and the associated skeleton are not available. Only Trachyrincus has a tail fin. The pectoral fins set to high, the pelvic fins sit far forward before. Below or just behind the pectoral fin base They are supported by five to 17 fin rays and missing only in Macrouroides. The scales are small and usually thorny. In the family, both round and comb scales occur. Some species along the midline of the ventral side, anterior to the anus, light organs. The lateral line is well developed. Some species can produce sounds using their swim bladder.

Most species are about 80 inches long. The smallest Grenadier, Hymenocephalus papyraceus is ten inches long, while the largest representatives of the giant grenadier ( Albatrossia pectoralis ) reaches a length of 1.5 meters.

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

Ecology

Grenadier fish live alone or in small flocks. They often gather at deep-sea havens such as hydrothermal vents or even shipwrecks. They also photographed the wreck of the Titanic. The animals eat smaller fish, such as lantern fish, pelagic crustaceans, small cephalopods and other animals.

Reproduction

Grenadiers lay up to 100,000 eggs from 1-2 millimeters in diameter in the open water. The eggs contain a drop of oil and float in the water. After hatching the larvae to keep in shallower water and migrate to greater depths until later. The type Coryphaenoides armatus the older animals die after spawning.

Inside systematics

The Grenadiers comprise four subfamilies, 38 genera and nearly 400 species. This makes them the most species-rich family of cod -like and represent more than half of the species:

• Subfamily Bathygadinae (26 species)
• Subfamily Macrourinae ( over 360 species)
• Subfamily Macrouroidinae ( 2 types)
• Subfamily Trachyrincinae (7 species)

In a 2009 study published phylogenetic systematics of the cod -like the Bathygadinae receive family rank, Macrouroidinae and Trachyrincinae are provided as sister groups in a newly established family Trachyrincidae and the Grenadiers thus limited to the Macrourinae.