Latin name

Albatrossia pectoralis

Other names

Giant rattail, mune dara.

Identification

It has a massive body, a broad head and a ribbon-like, tapering tail. The snout protrudes slightly above the upper jaw, which has two rows of teeth and one row on the lower jaw. The fish is characterised by a clear sexual dimorphism, consisting in the superiority of the females in both the maximum and average size indices, otherwise the individuals are similar in appearance.

Features of fish fins

The caudal fin is almost thread-like. The first dorsal fin is narrow and high, with 7-9 rays, the pelvic fin is also not broad, with 7-8 rays. The second dorsal and anal fins are low, elongated, and merge into the caudal fin, with the second dorsal fin beginning much earlier than the anal fin.

Fish colouring

Scales grey-brown, steely, uniform. Fin, lateral line and underside of snout darker. Scales shed easily; individuals lacking scales are pale, with a pattern of scale pockets.

Distribution

Found in the North Pacific Ocean from northern Japan to the Sea of Okhotsk and the Bering Sea, east to the Gulf of Alaska and south to northern Baja California in Mexico.

Habitat

Juveniles are partly bathypelagic, but become bathydemersal at a size of 50-60 cm. Adults have been recorded at depths from 140 to 3500 m, usually in the 500-1200 m range, and juveniles are often pelagic at depths of 200-1200 m. Giant grenadiers are cold water (up to 8 °C), with water temperatures in the range of 2.5-4 °C in areas of greatest aggregation.

Size

Can grow to 2.1 m in length, with a body mass of several tens of kilograms. Maximum reported weight: 86.0 kg. Catches are usually dominated by individuals between 6 and 12 years of age, with a mass of up to 4 kg and a length of 60-110 cm. This species is characterised by a high growth rate, reaching an average of 16 cm by the end of the first year of life. The greatest growth is observed in the first 5-6 years, at the end of which fish reach about 65 cm.

Behavior

The peculiarity of the lifestyle of these fish is the separate habitation of females and males. It has been found that females are usually caught at depths of 300-700 metres, while males are caught deeper. Further studies have shown that the proportion of males is insignificant at depths of up to 900 metres, that the sex ratio is approximately equal at depths of 1200-1300 metres, and that males predominate further down.

Maximum feeding activity is characteristic of the summer period (June to September). It is believed that the species begins to actively fatten after the peak spawning period from March to June.

Food and feeding habits

Main predator on the upper continental slopes of the North Pacific. Their main prey is the squid Octopoteuthis deletron and Vampyroteuthis infernalis. Crustaceans (shrimps, crabs) and various fish (anchovies, pollack, gobies, etc.) are the main food items, but cephalopods and worms are also included in the diet.

Reproduction

It is a spawning species that matures at the age of 5-11 years and measures 65-100 cm. Spawning takes place throughout the year, with the greatest activity in the winter-spring period in the Sea of Okhotsk and in the spring-summer period in other areas, at considerable depths. A mature female contains tens (up to 400) of thousands of eggs about 1.5 mm in diameter. Juveniles live in the water column and change to a benthic lifestyle when they reach a size of 50-60 cm.

Studies of scales and otoliths have shown that the age limit depends on the habitat of the individual, ranging from just over 20 years in the Sea of Okhotsk and Kuril Sea to 40 years in the Bering Sea. The use of radiometric methods suggests a maximum age of 56 years, but confirmed life expectancy does not exceed 32 years for females and 27 years for males.

Fishing

It has independent commercial importance or is fished together with other Macrurus species. 

Relationship with a person

Fish flesh is characterised by a high protein content and a low lipid content, which allows it to be used in dietetic nutrition.