| Merluccius polli | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Gadiformes |
| Family: | Merlucciidae |
| Genus: | Merluccius |
| Species: | M. polli |
| Binomial name | |
| Merluccius polli | |
| Synonyms | |
Merluccius cadenatiDoutre, 1960 | |
Merluccius polli, the Benguela hake, is a species of fish from the family Merlucciidae, the true hakes. It is found in the tropical waters of the eastern Atlantic Ocean off the west coast of Africa.
Merluccius polli has a large head which has a small depression in the cranium, the head is equivalent to just over a quarter of the fish's standard length. [3] The lower jaw and premaxillary have small teeth, the lower jaw is slightly projecting. [4] It has short, thick gill rakers which have blunt tips; and number 8–12 on the first arch. The anterior dorsal fin has a single spine and 8-11 fin rays and the posterior dorsal fin has 37-41 rays. The anal fin has 36–42 fin rays and the pectoral fin tips normally extend as far as the origin of the anal fin, except in large individuals. The caudal fin has a truncated marginal though this can occasionally be emarginate. The scales are loose and easily shed, there are 102 to 127 along the lateral line. It is usually blackish in colour on the back paling to steel grey to blackish on belly and the caudal fin has a white edge. [3] This species differs from the Panama hake in that in juveniles the caudal fin has a central lobe and is truncate in adults, whereas the caudal fin is emarginate in the Panama hake, its pectoral fin projects well beyond the anus in but does not do so in the Panama hake. [3] The inside of the mouth and the tongue are usually blackish and there is a black marking on the submandibular fold. They grow to a maximum length of 80 cm, although fish of 16–42 cm are commonest. [4]
Merluccius polli occurs in the eastern Atlantic off the west coast of Africa from Cape Barbas (22°N) in Western Sahara south to Cape Fria in Namibia (18°S). [1] It is also found off the Canary Islands, [5] although it has not been recorded from the Cape Verde Islands [6]
Merluccius polli is a bathydemersal species that, in the northern part of its range, occurs on the continental shelf and upper continental slope. Females reach sexual maturity when they reach a length of around 44 cm and spawning occurs in the autumn. The most successful recruitment happens between temperatures of 8–11 °C. It feeds mainly on small fish but its diet also includes squid and free swimming crustaceans. It occurs at depths between 50-910m, although it normally remains between 50 and 550 m. The mean size of individual fish increases with increasing depths. [1]
Two subspecies have been proposed for M. polli: [4]
These are parapatric and are separated by a 500 km gap in the Gulf of Guinea. [4]
Merluccius polli lives in deep water, is of relatively small in size and is of low abundance so it has been considered to be of low economic potential. The catch statistics of this species are lumped with those of Merluccius senegalensis over the northern part of its range and with M. capensis in Namibia. [3] In the Canaries 65 tonnes were landed in 2010 but in most years almost none are landed. [5]
The specific name polli honours the Belgian ichthyologist Max Poll (1908–1991) [7] while the name of the subspecies cadenati honours the French ichthyologist Jean Cadenat (1908–1992), who originally described the species. [8]
The term hake refers to fish in the:
The North Pacific hake, Pacific hake, Pacific whiting, or jack salmon is a ray-finned fish in the genus Merluccius, found in the northeast Pacific Ocean from northern Vancouver Island to the northern part of the Gulf of California. It is a silver-gray fish with black speckling, growing to a length of 90 cm (3 ft). It is a migratory offshore fish and undergoes a daily vertical migration from the surface to the seabed at depths down to about 1,000 m (3,300 ft). It is the object of an important commercial fishery off the West Coast of the United States, and annual quotas are used to prevent overfishing.
The silver hake, Atlantic hake, or New England hake is a merluccid hake of the genus Merluccius, found in the northwest Atlantic Ocean. It is highly predatory and typically feeds on fish and crustaceans.
The longfin sawtail catshark is a rare, little-known species of catshark, part of the family Scyliorhinidae. Once thought to be a subspecies of the roughtail catshark along with the Antilles catshark, it inhabits deep water off the Caribbean coasts of Panama and Colombia. This slim-bodied species has a marbled dorsal color pattern and a prominent crest of enlarged dermal denticles along the dorsal edge of its caudal fin. It can be distinguished from similar species by its relatively longer anal fin and small adult length of under 35 cm (14 in). The longfin sawtail catshark is oviparous.
The African sawtail catshark is a species of catshark, part of the family Scyliorhinidae. Demersal in nature, it is found at depths of 160–720 m (520–2,360 ft) off the western African coast from Morocco to South Africa. This slender species has a rather long, pointed snout, a series of dark saddles along the back and tail, and a prominent crest of enlarged dermal denticles along the upper edge of the caudal fin. Its maximum known length is 46 cm (18 in).
Merluccius merluccius, the European hake, is a merluccid hake of the genus Merluccius. Other vernacular names include Cornish salmon and herring hake. It is a predatory species which was often netted alongside one of its favoured prey, the Atlantic herring, thus the latter common name. It is found in the eastern Atlantic from the Norway and Iceland south to Mauritania and into the Mediterranean Sea. It is an important species in European fisheries and is heavily exploited with some populations thought to be being fished unsustainably.
Merluccius capensis is a ray-finned fish in the genus Merluccius, found in the south-eastern Atlantic Ocean, along the coast of South Africa. It is a long, lean fish with a large head, similar in appearance to the European hake and the deep-water Cape hake. By day, it lives close to the bottom on the continental shelf and upper slope at depths not usually exceeding 400 m (1,300 ft); it makes a large, daily vertical migration rising at night to feed in the nectonic zone, and it also migrates southwards in spring and northwards in autumn. It is an important commercial fish species in southern Africa.
Merluccius paradoxus, the deep-water Cape hake, is a merluccid hake of the genus Merluccius, found in the south-eastern Atlantic Ocean, along the coast of Southern Africa, south of Angola. Its range extends in decreasing abundance around the southern coast of Africa and into the Indian Ocean, but it is at its most plentiful in the cold, nutrient-rich fishing grounds of the Benguela Current.
The Panama hake, also known as the dwarf hake, is a merluccid hake found off the west coast of the Americas from Del Mar, California, to Ensenada de Tumaco, Colombia.
Lutjanus russellii, Russell's snapper, Moses snapper, fingermark bream, Moses seaperch or Russell's sea-perch, is a species of marine ray-finned fish, a snapper belonging to the family Lutjanidae. It is native to the western Pacific Ocean.
Trachyrincus scabrus, the roughsnout grenadier or Mediterranean longsnout grenadier, is a species of bathydemersal marine fish from the subfamily Trachyrincinae, part of the family Macrouridae. It is found in the eastern Atlantic Ocean and the Mediterranean.
Merluccius australis, the southern hake, is a species of fish from the family Merlucciidae, the true hakes. It is found in the southern Pacific and Atlantic Oceans with two disjunct populations, one around southern South America and the other in the waters around New Zealand.
Merluccius hernandezi, the Cortez hake, is a species of fish from the family Merlucciidae, the true hakes. It is endemic to the Gulf of California where it can be found in the epipelagic and mesopelagic zones over the continental shelf, open sea, and sea mounts, to a depth of around 300m. It is a small species which has been referred to as a "dwarf hake" and is of little interest to fisheries, other than small scale local fisheries. It was described in 1985 and small hake in the Gulf of California were previously considered to be Panama hakes. This species differs from the Panama hake in that in juveniles the caudal fin has a central lobe and is truncate in adults, whereas the caudal fin is emarginate in the Panama hake, its pectoral fin projects well beyond the anus in but does not do so in the Panama hake.
Merluccius senegalensis, the Senegalese hake, is a species of fish from the family Merlucciidae, the true hakes. It is found in the sub tropical waters of the eastern Atlantic Ocean off the north western coast of Africa.
Gadella maraldi, the gadella or morid cod, is a species of fish in the family Moridae from the warmer waters of the north eastern Atlantic Ocean and the Mediterranean Sea.
The pygmy snapper is a species of ray-finned fish, a snapper belonging to the family Lutjanidae. It is found in the western Pacific Ocean and is only known from fresh and brackish waters.
Lyconus brachycolus is a species of hake fish in the family Merlucciidae.
Physiculus normani is a bathydemersal fish found in the Western Indian Ocean.
Physiculus kaupi is a bathydemersal fish found in the Western Atlantic Ocean.
Physiculus grinnelli is a bathydemersal fish found in the Eastern Central Pacific Ocean.
