Argyrosomus regius

Argyrosomus regius

The meagre or croaker, jewfish, shade-fish, sowa, kir, corvina, salmon-bass, stone bass, (Argyrosomus regius Asso, 1801) is a fish that lives in the sea or brackish waters belonging to the Sciaenidae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Animalia,
Phylum Chordata,
Subphylum Vertebrata,
Class Actinopterygii,
Order Perciformes,
family Sciaenidae,
Genus Argyrosomus,
A.regius species.
The term is basic:
– Percha regia Ace, 1801.
The terms are synonymous:
– Argyrosomus procerus De la Pylaie, 1835;
– Argyrosomus regium (Asso, 1801);
– Cheilodipterus eagle Lacepède, 1803;
– Percha luth Walbaum, 1792;
– Perca vanloo Risso, 1810;
– Sciaena eagle (Lacepède, 1803);
– Sciaena regius (Asso, 1801).

Geographic Distribution and Habitat –
Argyrosomus regius is a fish present in the Mediterranean Sea, more rarely in the Black Sea and in the eastern Atlantic Ocean between Senegal and the English Channel; more rarely this species can reach the waters of Denmark, southern Norway and even Iceland (where only one capture has been recorded).
It is an uncommon fish in Italian seas and is one of the few species of fish that have migrated in reverse compared to the Lessepsian migration or from the Mediterranean to have passed into the Red Sea through the Suez Canal.
Its habitat is that of the waters near sandy coasts but which often lives in the dark at over 30 meters of depth (normally from 15 to 300 meters of depth); it is often found near freshwater outlets and, in any case, generally near the banks, and being euryhaline, it penetrates the mouths and brackish lagoons.

Description –
Argyrosomus regius is recognized by its elongated body, not much laterally compressed, with a dorsal profile that is more arched than the ventral one. It is covered in large scales on the sides and smaller ones on the head and can exceptionally measure 1.45 m for 36 kg in weight but larger specimens have been sighted.
The largest specimens have been found along the coasts of western Africa, in particular in the bay of Dakar and in Senegal, where the large specimens find refuge in the wrecks of sunken ships.
The lateral line has 50-55 scales, follows the profile of the back and extends also on the caudal fin. The head is large, with a circular and relatively small eye. The nasal openings are evident and the posterior one, oval, is located before the anterior margin of the orbit.
It has a large and almost horizontal mouth. The teeth are cardiform and arranged in bands. The swim bladder, full of numerous appendages, is very large and occupies the ventral cavity.
The dorsal fins are two and joined together; the first has thorny rays (the first and last very short) and a triangular shape; the second (1 spiny ray and 27-28 soft) is much longer and has an almost constant height. The anal is short with 7-8 soft rays, preceded by 2 thin spiny rays. The caudal (17 rays) is spatulate and the upper lobe is more protruding than the lower one. The pectoral fins are small and triangular in shape. Also the ventral ones (1 spiny ray and 5 soft) are reduced.
It has a lead gray colour, darker on the back and with bronze reflections; the flanks are lighter and silvery; the belly is white and the fins gray or brown. The inside of the mouth is golden yellow.

Biology –
This species has a highly developed swim bladder and can use it to produce audible sounds even out of the water for tens of metres.
Little is known about its biological cycle and its reproduction; it probably reproduces in the summer months. The generation time is very long, about 25 years.

Ecological Role –
Argyrosomus regius is a fish that feeds on sardines and other clupeiforms, white bream, bream, boghe and mullet.
It feeds above all on mullets, which it catches in shallow waters and also in the mouths of rivers.
This fish is caught with bottom trawls or gillnets. However, it is undermined with nets and lines (especially with the surf casting technique, for which it is one of the most valuable prey). It is also raised in the lagoons with excellent yields and is sold as “croaker” but this is not a scam because its meat is considered even better than the true croaker, albeit excellent.
According to the IUCN Red List, the species is classified as Critically Endangered (CR) as a decline of more than 80% is suspected in the last 75 years (3 generations) due to excessive overexploitation and the decline in habitat quality. In fact, the species is found in environments of coastal transitions and estuaries, which are subject to numerous threats of degradation and pollution.
The last sightings of large individuals date back to the 1990s and 2000s.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Louisy P., 2016. Guide to the identification of marine fish of Europe and the Mediterranean. Il Castello Editore, Milan.
– Nikiforos G., 2008. Fauna of the Mediterranean. Giunti Editore, Florence.
Photo source:
– http://photos.gbif.fr/mnhn_nice/aquarelles_animaux_marins_et_plantes/2005-0-1062.jpg
– https://upload.wikimedia.org/wikipedia/commons/b/b2/Argyrosomus_regius_LoroParqueTenerife_stone_basse_IMG_4967.JPG