Silver escolar
| Silver escolar | ||||||||||||
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Silver Escolar ( Promethichthys prometheus ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Promethichthys | ||||||||||||
| Gill , 1893 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Promethichthys prometheus | ||||||||||||
| ( Cuvier , 1832) |
Of the silver escolar ( Promethichthys prometheus ) Lowe gives a good representation in his “Fishes of Madeira” (1843; following Cuvier 1832). The fish market in Funchal was in the 19th century - due to the favorable subsea topography and currents and the beginning of longline fishing - a Mecca for ichthyologists and the curious with an interest in "deep-sea fishing". Promethichthys is one of the snake mackerels and is monotypical ( pacificus Seale 1906, was not recognized as a separate species), closely related to Rexea . In the sexually mature state, however, it differs from it in the complete absence of the pelvic fins . The name refers to Prometheus , the "mastermind" in Greek mythology , but what was decisive for this reference is unclear (perhaps: "self-assertion despite weakness"?). Important vernacular names are (English) Roudi, catfish, (Spanish) conejo and (Portuguese) coelho.
Appearance
This large-eyed fish, which can be several meters long, is quite compressed and "thin, limp and smooth". The head is large and pointed, the mouth is deeply split and reinforced with teeth of different sizes, one row above and one below. However, the large teeth cannot be folded down (as is the case with many other predatory fish, e.g. the pike ) (except when they are just moving into their definitive position as replacement teeth). The vomer is without teeth, the palatins each carry a row smaller. The scales (fully developed only when the fish is 20-25 cm long) are so small and delicate that you can hardly see them with the naked eye. They are only distinct (elongated) on the sidelines; this is similar to the front and lower sections of those of Rexea (sd), but less curved.
The color is a purple to black-blue iridescent silver with darker areas, e.g. B. on the head, back and the fins, which, initially yellowish, later become darker and darker. - The mouth, gill and body cavities are lined with black (this peculiarity is found, at least in part, often in fish - it should prevent bioluminescence penetrates outward from digestive processes and “betrays” the fish in the dark). Eight to ten short, thick pyloric tubes - The first gill arch has remarkably long, prickly gill pots - thorns - Large, simple swim bladder (in many other Gempylidae, however, reduced).
Fin formula : D1 XVII-XIX, D2 I-II / 17-19. A II-III / 15-17 (all spines soft and pliable, "sink" into the skin with increasing age). D1 still sail-like high in larvae. Behind D2 and A, two rafts adjoin each (which can be indistinct or elongated). Dorsal lobe of the C sometimes somewhat larger than the ventral - P (quite small :) 13-15. Larvae have a long V-spine, seem to break off later (Lowe even suspects “through soil life”!), At sexual maturity only remnants of the V can be found that sink into the skin.
behavior
Lowe writes that the fish (that is, his Prometheus atlanticus ) is called Coelho (<(lat.) Cuniculus "rabbit") in Madeira , because he likes the bait of the fishing rod, e.g. B. bite off a piece of mackerel (which, by the way, proves that, like many predators, it is also olfactory) and immediately "escapes". (How the fishermen were able to gain knowledge of this event in depth remains to be seen - it usually lives “in a hundred to four hundred fathoms ” near the bottom). Promethichthys lives in 80-800 (mainly 300-400) m depth on continental slopes, islands and underwater mountains bathy- to meso pelagic ; it usually rises at night. It eats fish, squid and shrimp and spawns from a size of approx. 40 cm (for example in the Canary Islands and Madeira) in summer (May – September); the eggs and larvae are pelagic.
distribution
worldwide between 40 ° N (south coast of England) and 35 ° S (ie it does not reach southern Chile and Patagonia); in the Southeast Pacific only over the undersea Salas-y-Gómez ridge. Missing in the Central and Northern Red Sea. Although it is often caught in places, it is not an important edible or sport fish; Lowe calls his meat "bland, thin and dry" and unpopular; at best it is sold smoked. Occasionally it is also suspected of being poisonous (" Ciguatera ").
literature
- Izumi Nakamura, Nikolaj V. Parin: Snake mackerels and cutlassfishes of the world. An annotated and illustrated catalog of the Snake Mackerels, Snoeks, Escolars, Gemfishes, Sackfishes, Domine, Oilfish, Cutlassfishes, Scabbardfishes, Hairtails, and Frostfishes known to date (= FAO Species Catalog. Vol. 15 = FAO Fisheries Synopsis. No. 125 , Vol. 15). Food and Agriculture Organization of the United Nations, Rome 1993, ISBN 92-5-103124-X .
Web links
- Silver Escolar on Fishbase.org (English)