Alfonsino

Northern mucus head ( Beryx decadactylus )

The Northern mucus head or orange roughy ( Beryx decadactylus ) is not a true perch, but a representative of the Berycidae, so to speak, of the ordinary form of the Perciformes in the Cretaceous only were close to - it belongs to the order as Berycide Beryciformes, so primitive Stachelflossern. How Beryx splendens he is " exploited " since the late 1960s increasingly commercial. The Cuviersche genus name (1829 ) is sometimes associated with the Italian berice. But since Cuvier the genus and species based on a ( dry ) specimen described, whose source document was lost, is not to assume that he merely a trivial name " berice " Graecized - yet that this name had yet been familiar with at the time.

Description

The names " Alfonsin ( o), Alfonsim " were given ( excellently chin) due to physiognomic resemblance to a Spanish rulers, " slime head " because of the well-developed head lateral-line system which was regarded at first (19th century) as " slime- producing ". Lowe ( lc ) describes this very well: The (usually lying in fish bone tubes) "channels" are here open, jelly- filled gutters, only skin covers (like the ruff or Sciaenidae - the feel of the fish you can feel both the hard edges the gutters as well as the soft curd in it). Meaning hill ( neuromasts ) in the jelly are very fine to pressure waves emanating from prey, and allow the fish to food acquisition in the dark ( night or deep sea ) -. Eyes very large, scarlet iris (not brighter).

Body laterally strongly flattened, shorter and rounder than in profile B. splendens, abdominal edge " cut ". Skin and fins scarlet ( " redfish, fish, bream "); Sides silvery ( netted ), ie the fish looks in depth always black out. Fins partly sometimes lined dark. The medium sized sheds (about 3 per vertebra; 24 vertebrae ) are always from something, the fish is rough. The Schuppendörnchen are not movable ( unlike the Perciformes - so actually Spinoid instead of ctenoid scales ). Lacrimale front with buckle. Two Supramaxillaria; Maxilla still involved at the mouth edge. Teeth as in B. splendens; In contrast to this pyloricae to 100 appendages at the pylorus 70. Up to 100 cm long, 5 kg, then allegedly over 100 J. old (at least slow-growing: secured is about a 52 cm long fish from the Azores with 13 years). The largest individuals are very rare, because even the natural mortality ( predation - eg Ruvettus, Thunnus, Latimeria ) is high.

Fins formula: D IV/18-20, A IV/26-30, PI/10 (name: " zehnfingrig " ) -11, VI/9-13, C ( 18 - ) 19 (16 oder17 divided, with just a short bias beams stiffened ).

There is a fish in the middle depths of the continental slopes and seamounts, mostly between 200 and 500 m alive; he preferred the nearby detritus sediment (eg mud ). On the night he rises and moves away from the substrate thereby into the open waters, where he also spawns ( in the "Winter": delivered in clumps eggs repeated; pelagic as well as the spiny larvae that develop near the coast ). He lives gregarious and feeds ( bathy - up mesopelagisch ) of crustaceans, small fish and squid. As an important food fish ( with the appropriate equipment: trawls, demersal nets, longlines - locally, eg in front of Madeira, 200-years - caught ), he is now in some places already threatened since it is only slowly increasing (cf. also hoplostethus atlanticus ). .

Occurrence

Between 70 ° N ( hence the name ) and 50 ° S: offshore in all oceans except for the polar ( to Patagonia ) - also in the western Mediterranean and the Aegean (of course not in black) and in the southern Red Sea. Rarely in the North Pacific or off Labrador. Due to genetic analysis can be assumed that the type only comprising a population because the larvae for slow gene replacement provide worldwide; regional meristic differences are thus developmentally limited.