Dipturus argentinensis Díaz de Astarloa, Mabragaña, Hanner & Figueroa, 2008
Argentine skate
photo by Díaz de Astarloa, J.M.

Family:  Rajidae (Skates)
Max. size:  93.5 cm TL (male/unsexed)
Environment:  benthopelagic; marine; depth range 87 - 142 m
Distribution:  Southwest Atlantic: Argentina, Patagonia.
Diagnosis:  This species is distinguished by the following set of characters: the dorsal surface of disc is brown purplish with no distinct ocelli or blotches margined with dark brown on pectoral and pelvic fins; the upper surface of the disc smooth except few small spinules scattered on tip of snout; presence of ocular thorns and absence of scapular thorns; single nuchal thorn may be either present or absent; one median row of 10 to 24 small caudal thorns; the dorsal and caudal fins scattered with very few spinules; 1-2 interdorsal thorns; tail relatively long and thin, approximately half the total length; ventral surface of disc as dark as the upper side, smooth except few small spinules scattered on tip of snout; interbranchial space with no prickles (Ref. 79571). Description: disc rhombic; snout greatly elongated; anterior margin of disc concave and posterior margin convex with rounded inner corner to level of pelvic fins; the tail is very slender and relatively long with a thin lateral tail fold; nostril flaps short, thick and tube-like; anterior nasal flap (nasal curtain) is well developed and fringed along distal margin; posterior nasal flap is poorly developed and smooth; mouth slightly arched; dorsal side of disc smooth except with a few small spinules scattered on tip of snout (one specimen with spinules also placed on both sides of eyes as well as in front of ocular region); the ventral side of disc, pelvics, claspers and tail are without dermal denticles except with a few small spinules scattered on tip of snout; midline of tail with 13 (10-24) small thorns, with oval bases and backwardly directed crowns. Coloration when fresh: upper surface of the disc plain purplish brown and margined with dark brown on pectoral and pelvic fins with no distinct ocelli or blotches; thorns are marked off pale milky-white pigment; lateral tail folds are creamy white pigment; dorsal fins are uniformly brown (Ref. 79571).
Biology:  According to the capture localities of the type specimens, Dipturus argentinensis appears to have a restricted range distribution occurring in the central and southern Patagonian region on the southwest Atlantic. No recorded specimens have been reported northwards 45º S. The region where the type specimens of the Argentine skate were collected is dominated by sub-Antarctic cold-temperate waters with low salinity. These waters have a predominantly NNE flow and form the Patagonian Current (Brandhorst & Castello 1971). Range temperatures and salinities of the localities where the specimens were collected were 5.9-9.38ºC, and 33.24-33.64 ups, respectively. These physical characteristics agree with the Magellanic Biogeographic Province where the specimens have been captured (Ref. 79571).
IUCN Red List Status: Data deficient (DD); Date assessed: 01 July 2019 Ref. (130435)
Threat to humans:  harmless
Country info:   
 


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