Glaucostegus cemiculus (Geoffroy Saint-Hilaire, 1817)
Blackchin guitarfish
Glaucostegus cemiculus
photo by FishBase

Family:  Glaucostegidae (Giant guitarfishes)
Max. size:  242 cm TL (male/unsexed); max.weight: 50 kg
Environment:  demersal; brackish; marine; depth range 9 - 100 m
Distribution:  Eastern Atlantic: northern Portugal to Angola, including the Mediterranean Sea.
Diagnosis:  Vertebrae: 68-73. This large to very large species has a plain beige to brownish wedge-shaped disc; long and rather broad triangular snout with a broadly rounded rostral cartilage at its tip and wide oblique nostrils with a narrow anterior opening; disc thickened centrally, length 1.2-1.3 times its width, anterior margins slightly undulate, often weakly concave before broadly rounded outer corner; snout moderately acute, its angle 59-63°, tip narrowly rounded not extended forward as a distinct lobe; large orbit, length 5-6 times in preorbital length, 1.5-2 in interorbital space; rostral ridges are narrowly separated posteriorly and almost joined anteriorly; 2 fleshy spiracular folds, with innermost fold smaller; upper jaw with 62-72 tooth rows; large and oblique nostrils, its length 1.4 in internasal width, ca 81 nasal lamellae, anterior nasal flaps are confined to anterior margin of nostril; rough skin covered entirely with small denticles; well-developed thorns, usually along edge of rostral cartilage and small patches around orbits and above spiracles; each shoulders with 1-3 thorns that persist in adults, a median row of enlarged thorns extending from nape to first dorsal fin, a few thorns between dorsal fin; long tail ca 1.5 times its disc length; dorsal fins are large and widely spaced, ca. 2.1 times base length of first dorsal fin, apices narrowly rounded; pectoral fin radials 68-73; 204-212 total vertebrae (Ref. 114953).
Biology:  A coastal and benthic species found on sandy and muddy bottoms, intertidal zone to at least 80 m depth. Feeds mainly on benthic crustaceans and small fishes. Maximum length would probably reach up to 265 cm TL, common at about 200 cm TL. Males mature at 138-154 cm TL, females at 153-164 cm TL. In the Mediterranean Sea, males mature at smaller size, about 100-110 cm TL and females at about 110 cm TL. Size at birth about 34 cm TL. Produces litters up to 20 pups (more common 6-7 pups) (Ref. 114953). Ovoviviparous, one or two litters per year, of 4-6 embryos.
IUCN Red List Status: Critically Endangered (CR); Date assessed: 03 December 2018 (A2d) Ref. (124695)
Threat to humans:  harmless
Country info:   
 

Entered by: Luna, Susan M. - 21.01.91
Modified by: Capuli, Estelita Emily - 08.08.19
Checked by: Capuli, Estelita Emily - 22.05.17

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