Scyliorhinus duhamelii (Garman, 1913)
Duhamel’s catshark

Family:  Scyliorhinidae (Cat sharks), subfamily: Scyliorhininae
Max. size:  43.6 cm TL (male/unsexed); 42 cm TL (female)
Environment:  demersal; marine; depth range 43 - 75 m
Distribution:  Mediterranean Sea: Croatia, Greece, Tunisia and Algeria, and the Adriatic Sea.
Diagnosis:  This species is distinguished from all its congeners by the following characters: (1) color pattern composed of scattered dark spots of varied sizes that also form aggregations (vs. no dark spots in S. capensis, S. comoroensis, S. hesperius, S. meadi, S. torazame, S. torrei; reticulated pattern in S. retifer; predominant dark spots greater than spiracles in S. cervigoni, S. garmani, S. haeckelii, S. stellaris; spots with well-defined borders and not forming aggregations in S. boa, S. cabofriensis, S. canicula, S. ugoi); (2) shallow nasoral grooves, the posterior nasal flaps laterally situated (vs. no grooves and posterior flaps on the posterior border of excurrent apertures in other species, except S. canicula); (3) distance between nasal flaps 3.5-5 times smaller than width of the anterior nasal flap (vs. 6-7.5 times smaller in S. canicula; two times in all other species); (4) lower labial furrow 1.7-2.4 times smaller than mouth width (vs. more than 3 times in other species, except S. canicula) (Ref. 120402). Description: Although less conspicuous, this species differs by having: dark spots scattered throughout the dorsolateral surface (vs. spots restricted to saddles in S. boa, S. cervigoni, S. haeckelii); anterior nasal flaps covering the upper lip (vs. flaps not reaching upper lip in other species, except S. canicula, S. cervigoni, S. comoroensis, S. garmani, S. stellaris); interdorsal distance 0.6-1.0 times anal base (vs. greater than the anal base in S. boa, S. cabofriensis, S. haeckelii, S. hesperius, S. meadi, S. retifer, S. torrei, S. ugoi); mandibular canal of lateral line system with 4 or 5 pores (vs. 6-7 in S. stellaris); oral canal of lateral line system with 10-12 (vs. < 10 pores in the other species, except S. torrei); commissural teeth with two cusplets (vs. one in S. cervigoni, S. torazame and S. torrei; four or more in S. boa, S. canicula, S. hesperius); pelvic apron extending almost the entire length of pelvic inner margins (vs. extending to 2/3 of length in other species, except in <>iS. capensis, S. canicula, S. torazame, S. torrei); clasper with smooth terminal dermal cover (vs. rough in S. canicula, S. capensis); terminal 3 cartilage absent (vs. present in S. boa, S. canicula, S. capensis, S. retifer, S. torazame); dorsal terminal 2 cartilage elongated and 1/4 length of dorsal terminal cartilage (vs. reduced and subtriangular in <>iS. cabofriensis, S. capensis, S. cervigoni, S. haeckelii, S. ugoi; 1/3 of dorsal terminal cartilage in S. boa, S. comoroensis; both cartilages the same length in S. torazame); counts of monospondylous vertebrae 35-37 (vs. 44-46 in S. capensis; 40-45 in S. cervigoni; 48 in S. garmani; 46-48 in S. meadi; 43-47 in S. stellaris; 32-35 in S. torrei); upper tooth rows 41-45 (vs. 45-58 in S. cabofriensis; 46-76 in S. capensis; 48-54 in S. haeckelii; 46-54 in S. meadi; 47-56 in S. ugoi); lower tooth rows 39-42 (vs. 44-50 in S. cabofriensis; 43-53 in S. haeckelii; 43-49 in S. meadi; 43-53 in S. ugoi); adult males at least 340 mm TL (vs. adult males greater than 450 mm TL in S. capensis, S. cervigoni, S. meadi, S. stellaris, S. ugoi; adult male 269 mm TL in S. torrei) (Ref. 120402).
Biology:  Occurs along the continental shelves, a benthic dweller (Ref. 120402).
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless


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