Common names
Tiburón, Tollo negro, Tollo negro peine, Aiguillat peigne, Loche, Loche à hexagone, Combtooth dogfish, Granular dogfish

Short Description
Original Diagnosis after GARMAN, 1899 [2930]: The proportions and shape of this species are similar to those of Centroscyllium fabricii Reinh., or of C. granulatum Günt. The type is moderately slender and elongate, and is compressed behind the shoulders ; the body cavity occupies about three fifths of the entire length. Head large, broad, depressed, inclusive of the gill openings little more than one fourth of the total. Snout broad, in length nearly equal to the width of the forehead, broadly rounded across the front. Nostrils at the edge of the snout, nearer to the end than to the eye. Eye large, lateral, without a nictitating membrane ; orbit with a moire distinct angle on the back than on the front border. Mouth wide, inferior, curving forward moderately in the middle, where it extends but little forward of a line joining the hind borders of the orbits, with a short groove around each angle, from which another groove continues backward nearly half-way to the first gill opening. Teeth small, numerous ; upper with three erect, slender, acuminate cusps, median cusp largest, and outer cusps each with a rudimentary cusp on the outer side ; lower with five similar cusps, median largest, and outer two small, Plate IV., fig. 5, C. Gill apertures five, hardly as wide as the eye, posterior two of each side closer together and near the base of the pectoral. Spiracles medium, superior, transversely crescent-shaped. Rostral ampullae numerous, Plate IV., fig. 3, those of the top of the head numbering a hundred, more or less, and those below the snout nearly twice as many. In the skull, Plate IV., fig. 1, 2, and Plate V., fig. 1, the affinities of this shark to Squalus acanthias Linn., to Etmopterus spinax Linn., and to Centrophorus granulosus Bl. Schn. and their allies are very apparent. The entire skull is shorter and broader and the rostral cartilage is broader and shorter than in either of the mentioned forms. The width across the olfactory capsules is considerably greater, but the post-orbital processes are nearly of the proportions of those of C granulosus. Above the symphysis of the upper jaws on the lower side of the skull there is a slender process, Plates IV. and V., fig. 1. At each side of the mouth there are three labial cartilages, Plate IV., fig-. 1. The two on the upper jaw, the premaxillary and the maxillary, are quite slender, and the anterior is shorter than the other. The one on the lower jaw is much stronger every way and widens toward its anterior extremity. In the branchihyal frame- Avork, Plate V., fig. 2, reduction has proceeded about as far as in any of the species mentioned above. The foremost hypobranchials have apparently consolidated with the anterior ceratobranchials. Behind the basihyal there are two basibranchials, the anterior one of which is short and joins the middle of the anterior border of the other one, separating the hypobranchials of the third pair, and itself meeting the hinder extremities of those of the second pair on its forward end. The hinder basibranchial is a large broad plate that narrows backward to a point ; at each side it directly supports the lower ends of the fourth and the fifth ceratobranchials. If this condition is compared with what obtains in Squalus acanthias, see Gegenbaur, 1872, Das Kopfskelet der Selachier, PI. XVIIL, fig. 3, it is found to be the case that in that species the branchihyals are rather less reduced, since it possesses three distinct pairs of hypobranchials, instead of only two, has its basibranchials separated by the hypobranchials instead of in contact, and has only the posterior pair of ceratobranchials, instead of the posterior two pairs, abutted directly against the sides of the hinder basibranchial. Thus in respect to the branchial skeleton the present species is the more specialized. On each side there are five extra-branchial cartilages. The small subquadrangular spiracular cartilage is nearly divided into three short bars. The skeletal elements of the pectorals vary to some extent in individuals, see Plate V., figs. 2 and 4. Generally the propterygium, the mesopterygium, and the metapterygium are comparatively large and about equal in size, the first bearing one or two radials, the second three or four, and the third about ten, of Avhich three or four of the posterior are unsegmented. There is an elongate basal cartilage in the skeleton of the ventral supporting about fifteen radials that are in most cases segmented near the distal end ; anteriorly against the end of the pelvic element three or four additional radials have coalesced to form a single large plate of cartilage. The viscera were destroyed. A few remnants are figured on Plate V., figs. 3 and G. Figure G shows the heart with three series of valves in the bulbus. Figure 3 exhibits the internal arrangement of the intestine. The number of circuits in the spiral is small, only four or five, and a diagrammatic representation would somewhat resemble that of Chimaera monstrosa as given by T. J. Parker, 1879, in the Transactions of the Zoological Society of London, XI., PI. II., fig. 6. The peculiar structural arrangement of the papillose ridges of the absorbing surfaces of the membranes within the intestine of Centroscyllium nigrum is to be seen on Plate V., fig. 3 of the present work. The cascal appendage of the intestine is elongate and subcylindrical. On the skin the scales are more or less distant from one another ; they are small harsh tubercular spines, each of which has an erect or hooked slender grooved cusp, and a comparatively broad stellate base, Plate IV., fig. 7. The lateral system is rather simple ; the arrangement of the canals on the head does not differ greatly from that of Isurus pundatus (Garman, 1888, Bull. Mus. Comp. Zool., XVII., Lat. Syst., Plate I.) or from that of Isistius brasiliensis, Plate LXIX,. fig. 2 of the present work, except perhaps in that the halves of the aural canal do not meet in the middle. This separation of the part of a cannl on one side from the part on the other side of the head is noted in widely different genera, for instance on Heptraanchias maculatus, Lat. Syst., PI. XIV., fig. 2, or particular canals on one or on both sides of the head may be similarly interrnpted, as on Somniosm carcharias, Lat. Syst., PI. XX., fig. 1, where cranials, orbitals, and occipitals are disunited. What credit for such breaks in canals ordinarily continuous may be given to individual variation is only to be determined by examination of a number of specimens of whatever species may be under consideration. The fins are of medium size ; the amount of fin area is much the same in dorsals, pectorals, and ventrals. The first dorsal originates very little backward of a vertical from the axil of the pectoral ; the spine is triangular in cross section, concave or grooved on each side, and is shorter and more erect than that of the second dorsal. The origin of the second dorsal is little, if any, backward of the middle of the bases of the ventrals; the spine is about one and one-half times as long as the anterior spine, and is similar in structure but more hooked. On the tail the upper lobe of the caudal is separated from the lower by a distinct notch and is subtruncate on the hind margin ; the lower lobe is the deeper, and has its lower angle slightly rounded off. Pectorals and ventrals are short, broad, and rounded on the margins, except in case of the hinder angle of the ventrals, which is sharp. Deep black, with a narrow edging of white on each of the fins excepting the caudal. This description is taken from a specimen of eleven and one-half inches in length. On a small individual, of four and three quarters inches, slight differences in the outlines and in the positions of the fins are presented ; the pectorals re.ach backward of the first dorsal spine, the spine of the second dorsal stands above the hind part of the bases of the ventrals, the eye is proportionally larger and the snout is shorter, the white of the margins of dorsals, pectorals, and ventrals is much broader, and the color of the muscular portions of the body is brown.

Distribution
Eastern Pacific: Hawaiian Islands, southern California (USA), Panama, Cocos Island (Costa Rica), Colombia, Ecuador, northern and central Chile, and the Galapagos Islands. Has been confused with Etmopterus granulosus (Günther, 1880) and Centroscyllium granulatum (Günther, 1887), but is quite distinct. Source: www.gbif.org

Human uses
fisheries: of no interest

Biology
Distinct pairing with embrace [17086]. A little-known deepwater dogfish found on the continental and insular slopes. Feeds chiefly on other fishes and invertebrates.

Size / Weight / Age
50.0 cm TL (male/unsexed; [518])

Habitat
benthopelagic; marine; depth range 269 - 1143 m [17640]

Dentition
Teeth small, numerous ; upper with three erect, slender, acuminate cusps, median cusp largest, and outer cusps each with a rudimentary cusp on the outer side ; lower with five similar cusps, median largest, and outer two small, Plate IV., fig. 5, C. [2930]

Remarks
shark-references Species-ID=1273;

Parasites (arranged by Jürgen Pollerspöck)
Thecostraca

• Anelasma sp. [14627]