Common names
Smalltail shark

Short Description
Diagnose after Gilbert (1898) [1234]: CARCHARHINUS CERDALE, Gilbert, new species. Body moderately compressed, not elevated, the depth at front of dorsal not more than 1/4 greater than the oblique anterior margin of dorsal fin, less than distance from the nostril to first gill slit. Head depressed, the snout flattened, long and narrow, acute; length of snout beyond mouth 1/6 to 1/10 greater than distance between angles of mouth in all but one (the largest) of our specimens, in which it is slightly less than width of mouth; 3/5 to 4/5 greater than distance from tip of lower jaw to a line connecting angles of mouth; 1/7 to 1/12 greater than width of snout opposite outer angle of nostrils. Interorbital width equaling distance from tip of snout to front of eye in young, to middle or posterior border of eye in older individuals; less than 1/2 distance to first gill opening. Middle of eye nearer nostril than angle of mouth by 1/2 to 4/5 its diameter; distance from eye to nostril 1/2 or slightly more than 1/2 distance from nostril to tip of snout; middle of nostrils much nearer front of mouth than tip of snout; nasal flap with a very narrow, short, acute lobe, placed at end of inner third of flap; outer angle of nostrils nearly at margin of snout, the inner angles separated by a distance equaling or slightly exceeding that between inner angle of nostril and back of eye. Lips very little developed, the lower entirely concealed in closed mouth, the upper visible as a very short fold. Teeth in lower jaw narrow, erect, serrulate on both margins, more coarsely so toward base; the serration more conspicuous in our smallest specimens (450 mm.), and is obsolescent on some of the teeth in adults; teeth in upper jaw broadly triangular, in front of jaw narrower and erect, those in sides of jaw growing at once broader and more and more oblique; the lateral teeth with a strong notch on the outer side; both margins strongly serrate, the serrations increasing toward base, one or more of those below notch sometimes enlarged and cusp-like in adults; teeth about if. Conspicuous areas of large and of small pores on underside of head. Gill openings of moderate width, the longest equaling distance between eye and nostril, the fifth much shortened, about f length of first. Eye small, equaling length of nasal opening, 1| to 2 in middle gill slit. Pectoral short and broad, the posterior margin not strongly incurved; tip of fin extending to a vertical intersecting dorsal base at origin of its posterior third or fourth ; anterior margin of pectoral 3 times length of inner or posterior margin, the latter less than width of base; first dorsal beginning behind a vertical from axil of pectoral a distance about equaling that which separates eye from nostril ; free margin of fin gently concave, the anterior angle extending to a point midway between base and tip of posterior lobe, when the fin is depressed ; base of first dorsal 2\ to 2? in interspace between dorsals ; base of second dorsal 7 in interspace between dorsals, 2i in its distance from anterior margin of pit; origin of second dorsal falling over or behind middle of anal base, the fin but slightly concave, with rounded anterior angle, its posterior angle much produced, the posterior margin exceeding base of fin, which about equals length of anterior margin; anal inserted more anteriorly than second dorsal, its base longer, its margin much more deeply concave, the length of base contained aboutly times in its distance from lower caudal lobe; lower caudal pit in advance of the upper; caudal broad throughout, the lower lobe not falcate, slightly less ( 1/10 to 1/4) than 1/2 length of upper lobe, which is about 4 1/4 in total length. Shagreen coarse. Color varying from light to dark gray above, the belly and lower part of sides whitish; fins all dusky or grayish, the caudal' often with a blackish border; pectoral with or without a black tip, the latter when present not as conspicuous as in C. aethalorus, usually not extended into inner face of fin. A specimen 730 mm. long has the claspers undeveloped, extending slightly beyond margin of ventrals. Another specimen, 850 mm. long, has the claspers fully developed, extending beyond the margin of the ventrals lor a distance of 50 mm. Strongly resembling C. aethalorus, with which it is associated in the Bay of Panama. It is distinguishable at sight by the narrower gill slits, broader and less falcate fins, and by the much less conspicuous black tips to the pectorals. The dentition is very dissimilar in the two, and makes it necessary to arrange them in different subgenera. Abundant at Panama, where numerous specimens were secured. (Gilbert.) (wary, fox-like).
Diagnose after Castro, 2011 [13055]: Carcharhinus cerdale is a smooth-backed species, although some specimens may have a very weak interdorsal ridge. The ridge is evident in embryos and neonates that I have examined, but was not noticeable in the holotype or on the 103.4-cm male. The first dorsal fin originates about the middle of the pectoral fin inner margin; its anterior margin is much longer than the distance from the apex to the free rear tip. The height of the first dorsal fin is about 9–10.5% of the total length. The second dorsal fin originates over or behind middle of anal base. The caudal fin measures about one-fourth of the total length. It has minute, inconspicuous hyomandibular pores behind the eye. The upper teeth (Fig. 11), from the first tooth to the fifth tooth have broadly triangular, increasingly oblique cusps with serrated edges, with a notch on both edges at about a third of length from the base to the cusp. The serrations from the notch to the base are much larger than those on the rest of the cusp. The lower teeth have narrow, erect to slightly oblique, triangular cusps with more finely serrated edges. Teeth number U:13 to 15-1 or 2-13 to 15, L:12 to 15-0 to 2-12 to 15. The denticles (Fig. 12) are roughly oblong and have minimal overlapping, with three central ridges, the central ridge being only slightly longer than the side ridges and terminating in a slightly longer point. The dorsal surface of the denticles has a fine microsculpture. Of the species coloration, Gilbert (in Jordan & Evermann 1898; Gilbert & Starks 1904: 11) stated that the species is from light to dark gray above, with a whitish belly and lower parts of sides, and “caudal often with a blackish border” and “pectorals with or without a black tip.” In most specimens I have seen, the first and second dorsal fins, the pelvic fins and the anal fin had dark or dusky edges, and the pectoral fins usually had dusky or black tips on their dorsal sides, and the lower caudal lobe was dusky or blacktipped. Neonates have caudal fins with a black border, and their pectoral fins have a wide, white rear margin. The species reaches about 140 cm (Castro, in press). The 103.4-cm specimen illustrated herein has developed but uncalcified claspers, indicating that it was approaching maturity. Carcharhinus cerdale inhabits the eastern Pacific from the Gulf of California to Peru (Kato et al. 1967).

Distribution
eastern Pacific from the Gulf of California to Peru [13055] Source: www.gbif.org

Size / Weight / Age
TL (max): 140 cm [13055]

Habitat
marine, [13055]

Dentition
The upper teeth, from the first tooth to the fifth tooth have broadly triangular, increasingly oblique cusps with serrated edges, with a notch on both edges at about a third of length from the base to the cusp. The serrations from the notch to the base are much larger than those on the rest of the cusp. The lower teeth have narrow, erect to slightly oblique, triangular cusps with more finely serrated edges. Teeth number U:13 to 15-1 or 2-13 to 15, L:12 to 15-0 to 2-12 to 15 [13055].

Remarks
shark-references Species-ID=734;