Nasolamia Velox (Gilbert, 1898)
Figs. 2-6

HOLOTYPE: SU 11893, 1200 mm (total length) female (now with trunk and tail skinned out), from Panama Market, January-February 1896, C. H. Gilbert and others.

Because only a few specimens of Nasolamia velox have been reported, we are listing all the specimens that we know of, and are providing data on the morphometrics, meristics and other features of a sample of these. This information, in conjunction with the characters given in the Generic Definition, should facilitate comparison of N. velox with similar species of Carcharhinus. The morphological and meristic data may also be important for study of intraspecific variation in N. velox, especially if this species is shown to range further south than presently recorded.

MATERIAL EXAMINED: The 40 specimens (including jaws and chondrocrania) listed below are from the collections of the American Museum of Natural History, New York (AMNH); Field Museum of Natural History, Chicago (FMNH), Los Angeles County Museum of Natural History (LACM); of one of us (LJVC); Scripps Institution of Oceanography, La Jolla, California (SIO); Division of Systematic Biology, Stanford University, Stanford, California (now housed at the California Academy of Sciences, San Francisco, California; SU); University of California at Los Angeles (UCLA); and U.S. National Museum of Natural History, Washington, D.C. (USNM).

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MEXICO: UCLA 49-38, 1390 mm female, Baja California, Outer Gorda Bank, 23°01ʹ 30ʺ N., 109° 26ʹ W., October 7, 1949, P.M. Roedel and R. C. Wilson; SIO-65-183, 1060 mm male, Baja California, Cabo San Lucas Bay; UCLA W52-247, ca. 1370 mm (jaws only), Baja Californa, Santa Maria Bay, November 25-26, 1952, M.A. Newman and others; SIO H47-53, 1400 mm adult male, (with trunk and tail skinned out), Gulf of Californa near San Felipe; UCLA 60-51, 2 males, 653-915 mm, and 1 female, 883 mm, Gulf of California, Bahia Las Animas, January 25-26, 1960, L. Pinkas and others; LJVC-0268, 526 mm newborn or late embryo female (cranium dissected); LJVC-G-148, est. 49 cm, LJVC-G-179, est. 104 cm, LJVC-G-192, est. 106 cm, LJVC-G-193, est. 96 cm, LJVC-G-194, est. 101 cm, LJVC-G-203, est. 96 cm, LJVC-G-205, est. 101 cm, LJVC-G-206, est. 94 cm, LJVC-G-207, est. 102 cm, LJVC-G-208, est. 110 cm, LJVC-G-209, est. 119 cm, LJVC-G-210, est. 106 cm, LJVC-G-211, est. 98 cm, LJVC-G-212, est. 115 cm, LJVC-G-213, est. 110 cm, LJVC-G-214, est. 117 cm, LJVC-G-215, est. 100 cm, LJVC-G-216, est. 106 cm, LJVC-G-217, est. 65 cm, LJVC-G-218, est. 98 cm, LJVC-G-219, est. 94 cm, LJVC-G-220, est. 110 cm, LJVC-G-221, est. 110 cm, LJVC-G-222, est. 61 cm, LJVC-G-252, est. 133 cm. (LJVC-G numbered specimens collected as severed heads from fisheries offal, jaws only saved for all specimens except G-184, G-192, G-193, G-214 and G-252, from which chondrocrania were prepared), all from Gulf of California, Guaymas, Sonora, Mexico; UCLA 58-47, 1018 mm female, Gulf of California, Sinaloa, S. of Bahia Topolobampo, February 10-14, 1958, J. Stevens; LACM F-211, 1325 mm male (jaws ony), Sinaloa, Mazatlan.

COSTA RICA: AMNH, 720 mm female.

PANAMA, PANAMA MARKET: USNM 79305, 564 mm female, April 21, 1911, S.E. Meek and S.F. Hilderbrand; FMNH 8170, 570 mm female, April 19, 1911, S.E. Meek and S.F. Hilderbrand; SU-11893, 1200 mm female (trunk and tail skinned out, holotype of Carcharhinus velox Gilbert).

MORFHOMETRICS AND MERISTICS: Proportional dimensions, tooth formulae, and vertebral counts for five specimens of Nasolamia velox are listed in Table 1; total tooth row counts and statistics for 35 specimens of N. velox in Table 2; and cranial proportions for 8 N. velox in Table 3.

COLOUR: Colour in general, when fresh, was described by Gilbert (in Jordan and Everman, 1898) as "bluish above, whitish or grayish below;..." After preservation in alcohol the general colour is gray or brownish gray above, paler to white below; distal margins of pectoral fins, pelvic fins, and ventral lobe of caudal fin narrowly edged with white; apical half of second dorsal fin black or dusky; a narrow dusky edging on dorsal and terminal margins of caudal fin; and a small but distinct black spot on upper side of tip of snout.

SIZE AND MATURITY: The smallest specimen we have seen was 526 mm long, and appeared to be either a late embryo or newly born, while two others of 564 and 570 mm still showed umbilical scars, indicating that they were fairly recently born. Assuming that size at birth is about 535 mm, then this suggests that adult Nasolamia velox must reach a length of at least 1500 mm. The largest female that we are aware of was 1390 mm long, and the largest male 1400 mm. Of the four males examined, three of 653, 915 and 1060 mm were immature, with clasper lengths of 2.3%, 2.9% and 2.8% of total lengths respectively, while the fourth of 1400 mm was mature, with claspers of 8.4% of total length.

DISTRIBUTION (See also MATERIAL EXAMINED): According to present information Nasolamia velox has a limited distribution along the coastline of the Eastern Pacific. Specimens we have examined were from the Gulf of California coasts of Baja California and mainland Mexico, and from Costa Rica and Panama. Kato et al. (1967) note that it has been reported from Ecuador and Chirichigno (1980) lists it from as far south as Peru. During the early summer of 1974 the senior author and Dr Bruce Welton found that N. velox was commonly caught by fishermen using light bottom longlines in the Gulf of California at Guaymas, Sonora, Mexico (see Material Examined).

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