Stellifer cervigoni, Chao & Carvalho-Filho & Santos, 2021

Chao, Ning Labbish, Carvalho-Filho, Alfredo & Santos, Jonas De Andrade, 2021, Five new species of Western Atlantic stardrums, Stellifer (Perciformes: Sciaenidae) with a key to Atlantic Stellifer species, Zootaxa 4991 (3), pp. 434-466 : 441-444

Stellifer cervigoni new species

( Figure 8 )

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Ophioscion sp. Cervigón (1966): 511, 515, Fig. 211 (key; description; northern coast of Araya, Venezuela).

Stellifer sp. A . Chao (1978): 55 (key); Chao, 2002 (key, description).

Holotype: USNM 435344, 108 mm SL, Morro de Puerto Santo , Estado Sucre, Venezuela, collected by F. Cervigón, 21 September 1961; formerly MHNLS 344 , Venezuela.

Paratypes: ANSP 109636 , 10 (67–103 mm SL), Peninsula de Araya , between Punta Horno and Punta Cardon, Estado Sucre, Venezuela, collected by William A. Lund, Jr., 06 March 1962 . MCZ 4581 , 3 (53.5–65.0 mm SL), near Belém , Pará, Brazil, 1 o 27'S, 48 o 29'W, collected by Agassiz, L. & D. Bourget, 10 August 1865 . NMMBP 21565 , 96.5 mm SL, formerly USNM 435344 , collected with the holotype . USNM 208558 , 2 (96.8–105 mm SL), collected with the holotype . USNM 283764 , 3 (47.6–50.7 mm SL), Mouth of Blenheim River , Dominica, collected by V.G. Springer & R.H. Reckweg , 7 November 1964 .

Diagnosis. Stellifer cervigoni can be distinguished from all other Atlantic species of the genus by having a jetblack mouth roof and inner opercular lining, except S. rastrifer , which also has a dark grayish lining, but never jetblack. In addition, S. cervigoni has a slightly oblique, subterminal mouth (vs. oblique in S. rastrifer ), usually 36–38 total gill-rakers on the first arch (vs. 44–50 in S. rastrifer ), and a shorter pelvic fin (4.8–5.3 times in SL vs. 4.0–4.8 times in S. rastrifer ); finally, the hind margin of the anterior chamber of the gas bladder has a pair of small knob-like, hammerhead-shaped diverticula ( Fig. 9 ), while S. rastrifer has a pair of tubular appendages ( Fig. 1C , right).

Description. Dorsal-fin rays XI+I or II, 22–25; anal-fin rays II, 9 (occasionally 8); pectoral-fin rays 17–19; gill rakers 11–15 + 24–26 = 35–41; preopercular spines 6–9; lateral-line scales 54–56. Anterior chamber of gas bladder with hammerhead-shaped posterior diverticula pair ( Fig. 9 ). Posterior tip of posterior chamber reaching first anal–spine base. Drumming muscles in males only ( Fig. 1B , hatched area). Sagitta ( Fig. 10A ) elongate with rostrum at middle of anterior margin; sulcus with oval ostium, deeply grooved, L-shaped cauda, and conspicuous marginal groove; outer surface elevated at center. Lapillus ( Fig. 10B ) smaller than sagitta, oval, with thin anterior flange; inner surface smoothly elevated, outer surface irregularly grooved. Asteriscus ( Fig. 10C ) triangular, with lanceolate groove near ventral margin of inner surface. Preopercular spines strong, sharp. Lowermost spine longest and strongest, directed obliquely downward and back at about 45 o, occasionally slightly antrorse; upper spines progressively shorter and weaker. Head low and broad, interorbital region wide and gently arched, 2.9–3.1 in HL. Head cavernous but moderately firm. Snout 4.0– 4.3 in HL, projecting beyond upper lip, its tip with three upper and five marginal pores ( Fig. 5A ); rostral fold slightly indented below marginal pores. Eye moderately large, 4.5–5.1 in HL, orbit round. Mouth small, slightly oblique, subterminal, upper jaw 2.9–3.1 in HL, lower jaw included within gape forming angle of about 20 o. Anterior tip of upper lip, horizontally, passing below ventral margin of orbit by about half eye diameter.

Posterior end of maxilla extending to vertical through center of pupil. Underside of lower jaw with six pores ( Fig. 6C ), medial pair lying together in common pit. Upper jaw with outer row of slender, nearly contiguous, slightly enlarged, conical teeth bordered medially by very fine villiform teeth band. Lower jaw teeth villiform, set in narrow bands, none noticeably enlarged. Gill rakers, moderately long and slender, longest about equal to length of filament at angle of arch or about three-quarters of eye diameter. Anal fin truncate, second spine moderately long and fairly stout, 2.0– 2.3 in HL. Caudal fin rounded, about three-quarters of HL. Vertical from tip of pectoral fin passing through or just anterior to vent. Tip of pelvic fin, exclusive of filamentous prolongation, reaching from half distance between pelvic base to anal fin insertion or to as far as first anal spine. Scales large, thin and ctenoid below lateral line posteriorly, ctenoid patch reducing and occasionally disappearing anteriorly. Scales above lateral line with small ctenoid patch posteriorly, scales becoming smooth in advance of soft dorsal origin. Head squamation cycloid, scales becoming reduced and embedded on snout and suborbital region. Spinous dorsal with one and a half irregular rows of cycloid scales forming basal sheath; membrane naked except for row of minute, elongated, cycloid scales along posterior border of each spine in anterior portion of fin. Soft dorsal and anal membranes heavily and uniformly covered from base to edge with small cycloid scales. Pectoral, pelvic and caudal fins with small cycloid scales at bases, naked distally. Lateral line pored scales smooth anteriorly, but with small patch of ctenii posteriorly. Canal systems usually with single dorsal and ventral branch, occasionally more arborescent.

Coloration. Preserved specimens with ground color light beige fading to yellowish white ventrally. Snout, top of head, nape, dorsum and sides above level of pectoral fin base profusely dusted with very small brown chromatophores, becoming larger and more widely dispersed ventrally, and disappearing from ventral body surface. Suborbital region and upper half of upper lip sprinkled with large brown chromatophores. Lower lip, tongue and floor of mouth pale. Roof of mouth interior to the oral valve and throat, jet black. Inner side of opercle jet black, appearing externally as a D-shaped blotch bordered by vertical portion of preopercle and following the contour but not extending to the edge of the opercle. Ramus of first gill-arch dark brownish at the angle or extends to entire length. Spinous dorsal finely stippled, chromatophores concentrated distally at apex of fin appearing dusky. Soft dorsal similarly colored, not finely stippled. Pectoral fin coarsely stippled. Posterior two-thirds of pelvic fins stippled, trailing edges appearing dusky; pelvic filament speckled. Anal fin peppered with chromatophores, dusky in appearance. Caudal fin lightly and evenly dusted. Peritoneum variably sprinkled with large, stellate, chromatophores, especially at the anterior portion of the body cavity.

Distribution. North coast of the Araya Peninsula and the Gulf of Paria, Venezuela, the Caribbean Islands, Less- er Antilles, Dominica and north coast of Brazil, Pará State. Additional collections probably will extend its range.

Etymology. In honor of late Dr. Fernando Cervigón M. formerly at Universidad de Oriente, Venezuela, for his contributions to ichthyology and for discovering the species.

Figures

FIGURE 1. Two-chambered gas bladders of Stelliferinae, left & right halves represent different forms or taxa. A. left, Bairdiella, Corvula, Elattarchus, Odontoscion & Stellifer (Ophioscion); right, S. naso & S. venezuelae. B. left, S. microps, hatched area indicates drumming muscle patch; right, small knob-like such as S. griseus, S. colonensis, S. lanceolatus, etc. C. left, S. brasiliensis; right, S. rastrifer.

FIGURE 5. Stellifer sensory pore system at the tip of the snout and on the ventral region of the lower jaw. A. species with subterminal or inferior mouth; B. species with oblique mouth (front view of snout pores on top).

FIGURE 6. Mental pore patterns of Stellifer species.A. Four pores (S. collettei new species); B. Five pores (S. stellifer); C. Six pores with the medial pair set in a pit (S. rastrifer); D. Six pores (S. colonensis).

FIGURE 8. Stellifer cervigoni new species Holotype USNM 435344, 108 mm SL, Morro de Puerto Santo, Estado Sucre, Venezuela. Scale: 10 mm.

FIGURE 9. Gas bladder of Stellifer cervigoni new species with a pair of small hammer-like appendages on the posterior margin of anterior chamber. X indicates position of vent; A indicates base of first anal spine.

FIGURE 10. Otoliths of Stellifer cervigoni new species A. Sagitta; B. Lapillus; C. Asteriscus (layout as in Fig. 3).