Suezichthys Smith

RUSSELL, BARRY C. & WESTNEAT, MARK W., 2013, A new species of Suezichthys (Teleostei: Perciformes: Labridae) from the southeastern Pacific, with a redefinition of the genus and a key to species, Zootaxa 3640 (1), pp. 88-94 : 89-90

Genus Suezichthys Smith

Suezia Smith, 1957: 106 (type-species, Labrichthys caudovittatus Steindachner , by original designation, preoccupied in Crustacea by Suezia Gurney 1927 ).

Suezichthys Smith, 1958: 319 (type-species, Labrichthys caudovittatus Steindachner , replacement name for Suezia Smith ).

Nelabrichthys Russell, 1983: 1 (type-species Labrus ornatus Carmichael ).

Description. Dorsal-fin rays IX,11–12 (rarely 13); anal-fin rays III,10–12; caudal-fin rays 4–6+2+12+2+4–5 (rarely 6); pectoral-fin rays 12–13 (rarely 14); pelvic-fin rays I,5; lateral-line scales 25–27; scale rows above lateral line 1½–2½ (plus small basal sheath scale); scales below lateral line 7½; predorsal scales 3–6; vertebrae 9+16–17 (rarely 18), ribs ending on ninth vertebra; epineural bones ending on twelfth to fourteenth vertebra; gill rakers 15– 25; branchiostegal rays 6.

Body elongate, the depth at origin of dorsal fin 3.2–5.3 in SL; mouth terminal, small, the maxilla reaching to or just beyond a vertical through anterior nostril; lips moderately fleshy, the upper lip with 4–7 longitudinal plicae and lower lip with 1–2, the anterior canines recurved; 10–15 progressively smaller canine teeth laterally in upper jaw, with an inner row of 4–8 small canines behind anterior most teeth; an enlarged canine (rarely two) at posterior end of upper jaw; lower jaw with 1–2 pair enlarged anterior canines, the second canine usually shorter than the first; 12–16 progressively smaller lateral teeth in lower jaw, with an inner row of 2–4 small canines behind anterior most teeth; lower pharyngeal plate broadly Y-shaped, the transverse limb with a medial posterior patch of large, blunt conical teeth and 2–3 rows of smaller conical teeth about one third to one half the size of other teeth; anterior median limb of lower pharyngeal narrow, with 2–3 rows of conical teeth.

Nostrils small, the anterior nostril terminating in a short membranous tube; posterior nostril without any flap or marginal ridge. Gill membranes not attached to isthmus, forming a free fold posteriorly. Preopercule entire, the free posterior margin reaching upward to or just above level of lower rim of orbit, the free lower membrane extending forward to below middle of lower rim of orbit. Opercular membrane rounded and extending posterior to pectoral base. Forehead, snout, and ventral side of head naked; cheek scales small, in 1–3 rows behind eye, and 2–4 (rarely one) rows below eye, extending forward to beneath middle of lower rim of orbit. Opercle with large scales posteriorly; anterior part of opercle and membranous opercular flap naked; subopercle naked. Body scales large, the scales on thorax about one half to three quarters the size of body scales. Lateral line complete, bent abruptly downward beneath ninth to eleventh soft dorsal rays; laterosensory canals unbranched, bifurcate or simply branched, the canal pores terminal. Dorsal fin length 1.4–1.8 in SL, the dorsal rays progressively longer posteriorly; dorsal spines pungent, the last spine 1.5–3.0 times length of first; membrane of dorsal fin emarginate, the posterior tip of fin pointed. Anal fin length 2.4–3.6 in SL, the rays progressively longer posteriorly; anal spines pungent, the first spine 1.5–3.5 in third anal spine; last or penultimate soft ray longest, 1.1–2.4 times length of third anal spine, the posterior point pointed. Low scaly sheath at base of dorsal and anal fin present or absent. Caudal fin rounded to truncate (upper rays slightly produced to form a short point in larger TP specimens in some species). Pectoral fins rounded to pointed (upper rays longest), not reaching a vertical through anus, length of fin 0.8–2.1 in head. Pelvic fins short to moderately long, pointed, not quite reaching to or reaching beyond tips of pectoral fins, length 1.2–3.2 in head.

Remarks. Suezichthys superficially resembles the temperate labrid genus Pseudolabrus , but is osteologically distinct in having the following characters: anterior preneural zygopophyses fused, slightly expanded (versus separate, small); urohyal with a posteroventral spike-like extension (versus no spike); and laterosensory canal tube simple tubular, bifurcate or branched (versus bifurcate or multi-branched). In these characters it appears most closely related to the genus Halichoeres , but differs in having anal-fin rays III,10–12 (versus anal-fin rays III, 11–13 in Halichoeres ), cheeks scaly (versus naked in Halichoeres ), and gill membranes forming a free fold across the isthmus (versus broadly attached in Halichoeres ).

Russell (1983, 1988) considered Suezichthys to be closely related to the genus Nelabrichthys , and separated the latter mainly on the basis of its higher dorsal and anal fin ray counts, greater number of vertebrae, and having branched lateral-line tubes. Kuiter (2002), however, pointed out the remarkable similarity of the TP colour pattern of the monotypic Nelabrichthys ornatus ( Carmichael 1818) to Suezichthys arquatus and S. notatus , and assigned it to Suezichthys .

With the inclusion now of Suezichthys bifurcatus and the new species described below it is clear that the genus Suezichthys shows much greater meristic range in fin ray and vertebral numbers than previously described ( Russell 1985). All species of Suezichthys , however, share the following derived traits: (1) anterior preneural zygopophyses fused mesially; (2) urohyal with a spike-like posteroventral projection; and (3) well-developed haemal arches on the first one or two caudal vertebrae (V10–11) ( Russell 1983). The same morphological characters are also present in Nelabrichthys , and based on these synapomorphies we here include Nelabrichthys in the genus Suezichthys .