Opistognathus cuvierii Valenciennes, 1836 Figures 14, 15; Tables 1, 2

Opisthognathus [sic] cuvierii Valenciennes in Cuvier and Valenciennes 1836: 504, color pl. 343 (original description; Bahia: holotype MNHN A. 2108); Roux 1964: 413, pl. 10 (listed; original illustration of holotype reproduced).

Opistognathus cuvierii: Menezes and Figueiredo 1985: 42, fig. 47 (description); Smith-Vaniz 1997: 1106, fig. 21 (description); Pinheiro et al. 2018, Southwestern Atlantic (SWA) Endemic reef fishes - Annotated Checklist: 28-29, color fig. 18.

Opistognathus cuvieri: Roux 1973: 151 (description); Carvalho-Filho 1999: 194 (abbreviated description and occurrence to São Paulo); Mincarone et al. 2017: 207 (listed).

Abbreviated description.

A species of Opistognathus with the following combination of characters: anterior nostril a short tube with simple cirrus on posterior rim; adults with posterior end of maxilla ending as thin, flexible lamina (slightly elongate in mature females and very elongate in males); supramaxilla present; subopercle without a broad, fan-like flap; most of nape without sensory pores; dorsal-fin spines thin, flexible, usually curved distally, and tips without pale, slightly swollen tabs; dorsal fin XI, 16, with all soft rays weakly branched distally; anal fin II, 16; body with 60-72 oblique scale rows in longitudinal series; vertebrae 10+19; supraneurals 1 or 2; gill rakers 9 –11+20–23=30– 35; spinous dorsal fin with an ocellus between spines 3-7, otherwise dorsal fin with rows of pale spots and dorsum without 5 or 6 dusky bands that extend onto base of dorsal fin; pelvic fins uniformly dark; caudal fin dark with two pale bands; underside of upper jaw and adjacent membranes in adults with two dark blotches, the innermost one poorly developed (males) (Smith-Vaniz 1997: fig. 9d), or these blotches absent (females); buccal pigmentation consisting of a dark blotch on either side of esophageal opening widely separated by pale median area that continues between upper pharyngeal tooth patches (Smith-Vaniz 1997: fig. 13c).

Material examined.

5 specimens (80.5-11.5 mm SL), including the holotype, cited in Smith-Vaniz (1997).

Distribution, habitat, and natural history.

A Brazilian endemic (Figure 6), known from Bahia to São Paulo but absent from oceanic islands. Distributed in coastal regions, in depths between 1-35 meters, associated with gravel and sand or silt and sand bottoms, near coral reefs and rocky areas. This species has been observed resting on the bottom (Figure 14) or in burrows (Pinto 1970).

Conservation.

The conservation status of this species has been assessed by the Ministério do Meio Ambiente/Instituto Chico Mendes de Conservação da Biodiversidade (MMA/ICMBio - Brazil) and it was listed as Least Concern.