CIUFES 2347, 45.4 mm SL, male, sandy rubble bottom at Praia do Lixo, Trindade Island, Brazil, 20°31'30"S, 29°19'20"W, 20 m, 20 February 2012, Thiony Simon and L.B.C. Xavier.

(12 specimens 23.4–53.5 mm SL) all from Brazilian Province: MNRJ 51283 (1, 39.9*) and ZUEC 16914 (1, 44.9*), sandy rubble bottom at Praia do Lixo, Trindade Island, Brazil, 20°31'30"S, 29°19'20"W, 15 m, 18 February 2012, T. Simon and E.F. Mazzei; CIUFES 2344 (4, 23.4-32.7 & 32.5 C&S) and UF 239658 (1, 32.9), sandy rubble bottom at Praia do Lixo, Trindade Island, Brazil, 20°19'30"S, 29°19'20"W, 21 m, 21 February 2012, T. Simon and L.B.C. Xavier; AMNH 267140 (1, 32.5*), sandy rubble bottom at Praia do Lixo, Trindade Island, Brazil, 20°30'S, 29°20'W, 20 m, 20 February 2012, T. Simon and L.B.C. Xavier; CIUFES 2393 (1, 53.5), male, sandy rubble bottom at Portinho, Fernando de Noronha Archipelago, Brazil, 03°50'S, 32°24'W, 15 m, 11 July 2012, R.M. Macieira and H.T. Pinheiro; NPM 5029 (1, 38.4*), male, sandy rubble bottom at Enseada dos Portugueses, Trindade Island, Brazil, 20°31'30"S, 29°19'20"W, 25m, 8 August 2012, T. Simon and E.F. Mazzei; MZUSP 123868 (1, 30.9) and USNM 440401 (1, 35.3*), sandy rubble bottom at Praia do Lixo, Trindade Island, 20°31'30"S, 29°19'20"W, 17 m, 7 August 2012, T. Simon and L.B.C. Xavier.

CIUFES 2054 (1, 27.5), sandy rubble bottom at Dogaressa seamount, Vitória-Trindade Chain, Brazil, 20°51'S, 33°40'W, 65 m, 12 April 2011, Expedição Cadeia Vitória-Trindade; CIUFES 2341-1 (1, 25.1), CIUFES 2341-2 (23.8) and CIUFES 2341-3 (1, 21.3), sandy rubble bottom at Praia do Lixo, Trindade Island, Brazil, 20°31'30"S, 29°19'20"W, 15 m, 18 February 2012, T. Simon and E.F. Mazzei; CIUFES 2346-3 (1, 29.2), sandy rubble bottom at Praia do Lixo, Trindade Island, Brazil, 20°31'30"S, 29°19'20"W, 20 m, 20 February 2012, T. Simon and L.B.C. Xavier.

A species of Opistognathus with the following combination of characters: anterior nostril a short tube with simple cirrus on posterior rim; maxilla rigid, not produced as a thin flexible lamina posteriorly; supramaxilla absent; subopercle with a broad, fan-like flap; vomer with 1 tooth; buccal area surrounding esophageal opening pale; body with 45–52 oblique body scale rows in longitudinal series; vertebrae 10+18; spinous dorsal fin with black blotch, when present, between spines 2–5. Body with five poorly defined irregular bands and sides sometimes with diagonal rows of pale spots smaller than eye diameter; when present, black blotch in spinous dorsal fin between spines 2–5; buccal area surrounding esophageal opening pale. This species is also easily distinguished from congeners by divergence in the mitochondrial gene COI, as specimens form a monophyletic group that differs from its closest relative (O. maxillosus) by an average of 9% (654 bp analyzed).

Morphometric data are given in Table 3 for the holotype and specimens indicated above by an asterisk; other comparative features are presented in Table 1. Where counts differ, those of the holotype are given first, followed in parentheses by those of the paratypes. Dorsal fin XI, 15 (15–16). Anal fin III, 15 (14–15, usually 15). Pectoral-fin rays 20 (19–20). Vertebrae: 10+18, last pleural rib on vertebra 10, epineurals 13–15. Supraneurals absent. Caudal fin: procurrent rays 5+5 (4-6+4-5); segmented rays 8+8, middle 12 branched, total elements 26 (24–26); hypural 5 absent. Gill rakers (number not increasing with increase in SL in adults) 9+19 (8–11+17–20=25–31).

Scales absent from head, nape, pectoral-fin base and breast; belly completely scaled, and sides fully scaled except for area above lateral line anteriorly. Body with 48 (45–52) oblique scale rows in longitudinal series. Lateral-line terminus below verticals between segmented dorsal-fin ray 3 (3–5). Anterior lateral-line pores relatively numerous and arranged in branched series along lateral-line tubes, all of which are embedded in skin. Mandibulo-preopercular pore positions all consisting of multiple pore series, except first two mandibular pore positions occupied by simple pores. Infraorbital pore positions consisting of multiple series that extend onto cheeks. Nape nearly to completely covered by sensory pores except for V-shaped naked area immediately in front of dorsal-fin origin (Figure 4A).

Anterior nostril positioned closer to posterior nostril than to dorsal margin of upper lip, and adults with a rounded cirrus that usually reaches anterior margin of orbit when depressed; height of cirrus 2.0–3.0 times maximum diameter of posterior nostril. Dorsal fin moderately low anteriorly, with posterior rays slightly longer; profile relatively uniform without noticeable change in fin height at junction of spinous and segmented rays. Dorsal-fin spines stiff and straight with pungent tips and in larger specimens the skin covered tips usually with pale, slightly swollen fleshy tabs. Segmented dorsal- and anal-fin rays all typically branched distally. Outermost segmented pelvic-fin ray not tightly bound to adjacent ray and interradial membrane strongly incised distally; tip of depressed pelvic fin in front of anal-fin origin. Upper margin of subopercle consisting of a broad, truncated flap (Figure 4A) and dorsalmost spine of opercle not noticeably elongate; posterior margin of preopercle distinct, with a well-developed groove dorsally. No papillae on inner surface of lips. Fifth cranial nerve passes over A1β section of adductor mandibulae muscle.

Upper jaw not sexually dimorphic, extending 0.45 (0.3–0.6) eye diameters behind orbit in specimens 32.5–53.5 mm SL; posterior end of maxilla rigid and truncate, without a thin flexible lamina; supramaxilla absent. Coronoid (ascending) process of articular slightly tilted backward and somewhat club-shaped with anterodorsal end bluntly pointed and posteroventral end bluntly rounded (Figure 5A). Premaxilla anteriorly with an outer row of stout teeth and an inner row of smaller, backward slanting teeth, some nearly horizontal; laterally teeth uniserial and becoming progressively smaller and more closely spaced. Dentary anteriorly with an outer row of stout teeth and an inner row of smaller, backward slanting teeth; laterally teeth uniserial and smaller but not progressively so. Vomer with 1 large tooth. Infraorbital bones tubular, with numerous openings for sensory canals; third infraorbital with a wide suborbital shelf. Postcleithra consisting of two well separated bones; dorsal postcleithrum an irregular elongate oval, narrowest ventrally, ventral postcleithrum rod-shaped with pointed ends.

Color in life (Figures 1, 2). Body coloration chestnut brown to dark brown with five very irregular and poor defined dark bands that extend onto base of dorsal fin; head sometimes with pale speckles on posterior half; upper jaw with a wide white band near posterior end; eyes reddish brown sometimes with narrow pale radiating bands; lips with alternating dark and pale bands; branchiostegal membranes dark, especially in mature males; dorsal fin light yellow sometimes with diagonal rows of pale spots and a black blotch, when present, between spines 2–5; anal fin with small pale spots; pelvic fins dark; pectoral fins speckled and a large white spot on pectoral-fin base; caudal fin with pair of pale basicaudal spots and fin rays with prominent black speckles or narrow bands.

Figure 1. 

Opistognathus thionyi, CIUFES 2054, 27.5 mm SL, Dogaressa Seamount, Vitória-Trindade Chain. Photograph by Raphael M. Macieira.

Figure 2. 

Opistognathus thionyi, NPM 5029, 38.4 mm SL, Enseada dos Portugueses, Trindade Island, Brazil. Photograph by Thiony Simon.

Preserved color (Figure 3). As above except with white, brown, and black markings. Inner margin of maxilla posteriorly and adjacent membranes with dusky blotch. Buccal area surrounding esophageal opening pale.

Figure 3. 

Opistognathus thionyi, CIUFES 2347, preserved holotype, 45.4 mm SL, male, Trindade Island, Brazil. Photograph by Zackary S. Randall.

The Caribbean allopatric Opistognathus maxillosus Poey, 1860 shares with O. thionyi the same subopercle shape but in addition to having more longitudinal body scale rows (69–85 vs. 45–52), the dark spot in the dorsal fin is always between spines 6–9 (vs. when present between spines 2–5), and the buccal area immediately surrounding the esophageal opening very dark (vs. pale). An updated description of Opistognathus maxillosus is given in Smith-Vaniz (1997). The only other species of Opistognathus with a broad, fan-like subopercle are the eastern Pacific O. galapagensis Allen & Robertson, 1991 and O. fossoris Bussing & Lavenberg, 2003. In addition to other characters discussed by Bussing and Lavenberg (2003), both species differ from O. thionyi most notably in having the posterior end of maxilla ending as thin, flexible lamina (vs. end of maxilla rigid), more body longitudinal scale rows, 83–105 (vs. 45–52), most of nape immediately in front of dorsal-fin origin without cephalic pores (vs. almost completely covered with pores), and in having very different color patterns. Comparison of the six species of Opistognathus known from the Brazilian Province is given in Table 1.

Figure 4. 

Cephalic sensory pores in selected species of Opistognathus. A O. thionyi, 45.4 mm SL, holotype B O. vicinus, NPM 5030, 47.4 mm SL, Brazil C O. lonchurus, CIUFES 1426, 75.3 mm SL, Brazil DO. aff. aurifrons, CIUFES 1450, 57.0 mm SL, Brazil.

Figure 5. 

Jaws and dentition (supramaxilla shaded) in selected species of Opistognathus. A O. thionyi, CIUFES 2393, 53.5 mm SL, Fernando de Noronha Archipelago, Brazil B O. vicinus, NPM 5030, 47.4 mm SL, Brazil C O. lonchurus, ANSP 126637, 75.0 mm SL, Gulf of Mexico DO. aff. aurifrons, ANSP 188905, 63.8 mm SL, Brazil.

The specific name honors our colleague and dear friend Thiony Simon (1985–2016), who passed away during preparation of this article. He collected most of the type material of the new species and dedicated his life to study and conservation of Brazilian reef ecosystems.

Opistognathus thionyi is known only from three oceanic sites, Trindade Island, Dogaressa Seamount, and Fernando de Noronha Archipelago (Figure 6), and is an endemic species of the Brazilian Province (sensu Briggs and Bowen 2012 and Pinheiro et al. 2018). This species is possibly broadly distributed along the coast on the outer shelf, an area that is virtually unsampled. It has been recorded from 10–65 m, and found solitarily, always in small constructed burrows on sandy rubble bottoms (Figure 7). It feeds on small benthic organisms that live near the bottom (e.g., small shrimps).

Figure 6. 

Distributions of Opistognathus species in Brazilian Province; light shaded areas indicate continental shelf.

Figure 7. 

Opistognathus thionyi, in typical habitat, sandy rubble bottom in 13 m at Enseada dos Portugueses, Trindade Island, Brazil. Photograph by Thiony Simon.

The conservation status of Opistognathus thionyi (cited as Opistognathus maxillosus Poey, 1860 – unpublished data) has been assessed by the Ministério do Meio Ambiente/Instituto Chico Mendes de Conservação da Biodiversidade (MMA/ICMBio - Brazil) and listed as Least Concern. However, anthropogenic activities on oceanic marine ecosystems (i.e., seamount mining, fisheries, marine traffic, tourism, and human occupation of the islands), and the inadequate protection from these impacts currently provided by new Brazilian marine protected areas in the Vitória-Trindade Seamounts Chain (see Brasil 2018; Giglio et al. 2018; Magris and Pressey 2018), could threat the existence of Thiony’s jawfish in that part of its range in the near future.

CIUFES 0796, 43.0 mm SL, male, Ilha Rasa de Dentro, Guarapari, Espírito Santo, 20°40'S, 40°21'W, 15m, 11 March 2008, R. M. Macieira and T. Simon.

(12 specimens 17.0–47.4 mm SL) all from Brazil Province: UF 239659 (2, 27.9–31.0), taken with the holotype; CIUFES 0868 (1, 38.3*), Ilha Rasa de Dentro, Guarapari, Espírito Santo, 20°40'S, 40°21'W, 10 m, 29 January 2008, V.C. Brilhante; USNM 440402 (1, 38.6*), Ilha das Garças, Vila Velha, Espírito Santo, 20°36'S, 40°22'W, 30 March 2000, J.L. Gasparini; MZUSP 123869 (1, 38.9), MNRJ 51284 (1, 17.0), ZUEC 16915 (1, 42.5*) and AMNH 267141 (2, 21.7–38.9*), Ilha Escalvada, Guarapari, Espírito Santo, 20°42'S, 40°24'W, 21 m, 23 February 2010, R.M. Macieira, T. Simon and C.R. Pimentel; NPM 5030 (1, 47.4*), Ilha Rasa de Dentro, Guarapari, Espírito Santo, 20°40'S, 40°21'W, 31 October 2005, R.M. Macieira and J.-C. Joyeux; CIUFES 0467 (1, 26.2), Ilhas Rasas, Guarapari, Espírito Santo, 20°40'S, 40°21'W, 17 m, 5 December 2005, R.M. Macieira and J.-C. Joyeux; CIUFES 131797 (1, 36.0), Ilhas Rasas, Guarapari, Espírito Santo, 20°40'S, 40°21'W, 14 August 1989, J.L. Gasparini.

A species of Opistognathus with the following combination of characters: anterior nostril a short tube with simple cirrus on posterior rim; maxilla rigid, not produced as a thin flexible lamina posteriorly; supramaxilla absent; subopercle without a broad, fan-like flap; vomer without teeth; body with 43–47 oblique body scale rows in longitudinal series; vertebrae 10+17; sides with two rows of pale spots, each approximately diameter of eye. Body with six vertically irregular, evenly spaced bands, widest on mid-side, and two rows of six pale spots, each spot approximately diameter of eye; buccal area surrounding esophageal opening pale. This species is also easily distinguished from congeners by divergence in the mitochondrial gene COI, as specimens form a monophyletic group that differs from its closest relative (O. whitehursti) by an average of 11% (654 bp analyzed).

Morphometric data are given in Table 4 for the holotype and specimens indicated above by an asterisk; other comparative features are presented in Table 1. Where counts differ, those of the holotype are given first, followed in parentheses by those of the paratypes. Dorsal fin XI, 14. Anal fin II, 13 (II or III [anterior spine minute if III], 12–13, usually II, 13). Pectoral-fin rays 18 (17–18). Vertebrae: 10+17, last pleural rib on vertebra 10, epineurals 12–14. Supraneurals absent. Caudal fin: procurrent rays 4+4 (5–4+3–4); segmented rays 8+8, middle 12 branched, total elements 24 (23–25); hypural 5 absent. Gill rakers (number not increasing with increase in SL in adults) 7+16 (7–8+15–17=23–25).

Scales absent from head, nape, pectoral-fin base and breast; belly completely scaled, and sides fully scaled except for area above lateral line anteriorly. Body with 46 (43–47) oblique scale rows in longitudinal series. Lateral-line terminus below verticals between segmented dorsal-fin ray 1 (2–3). Anterior lateral-line pores relatively numerous and arranged in branched series along lateral-line tubes, all of which are embedded in skin. Mandibulo-preopercular pore positions all consisting of multiple pore series, except first two mandibular pore positions occupied by simple pores. Infraorbital pore positions consisting of multiple series that extend onto cheeks. Nape nearly to completely covered by sensory pores except for V-shaped naked area immediately in front of dorsal-fin origin (Figure 4B).

Anterior nostril positioned closer to posterior nostril than to dorsal margin of upper lip, and adults with a slender cirrus that reaches anterior margin of orbit when depressed; height of cirrus 2.0 times maximum diameter of posterior nostril. Dorsal fin moderately low anteriorly, with posterior rays slightly longer; profile relatively uniform without noticeable change in fin height at junction of spinous and segmented rays. Dorsal-fin spines stiff and straight and in larger specimens the skin covered tips usually with pale, slightly swollen fleshy tabs. Segmented dorsal- and anal-fin rays all typically branched distally. Outermost segmented pelvic-fin ray not tightly bound to adjacent ray and interradial membrane strongly incised distally; tip of depressed pelvic fin in front of anal-fin origin. Upper margin of subopercle oval-shaped without a broad, truncated flap (Figure 4B) and dorsalmost spine of opercle moderately elongate; posterior margin of preopercle distinct, with a well-developed groove dorsally. No papillae on inner surface of lips. Fifth cranial nerve passes over A1β section of adductor mandibulae muscle.

Upper jaw not sexually dimorphic, extending 0.76 (0.62–0.88) eye diameters behind orbit in specimens 36.0–47.4 mm SL; posterior end of maxilla rigid and truncate, without a thin flexible lamina; supramaxilla absent. Premaxilla with a single row of teeth, largest anteriorly becoming smaller and more closely spaced posteriorly, except in mature males posteriormost three or four teeth stouter and more strongly hooked than adjacent teeth. Dentary anteriorly with two rows of teeth, innermost smaller and slanted backwards; laterally teeth uniserial and larger than anterior teeth, posterior teeth of males larger and more strongly hooked than others. Vomer without teeth. Infraorbital bones tubular, with numerous openings for sensory canals; third infraorbital with a wide suborbital shelf. Postcleithra closely attached; dorsal postcleithrum an irregular elongate oval, narrowest ventrally where it overlaps head of ventral postcleithrum; ventral postcleithrum club-shaped, broadest dorsally and with a pointed ventral end.

Color in life (Figure 8). Background color of head and body brownish to reddish brown. Body with six vertically irregular and evenly spaced dark bands, widest on mid-side, that extend onto base of dorsal fin; two rows of six pale spots on sides, one along dorsal-fin base and the other along anal-fin base, each spot approximately diameter of eye; upper jaw with a wide dark band behind which is a white band at posterior end; the eyes are red; the lips with dark and pale bands; branchiostegal membranes dark; dorsal fin with dark stripe, widest anteriorly, along middle of fin, and a dark blue blotch between the second and fourth spine; pectoral fins are translucent; pelvic fins pale blue to dark or entirely pale; caudal fin with pair basicaudal spots bordered posteriorly by dark continuous band and remainder of fin vertical rows of dark spots or narrow bands.

Figure 8. 

Opistognathus vicinus, CIUFES 0796, holotype, 43.0 mm SL, male, Ilha Rasa de Dentro, Guarapari, Espírito Santo, Brazil. Photograph by Raphael M. Macieira.

Preserved color (Figure 9). Body with dark bands and large pale spots as above; other makings various shades of brown. Inner margin of maxilla posteriorly and adjacent membranes with brownish blotch, best developed in males. Buccal area surrounding esophageal opening pale.

Figure 9. 

Opistognathus vicinus, NPM 5030, preserved paratype, 47.4 mm SL, Ilha Rasa, Guarapari, Espírito Santo, Brazil. Photograph by Zackary S. Randall.

Figure 10. 

Opistognathus whitehursti, USNM 396062, 22.0 mm SL, Saba Bank. Photograph by Jeffrey T. Williams.

Figure 11. 

Opistognathus whitehursti, UF 183105, 43.0 mm SL, St. Croix. Photograph by Howard L. Jelks.

Genetic differences (see discussion in “Phylogenetic relationships of western Atlantic Opistognathus”), suggested that Opistognathus vicinus and the Caribbean O. whitehursti could be separate species despite their very similar appearance, including meristic values and sexually dimorphic premaxillary teeth (see Smith-Vaniz 1997: fig. 33). Initially we considered both species to be only “genovariants” sensu Victor (2015). However, O. vicinus lacks the small supramaxilla (see Smith-Vaniz 1997: fig. 32a) present in O. whitehursti and vomer without teeth (typically one or two teeth present in O. whitehursti). The color pattern of juveniles of O. whitehursti (Figure 10) is virtually identical to those of adult Brazilian fish. Unlike Opistognathus vicinus, adults of O. whitehursti usually have more reduced body bands (Figure 11) and the spinous dorsal-fin spot is often absent. As noted by Böhlke and Chaplin (1968: 486) for Bahamas fish, “The spot on the spinous dorsal fin is … blue in color in young, frequently missing or poorly defined in adults.” Thus, the combined differences in COI, adult coloration, and the lack of a supramaxilla and vomerine teeth support the recognition of O. vicinus as a distinct species. Comparison of the six species of Opistognathus known from the Brazilian Province is given in Table 1.

From the Latin vicinus (near, neighboring), referring to the allopatric distribution and sister-species phylogenetic relationship of the new species and the Caribbean Opistognathus whitehursti.

A Brazilian endemic (Figure 6), known from Ceará to Espírito Santo State but absent from oceanic islands. Common in coastal regions, in depths of 10–25 meters, associated with gravel-sand bottoms, near coral reefs and rocky areas. Feeds on small benthic organisms near the bottom (e.g., small shrimps, crabs, and isopods).

The conservation status of this species [cited as Opistognathus whitehursti (Longley 1927) – unpublished data] 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.

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, 15–16; body with 59–75 oblique scale rows in longitudinal series; vertebrae 10+18; supraneurals 2; gill rakers 9–11+23–24=33–36; spinous dorsal fin with black spot encircled by a very narrow white ring between spines 4–7 and dorsum with 5 or 6 dusky bands that extend onto base of dorsal fin; pelvic fins uniformly dark; underside of upper jaw and adjacent membranes in adults with two elongate dark stripes (males) or one smaller stripe (females) (Smith-Vaniz 1997, Figure 9c).

Figure 12. 

Opistognathus brasiliensis, CIUFES 3361, 60.6 mm SL, female, Ilhas Escalvada, Guarapari, Espírito Santo, Brazil. Photograph by Raphael M. Macieira.

Figure 13. 

Opistognathus brasiliensis, ANSP 141861, 122.5 mm SL, male, southeastern Brazil. Drawn by Jack R. Schroeder; after Smith-Vaniz (1997).

5 specimens (107.5–129 mm SL), including the holotype, cited in Smith-Vaniz (1997) plus the following additional material: CIUFES 1459 (1, 64.0), Ilhas das Garças, Vila Velha, Espírito Santo, 20°36'S, 40°22'W, 30 March 2000, J.L. Gasparini.

A Brazilian endemic (Figure 6), known from Espírito Santo to São Paulo State, but absent from oceanic islands. A rare species only known from the type series collected in São Paulo’s coastal waters (trawled in 50–69 m) and two specimens from Guarapari Islands, Espírito Santo. Occurs in depths of 15–69 meters, associated with gravel and sand or silt and sand bottoms, near coral reefs and rocky areas.

In the diagnosis and description of Opistognathus brasiliensis, Smith-Vaniz (1997) stated, in part, “buccal pigmentation consisting of a dark area widely surrounding esophageal opening …” versus area around esophageal opening pale in O. cuvierii. This reported distinction is no longer valid because in a recently examined female specimen of Opistognathus brasiliensis (CIUFES 1459) the area around the esophageal opening is pale. Both species have black areas in front of each pharyngeal tooth patch that are separated by a pale median area.

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 Data Deficient.

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).

Figure 14. 

Opistognathus cuvierii, 80 mm TL estimated, Ilha dos Frades, Baía de Todos os Santos, Bahia, Brazil. Photograph by Cláudio L. S. Sampaio.

Figure 15. 

Opistognathus cuvierii, SU 52354, 102 mm SL, male, Bahia, Brazil. Drawn by Jack R. Schroeder; after Smith-Vaniz (1997).

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

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).

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.

A species of Opistognathus with the following combination of characters: anterior nostril a short tube without a cirrus on posterior rim; posterior end of maxilla rigid, not produced as a thin flexible lamina; supramaxilla present; subopercle without a broad, fan-like flap; most of nape without sensory pores (Figure 4C); dorsal fin XI, 12–13, with spines thin and flexible, usually curved distally, tips without pale, slightly swollen tabs, and anterior 5–8 soft rays unbranched; dorsal fin sexually dimorphic, fin rays distinctly higher in large males; anal fin III, 12, with 7–10 anterior rays unbranched; outermost segmented pelvic-fin ray tightly bound to adjacent ray and interradial membrane not incised distally; body with 63–87 oblique scales in longitudinal series; vertebrae 10+16; supraneurals 1; gill rakers 13–17+22–28=35–45; dentary without large canines (Figure 5C). Head and body brown to greenish-tan; upper lip blue; body with two narrow blue stripes on side; distal margins of dorsal and anal fins with narrow blue stripe; outer margin of caudal fin and outer ray of pelvic fin blue.

Figure 16. 

Opistognathus lonchurus, CIUFES 2361, 81.2 mm SL, female, Ilhas Escalvada, Guarapari, Espírito Santo, Brazil. Photograph by Raphael M. Macieira.

3 specimens (75.3–81.2 mm SL) from Brazil and 46 specimens (27–122 mm SL) from the Caribbean. Brazil: CIUFES 1426 (1, 75.3), Ilhas Rasas, Guarapari, Espírito Santo, 20°40'S, 40°21'W, 26 February 2000, D.A. Jório and J.L. Gasparini; CIUFES 2361 (1, 81.2), gravid female, Ilhas Escalvada, Guarapari, Espírito Santo, 20°41'S, 40°24'W, 23 m, 30 February 2012, R.M. Macieira and J.-C. Joyeux; ZUEC 3160 (1), Mar do Bom Nome, Espírito Santo, 21°09'S, 40°30'W, 30 m, 8 December 1996, J.L. Gasparini. Caribbean, only abbreviated localities, standard lengths and depths given: ANSP 83680 (1, 88), Haiti; ANSP 126637 (1, 75 C&S), off Mobile, Alabama, 35 m; ANSP 134237 (1, 96), Puerto Rico, 49 m; ANSP 138138 (1, 86), Puerto Rico, 52 m; ANSP 138362 (1, 93), Puerto Rico, 52 m; ANSP 140955 (5, 77-97), Puerto Rico, 50 m; ANSP 142700 (1, 107), Puerto Rico; 14 m; ANSP 174157 (1, 83), Gulf of Mexico, 74 m; ANSP 177885 (2, 82-97), Gulf of Mexico, 63 m; ANSP 136545 (1, 92), off South Carolina, 60 m; CAS 1863 (1, 84), CAS 29250 (1, 84) and CAS 36683 (1, 95), Pensacola, Florida; FSBC 1706 (2, 85.5-94), 32°01'N, 79°24'W, R/V Silver Bay sta. 1788, 64–82 m; FMNH 79582 (1, 76), off Guyana, 49–55 m; FSBC 3314 (1, 107), off St. Petersburg, Florida, 47 m; FSBC 3324 (1, 93), Gulf of Mexico, 37 m; FSBC 12575 (1, 99), Florida Keys, 76–80 m; MCZ 52103 (2, 112-122), 55 m; Dry Tortugas, 55 m; SIO 70–186 (2, 77–97), Florida Keys, 40 m; SIO 70–186 (2, 76–96), Florida Keys, 40 m; SIO 70–224 (1, 47), Florida Keys, 38 m; UF 186218 (1, 80), Gulf of Mexico; UF 186226 (1, 89), Gulf of Mexico, 61 m; UF 186239 (1, 102), Gulf of Mexico; UF 218742 (1, 28), Florida, 38 m; UF 203991 (1, 90), off Guyana, 55–60 m; UF 219018 (1, 35), Florida, 40 m; UF 238298 (1, 196), Gulf of Mexico; USNM 31903 (1, 64), Pensacola, Florida; USNM 34976 (1, 69), holotype of Gnathypops mystacinus), Pensacola, Florida; USNM 117035 (1, 27), Dry Tortugas; USNM 217802 (1, 96), off Colombia, 73 m; USNM 217083 (1, 106) off Colombia, 84 m; USNM 30712 (1, 104), Pensacola, Florida; USNM 358160 (1, 68), Gulf of Mexico, 62 m; USNM 358161 (1, 73), Gulf of Mexico, 67 m.

South Carolina, Gulf of Mexico, Greater Antilles and northern South America to Brazil (Figures 6, 17) in about 15–90 m. In the Brazilian Province known from the northern coast to Espírito Santo State but absent from oceanic islands. Occur in depths of 10–91 meters, in rubble-sand bottoms near coral reefs and rocky areas. It has been observed in burrows or resting on the bottom.

Figure 17. 

Distribution of Opistognathus lonchurus, including a few records from Robertson and Van Tassell (2015).

The conservation status of this species was assessed by the International Union for Conservation of Nature (IUCN) and listed as Lease Concern (Smith-Vaniz et al. 2015). The conservation status of this species was also assessed by the Ministério do Meio Ambiente/Instituto Chico Mendes de Conservação de Biodiversidade (MMA/ICMBio – Brazil) and listed as Least Concern.

A species of Opistognathus with the following combination of characters: anterior nostril a short tube without a cirrus on posterior rim; posterior end of maxilla rigid, not produced as a thin flexible lamina; supramaxilla present; dorsal-fin spines thin, flexible, usually curved distally, and tips without pale, slightly swollen tabs; subopercle without a broad, fan-like flap; most of nape without sensory pores (Figure 4D); dorsal fin XI, 14–15, with 6–11 anterior rays unbranched distally; anal fin III, 14–15, with 7–10 anterior rays unbranched; outermost segmented pelvic-fin ray tightly bound to adjacent ray and interradial membrane not incised distally; scales in longitudinal series 66–76; vertebrae 10+17; supraneurals absent; gill rakers 15–20+26–32=41–51; dentary with large lateral canines (Figure 5D). Life color of adults of the two different color morphs as in Figs 18–20 and discussed below in Remarks.

Figure 18. 

Opistognathus aff. aurifrons, CIUFES 0795-1, 61.8 mm SL, female, Ilhas Escalvada, Guarapari, Espírito Santo, Brazil. Photograph by Raphael M. Macieira.

Figure 19. 

Opistognathus aff. aurifrons, adult, Bellucia shipwreck, Guarapari, Espírito Santo, Brazil. Photograph by Raphael M. Macieira.

Figure 20. 

Opistognathus aff. aurifrons, CIUFES 2551, 69.2 mm SL, Fernando de Noronha Archipelago, Brazil. Photograph by Raphael M. Macieira.

As provisionally recognized, this species is known only from the Brazilian Province including continental localities from the State of Maranhão (0°53'S, 44°17'W) south to Armação de Búzios (22°45'S, 41°59'W) in the State of Rio de Janeiro and oceanic sites of the Vitória-Trindade Seamounts Chain and Fernando de Noronha Archipelago (Figure 6). It is common in coastal regions, in depths of 10–30 meters, and in oceanic sites of 10–65 meters, associated with rubble and sand bottoms, near coral reefs and rocky areas. Its behavior and life history are similar of that of the Caribbean O. aurifrons (Colin 1971; Colin 1973). In this species the burrows are constructed on sandy or rubble bottoms, near reefs, using small stones, shell or coral fragments. They feed on zooplankton while hovering at a small distance over the substrate during quick incursions and generally retreat tail first into the burrow.

33 specimens (30.4–73.7 mm SL) all from Brazilian Province. Mainland localities: ANSP 188905 (2, 35.4–63.8 C&S), Naufrágio Bellucia (shipwreck), off Guarapari, Espírito Santo, 20°40'S, 40°21'W, 24.6 m, 29 August 2008, A. Carvalho-Filho, R.M. Macieira and C.R. Pimental; CAS 238006 (3, 53.2–57.5), Ilha Escalvada, Guarapari, Espírito Santo, 20°42'S, 40°24'W, 30 March 2012, L.A. Rocha; CAS 238007 (4, 58.8–70.3), Ilha Escalvada, Guarapari, Espírito Santo, 20°42'S, 40°24'W, 15 February 2012, L.A. Rocha; CIUFES 0795 (4, 24.0–66.9), Naufrágio Bellucia (shipwreck), off Guarapari, Espírito Santo, 20°40'S, 40°21'W, 27.0 m, 11 March 2008, J.-C. Joyeux, R.M. Macieira and V.C. Brilhante; CIUFES 1450 (2, 57.1–73.7 C&S), Ilhas Rasas, Guarapari, Espírito Santo, 20°40'S, 40°22'W, 15 m, 14 August 1999, J.L. Gasparini; MZUSP 44937 (1, 52.4), Ilhas Rasas, Guarapari, Espírito Santo, 20°40'S, 40°21'W, January 1992, J.L. Gasparini; MZUSP 46191 (1, 67.5), male, Cabo Frio, Rio de Janeiro, 22°53'S, 42°00'W, March 1991, A. Carvalho-Filho; MZUSP 46541 (1, 61.8), gravid female, Vitória, Espírito Santo, 20°19'S, 40°21'W, December 1990, A. Carvalho-Filho; MZUSP 52271 (2, 35.0–42.8), Ilha Sueste, Abrolhos Archipelago, 17°58'S, 38°41'W, 11 January 1997, I. Sazima, C. Sazima, J.L. Gasparini and R.L. Moura; MZUSP 52453 (1, 46.9) and UF 191039 (3, 30.4–51.6), Ilhas Rasas, Guarapari, Espírito Santo, 20°40'S, 40°22'W, 22 April 1992, D.A. Jório; ZUEC 3105 (1, 72.6), Ilhas Rasas, Guarapari, Espírito Santo, 20°40'S, 40°22'W, 18 m, 1 June 1996, D.A. Jório; ZUEC 2739 (1, 61.6), gravid female, Ilha Escalvada, Guarapari, Espírito Santo, 20°42'S, 40°24'W, 16 m, July 1995, D.A. Jório and J.L. Gasparini; UFPB 4047 (5, 52.4–67.5), Três Ilhas Archipelago, Guarapari, Espírito Santo, 20°36'S, 40°22'W, 1 December 1997, J.L. Gasparini. Fernando de Noronha Archipelago: CIUFES 2550 (1, 58.4) and CIUFES 2551 (1, 69.2), Cabeço Submarino, 03°52'S, 32°25'W, 19.6 m, 8 April 2013, R.M. Macieira and T. Simon.

Brazilian specimens of Opistognathus aff. aurifrons (n=28) differ from Caribbean O. aurifrons (n=292) in consistently having 17 vs. 16 caudal vertebrae. Brazilian fish are represented by two allopatric and slightly different genetic populations (see discussion below in “Phylogenetic relationships of western Atlantic Opistognathus”). Mainland and Vitória-Trindade Seamounts Chain specimens have long pelvic fins that when depressed extend at least to the anal-fin origin (25.7–38.2% SL, mean 30.4%, in 22 specimens 30.4–74.8 mm SL) and in fresh adult specimens the top of the head is yellow, bordered posteriorly by a narrow blue band extending from slightly behind the eye to upper jaw and across the nape; remainder of the head and body greenish-yellow to bluish-yellow (Figures 18–19). Populations from the Fernando de Noronha Archipelago differ in having short pelvic fins that do not extend to the anal-fin origin (20.1–20.7% SL in 2 specimens 58.4–69.2 mm SL) and in fresh adults the head is pale tan-yellow, the body is pale grey-blue, and both are uniformly colored (Figure 20). To further complicate the situation, uncollected juveniles from Fernando de Noronha (Figure 21) and Bonaire (Figure 22) have identical life coloration consisting primarily of a white head crossed by diagonal brown-orange stripe about width of pupil extending from chin, through eye and across nape; body and fins pale grey. In preservation, adults from Tobago (USNM 317005) have the same head color pattern and long pelvic fins as those of the Brazilian mainland population but differ in having 16 caudal vertebrae. Unfortunately, life coloration was unrecorded and tissue samples were not obtained. A color photograph taken by Les Wilkes of a “Bluebar jawfish” from St. Vincent, Lesser Antilles (13°15'N, 61°12'W) also looks like mainland Brazilian adults. Overall, there are morphological characters that collectively differentiate the two Brazilian clades from the Caribbean haplotypes (i.e., vertebral counts) and from each other (i.e., pelvic fin length, but note the low sample size), but we know of no consistent phenotypic characters that differentiate the two Caribbean haplotypes from each other. The type locality for O. aurifrons is Dry Tortugas, Florida, making it likely that if the main groups here do indeed represent distinct species, the group containing specimens from Florida (green in Figure 24) represents the true O. aurifrons and the others new species. However, we refrain from making taxonomic changes pending a more thorough analysis comparing multiple genetic loci, and live coloration/morphology of vouchered specimens.

Figure 21. 

Opistognathus aff. aurifrons, juvenile, Fernando de Noronha Archipelago, Brazil. Photograph by João P. Krajewski.

Figure 22. 

Opistognathus aurifrons, juvenile, Bonaire. Photograph by Scott Michael.

Depending on the locality, adults of Caribbean Opistognathus aurifrons may have relatively short or long pelvic fins, color patterns not found in Brazilian populations or that duplicate them.

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