Review of Brazilian jawfishes of the genus Opistognathus with descriptions of two new species (Teleostei, Opistognathidae)

Abstract

A new species of jawfish, Opistognathusthionyisp. n., is described from the Vitória-Trindade Chain and Fernando de Noronha Archipelago off Brazil, a disjunct distribution of ca. 1,800 km. Opistognathusthionyi and its allopatric Caribbean sister-species, Opistognathusmaxillosus, both have a wide, fan-like upper margin of the subopercular flap and mostly over-lapping meristic data. The new species differs from O.maxillosus in having the darkest spot on the spinous dorsal fin, when present, between spines 2–5, versus always present between spines 6–9, the buccal area surrounding the esophageal opening pale versus very dark and fewer oblique scale rows in longitudinal series (45–52 vs. 69–85). A second new species, Opistognathusvicinussp. n., known from Brazil’s mainland, has completely over-lapping meristic values with its allopatric Caribbean sister-species O.whitehursti, but differs in lacking vomerine teeth and a supramaxilla and retaining the juvenile color pattern of the latter species in adults. Diagnoses, photographs, an identification key, and distributional maps are given for all Brazilian species of Opistognathus.Molecular phylogenetic analysis of partial cytochrome c oxidase subunit-I sequences indicates that specimens of the two allopatric pairs, O.thionyi – O.maxillosus and O.vicinus – O.whitehursti, form reciprocally monophyletic groups that differ from each other on average by 9 to 11%, with less than 1% average pair-wise genetic distance within-species. Similar patterns of phylogenetic structure were observed between reciprocally monophyletic (predominately allopatric) groups within nominal species of Opistognathusaurifrons, suggesting the possibility of at least two additional undescribed species from the Brazilian Province.

First Japanese Records of the Jawfish <i>Opistognathus solorensis</i> (Actinopterygii: Perciformes: Opistognathidae) from the Osumi Islands

“…Counts and measurements generally followed Smith-Vaniz and Yoshino (1985) and Smith-Vaniz (2009), with mandibular pore positions following Smith-Vaniz (2009). Measurements were made to the nearest 0.1 mm with needle-point calipers.…”

Opistognathus evermanni(Jordan & Snyder, 1902), the first distributional record from Indian coastal waters

“…Remarks: The genus Gnathypops (Gill, 1862) was revised into Opistognathus by Cuvier in 1816 and Synonym of the species is Gnathypops evermanni (Jordan & Snyder, 1902). No additional characters distinguish Gnathypops , name as a junior synonym of Opistognathus (Bussing & Lavenberg, 2003; Smith‐Vaniz & Yoshino, 1985).…”

“…In India only five species i.e, Opistognathus nigromarginatus , O. pardus , O. rosenbergii , O. macrolepis (Smith‐Vaniz et al., 2012) and O. ensiferus (Smith‐Vaniz, 2016) were documented. The type specimen of O. evermanni (Jordan & Snyder, 1902) and those addition specimens reported by Smith‐Vaniz and Yoshino (1985) were collected from Japanese coastal waters. Although there has been no documentation of this species outside Japanese waters, the finding of O. evermanni on the Parangipettai coast, is the first detailed morphometric and meristic description from Indian waters.…”

New records of fishes for the Vit&oacute;ria-Trindade Chain, southwestern Atlantic

“…Indeed, while there are 173 fish species recorded in Trindade, only 73 have been recorded in Martin Vaz (Pinheiro et al 2015a). Therefore, a close look into the marine fauna of oceanic islands and detailed analysis over some taxonomically complex groups could reveal more species, as suggested by the number of endemic species described in the past few years (Pinheiro et al 2013(Pinheiro et al , 2016Smith-Vaniz et al 2018).…”