Gobius uranoscopus Sauvage, 1882

Caires, Rodrigo Antunes, 2019, Comments on taxonomical status of three gobiid nominal species (genus Gobius) described from Brazilian coast (Teleostei: Gobiiformes: Gobiidae), Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 59, pp. 1-4 : 2

Gobius uranoscopus Sauvage, 1882 syn. nov. ( Fig. 1 )

Material examined: MNHN 4251-A, holotype, 57 mm SL, photographs in lateral view (C. Ferrara, 2014).

Description: SL 65 mm; HL 33.7% SL; D. VI.10; A. 9; P. ???; ll 42; GR ???.

The only information on type locality of this species is the term“ Brésil ”, written in the original description.The MNHN’s website informs that holotype would have been taken in 10°S- 30°W, but this is probably wrong since such coordinates are located outside the Brazilian EEZ.

The original description of Gobius uranoscopus is not much detailed, but counts of scales in longitudinal row (98 scales) are clearly wrong since only Sicydium plumieri , among western Atlantic gobiids, possesses so many scales on flanks ( Watson, 2000). Also, G. uranoscopus does not have long, comb-like teeth on upper jaw and five curved teeth on each side of lower jaw as in Sicydium . Further examination on images of the holotype revealed this specimen has about 42 scales on longitudinal row over flanks.

In MNHN’s website, Gobius uranoscopus was recognized as an unidentified Bathygobius , which is confirmed herein based on its head morphology and the presence of upper pectoral fin rays ( Fig. 1 ) as detached silk-like filaments ( Miller & Smith, 1989; Murdy & Hoese, 2003). Four Bathygobius species have been reported from the Brazilian EEZ: B. antilliensis, Tornabene, Baldwin, Weigt & Pezold, 2010 , in Atol das Rocas; B. brasiliensis , Carvalho- Filho & Araújo, 2017, in Atol das Rocas and Fernando de Noronha; B. geminatus, Tornabene, Baldwin, Weigt & Pezold, 2010 , in western North Atlantic, coast of Espírito Santo; and B. soporator, Valenciennes, 1837 , in western North Atlantic, coast of Santa Catarina. It is rather implausible that Gobius uranoscopus holotype has been taken in Atol das Rocas or Fernando de Noronha because most Brazilian material deposited in MNHN was taken by Delalande, who never visited those islands. Therefore, the affiliation of G. uranoscopus with Bathygobius antilliensis and G. brasiliensis may be rejected.

Bathygobius geminatus is distinguished from B. soporator by the presence of a row of round black spots ventrolaterally on trunk (over light yellow background) and 36-38 scales on longitudinal row, whereas B. soporator has rather dull black coloration with irregular markings on trunk (without row of black spots), black diagonal line along first dorsal fin and 38-44 scales on longitudinal row. Although the pigmentation of G. uranoscopus specimen is faded due to long period under preservation, the row of black spots typical of B. geminatus is not visible in this specimen; based on this feature and scale counts, G. uranoscopius is herein regarded as junior synonym of Bathygobius soporator .

Figures

Figure 1. Holotype of Gobius uranoscopus Sauvage. MNHN 251-A, holotype, 57 mm SL,in lateral view.Photograph by C.Ferrara,2014.