Gobius silveiraemartinsi Ihering, 1893

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 : 2-3

Gobius silveiraemartinsi Ihering, 1893 syn. nov.

Material examined: not available.

Description: SL 35 mm; HL 28.6% SL; D. V.14; A. 13; P. 15; ll ???; GR ???.

This species has been described based on two specimens taken in southern Brazilian coast, (Camaquã, Rio Grande do Sul state). The type material of this species is unknown and the original description is poorly detailed and without any image. Ihering stated G. silveiraemartinsi specimens present seven spines in first dorsal fin, 2 spines and 11 rays in second dorsal fin, two spines and 11 rays in first anal fin, and 15 pectoral fin rays. The presence of seven spines are typical of gobiid subfamily Gobiosomatinae ( Birdsong, 1975) , but no member of this subfamily encountered in Brazil possesses only 15 pectoral fin rays, fin counts provided by Ihering are possibly erroneous, and, evidently, Gobius silveiraemertinsi probably is not a gobiosomatinae , since all gobiosomatines reported from southern Brazilian coast present different values of dorsal, anal and pectoral fins, such as Microgobius meeki, Evermann & Marsh (D. VII+11-12; A. 9-10; P. 17-21; Birdsong, 1981), and Gobiosoma hemygymnum ( Eigenmann & Eigenmann, 1888) (D. VII+16-18; A. 16-18; P. 19-23; Van Tassell et al., 2015).

Other gobiid species assigned to southern Brazilian coast are: Awaous tajasica (Lichtenstein, 1822) ; Bathygobius soporator , Ctenogobius boleosoma ( Jordan & Gilbert, 1882); C. shufeldti ( Jordan & Eigenmann, 1887); Evorthodus lyricus (Girard, 1858) ; Gobioides broussonnetii (Lacépède, 1800) ; Gobionellus oceanicus (Pallas, 1770) ; and G. stomatus (Starks, 1913) (see also Fischer et al., 2011; Malabarba et al., 2013). Gobius silveiraemartinsi differs from Awaous tajasica by having larger eye (25% of HL vs. less than 20% of HL), more than 11 anal fin rays, and pigmentation without black oblique lines behind the pectoral fin base (present in Awaous ; Watson, 1996); from Evorthodus lyricus by the absence of two round black blotches on the caudal fin base (present in E. lyricus ; Murdy & Hoese, 2003); from Gobioides broussonnetii by having large eye (about 25% HL vs. 5% or less; Murdy, 1998); from Gobionellus oceanicus by possessing about 15 pectoral rays (vs. 16-20) and presumably less than 14 dorsal fin rays and 15 anal fin rays (vs., respectively, 14 and 15 rays); from G. stomatus by the absence of vertical dark markings on flanks ( Pezold, 2004), and from Ctenogobius boleosoma by not presenting humeral black blotch ( Ginsburg, 1932; Gilbert & Randall, 1979).

Gobius silveiraemartinsi is mostly similar to Ctenogobius shufeldti in pigmentation, particularly in the presence of “Von Augen zu Munde laufen zwei kurze braunen Streifen, über den Backen ein dritter längerer (p. 34)”; the presence of two dark brown stripes from eye to upper jaw, the largest one on cheek, is typical of C. shufeldti ( Fig. 2 ) and it is shared only with C. sagitulla from eastern Pacific ( Ginsburg, 1932). Regardless of the disagreement on counts of first dorsal fin spines between these taxa, G. silveiraemartinsi is herein regarded as junior synonym of Ctenogobius shufeldti .

Figures

Figure 2. Ctenogobius shufeldti, MZUSP 14346, Rio Grande do Sul, Lagoa de Tramandaí,female,55.3 mm SL,in lateral view.White arrows indicate brown oblique stripes on head beloweye that are diagnostic for this species.