Gobius boekeri Ahl, 1931

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 : 3

Gobius boekeri Ahl, 1931 syn. nov.

( Fig. 3 ; Table 1)

Material examined: not available.

Description: SL 141 mm; HL 12.9% SL; D. VI.15; A. 15; P. ???; ll 82; GR ???.

Holotype of this species was taken in Soure, Marajó, in the state of Pará, Brazil, but this type specimen, which would have been sent to Zoologisches Museum, Berlin (ZMB), is presumably lost. On the other hand, the description Ahl provided for this species is very straightforward and included a decent illustration of the type specimen. The author considered his new species quite similar to Gobionellus oceanicus , but argued his taxa differ from that species by having a more elongated body and body depth larger on dorsal fin origin. However, further examination of the original description and image compared with the material of Gobionellus oceanicus (see also Pezold, 2004) revealed that body depth and other morphometric values fall into the range, which is observed for G. oceanicus ( Table 1). Apparent differences between these taxa may be attributable to individual variation. Another possibility is that the original image, although already stated herein as of reasonable quality, might be somewhat distorted and it is not so detailed, thus making measurements difficult and rendering differences in some body proportions such as caudal peduncle length.

Gobius boekeri is remarkably similar to Gobionellus oceanicus in all meristic characters (e.g. dorsal and anal fin counts, scales counts), and also in many features as presence of ctenoid scales on trunk, black round umeral blotch below first dorsal fin ray, and dark vertical stripe below eye, thus G. boekeri is herein regarded as a junior synonym of Gobionellus oceanicus .

Comparative material examined: Ctenogobius shufeldti . MZUSP 14346 , 1 (55.3 mm), Brazil, Rio Grande do Sul, Lagoa de Tramandaí, Dec. 1973. Gobionellus oceanicus . MZUSP 10327 , 2 (100.1; 150.0 mm), Brazil, Rio de Janeiro, Atafona, Dec. 1963. MZUSP 12771 /12776, 3 (66.2-66.9mm), Brazil, Rio de Janeiro, Ilha da Convivência, Atafona, Dec. 1963. MZUSP 46762 , 2 (115.3; 135.7 mm), Brazil, Rio de Janeiro, Cabo Frio, lagoa de Araruama, em frente à Refinaria Nacional de Sal , Feb. 1983. MZUSP 65978 , 1 (98 mm), Brazil, Bahia, Maragogipe, Barra do Paraguaçu 12°45’S 38°56’W, 10 Dec. 1974. MZUSP 66060 , 5 (109.1-138.2 mm), Brazil, Bahia, Mercado de Santo Amaro , 14 Oct. 1971. MZUSP 66070 , 1 (115.7 mm), Brazil, Rio de Janeiro, Atafona, Jul. 1963. MZUSP 12810 /69666, 2 (122.3; 173.1 mm), Brazil, Rio de Janeiro, Atafona, Aug. 1963. MZUSP 79715 , 1 (131.4 mm), United States, Florida, Suwanee River , Dec. 1963. MZUSP 82225 , 2 (111.6; 112.0 mm), Brazil, Bahia, between Valença and Itacaré, 02-12 Sep. 2002 .

Figures

Figure 3. Gobius boekeri Ahl,image taken from the original description.