16. Glossogobius tenuiformis Fowler, 1934, Native

Fig. 40

Etymology: Glossogobius: the Greek, glossa = tongue, gobius = gudgeon.

Common name: Oman Freshwater Goby.

Taxonomy: Glossogobius tenuiformis was described by Fowler [H. W.] 1934:496, fig. 49 [Proceedings of the Academy of Natural Sciences of Philadelphia v. 86] from the St. Lucia Lake, 20 miles up, northern Zululand, Kwa-Zulu-Natal, South Africa.

Holotype: ANSP 60250 . Paratypes: ANSP 60248-49 (1, 1).

Short description: Glossogobius tenuiformis belongs to the G. giuris complex and is distinguished from G. giuris sensu stricto by each of the sensory papilla lines being composed of single rows (vs. 2–3 rows or more in several lines), the absence or very short (and often only a few papillae long) sensory papilla line 6 (vs. row 6 always distinctly present and long); lower pre-dorsal scale counts (7–16 vs. 15–24) and gill rakers on outer face of first arch 1+1+9–11 usually 1+1+10 (vs. 1–2+1+6–9, usually 1–2+1+7–8). Dorsal-fin rays VI, second dorsal-fin rays I, 9, anal-fin rays I, 8–9, pectoral-fin rays 17–21, caudal-fin rays 17, with 12–14 branched rays, pelvic-fins rays I, 5, lateral scales 28–32, transverse backward scales 8.5–10.5, predorsal scales 7–16, vertebrae 10+17=27.

Distribution: Glossogobius tenuiformis is currently known from its type locality, St. Lucia Lake, KwaZulu-Natal, localities along the South African coast from Mgeni River, Eastern Cape to KwaZulu Natal, and from Wadi Hasik and Wadi Shab, Oman (Fig. 41).

Remarks: Glossogobius giuris (Hamilton, 1822) was described from the Ganges River, India and is distributed in southern Red Sea; Indo-West Pacific: East Africa, Socotra, Seychelles, Madagascar and western Mascarenes, east to Society Islands, north to Philippines, south to Pilbara (Western Australia), Queensland (Australia) and New Caledonia (Fricke et al. 2022). Based on uncertainty about the type locality of Glossogobius giuris and its widespread distribution, a comprehensive study has been suggested to define the taxonomical status of this taxon. Hammer et al. (2021) grouped the G. giuris complex in four lineages based on molecular studies: “ giuris A” from Vietnam, Bangladesh and China; “ giuris B” from South Africa and India; “ giuris C” from India, Myanmar, Nepal, Bangladesh and Vietnam and “ giuris D” from South Africa. The Oman populations of Glossogobius is placed in the “ giuris D” group and it is now considered as G. tenuiformis (Al Jufaili et al. 2022) .

Examined material: ZM-CBSU: O001. Gt 101, 21, Oman: Dhofar Governorate, Salalah, Wadi Hasik, at Hasik, 17°22’01.2”N, 55°16’58.8”E, H. R. Esmaeili, S.M. Al-Jufaili, A.H. Masoumi, 04 Jan. 2022 . ZM-CBSU: O002. Gt 126, 18, Oman: Sur in Al Sharqiyah South Governorate, Wadi Shab, 22°50’01”N, 59°14’20”E. H. R. Esmaeili, S.M. Al-Jufaili, A.H. Masoumi, 04 Jan. 2022 .

Remarks on Gobiiformes: Boleophthalmus dussumieri Valenciennes, 1837, Periopthalmus waltoni (Koaumans, 1941) and Scartelaos tenuis (Day, 1876) have also been reported from the mud flats of Oman (Randall 1995, Al Jufaili et al. 2010).