Abstract
A single gobiid specimen identified with Oxyurichthys ophthalmonema (Bleeker) was obtained from the mouth of the River Shimoyama, Hayama, Kanagawa Prefecture, September 19, 1970.To my knowledge, this species has not yet been recorded from Japan.As this goby is found in southern waters, this individual probably strayed from the south.
Tomiyama (1936: 79) reported O.tentacularis (not of Cuvier and Valenciennes) based on two specimens from Taiwan and called them “matsugehaze” in Japanese. Besides the three specimens mentioned above, the syntypes of Gobius tentacularis Cuvier and Valenciennes, and the holotype of G.ophthalmonema Bleeker, were examined morpholog-ically together with many other specimens belonging to O.ophthalmonema or O.tentacularis listed on page 105.
Though Tomiyama (1936: 79) considered that G.ophthalmonema Bleeker is synonymous with his O.tentacularis (not of Cuvier and Valenciennes), the result of the present study revealed that O.ophthalmonema (Bleeker) and O.tentacularis (Cuvier and Valenciennes) are distinguished from each other significantly because of the following reasons. (1) In O.ophthalmonema the upper and lower rims of the upper lip are almost parallel with each other, but in 0.tentacularis the upper lip is constricted at the centre (Fig.2 and Table 2). (2) The spine of the first dorsal fin of 0.ophthalmonema is much longer than that of O.tentacularis in proportion to the standard length (Table 3). (3) The head of O.ophthalmonema is also somewhat longer than that of 0.tentacularis in proportion to the standard length (Table 4). (4) The length of the ascending process of the premaxillary of O.ophthalmonema is shorter, and its articular process is wider and clearly discernible from the ascending process, while the articular process of O.tentacularis has no apex and thus is not clearly distinguishable from the ascending process except for one among five specimens examined (Fig.4 and Table 5).
Reexamination ot two specimens reported by Tomiyama (1936) revealed that they belong to O.ophthalmonema.
