Systematics and biology of the Leopard-spotted Goby, Gobius ephippiatus [Teleostei: Gobiidae], with description of a new genus and notes on the identity of G. macrolepis Kolombatovic

Abstract

The leopard-spotted goby, Gobius forsteri Corbin 1958, described from the western English Channel, is identified with the Madeiran Gobius ephippiatus Lowe 1839, the latter name becoming a senior subjective synonym for this species. From study of variation, with size of fish, in number of lateral-line sensory papillae in preopercular-mandibular row i, it is concluded that the Aegean Gobius thori De Buen 1928 may also be referred to G. ephippiatus. Examination of the syntypes of G. macrolepis Kolombatovic 1891, from the Adriatic, has shown that this name belongs to a close relative of G. ephippiatus and not to Mediterranean populations of the Atlantic Lesueurigobius friesii (Malm), as recent authors have supposed. A new genus, Thorogobius, is proposed for G. ephippiatus, the type species, and G. macrolepis, and a key provided to these two species, which differ in meristic features, development of pelvic anterior membrane and disc, head coloration, and relative number of sensory papillae. Further systematic data on material studied, synonymies, body proportions, papillae and meristic counts are also given.As the complete list of known occurrences indicates, T. ephippiatus appears to be a warm temperate Mediterranean-Atlantic form which penetrates the eastern Atlantic boreal region around the British Isles at least as far north as the North Channel and eastwards to Lulworth Cove (western English Channel). As an inshore shelf species, T. ephippiatus occurs in or near crevices associated with vertical rock faces, from LWST to 30–40 m. Diet probably consists chiefly of crustaceans and polychaetes. Maximum total length recorded is 129 mm, and greatest age 9 years (determined from otoliths), with sexual maturity by the fifth year of life (age 4 +).