Review of the shrimp-associated goby genus Lotilia (Actinopterygii: Perciformes: Gobiidae), with description of a new species from the West Pacific

The Indo-West Pacific gobiid fish genus Lotilia, symbiotically associated with alpheid shrimps, is reviewed. The genus comprises two species, viz. L. graciliosa Klausewitz, 1960 and L. klausewitzi sp. nov., the latter of which is described herein based on 11 specimens (including seven type specimens) from Japan, Australia and the Bismark Archipelago. Lotilia klausewitzi, previously misidentified as L. graciliosa in the West Pacific, is readily distinguished from L. graciliosa by having the following features, in addition to some minor differences in the sensory-papillae configuration on the cheek: cephalic sensory canals and associated pores present (vs. absent in L. graciliosa); 7+6=13 branched caudal-fin rays (vs. 7+7=14); pale area on dorsum from snout to dorsoanterior part of body relatively long, extending posteriorly to, or beyond, base of fifth spine of first dorsal fin (vs. extending posteriorly to around base of third or fourth spine); a faint, relatively small dark grayish brown spot at center of first dorsal fin behind third or fourth spine, and its paler margin usually absent or obscure (vs. conspicuous ocellated black spot with vivid pale margin at center of first dorsal fin, extending anteriorly beyond third spine); and a submarginal row of black spots on caudal fin (vs. absent). Geographic records based on the specimens examined and underwater photographs indicate that L. graciliosa appears to be restricted to the Red Sea and its adjacent areas, whereas L. klausewitzi is widely found in the West Pacific. Lotilia is re-diagnosed, and L. graciliosa is re-described based on five specimens including the holotype.