Published online by Cambridge University Press: 11 May 2009
The north-eastern Atlantic gobiid genus Lebetus Winther, 1877, was formerly believed to contain two species, Lebetus scorpioides (Collett, 1874) and L. orca (Collett, 1874). These have been subsequently shown to represent females (and immature fish) and males respectively of a single, sexually dimorphic species whose valid name is L. scorpioides. The discovery of two forms of Lebetus postlarvae, differing in meristic characters, fin growth, and pigmentation, is shown not to affect this conclusion but to suggest provisional recognition of another species, L. guilleti (Le Danois, 1913), with fewer anal fin-rays (A I/5–6) and vertebrae (25–26) than L. scorpioides (A I/7–8; vertebrae 27-29). A key and limited synonymy for the species is provided. As a possible alternative view it is suggested that relatively high summer sea-temperatures during early development of L. scorpioides in certain areas may produce the lower meristic features of L. guilleti.