THE INNERVATION OF HEAD NEUROMAST ROWS IN ELEOTRIDINE-GOBIES (TELEOSTEI, GOBIOIDEI)

The innervation of free neuromast (sensory papillae) rows is described from Sihler wholemount preparations of four species of eleotridine gobies, one (Perccottus glenii) representing the 'longitudinal' type of neuromast arrangement, the others (Butis butis, Bostrychus urophthalmus, B. marmoratus) the 'transverse' arrangement. In the latter, the characteristic transverse cheek rows (1-7) are innervated from the infraorbital trunk of the anterior lateral-line nerve. Longitudinal cheek rows b and d, and the three opercular rows, ot, os and oi, common to all species, are innervated by rami of the hyomandibular trunk of the same nerve. Two neuromast groupings are shown to have a mixed nerve supply. For the median preorbital snout rows, there is innervation from the infraorbital (s3 and r) as well as the supraorbital (s1 and s2) trunks of the anterior lateral line nerve. The anterior dorsal rows are supplied both by the posterior lateral-line supratemporal ramus (rows g and m) and the anterior lateral-line supraorbital trunk (rows o and n). The neuromast rows, under the designations of Sanzo, are tabulated according to innervation and their putative origin in the phyletic replacement of a complete head canal system seen in more generalized percomorph fishes.