Distribution pattern of taste buds along hyoidal barbels of Mullus barbatus and M. surmuletus

The external taste buds of bony fishes are differentiated and grouped throughout the body epithelium, concentrating in the buccopharyngeal cavity or in certain external organs such as the lips, barbels or fins. The family Mullidae (goatfishes) is characterized by having barbels covered with taste buds (TBs). However, It is not known how the TBs are distributed and how their characteristics vary along the barbels. To obtain answers to these questions, the morphological variability in taste bud density (deltaTB), pore area (A(P)) and taste bud area (A(TB)) was studied in Mullus barbatus (L., 1758) (red mullet) and M. surmuletus (L., 1758) (striped red mullet), for fish ranging in size from 58 to 227 and from 56 to 287 mm in total length (L(T)), respectively. Assuming that larger fish are older, in both species the pore area (A(P)) and taste bud area (A(TB)) increased with ontogenic development. Also, in both species clear differences were observed along the barbel. The delta(TB) increased from the basal area to the apical area, whereas both the A(P) and A(TB) had an inverse pattern.