MORPHOLOGICAL COMPARISON OF THE FEEDING APPARATUS OF THREE CO-OCCURRING SPECIES OF PONYFISHES (LEIOGNATHIDAE)

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Morphological comparison of the feeding apparatus of three co-occurring species of ponyfishes (Leiognathidae)

Ponyfishes of the family Leiognathidae frequently show overlapping distribution pattems in the Indo-Pacific and South China Sea. The mouth morphology of three species of ponyfishes which feed at different lerels in the water column were compared. The species could be distinguished primarily by the mouth meropology. Gazza minuta (Bloch)feeds mainly on bethos, has the least protruding jaws; Secutor ruconius (Hamilton-Buchanan) feeds mainly on plankton, has the most protruding jaws, Leiognathus rivuatus (Temmink et Schlegel) has an intermediate deggree of jaw protrusion. This study showed that closely related species with overlapping distributions frequently exhibit morphologlcal, phpsiological or ecological differences related to the search for food, the intake of food or locomotion mode.