Juveniles of Amphelikturus dendriticus (Syngnathidae) and the Peculiarities of Ontogenetic Variability of the Species

Juveniles of Amphelikturus dendriticus SL 25 and 30 mm from the Caribbean Sea have been described. It was revealed that at the stage of “planktonic juvenile”, this species lacks the lamellar shelf of the ventral bony orbital margin, the medial snout ridge is less developed, the spinosity of the ends of the main ridges on the trunk rings is more pronounced, and melanophore pigmentation is present everywhere. The transition to the definitive structure occurs in this species upon reaching SL of about 30 mm, but some juvenile features (absence of lateral snout ridges, full opercular ridge) persist even with larger body sizes. The degree of development and branching of the dermal flaps is adaptive and does not always clearly correlate with growth.