Larvae of the Ophichthid Eel Genus Neenchelys in the Indo-Pacific

Larvae of Neenchelys Bamber are rather short and deep bodied, reaching about 75 mm before metamorphosis. They have a relatively short gut which is pigmented and slightly swollen at intervals along its length, as in larvae of other myrophine ophichthids. Neenchelys leptocephali also have a conspicuous midlateral patch of pigment about midway between the anus and caudal tip, and develop ova before metamorphosis. THE DANISH "Dana" Oceanographical Expedition Round the World (1928-30) collected huge numbers and many different species of eel larvae (leptocephali) in the Indo-Pacific. Included among these was one larval type of quite distinctive pigmentation, consisting principally of an obvious patch of deep and surface melanophores on the lateral musculature about halfway along the body (Figure lA, lD). This pigment patch is so conspicuous and so specific in shape and position that these leptocephali cannot be confused with any other eel larvae. There were some 150 specimens of this larval type in the "Dana" collection, mainly from the central West Pacific, but also from as far west as the southern tip of Africa. Other collections yielded further specimens. The size range was 26-85 mm with most about 50 mm total length (TL). Some were metamorphic, but as the distinctive pigment patch disappears before metamorphosis is complete, an immediate identification was not possible without reference to other characters.