First Record Of Leptocephali Of The False Moray, Chlopsis Bicolor Rafinesque 1810 Actinopterygii, Anguilliformes, Chlopsidae) From The Adriatic Sea: Morphological And Molecular Identification.

Leptocephali are the characteristic larval forms of the superorder Elopomorpha, very difficult to identify at the species level and sharing few or no characters with the respective adult forms. In this study we used DNA barcoding coupled to classical taxonomy for the species identification of Chlopsis bicolor (Rafinesque, 1810) leptocephali. In the Mediterranean some individuals of C. bicolor in developmental stage, collected along the Sicilian shore of the Messina Strait, were already identified and their detailed morphological descriptions were provided. However, very few specimens of C. bicolor from the Adriatic Sea have been reported and this work represents the first record of its larval form. Three leptocephali of the false moray C.bicolor were morphologically identified among other eel larvae collected during scientific cruises performed in South Adriatic between 2010 and 2012. Moreover we sequenced a 655bp region of COI (cytochrome c oxidase I) in addition to classical taxonomy to provide a larval barcode voucher for species identification. COI barcoding has proven to be successful in larval fish identification, revealing also a good performance as a diagnostic method for the identification of leptocephali. Anyway, the limited number of anguilliform species annotated in the reference databases (Barcode of Life Data Systems and GenBank) allowed us to validate our barcode only at the family level (Chlopsidae). Nevertheless, the morphological description provided in this work together with the barcode sequence published in the project ‘Barcoding of the Adriatic Leptocephali’ (BAL) on the Barcode of Life Data System (BOLD, http://www.barcodinglife.org), represent a useful contribution to the knowledge of this species.