DNA barcoding and morphological taxonomy: identification of lanternfish (Myctophidae) larvae in the Gulf of Mexico

Abstract

Accurate identification of fish larval stages is complicated and time-consuming due to the lack of diagnostic morphological characters, especially during early developmental stages. The distribution of lanternfish (Myctophidae) has been described based on the morphological identification of adult stages. Larvae of only a few species of Myctophidae have been described, and the description is not always precise. In this study, larvae were collected and morphologically identified as Diaphus mollis, Hygophum hygomii, H. reinhardtii, H. taaningi, Myctophum obtusirostre and M. selenops. The DNA barcode region of the mitochondrial cytochrome oxidase I gene (COI) was determined for all larvae. The COI sequences matched reference barcodes available in GenBank for 14 of the identified larvae. The remaining COI sequences matched reference barcodes for different species of Myctophidae including Centrobranchus nigroocellatus, Diogenichthys atlanticus and Lepidophanes guentheri. This effort demonstrated the importance of integrated morphological and molecular analysis of species diversity and distribution of the Myctophidae in the Gulf of México.

Keywords:

• Cytochrome oxidase I
• larval fishes
• Gulf of Mexico
• DNA barcoding
• Myctophidae

Acknowledgements

We thank the captain and crew members of the R/V Justo Sierra; and Dr Sharon Z. Herzka for facilitating our participation during the research cruise XIXIMI-4. We also thank the Centre for Scientific Research and Higher Education at Ensenada (CICESE) for all the logistical support during the collection and transportation of samples. We are also grateful to F. E. Ordonez Guillen for her contribution to the morphological identification of larvae and to Dr Ann Bucklin for her valuable suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by National Council for Science and Technology (CONACyT) of Mexico, under the SENER-CONACYT Hydrocarbons fund, project number 201441. This work is a contribution to the Gulf of Mexico research consortium (CIGOM).