Tripodfish (Aulopiformes: Bathypterois) locomotion and landing behaviour from video observation at bathypelagic depths in the Campos Basin of Brazil

Abstract

A video observation of a deep-sea tripodfish (Aulopiformes: Bathypterois) taken from a remotely-operated vehicle at a depth of 1443 m in the Campos Basin, Brazil is analysed for swimming and landing movements. The observed specimen is identified here as Bathypterois grallator, and this record is the first video observation of a tripodfish exhibiting periodic swimming followed by landing in a resting position on deep-sea substrate which we interpret as ‘bathypteroiform’ movement, a locomotive mode unique to taxa within Bathypterois. This observation describes the functional role of the fins associated with landing, including independent movements of the elongated fin ray elements. The specimen is observed to display subcarangiform body and/or caudal fin movement while swimming in a periodic state. Prior to landing, the specimen is observed to raise its elongated caudal fin element parallel to the body, a behaviour that has not been described previously. Following contact of the elongated pelvic fin elements with the deep-sea floor, the elongated caudal fin element is independently lowered, completing the tripod stance typically observed.

Keywords:

• Aulopiformes
• deep sea
• locomotion
• tripodfish

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

We would like to thank the NOAA-supported SERPENT Project for providing access to this video observation and A. Gates for supplying us with a high resolution version for analysis. Additionally we thank K.J. Sulak for his comments and suggestions regarding the manuscript. Support for this study was provided by the Chakrabarty lab at Louisiana State University, Museum of Natural Science, National Science Foundation Doctoral Dissertation Improvement Grant (DEB 0910081), NSF Euteleost Tree of Life (DEB 0732819) and NSF DEB 0916695.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark