Inferring ecological strategies of Psenopsis spp. (Teleostei: Centrolophidae) inhabiting Indian waters from morphological features

ABSTRACT

Morphology of the fish and otoliths are popularly used in the discrimination of species/stocks/populations and also to gather meaningful conclusions about their ecology. This approach is useful to enhance our understanding of the relationship between form and function in fishes when a direct assessment is impossible. Inter-species variation was analysed using geometric morphometric analysis for fish body shape, while morphometry and wavelet functions for sagittae morphology. A clear ecomorphological pattern in the body, as well as otolith shape, is evident among species as deeper inhabiting species possess a deeper body with oblong otoliths compared with shallower species that possess a more streamlined body with fusiform otoliths. We also observed that deeper species (P. obscura) possess bigger eyes for the optimum use of available light and bigger otoliths with higher otolith sensory area and otolith area ratio (S:O) for better sound reception capacities. Our hypothesis supports that the differences in fish morphological as well as sensorial traits (otoliths), which are closely related to their locomotion, foraging pattern and depth of habitation, lead to trophic segregation which in turn encourages their coexistence. This is the first work that discusses the relationship between body shape, otolith morphometry and morphology in deep-sea fishes and their ecomorphological interpretations.

http://zoobank.org/lsid:zoobank.org:pub:663DD393-80B0-407D-907C-51E3F33ECCFB

KEYWORDS:

• Fish body
• otoliths
• ecomorphology
• Psenopsis
• Centrolophidae
• Indian waters

Acknowledgements

The authors express their sincere thanks to the Secretary of the Ministry of Earth Sciences (MoES), New Delhi and the Director of the Centre for Marine Living Resources and Ecology (MoES), Government of India, for supporting the work and providing the facilities onboard FORV ‘Sagar Sampada’ for the sample collection. We are very grateful to the chief scientists, fishing master, fishing hands and all participants of FORV ‘Sagar Sampada’ for their excellent cooperation during the cruises. The study was carried out as part of the in-house project ‘Deep-sea and Distant water Fishery (DSDWF)’ under the Marine Living Resource Programme of CMLRE, MoES. The financial, technical and logistical support from CMLRE is thankfully acknowledged. This is CMLRE contribution no. 158.

Data availability statement

Data will be available on personal request to the corresponding author.

Disclosure statement

No potential conflict of interest was reported by the author(s).