Relative Influence of Environmental Factors on Biodiversity and Behavioural Traits of a Rare Mesopelagic Fish, Trachipterus trachypterus (Gmelin, 1789), in a Continental Shelf Front of the Mediterranean Sea

Armando Macali,Alexander Semenov,Alessia Dinoi,Elisa Bergami,Francesco Tiralongo,Francesco Paladini De Mendoza

doi:10.3390/jmse8080581

Abstract

Coastal environments can be influenced by water body masses with particular physical, chemical, and biological properties that create favourable conditions for the development of unique planktonic communities. In this study, we investigated a continental shelf front at Ponza Island (Tyrrhenian Sea) and discussed its diversity and complexity in relation to major environmental parameters. Moon phase and current direction were found to play a significant role in shaping species abundance and behaviour. During in situ observations, we also provided the first data on the behaviour of juveniles of a rare mesopelagic species, Trachipterus trachypterus, suggesting the occurrence of Batesian mimicry.

Highlights

Open water environments are highly dynamic ecosystems [1], with ecological processes spreading over a wide range of spatial and temporal scales [2]
We examined the extent to which key features of the hydrodynamic environment predict the presence of T. trachypterus in a Mediterranean continental shelf front over a 21-days timescale
Due to its bathymetric profile, the area is exposed to prominent surface and upwelling filaments, resulting in a complex hydrodynamism that favours the accumulation of planktonic species in patched areas, according to the prevalent weather forcing [29]

Summary

Introduction

Open water environments are highly dynamic ecosystems [1], with ecological processes spreading over a wide range of spatial and temporal scales [2]. At a meso- and sub-mesoscale (~1–100 km), these processes emerge as dominant structuring regimes for populations of marine organisms in the short time span (days to months) [3,4], encompassing key biological dynamics, such as bloom lifetime or behavioural switches of marine predators [5] These ecological processes are relevant for drifting organisms (plankton) that are advected and dispersed by the ocean currents [6]. Within this complex scenario, sampling probabilities for uncommon and little-known species can be higher than those reported in all other marine environments, in which these species are typically rare and occur at low abundances. Modern biodiversity surveillance programs often investigate the occurrence of species mostly present at moderate-to-high abundance level [7,8]

Methods

Results

Conclusion