Ecological and Geographic Influences on Cumacea Genetics in the Northern North Atlantic

Cumacea (crustaceans: Peracarida) are vital indicators of benthic health in marine ecosystems. This study investigated the influence of environmental (i.e., biological or ecosystemic), climatic (i.e., meteorological or atmospheric), and geographic (i.e., spatial or regional) attributes on their genetic variability in the Northern North Atlantic, focusing on Icelandic waters. We analyzed mitochondrial sequences of the 16S rRNA gene from 62 Cumacea specimens. Using the aPhyloGeo software, we compared these sequences with relevant parameters such as latitude (decimal degree) at the start of sampling, wind speed (m/s) at the start of sampling, O 2 concentration (mg/L), and depth (m) at the start of sampling. Our analyses revealed variability in most spatial and biological attributes, reflecting the diversity of ecological requirements and benthic habitats. The most common Cumacea families, Diastylidae and Leuconidae, suggest adaptations to various marine environments. Phylogeographic analysis showed a divergence between specific genetic sequences and two habitat attributes: wind speed (m/s) at the start of sampling and O2 concentration (mg/L). This indicates potential local adaptation to these fluctuating conditions. These results reinforce the importance of further research into the relationship between Cumacea genetics and global environmental factors. Understanding these relationships is essential for interpreting the evolutionary dynamics and adaptation of deep-sea Cumacea. This study sheds much-needed light on invertebrate acclimatization to climate change, anthropomorphic pressures, and deep-water habitat management. It can contribute to the evolution of more efficient conservation strategies and inform policies that protect vulnerable marine ecosystems. The aPhyloGeo Python package is freely and publicly available on GitHub and PyPi , providing an invaluable tool for future research.