4.1.2 Genus level
Environmental variables play a significant role in shaping the abundance and distribution of prey species, influencing the availability of suitable habitat for sea snakes. Studies on Aipysurus indicate that environmental factors play crucial roles in shaping their distribution and abundance. (Lynch et al. 2023) reported that environmental factors are important in shaping the behavior and distribution of A. laevis , while (Borczyk et al. 2021) found sexual dimorphism in skull size and shape for A. eydouxii , which may affect feeding and ecological niche differentiation between males and females.
Previous studies have also highlighted the importance of environmental variables in the distribution and population dynamics ofEmydocephalus . (Lukoschek et al. 2007) found that E. annulatus exhibited metapopulation dynamics influenced by prey abundance, habitat quality, and complex reef habitats, while (Goiran and Shine 2013) reported a decline in E. annulatus abundance on a protected coral reef system in the New Caledonian Lagoon, attributed to changes in the physical environment resulting from anthropogenic modification to the system. Our study found that Sal, Sil, and Tem are significant variables for both PC and PI at different resolutions, consistent with (Brischoux et al. 2012) finding that oceanic salinity influences body condition. However, we found a discrepancy in our results regarding the importance of Tem compared to a previous study onE. annulatus , which reported no significant effects of annual thermal variation on population densities. Further research is necessary to clarify these discrepancies and enhance our understanding of the importance of environmental variables, such as salinity and other nutrient variables, in the distribution and population dynamics ofEmydocephalus .
For Ephalophis , our findings align with the idea of a rapid radiation of sea snakes, driven by adaptations to environmental factors. The importance of adaptation to the marine environment is highlighted by the variable importance of environmental factors observed inEphalophis . This is supported by previous studies on sea snakes in Australian waters (Sanders et al. 2013), molecular phylogeny of sea snakes (Lukoschek and Keogh 2006), association between habitat type and skin thickness in snakes (Shine et al. 2019), presence of paddle-shaped tails in viviparous sea snakes (Sanders et al. 2012), and the feeding strategies and foraging ecology of the Hydrophiinae sea snakes, as analyzed in previous studies (Hampton 2019).
The Hydrophis genus is found to have almost identical results to the whole lineage analyzed, indicating a similar influence of environmental variables on their distribution and abundance. Meanwhile, discussing the Laticauda genus alone may be redundant as it represents the whole Laticaudinae subfamily. Further diverse ecological research is needed to support the findings and test the relative importance of variables for the Microcephalophis genus. Overall, the importance of environmental factors in shaping the ecology and evolution of sea snakes is reinforced by the results obtained from our analysis. We also emphasize the importance of further diverse ecological research to support the findings and test the relative importance of variables for this genus.