Disentangling the Taxonomic Status of Caprella penantis sensu stricto (Amphipoda: Caprellidae) Using an Integrative Approach.

M Pilar Cabezas,António M Santos,José M Guerra-García

doi:10.3390/life12020155

M Pilar Cabezas, António M Santos + Show 1 more

Open Access

https://doi.org/10.3390/life12020155

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Journal: Life	Publication Date: Jan 21, 2022
Citations: 1	License type: CC BY 4.0

Affiliation: University of Porto, Universidad de Sevilla

Abstract

Despite its importance in intertidal and shallow-water marine ecosystems, Caprella penantis continues to be one of the most taxonomically challenging amphipods in the world. A recent molecular study focusing on C. penantis sensu stricto pointed out the existence of three highly divergent lineages, indicating the possible existence of a process of ongoing speciation and, thus, casting doubt on the taxonomic status of this species. In the present study, we used an integrative approach to continue to shed light on the taxonomy and distribution of this caprellid. To this end, we combined morphological and genetic data (COI and 18S) and included, for the first time, populations from its type locality. Our analyses provide strong evidence of the existence of potentially three distinct species, genetically and geographically restricted, within C. penantis sensu stricto, with the distribution of the true C. penantis sensu stricto restricted to the UK (type locality), the northern coast of the Iberian Peninsula, and the Azores. Results show the co-occurrence of two of these species in a locality of northern Portugal and indicate the existence of distinct evolutionary and diversification patterns along the eastern Atlantic region. Overall, our study highlights the use of an integrative approach to properly assess species boundaries and unravel hidden biodiversity in amphipods.

Highlights

Amphipods constitute one of the dominant taxa in shallow-water marine ecosystems worldwide
Caprella Lamarck, 1801, is by far the most species-rich genus within the family Caprellidae, with nearly 200 species distributed throughout marine ecosystems around the world [78,79], its actual diversity remains underestimated [29,30,80,81]
Our phylogenetic analyses are in agreement with those of [29], recovering three well-differentiated and supported mitochondrial lineages within C. penantis s.s. (Clades VA, VB, and VC) (Figures 3 and 5), which were confirmed by three approaches of species delimitation methods (Figure 3)

Summary

Introduction

Amphipods constitute one of the dominant taxa in shallow-water marine ecosystems worldwide They can be found as epibionts of a wide variety of natural substrata, including macroalgae, hydrozoans, ascidians, sponges, corals, etc. [1,2,3,4,5], but they are very successful colonisers of artificial substrata such as buoys, ropes, boat hulls, or pontoons, where they can reach high densities under optimal environmental conditions [6,7,8,9] These small, benthic crustaceans form an important trophic link between primary producers and higher trophic levels [10,11,12], as they are important dietary components for many coastal marine fish species [10]. An accurate morphological identification frequently requires experienced taxonomists, most of whom are nearing retirement, and who are becoming increasingly rare due to inadequate funding and the subsequent low recruitment of young scientists into this discipline [26,33,35]

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Results

Conclusion