Taxonomic and Biogeographical Status of Three Species of the Spider Crabs ofthe Genus Acanthonyx Latreille 1828 (Majoidea: Epialtidae) as Determinedby DNA Barcoding and Morphological Analyses Along the Western Atlantic

摘要

The genus Latreille, 1828 contains 17 valid species, including Coelho, 1993, H. MilneEdwards, 1834 and (Dana, 1851), which occur along theBrazilian coast. The high degree of intraspecific variation in the angle of hepaticregion, size of the tubercles of the carapace and length of setae on the carapace andpereopods has resulted in difficulties with the taxonomy of this genus. Analysis of moreconsistent morphological and molecular characters are required to clarify the status ofthe three species that occurs in Brazil. For the molecular data, we used the barcoderegion of the mitochondrial gene COI as a marker, and we correlated this withmorphological characters of adults and juveniles. The three species of were morphologically similar and the matrix of genetic distances and maximumlikelihood trees showed that and belonged to the same group with . They could not beseparated using the diagnosing characters proposed in the original description orgenetically (present study), thus indicating that the taxonomic status of the first twospecies is questionable. The division into two distinct groups corresponding to A(Caribbean, Brazil, Venezuela) and B (USA, Mexico) was well supported and indicated thatthere are genetic differences between these populations. Present study suggests theexistence of a single species in Brazil and Caribbean, assigned to (type locality in Antilles). The existence of a new species restricted to NorthAmerica confirms the cryptic diversity within .