The systematic position of Ergasticus (Decapoda, Brachyura) and allied genera, a molecular and morphological approach

Abstract

The complete larval series (zoea I, zoea II and megalopa) of the crab Ergasticus clouei is described and illustrated based on plankton samples from Mediterranean waters. The zoea II and megalopal stages, previously unknown, are described here for the first time. Nucleotide sequence analysis of two gene regions (16S rDNA and Cox1 genes) confirmed the assignment of these larvae to Ergasticus clouei. The molecular analyses and the morphology of the larval stages revealed large differences between Ergasticus and Inachus, the type genus of the family Inachidae. In fact, E. clouei larvae presented a series of morphological characters, such as antennal shape and mouthparts setation pattern that placed them closer to the family Oregoniidae. The phylogenetic analyses also showed significant support for the monophyly of the Oregoniidae + Ergasticus group. The data argue for removal of Ergasticus and the related genera (Bothromaia, Pleisticanthoides, Parapleisticantha and Pleistacantha) from the Inachidae and their placement within the Oregoniidae as a separate subfamily, Pleistacanthinae Števčić, 2005. Our results demonstrate that larval stages provide reliable morphological traits, independent from those of adults, to help resolving relationships among Majoidea genera.

Annotated checklist of brachyuran crabs (Crustacea: Decapoda) of the Iberian Peninsula (SW Europe)

“…A recent study based on larval morphology and DNA did not support a clear separation between epialtid and pisid crabs (Hultgren and Stachowitz 2008). Neverthe- (Marco-Herrero et al 2013a). Within the Grapsoidea superfamily, the former Grapsidae is now restricted to the previous subfamily Grapsinae, while other subfamilies that acquired familial level (e.g.…”

Brachyuran crabs (Crustacea: Decapoda) from the Canary Islands (eastern Atlantic): checklist, zoogeographic considerations and conservation

“…Marco-Herrero et al (2013) for Majoidea; Schubart and Reuschel (2009) and Spiridonov et al (2014) for Cancroidea and Portunoidea). Superfamilies are listed by systematic order following the Sections and Subsections as currently accepted, and by alphabetical order within them.…”

Larval stages of the deep-sea lobster Polycheles typhlops (Decapoda, Polychelida) identified by DNA analysis: morphology, systematic, distribution and ecology

“…Morphology of Polycheles typhlops larvae Accurate identification of marine larvae has traditionally required the rearing of larval stages in aquaria, but the development of species-specific markers (DNA barcoding) facilitates now the assignment of wild-caught planktonic larvae (Palero et al 2008;Marco-Herrero et al 2013). Matzen da Silva et al (2011) have recently shown that the standard DNA barcoding COI gene region resolves relationships among decapod crustaceans.…”