Deep sea swimming crabs of theCharybdis milesspecies group in the western Indian Ocean (Crustacea: Decapoda: Portunidae)

Abstract

The deep-sea species of the Charybdis miles group occurring in the western Indian Ocean are revised on the basis of recent collections obtained by German and Russian expeditions. Two new species are described, Charybdis meteor sp. n. from the Straits of Bab el Mandeb and Charybdis crosnieri sp. n. from the insular margins and seamounts of the western Indian Ocean, which has been previously identi® ed as Charybdis sagamiensis Parisi, 1916. The C. miles group represents a lineage with a probably relatively recent tendency for submergence which culminated in the formation of C. acutidens Tu È rkay, 1986, a characteristic species of the deep Red Sea water mass.

An update of phylogenetic reconstructions, classification and morphological characters of extant Portunoidea Rafinesque, 1815 (Decapoda, Brachyura, Heterotremata), with a discussion of their relevance to fossil material

“…Portunoid crabs have a worldwide distribution (with the exception of subarctic waters of the North Pacific, Arctic and Antarctic), live in a variety of biotopes, although predominately on soft bottoms, from the intertidal and upper subtidal ( Fig. 1) to deep waters of the continental slope and underwater rises (e.g., Geryonidae; see Manning & Holthuis, 1989; but also some representatives of generally shallow-water groups; see Spiridonov & Türkay, 2001). Particular groups have symbiotic relationships with a variety of animal and plant taxa (Evans, 2018).…”

Xiphonectes tuerkayi sp.n. from the Indian Ocean with notes on Xiphonectes longispinosus Dana, 1852 (Crustacea: Decapoda: Portunidae)

“…The Portunidae are one of the most diverse brachyuran crab families mostly occurring in the tropical waters [Ng et al, 2008;Spiridonov, 2013]. Portunid classification at the generic level has been relatively stable for long time since the studies of Stephenson [Stephenson, 1972 and references to earlier works of the 1950-60s herein] and Crosnier [1962] but recently it is in the process of revision [Ng et al, 2008;Schubart, Reuschel, 2009;Spiridonov, 2013;Spiridonov et al, 2014].…”

“…The Portunidae are one of the most diverse brachyuran crab families mostly occurring in the tropical waters [Ng et al, 2008;Spiridonov, 2013]. Portunid classification at the generic level has been relatively stable for long time since the studies of Stephenson [Stephenson, 1972 and references to earlier works of the 1950-60s herein] and Crosnier [1962] but recently it is in the process of revision [Ng et al, 2008;Schubart, Reuschel, 2009;Spiridonov, 2013;Spiridonov et al, 2014]. In particular, a large genus Portunus Weber, 1795 which previously encompassed portunids having nine anterolateral teeth with a broad carapace, and long and relatively narrow chelae [Stephenson, 1972;Ng et al, 2008] was proved to be heterogenous and polyphyletic [Schubart, Reuschel, 2009;Spiridonov et al, 2014;Koch et al, in prep.].…”

“…In particular, a large genus Portunus Weber, 1795 which previously encompassed portunids having nine anterolateral teeth with a broad carapace, and long and relatively narrow chelae [Stephenson, 1972;Ng et al, 2008] was proved to be heterogenous and polyphyletic [Schubart, Reuschel, 2009;Spiridonov et al, 2014;Koch et al, in prep.]. Small species with spiny posterolateral angles of the carapace formerly included in Portunus are currently assigned to the genus Xiphonectes A. Milne-Edwards, 1873 which appears to be heterogenous itself [Spiridonov, 2013;Spiridonov et al, 2014;Koch et al, in prep]. The status of several species of Xiphonectes remains unclear.…”

Histórico de introdução do siri invasor <i>Charybdis hellerii</i> (A. Milne-Edwards, 1867) (Decapoda, Portunidae) na costa americana: ferramentas moleculares e morfologia comparativa

“…A maioria das espécies com sequências de mais de um exemplar incluídas mostraram-se monofiléticas, subsidiando suas validades taxonômicas (Figura 6). A única e expressiva exceção foi observada para as espécies do complexo Charybdis miles, as quais são caracterizadas por extrema semelhança morfológica e habitam ambientes de grande profundidade (Spiridonov & Türkay, 2001). As diferenças genéticas entre suas espécies foram similares ao valores de variação intraespecífica calculados para C. hellerii e, justamente por representarem um complexo de espécies, foram desconsiderados para a detecção do gap entre as variações intraespecíficas de C. hellerii e interespecíficas esperadas para o gênero Charybdis.…”