Molecular phylogeny of hinge-beak shrimps (Decapoda: Caridea:RhynchocinetesandCinetorhynchus) and allies: a formal test of familiar and generic monophyly using a multilocus phylogeny

Abstract

The Rhynchocinetidae (‘hinge‐beak’ shrimps) is a family of marine caridean decapods with considerable variation in sexual dimorphism, male weaponry, mating tactics, and sexual systems. Thus, this group is an excellent model with which to analyse the evolution of these important characteristics, which are of interest not only in shrimps specifically but also in animal taxa in general. Yet, there exists no phylogenetic hypothesis, either molecular or morphological, for this taxon against which to test either the evolution of behavioural traits within the Rhynchocinetidae or its genealogical relationships with other caridean taxa. In this study, we tested (1) hypotheses on the phylogenetic relationships of rhynchocinetid shrimps, and (2) the efficacy of different (one‐, two‐, and three‐phase) methods to generate a reliable phylogeny. Total genomic DNA was extracted from tissue samples taken from 17 species of Rhynchocinetidae and five other species currently or previously assigned to the same superfamily (Nematocarcinoidea); six species from other superfamilies were used as outgroups. Sequences from two nuclear genes (H3 and Enolase) and one mitochondrial gene (12S) were used to construct phylogenies. One‐phase phylogenetic analyses (SATé‐II) and classical two‐ and three‐phase phylogenetic analyses were employed, using both maximum likelihood and Bayesian inference methods. Both a two‐gene data set (H3 and Enolase) and a three‐gene data set (H3, Enolase, 12S) were utilized to explore the relationships amongst the targeted species. These analyses showed that the superfamily Nematocarcinoidea, as currently accepted, is polyphyletic. Furthermore, the two major clades recognized by the SATé‐II analysis are clearly concordant with the genera Rhynchocinetes and Cinetorhynchus, which are currently recognized in the morphological‐based classification (implicit phylogeny) as composing the family Rhynchocinetidae. The SATé‐II method is considered superior to the other phylogenetic analyses employed, which failed to recognize these two major clades. Studies using more genes and a more complete species data set are needed to test yet unresolved inter‐ and intrafamilial systematic and evolutionary questions about this remarkable clade of caridean shrimps. © 2014 The Linnean Society of London

Host-use pattern of the shrimp Periclimenes paivai on the scyphozoan jellyfish Lychnorhiza lucerna: probing for territoriality and inferring its mating system

“…This 'pure-search' behavior is expected to favor small body size and weapons (e.g., claws) in males because that leads to an increase in agility and encounter rates with receptive females [28,47,58]. Supporting the idea of a pure-search mating system in P. paivai, males were much smaller than females, and these males did not exhibit well developed claws used as weapons to fight for females [60]. Our results agree with the idea that P. paivai features a pure-search mating system.…”

Reproductive morphology and mating behaviour in the hingebeak shrimp Rhynchocinetes durbanensis Gordon, 1936 (Decapoda: Caridea: Rhynchocinetidae) in India

“…These variations in male morphology are associated with differences in mating behaviour (Correa et al , 2000; Thiel et al , 2010; Bauer & Thiel, 2011). Description and analysis of sexual morphology and mating systems of other species in the family are necessary to test hypotheses about ancestral states and evolution of these features (Baeza et al , 2014a).…”