Narrow-clawed crayfish (Astacus leptodactylus Eschscholtz, 1823 species-complex) is one of five European freshwater crayfish species. Even though widely distributed, it hasn’t been frequently studied and its taxonomy and systematics are unresolved. The results of a recent comparative morphometric character study revealed that morphometry of Asian and European populations differ significantly. In this research, for the first time, mitochondrial molecular markers (16S rRNA and COI) were used with the aim of elucidating the phylogenetic relationship between European and Asian populations of the narrow-clawed crayfish. Analyses included crayfish from Croatia, Bulgaria, Armenia, Russia, Poland and Turkey, and three different optimality criteria were applied. Phylogenetic relationships were reconstructed using the COI dataset, as well as the concatenated one (COI   16S rRNA). For both datasets, congruent topologies were obtained and trees were characterised by the existence of two well supported phylogroups, one that included European populations, and the other Asian. Results indicate the presence of distinct evolutionary lineages within the A. leptodactylus species-complex, and corroborate previous results obtained using morphometric analyses.

Ameripassalus, gen. nov., is described as the first genus of Passalini with a distribution restricted to Mesoamerica. The species include A. guatemalensis (Kaup, 1869), comb. nov. from Passalus Fabricius, A. difficilis, sp. nov. and A. tamaulipensis, sp. nov. from Mexico, and A. jacki, sp. nov. and A. nigritus, sp. nov. from Guatemala. A matrix of 46 morphological characters, including the species from Ameripassalus, gen. nov. and 13 species of the genera Paxillus MacLeay, Ptichopus Kaup, Heliscus Zang, Veturius Kaup, Spasalus Kaup, Passipassalus Fonseca & Reyes-Castillo, Passalus Fabricius and Leptaulax Kaup were analysed. Only a single most parsimonious tree was found; in this Ameripassalus is retrieved as a monophyletic group. Ameripassalus difficilis, sp. nov. is shown as the sister group of the rest of the species in the genus. The species with the southernmost distribution (A. guatemalensis (A. nigritus, sp. nov.   A. jacki, sp. nov.)) form a nested clade within the species with the northernmost distribution. Keys to identify adults of the genera of Passalini and to the species of Ameripassalus are provided.

Mithracid crabs comprise a primarily subtidal reef- and rubble-dwelling group inhabiting both tropical and subtropical seas. Despite their relative ubiquity in many hard-substrate environments, there has been little consensus about their phylogenetic relationships or whether their group rank should be that of subfamily or family. We have used a combined molecular dataset of two nuclear (18S, H3) and three mitochondrial (12S, 16S, COI) genes to build a preliminary molecular phylogeny of Majoidea in order to examine the membership of Mithracidae. We then built a second molecular phylogeny based on three mitochondrial genes to assess the internal composition of the family, and conducted comparative morphological examinations of genera and species that resolved in unexpected positions on the phylogram. Four genera are designated under new or resurrected names on the basis of molecular and morphological characters, while memberships of several other existing genera are modified. Following review of molecular and morphological characters, the genera Coelocerus, Cyclocoeloma, Cyphocarcinus, Leptopisa, Micippa, Picrocerodes, Stenocionops and Tiarinia are provisionally excluded from Mithracidae s.s., while Hemus and Pitho are included in it. A key to genera of Mithracidae is provided.

A recent molecular phylogenetic study on Glaucus, a genus of neustonic aeolid nudibranchs, revealed undescribed cryptic diversity. Glaucus atlanticus is sister to the traditional species Glaucus marginatus, which is a complex of four genetically distinct cryptic species (Informal clade ‘Marginatus’). The present paper revises the systematics of Glaucus and provides formal descriptions for three new species in the informal clade ‘Marginatus’ substantiated by species delimitation analyses. Molecular and morphological evidence confirms that the type species of Glaucus, Glaucus atlanticus, has a cosmopolitan subtropical distribution and is characterised by having a uniseriate ceratal arrangement, a penial spine and a longitudinal, medial silver stripe on the sole of the foot. Examination of type material indicates that the name G. marginatus should be retained for the most widespread of these species, found in the Indian and Pacific Oceans. This species is characterised by molecular diagnostic characters as well as the presence of a bursa copulatrix. Glaucus marginatus is sister to the undescribed species Glaucus bennettae, sp. nov., which is found in the South Pacific Ocean and lacks a bursa copulatrix. The other two undescribed species, Glaucus thompsoni, sp. nov. and Glaucus mcfarlanei, sp. nov. are only known from the North Pacific Ocean, and are characterised by molecular diagnostic characters as well as possessing and lacking a bursa copulatrix, respectively. Because sister species of Glaucus differ in their reproductive anatomy, we hypothesise that mating behaviour has played a role in cladogenesis in this group.

ZooBank Publication code:  http://zoobank.org/References/E352E264-A440-4AF1-8565-B57B7EEE25BC

Cyliosoma Pocock, 1895, the oldest available genus name for Australian giant pill-millipedes, is revised with a redescription of its type species, Sphaerotherium angulatum Butler, 1878. All 16 species of Epicyliosoma Silvestri, 1917 are transferred to Cyliosoma, together with two species, Sphaerotherium fraternum Butler, 1872 and S. marginepunctatum Karsch, 1881, which are redescribed here. A new phylogenetic analysis of the Sphaerotheriida was conducted using 100 morphological characters and including two Cyliosoma species and four recently described or redescribed species of the family Zephroniidae. Most character states are illustrated for Cyliosoma, including the first SEM images of a member of the genus. Cyliosoma is neither closely related to the South African Sphaerotherium, nor to the other Australian genus, Procyliosoma, and is here placed in a new family, Cyliosomatidae. The monotypic Australian genus Cynotelopus Jeekel, 1986 is also referred to the Cyliosomatidae. The current position of the Cyliosomatidae is in a trichotomy including the South African Sphaerotheriidae and the Malagasy–Indian Arthrosphaeridae.

Scleractinian corals are widely distributed in all oceans and at all bathymetric levels. Corals are among the most important bio-building organisms in marine ecosystems. The systematics of this hexacoral group is currently undergoing much change owing to studies that combine molecular analyses with morphological research on the calcareous skeletons. However, information from polyp anatomy has been widely ignored, and some aspects, such as the diversity and distribution of the cnidocysts, might help to obtain a better understanding of the relationships at different taxonomic levels. In this study, the cnidocysts of four species of the family Dendrophylliidae (Dendrophyllia ramea, D. cornigera, D. laboreli and Astroides calycularis) are analysed to evaluate the application of cnidae in phylogenetic analyses, and to complete our knowledge of cnidae composition (types, distribution and sizes) for these species. A discriminant analysis based on the cnidae of these species supports the usefulness of these structures. The obtained results indicate that additional morphological characters in scleractinian corals that may help to clarify their phylogenetic relationships can still be found.