An enigmatic new tapeworm is described from pelagic thresher sharks in México and Taiwan. While lsrRNA (D1-D3) data robustly place it in the Litobothriidea, it bears essentially no morphological resemblance to other members of the order. Instead it superficially resembles the freshwater fish-inhabiting Caryophyllidea. Its scolex consists of a simple dome-shaped scolex proper and an extensive cephalic peduncle housing four distinct tissue types. It is hyperapolytic, thus reproductive anatomy is unknown. Developmental data show typical litobothriideans bear basic elements of their adult scolex upon entering the definitive host, undermining the notion that the new cestode represents a distinct litobothriidean life cycle stage. Scanning electron microscopy revealed the new species shares bands of distinctive microtriches with its congeners. In combination these data justify establishment of Litobothrium aenigmaticum, sp. nov.; the generic, familial and ordinal diagnoses are emended accordingly. Unlike typical litobothriideans, each worm is associated with a mucosal expansion at its attachment site, like those seen in some caryophyllideans. This pathological change may represent a worm-induced host response serving to reinforce attachment of the simple scolex to the mucosa. If so, the convergence of this litobothriidean on a morphology like that seen in the distantly related Caryophyllidea is a result of similarity in mode of attachment.

Recent collecting in the remote Pilbara region of Western Australia has revealed substantial increases in the apparent distributions of species of the genus Quistrachia, and the discovery of new forms, raising questions about the morphological taxonomy. To resolve these questions, we examined mtDNA sequences in all known species of Quistrachia, the unidentified new forms and other members of the subfamily Sinumeloninae. Phylogenetic analysis confirmed the monophyly of Quistrachia, including one of the new forms. The two other new forms represent new genera within the Sinumeloninae. Monophyly of each species was confirmed, with the exception of Q. legendrei, in which populations from the Dampier Archipelago and those from the adjacent Burrup Peninsula are in separate clades. Based on phylogeny and levels of divergence within other species in the genus, the Burrup populations appear to be conspecific with Q. turneri. This is supported by anatomical comparisons, but not by shell morphology, which may well reflect the evolutionary plasticity of shell form. Given the patchiness of searches for land snails in the largely inaccessible Pilbara region, additional species almost certainly remain to be discovered. Our study shows the value of including molecular analyses in determining the taxonomic status of new forms.

Early reports on larval distributions are frustratingly obscure due to ambiguous identification of plankton samples. A particularly striking case is posed by the so-called ‘giant phyllosoma’ which attain 80 mm in total length and are among the largest larvae known in marine invertebrates. Based on the supposition that these giant larvae are produced by local species, Philip Robertson (1968) assigned them to Parribacus. In the present study, 12 phyllosoma larvae collected in the Coral Sea and corresponding to intermediate stages VI to IX are described in detail. The identity of these freshly caught specimens was confirmed as belonging to Parribacus antarcticus (Lund, 1793) by using DNA barcoding methods. This new collection further allowed us to complete the larval series for the genus. The intermediate stage VI, which was missing in previous accounts, is described here for the first time. Besides the Coral Sea larvae, another five phyllosoma specimens previously deposited in UK and German museum collections are also described. Given that no useful DNA could be obtained from the old collection specimens, these larvae were identified as Parribacus sp. based on morphology only. Furthermore, a complete morphometric analysis of Parribacus larvae was undertaken including information from literature dating back to 1830. The first detailed description of all dactyli from a complete phyllosoma of the genus Parribacus is presented, with further comparison with those from other genera of Scyllaridae.

Pontomyia (Diptera : Chironomidae) is an exclusively marine and flightless insect genus with four described species from the Indo-Pacific and one undescribed taxon known only by its larvae, pupal skins and females from the western Atlantic. A previous study of relationships among three of the Indo-Pacific species reported each of them to be monophyletic, with high genetic diversity within P. natans Edwards, 1926, the type species, and P. pacifica Tokunaga, 1932. The evolutionary affinities of the Australian endemic P. cottoni Womersley, 1937, which resembles P. natans, as well as the putative Atlantic species are hitherto undetermined. A complete molecular phylogeny of the genus based on two nuclear and two mitochondrial DNA markers indicates that P. cottoni and a Puerto Rican (Atlantic) larval population are nested within the P. natans clade. Furthermore, P. natans and P. cottoni are inseparable in all morphological characters used previously to distinguish them. Therefore, we synonymise P. cottoni with P. natans, syn. nov., whose known range now encompasses all three ocean basins after including the Puerto Rican population. This distribution warrants further investigation into the life history of Pontomyia, a midge with one of the shortest known adult lifespans among insects.

Although some clades of ribbon worms (phylum Nemertea) are consistently recovered with high support in molecular phylogenies, the placement and inter-relationships of some taxa have proven problematic. Herein, we performed molecular phylogenetic analyses aimed at resolving these recalcitrant splits, using six loci (nuclear 18S rRNA, 28S rRNA, histones H3 and H4, and mitochondrial 16S rRNA and COI) for 133 terminals, with particular emphasis on the problematic families Hubrechtidae and Plectonemertidae. Three different datasets were used for phylogenetic analyses and both maximum likelihood and maximum parsimony methodologies were applied. All but one of the resulting tree topologies agree on the paraphyly of the class Palaeonemertea, whereas Heteronemertea, Hoplonemertea, Polystilifera, Monostilifera and Hubrechtidae are always recovered as reciprocally monophyletic. Hubrechtidae is sister group to Heteronemertea (the Pilidiophora hypothesis) only when length variable regions of 18S rRNA and 28S rRNA are excluded. Moreover, the terrestrial and freshwater family Plectonemertidae is recovered with high support and the implications of this finding are further discussed. Finally, we evaluate the utility of DNA barcoding for specimen identification within Nemertea using an extended dataset containing 394 COI sequences. Results suggest that DNA barcoding may work for Nemertea, insofar as a distinct barcoding gap (the gap between the maximum intraspecific variation and the minimum interspecific divergence) may exist, but its recognition is regularly hampered by low accuracy in species level identifications.

A new lithophoran proseriate flatworm, Prosogynopora riseri, gen. et sp. nov. (Platyhelminthes: Rhabditophora: Proseriata), is described from the New England coast (USA). The species shares characters with members of the families Calviriidae and Coelogynoporidae, e.g. the presence of paracnida, the short common female duct, a septum and diaphragm at the base of the pharynx. However, the inverted topology of the genital system, presenting an anterior female pore shortly behind the mouth and a male pore opening nearly on the caudal terminus, is unique within the Proseriata, and permits inclusion into neither family on morphological grounds. We investigated the phylogenetic position of the new species within the available diversity of proseriate 18S and 28S rRNA sequences. However, an exploration of diverse homology schemes, alignment conditions and optimality criteria proved the position of P. riseri, gen. et sp. nov. to be remarkably unstable, particularly with respect to the method of alignment, variously suggesting sister-group relationships with (or within) Coelogynoporidae, with Calviriidae, or with a clade composed of all other Lithophora. Despite its unique morphology and the absence of molecular phylogenetic evidence for its inclusion within any family as currently defined, we refrain from assigning a higher taxonomic rank to the new lineage, pending critical re-assessment of homology in several character systems and the availability of further taxon- and gene-rich enquiries into the phylogeny of Proseriata. Apingospermata, new taxon and Dolichogynoducta, new taxon are proposed as two rankless taxonomic names of Lithophora, corresponding to well-supported clades in our molecular phylogenetic hypothesis.

The flightless Cape High-mountain stag beetle genus Colophon (Coleoptera: Lucanidae) is studied. All species are endemic to the Cape Floristic Region of the Western Cape, South Africa. The study aimed to determine the specific and phylogenetic status of the described species of Colophon and to determine the main factors driving their evolution by testing the hypothesis of a lowland origin. This was achieved by analysing the mitochondrial COI, 16S rRNA and nuclear CAD genes, using a maximum likelihood and Bayesian approach. Timing of key biogeographical events in the diversification of Colophon was estimated in BEAST. The combined molecular dataset supports the described species. High genetic divergence was found between the described taxa. The mean estimated divergence of the genus was mid-Cretaceous, with a split into two lineages during the early Paleocene to mid Eocene. Species divergence was shown to have occurred during mid to late Miocene. Most species of Colophon showed an allopatric distribution, although contact zones between geographically adjacent species are likely. Climate seems to be the main driving factor behind Colophon evolution and the hypothesis of a lowland origin appears to be supported.