This study provides new and additional data on morphology and a phylogenetic analysis of the recently described species Pelagia benovici Piraino, Aglieri, Scorrano & Boero, 2014 from the Northern Adriatic (Mediterranean Sea). Comprehensive morphological analyses of diagnostic characters, of which the most significant are marginal tentacles anatomy, basal pillars, gonad pattern, subgenital ostia and exumbrellar sensory pits, revealed significant differences from the currently known genera Sanderia, Chrysaora and Pelagia in the family Pelagiidae. A phylogenetic analysis of mitochondrial genes (COI, 16S rRNA, 12S rRNA) and nuclear ribosomal genes (28S rRNA, ITS1/ITS2 regions), together with cladistic analysis of morphological characters, positioned Pelagia benovici as a sister taxon with Sanderia malayensis, and both share a common ancestor with Chrysaora hysoscella. Pelagia benovici does not share a direct common ancestor with the genus Pelagia, and thus we propose it should not belong to this genus. Therefore, a new genus Mawia, gen. nov. (Semaeostomeae : Pelagiidae) is described, and Pelagia benovici is renamed as Mawia benovici, comb, nov.

The genus Xiphinema constitutes a large group of ∼275 species of polyphagous, plant-ectoparasitic nematodes that are distributed almost worldwide. Some species affect agricultural crops by feeding directly on root cells as well as by transmitting nepoviruses. Despite their agricultural importance, species discrimination in Xiphinema is difficult, leading to potential misidentification. Integrative taxonomy, based on the combination of molecular analyses and morphology, constitutes a new insight into Xiphinema species identification. In this study we describe two new species of Xiphinema from the Iberian Peninsula (X. macrodora, sp. nov. and X. oleae, sp. nov.) associated with cultivated and wild olive trees. Both species have specific rRNA sequences. Morphologically, Xiphinema macrodora, sp. nov. is characterised by a very long body (7.2–8.7 mm), a very long odontostyle and odontophore (190–206 and 105–120 µm, respectively), and a well developed pseudo-Z-organ, comprising 8 to 12 sclerotised bodies. Xiphinema oleae, sp. nov. is characterised by an odontostyle and an odontophore 136–149 and 65–80 µm long, respectively, and a well developed Z-organ with refractive inclusions (3–5), variable in shape. Additionally, X. macrodora, sp. nov. has the longest body size, and the longest odontostyle and odontophore of any Xiphinema, whereas X. oleae, sp. nov. is the first species with a well developed Z-organ from the Iberian Peninsula.

Pimoidae is a small family of araneoid spiders, hitherto represented in Europe by two species with disjunct distribution in the Alps and in the Cantabrian Mountains of northern Spain. Here we report the description of two additional European species of Pimoa, discovered within the range of the only former alpine species, P. rupicola: P. graphitica sp. nov. and P. delphinica sp. nov. The new species are distinguished from the latter by genitalic characters as well as by molecular characters. On the basis of the re-examination of old and recent abundant material collected in caves and other subterranean habitats, we revise the distribution patterns of the genus Pimoa in the Alps and outline the species distribution ranges. Molecular data suggest the existence of gene flow between populations of the two new species when in sympatry. The different species probably originated in the alpine region as a result of range contractions following dramatic climatic changes in the Alps since the mid Miocene. We interpreted the present-day overlapping distribution in light of a possible postglacial expansion. Finally, we provide insights on the natural history and life cycles of the new species and discuss their phylogenetic relationships within Pimoidae.

High-mountain regions are known to harbour considerable biodiversity, although it is not all well known. The terrestrial fauna of the world’s largest mountain range, the Himalayas, has been moderately well studied, but this is not the case with the limnic fauna, and especially molluscs. During intensive malacozoological field surveys conducted over the past 20 years, the bivalve family Sphaeriidae has been studied in Nepal along an elevational gradient from 100 to 4010 m above sea level (a.s.l.). Here we describe a new species of Sphaeriidae, Pisidium alexeii, sp. nov., based on comprehensive molecular phylogenetics, anatomy and shell morphology. The species can be clearly distinguished from all other sphaeriid species occurring in Nepal. A molecular phylogeny based on mitochondrial and nuclear data inferred the oriental biogeographical affinity of the new species. The species is ecologically restricted and only occurs at a few sites between 1010 and 1700 m a.s.l. A review and updated checklist of the sphaeriid fauna of Nepal is provided and biodiversity and biogeographical patterns are discussed.

Body scales are fundamental in the classification of Entomobryidae at all taxonomical levels. Traditionally, scales on dens were considered to be absent in Entomobryinae, but present in other scaled subfamilies; however, this opinion was strongly challenged by recent morphological advances in tergal specialised chaetae (S-chaetae). A new genus, Lepidodens, is strikingly similar to the scaled Entomobryinae genus Willowsia in having pointed scales with relatively long ribs and 2, 2|1, 2, 2, 8, 3 tergal S-chaetae, but differs from it in having dental scales and a unique position of S-microchaetae on the first abdominal segment. Multilocus phylogeny and topology tests also support this view, the new genus clustering with Entomobryinae rather than Seirinae. Three new species, L. nigrofasciatus, L. similis and L. hainanicus, are described from South China. This study clearly undermines the traditional separation of Entomobryinae and Seirinae/Lepidocyrtinae, and demonstrates that dental scales could occur in all entomobryid subfamilies containing scaled taxa. In this new phylogenetic hypothesis, Entomobryinae has the greatest diversity in scale morphology and distribution among scaled collembolan groups, indicating multiple independent origins of scales.

The laciniate, relatively large-bodied tetraphyllidean tapeworm genus Calliobothrium van Beneden, 1850 parasitises triakid sharks with all but one species found parasitising sharks of the genus Mustelus Linck, 1790. Historically, species of this genus were thought to exhibit a relaxed degree of host specificity relative to species of their sister genus Symcallio Bernot, Caira, & Pickering, 2015. However, several more recent studies have begun to question this difference and, in particular, the conspecificity of specimens identified as the types species, C. verticillatum (Rudolphi, 1819) van Beneden, 1850, from multiple host species. Our results suggest that diversity in the genus Calliobothrium has been under-reported. To explore this situation, specimens previously identified as C. verticillatum were collected from Mustelus asterias Cloquet, 1819 off the United Kingdom and Mustelus canis (Mitchell, 1815) off Connecticut, USA; these sharks each were found to host distinct species both of which are described here. Mustelus asterias was also confirmed to host Symcallio leuckarti (van Beneden, 1850) Bernot, Caira & Pickering, 2015, which is redescribed. In combination with newly collected material from Mustelus palumbes Smith, 1957 off South Africa and data available from GenBank, molecular phylogenetic analyses based on 28S rDNA data for four of the seven known species of Calliobothrium, including both new species and five of the 11 known species of Symcallio, were conducted. The resulting phylogeny supports the mutual monophyly of the two genera, which are readily distinguished based on whether they exhibit proglottid laciniations, and supports subclades of Symcallio with and without hook accessory pieces. These subclades of Symcallio appear to exhibit an intriguing congruence with two known subclades of their host genus, Mustelus.

Antarctica is an ice-dominated continent and all its terrestrial and freshwater habitats are fragmented, which leads to genetic divergence and, eventually, speciation. Acutuncus antarcticus is the most common Antarctic tardigrade and its cryptobiotic capabilities, small size and parthenogenetic reproduction present a high potential for dispersal and colonisation. Morphological (light and electron microscopy, karyology) and molecular (18S rRNA and cytochrome c oxidase subunit I (COI) genes) analyses on seven populations of A. antarcticus elucidated the genetic diversity and distribution of this species. All analysed populations were morphologically indistinguishable and made up of diploid females. All specimens presented the same 18S rRNA sequence. In contrast, COI analysis showed higher variability, with most Victoria Land populations presenting up to five different haplotypes. Genetic distances between Victoria Land specimens and those found elsewhere in Antarctica were low, while distances between Dronning Maud Land and specimens from elsewhere were high. Our analyses show that A. antarcticus can still be considered a pan-Antarctic species, although the moderately high genetic diversity within Victoria Land indicates the potential for speciation events. Regions of Victoria Land are considered to have been possible refugia during the last glacial maximum and a current biodiversity hotspot, which the populations of A. antarcticus mirror with a higher diversity than in other regions of Antarctica.

(Vol. 30, Issue 5, pp. 479–490)

The author wishes to add the following paragraph at the end of the Acknowledgements (p. 489), identifying some important funding sources for some of the material used in the study.

‘The molecular material in this paper originates from various shore-based expeditions and deep sea cruises, conducted respectively by MNHN and Pro-Natura International (PNI) as part of the Our Planet Reviewed programme, and by MNHN and Institut de Recherche pour le Développement (IRD) as part of the Tropical Deep-Sea Benthos programme. Funders and sponsors include the French Ministry of Foreign Affairs, the Philippines Bureau of Fisheries and Aquatic Research (BFAR), the Total Foundation, Prince Albert II of Monaco Foundation, Stavros Niarchos Foundation, and Richard Lounsbery Foundation.’

In addition, in Table 1 (p. 483, column 2, rows 2, 3 and 19 of table), ‘French Guinea’ should read ‘French Guyana’.