The world’s tiniest land snails from Laos and Vietnam (Gastropoda, Pulmonata, Hypselostomatidae)

Two new, extremely small land snail species, Angustopila coprologos Páll-Gergely, Jochum & Hunyadi n. sp. and Angustopila psammion Páll-Gergely, Vermeulen & Anker n. sp. are described from northern Vietnam and northern Laos, respectively. The former is characterized by a rough surface sculpture and bears tiny mud granules arranged in a pattern of radial lines on its shell surface. The latter species is the new global record-holder of the tiniest land snail title, with a shell width of 0.6–0.68 mm and a shell height of 0.46–0.57 mm. These measurements surpass the former records of Angustopila pallgergelyi and Acmella nana.

Split distribution, biogeography and morphological and genetic diversity of the Iberobathynellini Tribe in the family Parabathynellidae (Crustacea, Malacostraca, Bathynellacea)

The “Iberobathynella group”, or Iberobathynellini tribe, is a complex of six genera consisting of 33 nominal species and several cryptic species with an amphiatlantic distribution (in Europe, North Africa and North America). A modern systematic revision of this group of subterranean crustaceans is presented here. A phylogenetic and biogeographic study using morphological and molecular data (mitocondrial coi and nuclear 18S) was carried out and allowed to a) re-evaluate the taxonomic status and validity of previously erected subtribes, genera and subgenera that show congruence in the data; b) assess whether the identified mitochondrial lineages represent cryptic species; c) provide a plausible phylogenetic hypothesis for the relationships within Iberobathynellini and with the other two genera of the family Parabathynellidae that inhabit North America and Europe (Montanabathynella and Parabathynella, respectively); d) propose a plausible temporal and historical framework (paleobiogeographic scenario) for the diversification and evolution of the Iberobathynellini tribe based on the current distribution of morphotypes and their estimated times of divergence. Our results show that in parabathynellids, molecular and morphological divergences are not always congruent. Subtribe and subgenus are invalid categories so they must be eliminated. Paraiberobathynella genus needs to be revisited. The molecular dating results support the early divergence of the Iberobathynellini Tribe (Upper Cretaceous, around 78 Mya) and the vicariance by plate tectonics as main factor to explain the amphi-Atlantic distribution shown by this ancient subterranean crustacean group. Since there are species morphologically very similar to I. magna and I. imuniensis, but genetically different, we can ensure the existence of at least three cryptic species. Texanobathynella is undoubtedly a valid genus distinct from Iberobathynella. Montanabathynella and Parabathynella are two well-differentiated genera closely related to the Iberobathynellini tribe.

Cryptic diversity and gene introgression of Moinidae (Crustacea: Cladocera) in Nigeria

The distribution and species/lineage diversity of freshwater invertebrate zooplankton is understudied in Sub-Saharan Africa. In the present study, we explored the lineage diversity and regional distribution of Moinidae (Crustacea: Cladocera) species in Southeast Nigeria. Three species of Moinidae were identified, based on morphology, in 11 of 32 Nigerian lakes examined. Their phylogenetic relationships were investigated based on mitochondrial dna sequences (cytochrome oxidase c subunit I gene; coi) and two nuclear internal transcribed spacer regions (its-1 and its-2). Three coi lineages were detected, corresponding to the morphological species. Two of the coi lineages are newly reported, but one coi lineage (and the haplotype found) is globally distributed, suggesting an ability of moinids to disperse over long distances. Interestingly, two individuals that were morphologically M. cf. macrocopa and had its alleles typical of that species had mtDNA sequences typical of M. cf. micrura. Additionally, one individual that corresponded morphologically to M. cf. macrocopa (and also had a mitochondrial sequence typical of M. cf. micrura) had one its-2 allele typical of that species and one typical of M. cf. micrura. This discordance between mtDNA and nuclear phylogenies suggests gene introgression and/or hybridization between different species within the genus. Our data shows the lineage distribution/diversity and the presence of gene introgression/interspecific hybridization among moinid species from a tropical region.

DNA-barcode and endophallus morphology delimit congruent species in a systematic revision of the oxyporine rove beetles of Russia (Coleoptera: Staphylinidae: Oxyporinae)

Rigorous species delimitation is a challenge in biology and systematics in particular. In insects, male genitalia traditionally, and the barcoding region of the CO1 gene recently, are the main markers to identify species, even though a standalone use of CO1 for that is often criticized. In our systematic revision of the mycophagous and in other ways peculiar oxyporine rove beetles of Russia, the legacy alpha-taxonomy could not be improved by traditional investigation of genitalia as they are unusually character-poor in this group. Using phylogenetic inference and ancestral state reconstruction, we demonstrate that CO1 and endophallus are useful markers for species delimitation in Oxyporus. We also show that many morphological traits previously used for species delimitation in Oxyporus are in fact highly variable and thus inconsistent. We hypothesize that in Oxyporus diversification of the endophallic structures is driven by intense intra- and inter-species interactions of multiple individuals co-occurring in narrow spaces inside fungal bodies during mating. Our results encourage broader use of both markers, especially easy-to-generate dna barcodes, for the desired alpha-taxonomical work in Oxyporinae globally. The revision revealed 10 species of Oxyporus in the fauna of the Russian Federation; eliminated erroneous species records; established two new synonyms, Oxyporus (Oxyporus) basicornis Cameron, 1930 = O. (O.) aequicollis Bernhauer, 1935, syn.nov. = O. (O.) parvus Lee et al., 2020, syn. nov.; and raised the hypothesis that O. (O.) aokii Dvořák, 1956, O. (O.) basiventris Jarrige, 1948 and O. (O.) kobayashii Hayashi, 2015 are conspecific with O. (O.) maxillosus Fabricius, 1793. Lectotypes are designated for O. (O.) basicornis Cameron, 1930, O. (O.) germanus Sharp, 1889, O. (O.) niger Sharp, 1889, and O. (O.) triangulus Sharp, 1889. Comprehensive taxonomic treatment and an identification key are provided for all species.

The Hyalella species flock of Lake Titicaca (Crustacea: Amphipoda): perspectives and drawbacks of dna-based identification

Lake Titicaca, in the High Andes of Perú and Bolivia, harbours the world’s third most speciose ancient-lake amphipod radiation on record. A minimum of nineteen species of Hyalella derived from at least five independent colonization episodes concentrate in this high altitude water body, although the actual species number present has not yet been established and could be much higher. Herein, we take advantage of the description of three new species (H. krolli, H. gonzalezi, and H. hirsuta) and the re-description of other two (H. solida and H. nefrens) to assess the feasibility of adopting a dna-based identification approach to resolve the magnitude of this highly speciose amphipod assemblage. A Bayesian phylogenetic analysis of the evolutionary relationships among South American Hyalella cox1 haplotypes, including those of four out of the five species dealt with herein, shows a great disagreement between taxonomic units delimited under morphological and genetic data, hampering species identification exclusively based on cox1 dna barcode sequences.

Paul Kammerer and epigenetics – a reappraisal of his experiments

During recent years, the scientific interest in the work of Austrian biologist Paul Kammerer (1880‒1926) has risen again. This development can largely be attributed to advances in the fields of epigenetics and epigenetic inheritance, and it resulted in provocative discussions. This article contributes to enhancing the knowledge about Kammerer’s publications in two respects. First, I provide a brief overview and contextualization of Kammerer’s main works on phenotypic plasticity and its inheritance, some of which seem little known at present. Thereafter, to ensure an accurate transmission of the historical record, I comment on recently published suggestive information about what Kammerer did and wrote, chiefly referring to Kammerer’s original writings on fire salamanders (Salamandra salamandra) and cave salamanders (Proteus anguinus). Although the exact contents of Kammerer’s writings remain controversial and must be regarded with caution, his writings need to be treated objectively and accurately to avoid historical record distortion and to render the performance of adequate replications of his experiments possible.

Zebrus pallaoroi sp. nov.: a new species of goby (Actinopterygii: Gobiidae) from the Mediterranean Sea with a dna-based phylogenetic analysis of the Gobius-lineage

The gobies (Gobiidae) are the most diverse fish family in the Mediterranean Sea. Nevertheless, knowledge on their diversity, taxonomy, and phylogenetic relationships is still inadequate. The phylogenetic analyses reveal two genetically highly distinct clades among specimens identified as Zebrus zebrus. A new species, Zebrus pallaoroi sp. nov., is described based on an integrative approach. The neotype of Zebrus zebrus is designated. Genetic data confirm a pronounced level of divergence between Z. pallaoroi and Z. zebrus, with the mean genetic distance on cytochrome b being 18.1% and 1.07% on rhodopsin. Phylogenetic relationships within the Gobius-lineage were estimated on both markers. Morphologically, Z. pallaoroi is distinguished from the only congener Z. zebrus by having a snout longer than its eye, posterior nostril about 4/5–9/10 of the anterior nostril, eye diameter 4.3−4.7 in head length, ventrolateral head ridges transversally connected on the anterior side by a short transversal ridge, anterior membrane midline depth about 2/3 of the spinous ray, head canal pore α diameter about half of the distance between pore ρ and ρ1, suborbital sensory papillae row 5i going downwards to or near the level of row d, the distance between row 5i and row d absent or much smaller than the length of row 5i, and the body with ten to eleven vertical dark brown bands. Zebrus pallaoroi was recorded from the southern Adriatic, northern Ionian, and northern and western Aegean Seas, and is a cryptobenthic fish from very shallow waters.

Ptomaphagus thebeatles n. sp., a previously unrecognized beetle from Europe, with remarks on urban taxonomy and recent range expansion (Coleoptera: Leiodidae)

Anthropogenic environmental change is leading to changes in distribution for many organisms. While this is frequently discussed for prominent organisms of high conservation value, the same is true for the many cryptic species that rarely figure in debates on the human impact. One such cryptic taxon is the European Ptomaphagus sericatus (Chaudoir, 1845) and related forms. During a citizen science expedition in the Vondelpark, Amsterdam, the Netherlands, we obtained two forms of this species complex. We placed the examination of these specimens in the context of a re-analysis of the species group, and, using DNA barcoding and genital study on material collected thoughout Europe, found that the P. sericatus species complex consists of three distinct, partly sympatric species, one of which was previously undescribed. On the basis of collection data, at least two species, P. medius and P. thebeatles sp. n., show signs of having recently undergone (possibly anthropogenic) range changes, with P. medius even reaching North America. We describe P. thebeatles sp. n.; we raise two subspecies, viz. P. sericatus sericatus (Chaudoir, 1854) and P. sericatus medius (Rey, 1889) to the level of species, and designate a neotype for the former; we identify P. dacicus Jeannel, 1934 and P. pyrenaeus Jeannel, 1934 as junior synonyms of P. sericatus, and P. compressitarsus (Rey, 1889) as a junior synonym of P. subvillosus Goeze, 1777; we identify P. septentrionalis Jeannel, 1934 and P. miser (Rey, 1889) as junior synonyms of P. medius; we designate lectotypes for P. medius and P. miser.

Biodiversity hotspot in cold waters: a review of the genus Cuthonella with descriptions of seven new species (Mollusca, Nudibranchia)

Cuthonella Bergh, 1884 is of one of the most neglected nudibranch groups, with a long history of taxonomic confusion with other aeolidacean genera. Owing to its predominantly Arctic distribution with cold water, its species are difficult to find and to collect, and thus to describe. In this study we revise the genus by presenting molecular and morphological data for a majority of the species, including the type, C. abyssicola Bergh, 1884. The material is based on a broad geographic sampling throughout the Northern Hemisphere. Particular emphasis is placed on the Kuril Islands, a diversity hotspot for the genus. Seven new species and two subspecies of Cuthonella are described from the Arctic and North Pacific regions. The number of species of Cuthonella is thus increased over threefold and now comprises 15 species plus two subspecies instead of five species. This work is the most substantial update of the genus Cuthonella since its description in 1884. To delineate taxonomic and phylogenetic limits of Cuthonella-like aeolidaceans, the molecular phylogeny of the wider traditional “tergipedids” is presented and shows that Cuthonella-like aeolidaceans form a distinct molecular clade as the family Cuthonellidae Miller, 1977, corroborated by reliable morphological apomorphies.