New species of the genus Spio (Annelida, Spionidae) from the southern and western coasts of Korea

A new spionid polychaete, Spio pigmentata sp. nov., is described from the southern and western coasts of Korea. This new species differs from its congeners by the following morphological characteristics combined: the presence of orange-brown pigmentation on the anterior part of the prostomium, black pigmentations on the peristomium and along the body, U-shaped nuchal organs, a comparatively long extension of metameric dorsal ciliated organs, three pairs of ventral epidermal glands per chaetiger, two to three abranchiate chaetigers, and the presence of tridentate neuropodial hooded hooks. The partial 16S ribosomal DNA (rDNA) and nuclear 18S rDNA sequences of the new species and Spio sp. 2 reported by Abe and Sato-Okoshi (2021) from Japan showed high similarity, indicating that these two belong to the same species. A detailed description and illustrations of the new species, together with molecular information, are provided.

When SEM becomes a deceptive tool of analysis: the unexpected discovery of epidermal glands with stalked ducts on the ultimate legs of geophilomorph centipedes

Background The jointed appendage is a key novelty in arthropod evolution and arthropod legs are known to vary enormously in relation to function. Among centipedes, the ultimate legs always are distinctly different from locomotory legs, and different centipede taxa evolved different structural and functional modifications. In Geophilomorpha (soil centipedes), ultimate legs do not participate in locomotion and were interpret to serve a sensory function. They can be sexually dimorphic and in some species, male ultimate legs notably appear “hairy”. It can be assumed that the high abundance of sensilla indicates a pronounced sensory function. This study seeks for assessing the sensory diversity, however, documents the surprising and unique case of an extensive glandular epithelium in the ultimate legs of three phylogenetically distant species. Results The tightly aggregated epidermal glands with stalked ducts – mistakenly thought to be sensilla – were scrutinized using a multimodal microscopic approach comprising histology as well as scanning and transmission electron microscopy in Haplophilus subterraneus. Hence, this is the first detailed account on centipede ultimate legs demonstrating an evolutionary transformation into a “secretory leg”. Additionally, we investigated sensory structures as well as anatomical features using microCT analysis. Contrary to its nomination as a tarsus, tarsus 1 possesses intrinsic musculature, which is an indication that this podomere might be a derivate of the tibia. Discussion The presence and identity of ultimate leg associated epidermal glands with stalked ducts is a new discovery for myriapods. A pronounced secretory as well as moderate sensory function in Haplophilus subterraneus can be concluded. The set of characters will improve future taxonomic studies, to test the hypotheses whether the presence of these specialized glands is a common feature in Geophilomorpha, and that tarsus 1 may be a derivate of the tibia. As the number of epidermal glands with stalked ducts is sexually dimorphic, their function might be connected to reproduction or a sex-specific defensive role. Our results, in particular the unexpected discovery of ‘glandular hairs’, may account for a striking example for how deceptive morphological descriptions of epidermal organs may be, if based on non-invasive techniques alone.

Investment in chemical signalling glands facilitates the evolution of sociality in lizards

The evolution of sociality and traits that correlate with, or predict, sociality, have been the focus of considerable recent study. In order to reduce the social conflict that ultimately comes with group living, and foster social tolerance, individuals need reliable information about group members and potential rivals. Chemical signals are one such source of information and are widely used in many animal taxa, including lizards. Here, we take a phylogenetic comparative approach to test the hypothesis that social grouping correlates with investment in chemical signalling. We used the presence of epidermal glands as a proxy of chemical investment and considered social grouping as the occurrence of social groups containing both adults and juveniles. Based on a dataset of 911 lizard species, our models strongly supported correlated evolution between social grouping and chemical signalling glands. The rate of transition towards social grouping from a background of ‘epidermal glands present’ was an order of a magnitude higher than from a background of ‘no epidermal glands’. Our results highlight the potential importance of chemical signalling during the evolution of sociality and the need for more focused studies on the role of chemical communication in facilitating information transfer about individual and group identity, and ameliorating social conflict.

A novel epidermal gland type in lizards (α-gland): structural organization, histochemistry, protein profile and phylogenetic origins

Chemical signalling is an essential component of the communication system of lizards, and epidermal glands are responsible for producing semiochemicals that regulate many behavioural interactions. Two types of epidermal glands have been previously described for lizards: follicular and generation glands. Generation glands are characterized by the aggregation of novel glandular cell types in the epithelium and the lack of a lumen or external pore. Despite the fact that several subtypes of generation glands have been recognized over the years, the morphology, taxonomic distribution, function and evolutionary origins of generation glands remain nearly unexplored in Neotropical clades. Here, we describe a novel escutcheon-type generation gland (‘α-gland’) for lizards of the South American family Tropiduridae, characterize its structural and ultrastructural organization, and study the homology of the constituent parts in a phylogenetic framework. The α-glands emerged in the ancestor of Eurolophosaurus, Plica, Strobilurus, Tropidurus and Uracentron, and are found in at least 39 species with diverse ecological habits. We preliminarily analysed the protein profile of α-glands and discovered differential expression of protein components between sexes. Our investigations change the general view about epidermal gland homology, leading us to argue that generation and follicular glands are possibly more closely related functionally and evolutionarily than previously thought.

Epidermal Gland Inspired Self-Repairing Slippery Lubricant-Infused Porous Coatings with Durable Low Ice Adhesion

The limited durability of slippery lubricant-infused porous surfaces (SLIPS) restricts their practical applications. Inspired by the epidermal glands of skins, we developed a facile approach to durable SLIPS with gland-like storage and release functions for icephobicity. By introducing a hybrid surfactant as a lubricant into the polydimethylsiloxane (PDMS) matrix, lubricant capsules were formed and mono-dispersed in the matrix, working as gland-like structures to release lubricant. The obtained SLIPS showed durable low ice adhesion strength and thermal durability simultaneously. In detail, the enhanced durability for icephobicity was demonstrated by 20 icing/deicing tests, in which the lubricant remains on the surface; the coatings showed negligible weight loss when stored at 100 °C for 60 h, displaying pronounced thermal durability of the slippery effect. Our current strategy sheds new light on a facile fabrication of mechanically and thermally durable SLIPS for icephobicity.

Campydoroides manautei gen. et sp. nov. from New Caledonia and a reappraisal of the suborder Campydorina (Nematoda)

The new genus and species Campydoroides manautei Holovachov gen. et sp. nov. is placed in the suborder Campydorina and is characterised by a transversely striated cuticle without lateral alae, body pores or epidermal glands; somatic sensilla only on pharyngeal region and on tail; a truncate labial region with papilliform inner labial, outer labial and cephalic sensilla; a stirrup-shaped amphid with transverse slit-like opening; a conoid stoma with strongly cuticularised walls and large protrusible dorsal tooth; a cylindrical pharynx with distinct basal bulb but without valves; a large ovoid cardia; didelphic, amphidelphic female gonads with antidromously reflexed ovaries and without spermatheca; a transverse vulva; a straight vagina without pars refringens vaginae or epiptygmata; an elongate tail with caudal glands and spinneret. The new genus is similar to the genera Campydora Cobb, 1920 and Udonchus Cobb, 1913 in having papilliform labial and cephalic sensilla, a stirrup-shaped amphid with a transverse slit-like opening, a stoma with a well-developed protrusible dorsal tooth, and a muscular pharynx with a strongly developed basal bulb, but can be easily separated from both in details of a stoma morphology. The systematics of the suborder Campydorina is revised. Halirhabdolaimus Siddiqi, 2012 is synonymised with Syringolaimus de Man, 1888.

Lithobius (Monotarsobius) meifengensis, a new species of centipede from high altitude forest in central Taiwan (Chilopoda, Lithobiomorpha, Lithobiidae)

Lithobius (Monotarsobius) meifengensissp. n.occurring at Mei-Feng Farm, Highland Experimental Farm of National Taiwan University, Nantou, Taiwan, is characterised by a male secondary sexual character on leg 15, a very large ventral swelling occupying almost 50% of the ventral surface of the femur; the gently curved apical region bearing approximately 20 short setae and numerous very small pores of flexo-canal epidermal glands. This male secondary sexual character is described for the first time in the genusLithobius.