A new species of the genus Caenorhinus Thomson, 1859 (Coleoptera, Rhynchitidae) from North Vietnam

A new species, Caenorhinus (Flavodeporaus) nahangensis Legalov, sp. nov. from North Vietnam is described and illustrated. This new species is similar to Caenorhinus (Flavodeporaus) lobanovi Legalov, 2021 Laos but differs from it in the different body coloration, narrower rostrum, very weakly curved mesotibiae, densely punctate elytral interstriae, obtuse apex of the aedeagus, and the form of the basal sclerite. From C. nigrobasalis Legalov, 2003, it is distinguish in the narrower rostrum, finely punctate forehead, greenish elytra, red ventrites 4 and 5, pygidium and propygidium, obtuse apex of the aedeagus, and the form of the basal sclerite.

Phenotypic differentiation of the slow worm lizards (Squamata: Anguis) across their contact zone in Central Europe

Background The application of molecular-phylogenetic approaches to taxonomy has had a dramatic effect on our understanding of the diversity of reptiles. These approaches have allowed researchers to reveal previously hidden lineages as well as taxonomic overestimation in morphologically plastic taxa. Slow worms, legless lizards of the genus Anguis (Squamata: Anguidae), were previously considered to comprise either one or two species, and morphology-based intraspecific taxonomy of Anguis fragilis remained controversial throughout the 20th century. After the discovery of deep genetic divergences within the genus, its taxonomy was reconsidered, and as a result, five extant species have been recognized. In order to better understand the patterns of their interspecific differentiation, here we studied phenotypic differences between the two most widespread of them—A. fragilis and A. colchica, and their putative hybrids across the contact zone of both species in Central Europe. Methods We used multivariate and univariate statistics and analyzed ten metric, eleven meristic, and six categorical phenotypic variables in material comprising a total of 326 individuals. We also genotyped individuals from the contact zone for one mitochondrial and two nuclear DNA fragments in order to delineate the distribution of individuals of hybrid and non-hybrid origin. The clines in morphological traits were studied using HZAR. Results We show that the two species are morphologically differentiated. Anguis fragilis has a less robust head, fewer scales covering the body, lower frequency of the external ear opening presence, lower frequency of separated prefrontal scales, higher frequency of prefrontal scales in contact with each other, and body coloration more similar to the juvenile coloration than A. colchica. Slow worms from the contact/hybrid zone are characterized by an intermediate morphology, with more similarities to A. fragilis than to A. colchica. Discussion None of the analyzed characters alone proved to be fully diagnostic, although more than 90% of all individuals could be successfully assigned to one or another species based on numbers of scales around the body. Our results indicate concordant, coincident, and steep clines in character states change. We present several hypotheses on the origin and evolutionary maintenance of the morphological divergence between both species and suggest that different evolutionary histories of the taxa rather than recently acting selection explain the observed morphological variation.

NATURE OF VARIABILITY OF CANDAHARIA LEVANDERI (SIMROTH, 1902) IN THE FERGHANA AND SURKHAN - SHERABAD VALLEYS, UZBEKISTAN

The variability of Candaharia levanderi (Simroth, 1902)(Gastropoda, Stylommatophora, Parmacellidae) in two biotopes (southern and northern slopes, the Kampirtepa gorges, the Kugitang Tau ridge) has been investigated using polymerase chain reaction (PCR) with the implementation of primers, the 18S DNA of the region is amplified, the variability (sharply differing in color) of two populations of C. levanderi is studied. The first population is in the suburbs of Namangan, (Namangan Region); the second population is in Kampirtepa gorges, Kugitang Tau ridge (Surkhandarya Region). It is established that, most often, the variability of morphological signs is observed on the coloration of mollusks. The development of body coloration is an adaptive feature that reflects the adaptability to certain biotopes on the one hand, and landscape and climatic conditions on the other.

An unusual body colouration of Ceylon roughside snake (Aspidura ceylonensis)

The small sized, non-venomous, and fossorial colubrid snake genus Aspidura Wagler, 1830 is endemic to Sri Lanka. Aspidura ceylonensis (Günther, 1858) is rare and restricted to mid-elevation to montane and sub-montane forests at elevation of 500–1300 m a.s.l. in the Central Highlands and the Knuckles massif. It is found in cool and well-shaded forest areas, with thick moist leaflitter, woody debris, and loose soil. The usual adult body coloration on dorsum is dark reddish or dark orange, rarely yellowish, with a continuous black vertebral line and two rows of dorsolateral black spots along the body.

First record of Anax nigrofasciatus Oguma, 1915 (Odonata: Aeshnidae) from Russia

Dragonfly Anax nigrofasciatus Oguma, 1915 (Odonata: Aeshnidae) was collected on a small pond in the vicinity of Vityaz settelment, Gamov Peninsula, Primorsky Krai in 2021. It is the first record of this East Asian species from Russia. A. nigrofasciatus clearly differs from A. parthenope julius Brauer, 1865, more common in the south of the Russian Far East, by body coloration and by details of morphology.

Definitions of two species groups of Stenothemus Bourgeois (Coleoptera, Cantharidae), with descriptions of three new species from China

Two new species-groups of the cantharid genus Stenothmeus Bourgeois are defined, S. laterophysus species-group and S. notaticollis species-group. The S. laterophysus species-group is composed of two species, including S. laterophysus Švihla, 2004 and a new species, S. nigritibius Y. Yang et H. Liu, sp. nov., and characterized by the pitch black elytra and bicolored legs, the subrounded pronotum with widely rounded anterior angles and projecting posterior angles, male genitalia with slender ventral processes of parameres which are slightly bent inwards at apical parts, laterophyses tilting ventrally at an angle of more than 45° with dorsal plates, compressed at apical parts, as well as the slender spermathecal duct, extremely long spermatheca and diverticulum. The S. notaticollis species-group consists of five species, including S. notaticollis (Gorham, 1895), S. bourgeoisi Wittmer, 1974, S. tamil Švihla, 2011 and two new species, S. parameratus Y. Yang et S. Ge, sp. nov. and S. acutiapicis Y. Yang et X. Yang, sp. nov., which is differentiated from the S. laterophysus species-group by the more variable body coloration, elytra pitch black or black brown or pale-yellow, male genitalia with thick or flattened ventral processes of parameres which are diverging apically, laterophyses parallel to dorsal plates, expanded at apices, as well as the stout spermathecal duct, moderately long spermatheca and diverticulum. The above species are illustrated with photographs of habitus, male genitalia, abdominal sternites and internal genitalia of female. A key for the identification of these species is provided and a distribution map is presented.

A new species of Stegonotus (Serpentes: Colubridae) from the remnant coastal forests of southern Timor-Leste

During the first amphibian and reptile survey of Timor-Leste, we discovered a population of groundsnakes, genus Stegonotus, in the last remnant of lowland coastal forest along the country’s southern coast, which represents a new species. This sexually dimorphic species can be differentiated from all other Wallacean Stegonotus by a combination of 17-17-15 dorsals, ventrals (female 206; males 197–207), paired subcaudals (female 61; males 71–75), the “gull wing +” condition of the rostral, large squared prefrontals that each are 2.5 times the area of the internasals and two-thirds the size of the frontal, a snout-scale ratio of near 0.4 and a frontal-parietal suture ratio of ≤ 1.0, a labial scale formula of 73+4 | 94, five gulars separating the posterior genial and the anteriormost ventral, and an overall brown body coloration that lightens progressively from the vertebral scale row in a dorsal–lateral direction and features color gradients of dark brown posterior edges to lighter brown anterior edges on individual scales. The species is most similar in overall morphology to S. modestus from the central Moluccas and to S. lividus, a species known only from tiny Semau Island that lies off the western end of Timor Island, in close proximity to Kupang, the capital of the Indonesian province of East Nusa Tenggara.

Catabolism of lysosome-related organelles in color-changing spiders supports intracellular turnover of pigments

Pigment organelles of vertebrates belong to the lysosome-related organelle (LRO) family, of which melanin-producing melanosomes are the prototypes. While their anabolism has been extensively unraveled through the study of melanosomes in skin melanocytes, their catabolism remains poorly known. Here, we tap into the unique ability of crab spiders to reversibly change body coloration to examine the catabolism of their pigment organelles. By combining ultrastructural and metal analyses on high-pressure frozen integuments, we first assess whether pigment organelles of crab spiders belong to the LRO family and second, how their catabolism is intracellularly processed. Using scanning transmission electron microscopy, electron tomography, and nanoscale Synchrotron-based scanning X-ray fluorescence, we show that pigment organelles possess ultrastructural and chemical hallmarks of LROs, including intraluminal vesicles and metal deposits, similar to melanosomes. Monitoring ultrastructural changes during bleaching suggests that the catabolism of pigment organelles involves the degradation and removal of their intraluminal content, possibly through lysosomal mechanisms. In contrast to skin melanosomes, anabolism and catabolism of pigments proceed within the same cell without requiring either cell death or secretion/phagocytosis. Our work hence provides support for the hypothesis that the endolysosomal system is fully functionalized for within-cell turnover of pigments, leading to functional maintenance under adverse conditions and phenotypic plasticity. First formulated for eye melanosomes in the context of human vision, the hypothesis of intracellular turnover of pigments gets unprecedented strong support from pigment organelles of spiders.