First records of cave-dwelling pseudoscorpions of the genus Ephippiochthonius Beier, 1930 (Arachnida: Pseudoscorpiones: Chthoniidae) from the Caucasus, with description of three new species from Abkhazia and taxonomic comments on the genus.

Three new hypogean Ephippiochthonius species from karst caves of Abkhazia (Western Caucasus) are described, including detailed diagnoses and illustrations: Ephippiochthonius kovali sp. nov., E.vargovitshi sp. nov. and E.dbari sp. nov. These are the first cave-dwelling species of the genus described from the Caucasus. The taxonomic significance of the position of the intermediate setae ih3 and ih4 on the antiaxial side of chelal hand in the genus Ephippiochthonius is discussed. Based on this and other features, the heterogeneity of the tetrachelatus-group is demonstrated. Given the presence of seta ph3, the following new combinations are proposed for the species formerly assigned to Ephippiochthonius: Occidenchthonius kemza (uri, Lee et Makarov, 1993) comb. nov. from Pecina u Kozuvarskoj Glami Cave, Serbia and Occidenchthonius romanicus (Beier, 1935) comb. nov. from Comana, Romania (all ex Ephippiochthonius).

The pseudoscorpions of the Caucasian Sphagnum bogs: part I. Description of Neobisium (Neobisium) adjaricum sp. nov. and redescription of the holotype of N. (N.) vilcekii Krumpál, 1983 (Arachnida, Pseudoscorpiones, Neobisiidae).

A new species of pseudoscorpions, Neobisium (Neobisium) adjaricumsp. nov., is described and diagnosed. It was collected in the Sphagnum habitats of Ispani lowland mires in Transcaucasia (Republic of Adjara, Georgia). The habitat of N. (N.) adjaricumsp. nov. is described. The holotype of N. (N.) vilcekii Krumpál, 1983, a species most similar morphologically to N. (N.) adjaricumsp. nov., known from the North Caucasus (Republic of North Ossetia-Alania, Russia), is redescribed. Diagnostic characters of the relative Caucasian species of the subgenus Neobisium Chamberlin, 1930 are analysed.

Fish occurrence in the Kama River Basin (Russia).

Background: Dataset contains information on fish occurrences in the Kama River Basin (Russian Federation). The Kama River is the largest tributary (1805 km) of the Volga River and is geographically often considered the main river due to the larger volume of water at their confluence. New information: Dataset is based on our own field studies conducted during 2008-2021. It includes 6,447 occurrences relating to 48 taxa, 46 of which were identified at species level and two at the genus level. All occurrences have coordinates and belong to 13 families of Actinopterygii. All presented data are published for the first time.

A new species of the genus Lucasioides Kwon, 1993 (Isopoda, Oniscidea, Agnaridae) from Siberia, Russia.

A new species of the family Agnaridae, Lucasioides altaicus sp. nov., is described from the Altai Mountains, southwestern Siberia, based both on morphological characters and molecular data. This species is the first record of Lucasioides from Russia, whose location is the northernmost habitat of terrestrial isopods in indigenous habitats presently known to Eurasia. The diagnostic characters of the new species and a preliminary phylogenetic analysis within Agnaridae are provided.

Description of a new species of the genus Protracheoniscus Verhoeff, 1917 and redescription of Protracheoniscuskryszanovskii Borutzky, 1957 from the southeast of European Russia (Isopoda, Oniscidea, Agnaridae).

A new species of woodlice, Protracheoniscuspokarzhevskii Gongalsky & Turbanov, sp. n. is described from Kalmykia, NE Pre-Caspian region, Russia. Protracheoniscuskryszanovskii Borutzky, 1957 from the same area is also redescribed. Diagnostic features of these species as well as affinities within the genus are provided and discussed.

The cave-dwelling false scorpion genus Pseudoblothrus Beier, 1931 (Arachnida: Pseudoscorpiones: Syarinidae) in the Crimean Peninsula.

Based on morphological and molecular studies of material from caves in three karst regions of Crimea, the small, apparently relictual, Euro-Mediterranean and Macaronesian false scorpion genus Pseudoblothrus Beier, 1931 is shown to contain only one troglobiont species there, P. roszkovskii (Redikorzev, 1918), of which P. ljovuschkini Krumpál, 1984 and Obisium tauricum Lebedev, 1927 are junior subjective synonyms. A detailed redescription of the adults and tritonymph of P. roszkovskii is provided, together with phylogenetic and zoogeographical analyses.

From the depths: Heterocaucaseuma deprofundum sp. nov., the world's deepest-occurring millipede (Diplopoda, Chordeumatida, Anthroleucosomatidae) from caves in the western Caucasus.

We describe a new anthroleucosomatid millipede, Heterocaucaseuma deprofundum sp. nov., found in the second and third deepest caves of our planet, Krubera-Voronja and Sarma, in Abkhazia, western Caucasus. A brief discussion on its taxonomy and relationships within the Caucaseuma complex and genus Heterocaucaseuma is provided, together with new faunistic records on other three species of Heterocaucaseuma. Notes on the distribution and troglomorphy of the genus Heterocaucaseuma are added. Ecological information and data on the subterranean community of the Krubera-Voronja Cave are updated. We also discuss the vertical distribution of the new species in caves and the presence of an ectoparasitic fungi of the order Laboulbeniales. This new species is currently the world's deepest-occurring millipede, also representing one of the largest known chordeumatidans.