taxonID	type	description	language	source
FF9132655D66505C9634C179552C90E7.taxon	description	Figs 13 C, D, 14 B 1 – 14, 3	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
F3BABBF30D2658AFBCB046F1349C51FD.taxon	description	Fig. 1	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
F3BABBF30D2658AFBCB046F1349C51FD.taxon	distribution	Distribution. North Vietnam (Schileyko 2011).	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
9178EF8EE27E51DD8E9F18034EC309A2.taxon	type_taxon	Type species. Vitrina praestans A. Gould, 1843: 140; by typification of replaced name. Nom. nov. pro Cryptosoma Theobald, 1857, non Milne-Edwards, 1837 (Crustacea).	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
35EBE80CC64B594EAD8558F7C2FA287D.taxon	type_taxon	Type species. Muangnua limax Solem, 1966: 65, by original designation.	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
B843AD375A7D5B00B8715E07408D55AC.taxon	description	Fig. 12	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
65B1E91112185D27A3E5ECFFE074B08D.taxon	description	Figs 2, 3 A, B, 4, 5, 6, 7, 8	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
65B1E91112185D27A3E5ECFFE074B08D.taxon	description	Description. The body is relatively wider and shorter than Ostracolethe penevi Dedov & Vu, sp. nov. The visceral hump is large and elevated, but this elevation is better visible in fixed animals (Fig. 2 A, C). The preserved body dimensions (N = 1, adult specimen) are: body length 24 mm, body width 5.2 mm, visceral hump length 11.9 mm, visceral hump width 5.2 mm, length of free mantle flap 5.2 mm, sole length 21.2 mm, sole width 2.6 mm, width of lateral zones of sole 0.75 – 0.85 mm, central zone of sole 0.85 – 0.95 mm, length of the genital pore 0.5 mm, width of the genital pore 0.6 mm (Fig. 2 A – D). The primary color of the body is pinkish-ocher-brownish (Fig. 3 A, B), although variable (see Discussion). On the neck, three well-defined, blackish-gray- stripes are visible (one on the top and two laterally, best visible in fixed specimens). The tentacles are pale grayish, which are more intensely colored near the ommatophores and visible in active live animals. On the pinkish-ocher-brownish visceral hump, numerous yellowish spots are visible and grouped in larger stains and zones of irregular shapes. The posterior of the body has similar colors; yellowish pigment is grouped on the edge of the Y-shaped dorsal groove behind the visceral hump. The sole of living specimens is generally pale, but with lateral zones more pinkish in color, while the central zone is milky whitish. The differences in coloration between central and lateral zones is still visible in preserved specimens. The body cavity is not enlarged in the posterior part of the foot, but this part is not as muscular as in Ostracolethe sp. nov. and Laocaia simovi (Dedov et al. 2019). The caudal horn is not very prominent. Shell is fingernail-like (3.2 × 2.3 mm), and sparse growth lines are visible on the upper surface. The rudimentary shell is fully covered by the mantle (Fig. 4 A – C). Reproductive system (Fig. 5 A – E). The penis is relatively short and thinner in the area towards the atrium. The penis retractor muscle is apically attached to the bulbiform posterior end of the penis. The epiphallus is relatively short, with two caeca, one shorter and another longer, located opposite each other (Fig. 5 D, E). The vas deferens is short and entering epiphallus laterally. The vagina is thick and short. The bursa copulatrix is not well visible and is not visible in the drawing by Schileyko (2003: fig. 1752); it is most probably closely adjacent to the spermoviduct duct, as in O. penevi sp. nov. The albumen is gland small.	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
65B1E91112185D27A3E5ECFFE074B08D.taxon	distribution	Distribution. North Vietnam (Schileyko 2003).	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
1869456B986E5CE288BF5D1E928C1E53.taxon	description	Figs 3 C, 9, 10, 11	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
1869456B986E5CE288BF5D1E928C1E53.taxon	description	Description. The body is gracile (Fig. 3 C). The visceral hump is relatively long, slightly raised, and is displaced towards the front of the body. The preserved body dimensions (N = 1) are: body length 38.3 mm, body width 5.7 mm, visceral hump length 15.5 mm, visceral hump width 5.7 mm, length of free mantle flap 5.4 mm, sole length 36.3 mm, sole width 3.0 mm, width of lateral zones of sole 0.85 – 1.15 mm, width of central zone of sole 0.85 – 0.9 mm, length of the genital pore (not well visible) 0.8 mm, width of the genital pore 0.55 mm (not well visible) (Fig. 9 A – D). Body primary color is light-yellowish-ocher. On the neck, three well-defined gray-blackish stripes are visible (one on the top and two laterally). The tentacles are yellowish. On light-yellowish-ocher (slightly ocher-reddish in its posterior part) visceral hump numerous gray-blackish dots are visible, sometimes grouped in short stripes or spots with irregular shape. Posterior body almost uniformly light-yellowish-ocher with very small dots, well visible under magnification. The dorsal edge of the Y-shaped dorsal groove behind the visceral hump is yellowish. The sole in living specimens is pale-yellowish, more intense yellowish in its lateral margins. In preserved animals, the complete sole loses its pigmentation, which is also the case for all other body parts of the specimens (Fig. 3 C). All colorful pigments (besides melanin) are dissolved in ethanol during the preservation. The body cavity is not enlarged into the posterior part of the foot, which is fully muscular. The caudal horn protrudes slightly beyond the contour of the body and is similarly colored. The shell is plate-like, oval-rhomboid (3 × 2 mm), at one end with visible, and with sparse growth lines (Fig. 10 A – C). The rudimentary shell is fully covered by the mantle. Reproductive system (Fig. 11 A). The penis is long, thick-walled, and spindle-shaped but slightly pinched around the middle. The penis retractor muscle is attached apically to the posterior end of the penis. The epiphallus is long, about 2 / 3 of the penis length, with 2 caeca: a longer and smaller (1 / 3 of the longer caeca). The vas deferens is comparatively short and entering epiphallus slightly laterally. The free oviduct is relatively short. The vagina is thick and short. The bursa copulatrix is relatively long, finger-like (not divided into a bursa copulatrix and bursa copulatrix duct), closely adjacent to the spermoviduct duct, and reaching about halfway to the albumen gland. The albumen gland is small and pearly-yellowish. An unusual net-like structure was found close to the female part of the reproductive system (Fig. 11 B, C). The structure is relatively large and resembles a symmetric net-like formation with eight holes and has dimensions of 3.7 × 1.7 mm (compared to the 14.5 mm length of the reproductive system). Its function remains a mystery, but given its position, it could be homologous to the mucus glands in Helicidae. However, there are no clearly visible channel (s) between this structure and the rest of the reproductive system, even under high magnification. The structure appears to be attached to the female reproductive system by a tangle of connective tissue. The atrium is tubular.	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
1869456B986E5CE288BF5D1E928C1E53.taxon	distribution	Distribution. North Vietnam, type locality.	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
1869456B986E5CE288BF5D1E928C1E53.taxon	etymology	Derivatio nominis. The new species is named after Prof. Dr Lyubomir Penev for his incredible contribution to the reputation of Bulgarian science and his tireless, friendly support over the years.	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
13FC345F503A55DF843DE2F3013B1A29.taxon	type_taxon	Type species. Ostracolethe fruhstorfferi Simroth, 1901: 64.	en	Dedov, Ivailo, Manh Vu, Quang, Trieu Anh, Tuan (2025): Slugs and semi-slugs of the superfamily Helicarionoidea (Gastropoda, Stylommatophora) collected in North Vietnam during the 2023 Bulgarian Zoological Expedition, with emphasis on the genus Ostracolethe. ZooKeys 1249: 317-338, DOI: 10.3897/zookeys.1249.155684
