Dina imeretiensis Grosser, Barjadze & Maghradze, 2023

Grosser, Clemens, Barjadze, Shalva, Maghradze, Eter, Shavadze, Lado, Pešić, Vladimir & Faille, Arnaud, 2023, On the taxonomic status of Dina ratschaensis Kobakhidze, 1958 with a description of two new species - Dina imeretiensis sp. nov. and D. samegreloensis sp. nov. (Annelida, Hirudinida: Erpobdellidae), European Journal of Taxonomy 891, pp. 110-127 : 112-116

Dina imeretiensis Grosser, Barjadze & Maghradze sp. nov.

urn:lsid:zoobank.org:act:79022D28-40B5-4D14-A833-9EBD88259814

Figs 1–3

Diagnosis

Living specimens are tricolor, the anterior part is flesh coloured, the posterior part is dark bluish and the caudal sucker is white ( Fig. 1 ). Medium sized leeches with a Dina -like heteronomous annulation. The midbody somites are subdivided into annuli b1, b2, a2, b5 and the broadened annulus b6 ( Fig. 2F ). The male genital pore is situated in furrow b2/a2 and the female one in furrow b6/b1. The genital pores are separated by three annuli. Preserved leeches show numerous small papillae on the dorsal and ventral sides. The cornua of the genital atrium are short, nearly parallel, curved ventrally with straight ends. The vasa deferentia are strongly curled in their entire course. The ovisacs are strongly winded in their entire caudal course ( Fig. 3 ).

Etymology

Dina imeretiensis sp. nov. is named after the region of Georgia from which the type material was collected.

Type material

Holotype GEORGIA • body length 46 mm, width 7 mm, caudal sucker width 4 mm; Imereti region, Tskaltubo Municipality, village Kumistavi , Prometheus Cave ; 42°22′36″ N, 42°36′02″ E; altitude - 40 m; 1 Aug. 2021; Sh. Barjadze, E. Maghradze and L. Shavadze leg.; IZISU: Al-T-00002.

Paratype

GEORGIA • 1 spec. (body length 45 mm, width 7 mm, caudal sucker width 4 mm); same collection data as for holotype; GenBank accession number (partial fragment of cox1 gene): OQ001264; IZISU: AL-T-00003 .

Comparative material

Dina ratschaensis Kobakhidze, 1958

GEORGIA • 1 spec. (body length ×width× caudal sucker width in mm: 50 ×9×6); Caucasus, Racha region, Ambrolauri municipality, Sakishore Cave ; 30 Oct. 2021; Sh. Barjadze and E. Maghradze leg.; IZISU • 2 specs (body length ×width× caudal sucker width in mm: 37 × 8×5, 15 ×4× 2); same collection data as for preceding; private collection of the first author (Elstertrebnitz, Germany ) .

Description

HABITUS. Medium sized leeches; preserved and contracted adults reach a body length up to 46 mm and a width up to 7 mm (holotype, Fig. 2A ). The body shape is in the preclitellar and clitellar regions cylindrical and in the postclitellar region dorso-ventrally flattened ( Fig. 2B–C ). The mouth opening is wide with barely noticeably elongated upper lip ( Fig. 2E ). The caudal sucker is slightly wider than half of maximum body width ( Fig. 2D ). Small but distinct papillae numerous on dorsal and ventral surface.

ANNULATION. The annulation is typical of the genus Dina . The midbody somites are quinqueannulate and heteronomously subdivided by clear furrows into annuli b1, b2, a2, b5 and the clearly broadened annulus b6. No tendency to split into further annuli visible ( Fig. 2F ). The male genital pore is situated in furrow b2/a2 and the female one in furrow b6/b1. The genital pores are separated by three annuli. The dorsal and ventral sides are roughened by a multitude of small but clearly visible papillae.

COLOURATION. The head, preclitellar and clitellar regions of living specimens are flesh coloured, the postclitellar region is dark bluish and the caudal sucker white ( Fig. 1 ). Preserved specimens are unicolored bright greyish. Dark pattern like spots or stripes are absent ( Fig. 2A ).

EYES. No eyes are visible.

SEXUAL ORGANS. The body of the genital atrium is large. The cornua are short, nearly parallel and curved ventrally. The ends of the cornua are straight and clearly offset from the vasa deferentia ( Fig. 3B–C ). The vasa deferentia are strongly curled in their entire course, extending to the beginning of the sixth somite behind the female genital pore (on annulus b1 of the sixth somite). They are particularly thickened from the fifth ganglion ( Fig. 3A ). The ovisacs are short and strongly winded in their entire caudal course. They run dorsally over the vasa deferentia and reach on both sides up to the second ganglion behind the female genital pore ( Fig. 3A ).

Variability

The variability between the two examined specimens (holotype and paratype) is low. Only the shape of the genital atrium showed noticeable differences. The cornua of the holotype are straight. The paratype has asymmetrical cornua; straight on the left and with a strong ventral-curved end on the right.

Habitat

Individuals of the new leech species were sampled on the wet surface of the stalagmite in the dark zone of Prometheus Cave.

Distribution

The new species is only known from the type location.

Figures

Fig. 1. Dina imeretiensis Grosser, Barjadze & Maghradze sp. nov. Living holotype and paratype from Prometheus Cave.

Fig. 2. Dina imeretiensis Grosser, Barjadze & Maghradze sp. nov., external morphology. A, D–E. Holotype (IZISU:Al-T-00002).B–C, E. Paratype (IZISU:AL-T-00003).A. Dorsal view.B. Lateral view. C. Dorso-lateral view. D. Caudal sucker (above holotype, below paratype). E. Oral sucker (left paratype, right holotype). F. Annulation of two midboddy somites, dorsal view. Abbreviations: a2, b1, b2, b5, b6 = annuli of somites.

Fig. 3. Dina imeretiensis Grosser, Barjadze & Maghradze sp. nov., holotype (IZISU: Al-T-00002), sexual organs. A. Schematic drawing of reproductive system. B. Schematic drawing of genital atrium. C. Photograph of genital atrium. a = genital atrium; b = ovisacs; c = vas deferens; d = testisacs.