Limax macedonicus leucopus

Dedov, Ivaylo K., Schneppat, Ulrich E., Glogger, Fabia Knechtle, Cornu, Regula, Hristovski, Slavčo & Borissov, Simeon, 2025, Morphological, anatomical, and molecular notes on two neglected high-altitude taxa of the genus Limax (Stylommatophora: Limacidae) from North Macedonia and their unusual adaptation to extreme alpine conditions, Zootaxa 5719 (1), pp. 91-107 : 101-103

Limax macedonicus leucopus P. Hesse, 1928 (reinst. stat.)

( Figs. 4 D ; 5 B ; 7 A, B, E ; 8 A, B )

Limax macedonicus leucopus P. Hesse, 1928 — Hesse, 1928: 12–13, Pl. 1, Fig. 8 . [Original description]; Wagner, 1934: 53. [Misidentification in literature of L. graecus ]; Wagner, 1940: 140–141. [Misidentification in literature of L. graecus ]; Jaeckel, 1954: 68.

Limax ( Limax) graecus, Simroth, 1889 — Wiktor, 1996: 77–78. Material examined. North Macedonia • Pelister Mountains (=Baba Planina Mountains ), high-mountain pasture, 40.9939°N 021.1798°E, 2370 m, leg. S. Hristovski, 21.06.2023, IBER-BAS, Coll.No. 11010/ 6 specimens ( Fig. 2D ).

Diagnosis

Limax macedonicus leucopus has similar reproductive system but differs from the nominate species by its smaller size ( Table 2) and the creamy-yellowish-whitish colouration of the whole three sole parts (middle and both lateral sides). Limax macedonicus leucopus is only known from the type locality. As already described by P. Hesse (1928), the wrinkle rows from pneumostome to the back edge of the mantle in L. macedonicus (both subspecies) are finer and more numerous than in other Limax species with penial appendage ( Table 2).

Morphology

Body measurements are presented in Table 1. All measurements are taken from specimens preserved in ethanol 75% + 3% glycerol (N2), in millimeters. No measurements of live specimens. Limax macedonicus leucopus , like the nominate subspecies, has a strikingly uniform deep black color. ( Fig. 4 D ). The only difference from the coloration of L. macedonicus macedonicus is that in L. macedonicus leucopus the entire sole is creamy white. In L. macedonicus leucopus some blackish spots could be observed on the edge of the lateral zones of the sole, but never total pigmentation as in L. macedonicus macedonicus . The mantle of L. macedonicus leucopus has similar colouration and pattern as in L. macedonicus macedonicus .

Shell

Shell is typical for the genus (see comments on the previous subspecies) ( Wiktor 1983) ( Fig. 5 B ). Size: c. 8.5 mm.

Anatomy

The anatomy of L. macedonicus leucopus is similar to L. macedonicus macedonicus . The reproductive anatomy of L. macedonicus leucopus is visualized on Fig. 7 A, B, E .

Biology and mating behaviour

We observed unusual mating behaviour of L. macedonicus leucopus from the alpine area of Pelister Mountains. Both pictures ( Fig. 8 A, B ) were taken on 07 July 2013, between 13.00 and 13.15 h. The specimens copulated in circle position, attached to vertical rock surface, without mucus thread, and their penises are hanging down.

Molecular phylogeny

The p-distances were calculated on a 1206 bp dataset and are given in Table 2. The dataset used for phylogeny included 31 DNA sequences and consisted of 573 bp from which 209 variable and 176 parsimony-informative sites. The new tree is similar to the one shown by Nitz et al. (2009). Although some of the branches received weak support, the populations from the Pelister and Jakupitsa mountains grouped together to form a strongly supported clade sister to a L. graecus + L. conemenosi clade ( Fig. 3 ).

Figures

FIGURE 2. Habitats: A–C L. macedonicus macedonicus, A—Jakupica Mts., the first site (red spot) detected in 2011 and general habitat of L. macedonicus, with Solunska Glava peak in the background, where the first topotype series was collected; Rep. Macedonia, Jakupica Mountains, site above Begovo Pole (to the left) just below Solunska Glava peak. Well visible the stony area of a sinkhole below the road, just behind the Pinus mugo bush; B—Jakupica Mts., the second area, detected in 2017, Marina Rupa, area of sinkholes, between the peaks of Cheples and Kantarica. Well visible the big rocky area of two sink holes. In the background the southern extending ridge of Solunska Glava with Kantarica peak; C—Jakupica Mts., the third site detected in 2017; Marina Rupa, area of sinkholes, between the peaks of Ceples and Kantarica; D—Pelister Mts., view of the area were L. macedonicus leucopus was found.

FIGURE 3. A maximum likelihood tree based on a COI fragment (573 bp).

FIGURE 4. Body and sole colouration of L. macedonicus macedonicus (A, B), Jakupica Mountains, North Macedonia and L. graecus (C), Shar Mountains, North Macedonia. Sole colouration of L. m. leucopus (D). The deep dark colouration of the body and distinctive dark lateral sole fields (A) of L. macedonicus macedonicus, as well as fingerprint pattern on the mantle (B) are well visible in contrast to L. graecus (C).

FIGURE 5. Vestigial shell of L. macedonicus macedonicus (A), and L. macedonicus leucopus (B).

FIGURE 7. Comparative pictures of the reproductive system of: A. L. macedonicus leucopus, North Macedonia Pelister Mts., B. L. macedonicus leucopus, North Macedonia Pelister Mts., female parts are still not developed; C. L. macedonicus macedonicus, North Macedonia, Jakupica Mts., D. L. graecus, after Wiktor (2001), Zoomed male parts of the reproductive systems: E. L. macedonicus leucopus, North Macedonia Pelister Mts., F. L. macedonicus macedonicus, North Macedonia, Jakupica Mts., G. L. graecus, SW Bulgaria, Kresna gorge.

FIGURE 8. Copulation of A., B. L. macedonicus leucopus, North Macedonia Pelister Mts., C. L. conemenosi.