Karadenizia merti Antić 2023, gen. nov., sp. nov.

Karadenizia merti gen. nov., sp. nov. Figs 1–5 Diagnosis. As for the genus, with the addition that the metazonal setae are very long, ca 45% of the vertical diameter of the rings. Name. The new species is dedicated to Mert Elverici, a Turkish biospeleologist and the collector of this beautiful animal. The epithet, a name in the genitive case, is a patronym. Material examined. Holotype: TURKEY ● ♁; Zonguldak Province, Erçek village, Erçek cave (41.4358, 31.8631), 260 m asl; 12 August 2020; M. Elverici leg.; ABBM. Paratype: TURKEY ● 1 juvenile; same data as for holotype; ABBM. Description (based on holotype). Size and number of body rings. Body moniliform, 12 mm long, vertical diameter of largest body ring 1.10 mm, body with 34 podous rings + 3 apodous rings + telson. Colour (Fig. 1). Generally dichromatic. Head, first three rings, last two rings and telson orange, the rest of the rings dark indigo with anterior halves of prozonae pale. Antennae and legs greyish. Ommatidia blackish. Head (Figs 1A–D, 2A). Number of ommatidia 25–26 in 7 horizontal rows, ocular fields rather trapezoidal (Fig. 1A–D). With a pair of frontal setae (Fig. 1A–D). Mandibular stipites expanded (Fig. 1D, white arrow). Labrum with three labral teeth, 9+9 labral and 3+3 supralabral setae. Gnathochilarium (Fig. 2A) with a subdeltoid, elongated promentum; lamellae linguales with 5+5 setae in one longitudinal row, stipites with 3+3 long distolateral setae and 4+3 short medial setae. Antennae 1.2 mm long, their length 110% of vertical diameter of widest body ring. Lengths of antennomeres I–VIII (in mm): 0.12 (I), 0.25 (II), 0.20 (III), 0.20 (IV), 0.25 (V), 0.10 (VI), 0.05 (VII) and 0.03 (VIII). Length/width ratio of antennomeres I–VII: 1 (I), 2.3 (II), 1.7 (III), 1.7 (IV), 1.7 (V), 1 (VI) and 0.7 (VII). Antennomeres V and VI each with a terminal corolla of large sensilla basiconica bacilliformia; antennomere VII with a terminal corolla of small sensilla basiconica bacilliformia. Body rings (Fig. 1A, C, E). Entire metazonal area with longitudinal striations. Metazonal setae long, length of midbody setae ca 45% of vertical diameter of rings, ca 20 per ring. Ozopores behind the suture. Telson (Fig. 1G, H). Epiproct with a short and rather blunt process. Paraprocts rounded, each with ca 15 long setae over the entire surface. Hypoproct lanceolate, without any modifications, with two long distal setae. Legs. First pair of legs modified, hook-shaped (Fig. 2B), with three complete podomeres; coxa with one seta; prefemur with four setae; femur, postfemur and tibiotarsus coalesced; femur with two setae; postfemur with one seta; no other peculiarities.All other legs with postfemoral and tibial ventral pads (Fig. 2C), and a setiform accessory tarsal claw almost twice as long as the main claw. Pleurotergum 7 (Fig. 1A, C, F). With high, well-developed, subtriangular lobe. Penis (Fig. 2D). Small, not sclerotized, set deeply below coxae 2, rather trapezoidal, with two elongated lobes fanlike distally and a short basal part. Gonopods (Figs 2E–G, 3–5). Stout and rather robust. Anterior gonopods or promeres (p in Figs 2F, G, 5A, B; Figs 2E, 3, 5C, D) spoon-shaped; lateral ridge (lr), with 5 or 6 setae, extending continuously to half the height of promere, then continuing discontinuously to 2/3 of height and moving towards mesal side; mesal margin with noticeable folds in basal and central part, distally with a triangular tooth (t); distal half with diagonal posterior shallow cavity to accommodate mesomeral process. Posterior gonopods same height as promere, with two parts also of same height: a mesomeral process (m) and an opisthomere (o). Mesomeral process strongly developed; anteriorly originating from base of posterior gonopod, laterally fused to opisthomere at half its height; anterolaterally very wide; distal half slender, digitiform, significantly curved mesad and slightly laterad; mesally with accessory membrane (am) forming a pocket to connect mesomeral process and opisthomere from mesal side. Opisthomere slightly sigmoid in mesal and lateral view; sperm groove (sg) beginning mesally from mesal pocket,, extending over entire height of opisthomere and terminating in distal part, just proximally to beaklike solenomere (s) with spoutlike anterior part. Anteriorly, below solenomere, a strongly developed fimbriate velum (v) or anterior lamella is formed. The entire distal part of opisthomere in mesal and lateral view resembles head of a singing songbird (with open beak). Additionally, mesal side of opisthomere has a rib or ridge ending in a small subtriangular lobe (l) Remarks. Although this species is characterised by a particular colour pattern, it is not unique in this sense, as there are other millipedes with a similar pattern (see in the discussion). Interestingly, a very similar looking animal (Fig. 6) was found in the cave near Trabzon, also on the southern coast of the Black Sea, but ca 600 km to the east of where Karadenizia merti gen. nov., sp. nov. was found. Unfortunately, the only specimen collected is a female. Although both animals have a moniliform body and orange anterior and posterior body ends, the female from near Trabzon differs from the species described here by the presence of an elliptical ocular field, by conspicuously shorter metazonal setae and by the presence of a black transverse band on the head. Locality and ecology. The Erçek Cave (Fig. 7) is a horizontal cave with a planimetric length of 890 metres and a depth of -26 metres. The entrance of the cave lies in a north-western direction, is rectangular, 14 x 14 m in size and forms a large habitat in the twilight zone. The cave bifurcates shortly after the entrance. The left part is mainly active, while the right part (including the entrance) is semi-active or fossil and forms a large terrestrial habitat. The active (left) part of the cave has the shape of a narrow, weakly flowing water stream with many meanders, flowing through a huge massif of red marble, with the floor almost completely submerged. The cave is also characterised by beautiful cave speleothems, especially stalactites in different colours (Mert Elverici, pers. comm.) The holotype was found crawling on the ground in the twilight zone, while the paratype juvenile was found clinging to the red marble wall in the active part of the cave. Besides this new genus, the cave is also inhabited by a possibly new species of the genus Polydesmus Latreille, 1802 /1803. Karadenizia merti gen. nov., sp. nov. is probably an epigean taxon without troglobiomorphisms. Distribution. A Turkish endemic known so far only from its type locality, Erçek cave, near Erçek village, the southern coast of the Black Sea (Zonguldak Province).Published as part of Antić, Dragan, 2023, Karadenizia, a new monospecific pachyiuline genus (Diplopoda: Julida: Julidae) from Turkey, pp. 456-468 in Zootaxa 5315 (5) on pages 457-465, DOI: 10.11646/zootaxa.5315.5.2, http://zenodo.org/record/814233