Protracheoniscus gakalicus, Kashani, Ghasem M., Malekhosseini, Mohammad-Javad & Sadeghi, Saber, 2013

Kashani, Ghasem M., Malekhosseini, Mohammad-Javad & Sadeghi, Saber, 2013, First recorded cave-dwelling terrestrial isopods (Isopoda: Oniscidea) in Iran with a description of a new species, Zootaxa 3734 (5), pp. 591-596 : 593-595

publication ID	https://doi.org/ 10.11646/zootaxa.3734.5.8
publication LSID	lsid:zoobank.org:pub:4FC66E64-F279-459D-83DF-7AF945B10DBD
DOI	https://doi.org/10.5281/zenodo.6146109
persistent identifier	https://treatment.plazi.org/id/B30B2C4A-FF81-0413-FF1B-EF78FBE7E242
treatment provided by	Plazi
scientific name	Protracheoniscus gakalicus
status	sp. nov.

Treatment

Protracheoniscus gakalicus n. sp.

Material examined. Holotype: male, 9 mm, East of Gachsaran, Gakal cave, 18 May 2012 (CBSU-Cr-Is.1001). Paratypes: one male, same data as for holotype (SMNS T615); one female, same data as for holotype (SMNS T616); one male, same data as for holotype (SMF 43366); four males and two females, same data as for holotype (PCGMK 1603); one male and two females, same data as for holotype (CBSU-Cr-Is.1002); three males and three females, same locality as for holotype, 2 October 2012 (CBSU-Cr-Is.1003)

Diagnosis. Body pigmentless. Cephalon with developed lateral lobes, eyes absent. Male pereiopod VII ischium stout with several strong setae on tergal margin. Male pleopod endopodite I straight, exopodite subrectangular.

Description. Maximum length: male and female 10 mm. Body elongated, pigmentless ( Fig. 2 View FIGURE 2 ). Eyes absent. Cephalon with well developed lateral and median lobes ( Fig. 3 View FIGURE 3 A), no supraantennal line.

Antenna long, reaching the posterior margin of fourth pereion tergite; fifth article of peduncle as long as flagellum; flagellum with two articles of the same size ( Fig. 3 View FIGURE 3 D).

Antennule of three articles with a tuft of long aesthetascs at apex ( Fig. 3 View FIGURE 3 E).

Mandible with molar penicil consisting of several plumose setae; 1+3 free penicils on the right mandible and 2+3 on the left ( Fig. 4 View FIGURE 4 A, B).

Maxillule with outer branch bearing 4+5 simple teeth ( Fig. 4 View FIGURE 4 C); inner branch with two long penicils and a triangular posterior point ( Fig. 4 View FIGURE 4 D).

Maxilla distally bilobate and setose, inner lobe wider than outer one, three aesthetascs between the two lobes ( Fig. 4 View FIGURE 4 E).

Maxilliped endite with two small triangular teeth on anterior margin ( Fig. 4 View FIGURE 4 F).

Pereion smooth; posterolateral margins of first pereionite convex ( Fig. 3 View FIGURE 3 A); noduli laterales on pereionites 1–4 distinctly more distant from the lateral margins than those on pereionite 5–7 ( Fig. 3 View FIGURE 3 C).

Pleon smooth, pleopod exopodites I–V with monospiracular covered lungs ( Fig. 5 View FIGURE 5 B–F).

Telson triangular, almost as long as wide, with slightly concave sides and acute apex, slightly surpassing uropod protopodites.

Uropod protopodites with conspicuous incision on lateral margins; exopodite long, twice as long as telson ( Fig. 3 View FIGURE 3 B).

Male: pereiopod I merus and carpus with brushes of trifid setae ( Fig. 3 View FIGURE 3 F).

Pereiopod VII ischium stout with straight sternal margin, several strong setae on tergal margin ( Fig. 3 View FIGURE 3 G).

Pleopod exopodite I somehow rectangular, with a row of fine setae on outer margin ( Fig. 5 View FIGURE 5 B); endopodite straight, with a line of small setae at apex ( Fig. 5 View FIGURE 5 A).

Pleopod endopodite II as long as exopodite; exopodite triangular with a row of fine setae on outer margin ( Fig. 5 View FIGURE 5 C).

Pleopod exopodites III–V as in Fig. 5 View FIGURE 5 D–F.

Remarks. A species of Protracheoniscus characterized by the smooth body, rounded posterolateral margins of the first pereionite, the head bearing short or well-developed lateral lobes, the triangular telson and pleopodexopodites I–V with monospiracular covered lungs (Schmidt 2003). Diagnostic characters of this species including shape of antenna, cephalon, posterolateral margins of first pereionite and telson are well corresponding with the genus Protracheoniscus . The genus includes more than 60 valid species (see Schmalfuss 2003) distributed in Eurasia from Spain to Japan. This is the first known species of the genus adapted for a cavernicolous way of life, acquiring some unique traits that distinguish it readily from other species. Lack of pigmentation and eyes, and possessing long antenna and uropodal exopodites are among these adaptations.

Distribution. Southwest of Iran.

Etymology. The name of the species is after the type locality, Gakal cave.