Troglonethes olissipoensis Reboleira & Taiti, 2015

Reboleira, Ana Sofia P. S., Gonçalves, Fernando, Oromí, Pedro & Taiti, Stefano, 2015, The cavernicolous Oniscidea (Crustacea: Isopoda) of Portugal, European Journal of Taxonomy 161, pp. 1-61 : 21-25

Troglonethes olissipoensis Reboleira & Taiti sp. nov.

urn:lsid:zoobank.org:act:7E09D1C5-19F8-44DF-A1AE-B2D741C411AE

Figs 13 A–G, 14A–E, 15A–D

Diagnosis

A species of Troglonethes characterised by the antenna having five flagellar articles, the male pleopod 1 exopod triangular, as wide as long, and the male pleopod 2 endopod with the distal article bearing a basal and a distal hook-like process.

Etymology

The new species is named after Olissipo, the old name of Lisbon, on the peninsula of which the Gruta de Alvide is located.

Material examined

Holotype

PORTUGAL: ♂, Gruta da Alvide, Cascais, Lisbon Peninsula , 26 Dec. 2009 ( MZUF). Paratypes

PORTUGAL: 5 ♂♂, 2 ♀♀, 3 juvs, same data as holotype ( MZUF); 5 ♂♂, 2 ♀♀, same data as holotype ( SR); 5 ♂♂, 2 ♀♀, same data as holotype ( ZMUC).

Description

Maximum size: ♂ 3.5 × 0.8 mm; ♀ 4.2× 1.2 mm. Body colourless and elongated ( Fig. 13A ). Dorsum of cephalon and pereon granulated; each granule equipped with a triangular scale-seta ( Fig. 13B ); pleon and telson smooth. Cephalon ( Fig. 13 C–D) with quadrangular frontal lateral lobes slightly protruding outwards. Eyes absent. Pereonites 1–4 ( Fig. 13A ) with rounded posterior corners; pereonites 5–7 ( Fig. 13A ) with epimera pointing backwards. Pleon ( Fig. 13A, E ) narrower than pereon; pleonites 3–5 with small epimera and very short posterior points. Telson ( Fig. 13E ) about twice as wide as long, with distal part trapezoidal with concave sides. Antennula ( Fig. 13F ) with three articles; third article with spine and three long aesthetascs at apex. Antenna ( Fig. 13G ) with third, fourth and fifth article of peduncle with distinct tubercles bearing scale-setae; fifth article as long as flagellum; flagellum with five articles, with two long aesthetascs on second and third article. Mandibles ( Fig. 14 A–B) with one penicil on the right and three on the left. Maxillula ( Fig. 14C ) with inner branch bearing three penicils at apex, inner one distinctly longer than other two; outer branch with 12 teeth and thin, setose stem among outer group of teeth. Maxilla ( Fig. 14D ) apically bilobed and setose, with outer and inner lobes subequal; inner lobe with several long stout setae along margin. Maxilliped ( Fig. 14E ) endite triangular, with stout triangular penicil at apex; palp distally rounded, with long setae, basal article with two short, compound setae. Uropod ( Fig. 13E ) with exopod slightly longer than endopod and more distally inserted; exopod with several long pointed setae and endopod with a long and a short seta at apex.

MALE. Pereopod 1 ( Fig. 15A ) with no particular modifications. Pereopod 7 ( Fig. 15B ) ischium with straight sternal margin, carpus with row of scales on distal margin, and propodus with long, thin setae on distal half of tergal margin. Genital papilla ( Fig. 15C ) fusiform, with rounded apex, much longer than pleopod 1. Pleopod 1 ( Fig. 15C ) exopod triangular, as wide as long, with broadly rounded apex; endopod with basal article elongated, longer than exopod, with sinuous outer margin, distal article flagelliform with setose apex. Pleopod 2 ( Fig. 15D ) exopod triangular, with broadly rounded apex with few short setae; endopod biarticulated, basal article about three times as long as distal one, with parallel sides, distal article with outer margin bearing hook-like process at base and one at apex.

Remarks

The genus Troglonethes was erected by Cruz (1989) for the new species T. aurouxi from a cave north of Valencia, Spain. Tabacaru (1993) included the genus in the tribe Speleonethini . The new species from Portugal is included in the genus since it has all the characters listed in the diagnosis. Troglonethes olissipoensis Reboleira & Taiti sp. nov. differs from T. aurouxi in having an antennal flagellum with five, instead of four, articles, the male pleopod 1 exopod shorter than the basal article of the endopod, and the male pleopod 2 endopod with a basal hook-like process on the outer margin of the distal article.

Ecological notes

This species was only found in Gruta de Alvide, located in an overurbanized area, with part of the cave ceiling used as the base of a residential building. The specimens were collected in the deepest parts of the cave, the so-called third level. It is the second troglobiotic species from karst caves in the Lisbon Peninsula, after the record of the bristletail Coletinia sp. in Gruta de Colaride ( Reboleira et al. 2012 a). Unidentified springtails and blaniulid millipedes were also collected.

Figures

Fig. 13. Troglonethes olissipoensis Reboleira & Taiti sp. nov. from Gruta de Alvide, Lisbon Peninsula. — Paratype, ♀. A. Adult specimen in dorsal view. — Paratype, ♂. B. Dorsal scale-seta. C. Cephalon in frontal view. D. Cephalon in dorsal view. E. Pleonites 4, 5, telson and left uropod. F. Antennula. G. Antenna.

Fig. 14. Troglonethes olissipoensis Reboleira & Taiti sp. nov. from Gruta de Alvide, Lisbon Peninsula, paratype, ♂. A. Right mandible. B. Left mandible. C. Maxillula. D. Maxilla. E. Maxilliped.

Fig. 15. Troglonethes olissipoensis Reboleira & Taiti sp. nov. from Gruta de Alvide, Lisbon Peninsula, paratype, ♂. A. Pereopod 1. B. Pereopod 7. C. Genital papilla and pleopod 1. D. Pleopod 2.