Trichoniscoides bellesi 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 : 9-13

Trichoniscoides bellesi Reboleira & Taiti sp. nov.

urn:lsid:zoobank.org:act:FE37F766-5E77-430F-87C2-C5CB28A78D5D

Figs 4 A–G, 5A–E, 6A–D

Diagnosis

A blind and colourless Trichoniscoides characterised by the male pleopod 1 exopod having a broadly rounded outer margin and two equal distal lobes, and the male pleopod 2 endopod having a distal article thickset for ⅔ of its length, ending with a narrow point.

Etymology

The new species is named after Prof. Xavier Bellés for his invaluable contribution to the synthesis of knowledge on the subterranean fauna from the Iberian Peninsula.

Material examined

Holotype

PORTUGAL: ♂, Algar do Javali , Montejunto Massif, 26 Dec. 2012 ( MZUF).

Paratypes

PORTUGAL: 1 ♂, 1 ♀, same data as holotype ( MZUF).

Description

Maximum size: ♂ 1.7× 0.8 mm; ♀ 1.8× 0.8 mm. Body colourless and slightly convex ( Fig. 4A ). Cephalon and pereon with granulated dorsal surface; granules on pereonites arranged in double rows; each granule bearing a triangular scale-seta ( Fig. 4B ) on top. Cephalon ( Fig. 4 C–D) with quadrangular frontal lateral lobes not protruding frontwards. Eyes absent. Pereonites 1–4 ( Fig. 4A ) with rounded posterior corners; pereonites 5–7 ( Fig. 4A ) with epimera pointing backwards. Pleon ( Fig. 4A, E ) narrower than pereon; pleonites 3–5 with small epimera and short posterior points. Telson ( Fig. 4E ) more than twice as wide as long, distal part trapezoidal with concave sides and slightly convex apex. Antennula ( Fig. 4F ) with three articles; third article with distinct spine and three long aesthetascs at apex. Antenna ( Fig. 4G ) with fifth article of peduncle shorter than flagellum; flagellum with three articles, with three long aesthetascs on second article. Mandibles ( Fig. 5 A–B) with two penicils on the right and three on the left; molar process without penicils. Maxillula ( Fig. 5C ) with inner branch bearing three penicils at apex, proximal one distinctly longer than other two; outer branch with 11 teeth and two thin stems, one among outer group and one among inner group of teeth. Maxilla ( Fig. 5D ) apically bilobed, with outer lobe smaller than inner one; inner lobe with several long, stout setae. Maxilliped ( Fig. 5E ) endite triangular, with stout penicil at apex; palp distally rounded, with long setae, basal article with two short, compound setae. Uropod ( Fig. 4E ) with exopod distinctly longer than endopod; exopod with several long, pointed setae and endopod with a long and a short seta at apex.

MALE. Pereopod 1 ( Fig. 6A ) and pereopod 7 ( Fig. 6B ) with no particular modifications. Pleopod 1 ( Fig. 6C ) exopod almost as long as wide, with broadly rounded outer margin and two equal distal lobes each bearing a short seta at apex; endopod with triangular and flagelliform basal article and setose distal article. Pleopod 2 exopod missing in the specimen examined; endopod ( Fig. 6D ) biarticulated, distal article about twice as long as basal one, thickset for first ⅔ and ending with narrow point.

Remarks

In the shape of the male pleopod 2 exopod, with a thickset distal article ending in a narrow point, the new species is similar to Trichoniscoides lusitanus Vandel, 1946 , T. broteroi and T. heroldi Vandel, 1952 . It differs from T. lusitanus , an epigean species from north-western Spain and northern Portugal, in lacking eyes and pigment, in the male pleopod 1 endopod having a triangular basal article, and in the male pleopod 2 endopod having a stouter distal article ending in a shorter point; from T. broteroi in lacking the hook on the male pereopod 7 merus, and in the triangular shape of the basal article of the male pleopod 1 endopod; from T. heroldi , an epigean species from eastern France, in the lack of eyes and the shape of the male pleopod 1.

Ecological notes

Trichoniscoides bellesi sp. nov. is typically a troglobiotic species, lacking eyes and body pigment. It was discovered in the deepest and most thermally insulated parts of Algar do Javali, around 10 m deep. Javali is currently the richest cave of the Montejunto karst massif. Four other caves in the same massif were also sampled (Algar do Escorpião, Ralo das Fontaínhas, Algar da Terra da Rolha and Buracos Mineiros) without recovering any specimens of T. bellesi . The subterranean community of Algar do Javali includes other troglobiotic species, such as the campodeid Podocampa cf. fragiloides, a species of the oniscidean genus Paraschizidium (see below), the ground beetle Trechus tatai Reboleira & Ortuño, 2010 , a new pselaphid beetle, and the pseudoscorpions Chthonius cardosoi Zaragoza, 2012 and Roncocreagris occidentalis Zaragoza & Reboleira, 2013 ( Reboleira et al. 2010 a, 2013 c).

Figures

Fig. 4. Trichoniscoides bellesi Reboleira & Taiti sp. nov. from Algar do Javali, Montejunto. — Paratype, ♀. A. Adult specimen in dorsal view. B. Dorsal scale-seta. C. Cephalon in frontal view. D. Cephalon in dorsal view. — Paratype, ♂. E. Pleonites 4, 5, telson and right uropod. F. Antennula. G. Antenna.

Fig. 5. Trichoniscoides bellesi Reboleira & Taiti sp. nov. from Algar do Javali, Montejunto, paratype, ♀. A. Right mandible. B. Left mandible. C. Maxillula. D. Maxilla. E. Maxilliped.

Fig. 6. Trichoniscoides bellesi Reboleira & Taiti sp. nov. from Algar do Javali, Montejunto, paratype, ♂. A. Pereopod 1. B. Pereopod 7. C. Pleopod 1. D. Pleopod 2 endopod.