Spherarmadillo nebulosus, Schmidt, 2007

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 29-31

publication ID	https://doi.org/ 10.1111/j.1096-3642.2007.00286.x
DOI	https://doi.org/10.5281/zenodo.5489290
persistent identifier	https://treatment.plazi.org/id/03858799-4220-FFF4-9818-7C62A847FD63
treatment provided by	Felipe
scientific name	Spherarmadillo nebulosus
status	sp. nov.

Treatment

SPHERARMADILLO NEBULOSUS View in CoL SP. NOV.

Material examined

One ♂ holotype, one ♀ m paratype ( Venezuela, Parque Nacional Henri Pittier , near Estación Biológica Rancho Grande, leg. C. Schmidt, 14 March 1998, UCV) ; one ♀ m, paratype ( Venezuela, Parque Nacional Henri Pittier , above Estación Biológica Rancho Grande, leg. C. Schmidt, 14 March 1998, UCV) ; one ♀ m, one ♀, paratypes ( Venezuela, Parque Nacional Henri Pittier , above Estación Biológica Rancho Grande, leg. C. Schmidt, 14 March 1998, cCS 181b) .

Description ( Figs 65–71 View Figure 65 View Figure 66 View Figure 67 View Figure 68 View Figure 69 View Figure 70 View Figure 71 )

Male 8.7 × 3.8 mm, cephalothorax 2.05 mm wide; adult females (with marsupium) c. 8.5 mm long, 4.1– 4.3 mm (N = 3) wide, cephalothorax 2.25–2.30 mm (N = 3) wide. Eyes absent. The animals can roll up into a perfectly spherical ball. Dorsal surface dark slategrey, with pale muscle insertion spots and pale patches. Ventral surface pale, with some isolated chromatophores scattered over pereiopods, sternites and genital papilla. Tergites smooth and shining, with small tricorns and large, distinct noduli laterales at a short distance from the posterior margin of the tergites; distances to the lateral margins all equal and similar to those in other members of the Scleropactidae . One row of scale setae along the posterior margin of the tergites. Behind the position of the noduli, there is a gap in this row.

First antenna three-jointed; the distal article has two apical aesthetascs and a row of subapical aesthetascs. Second antenna has a three-jointed flagellum that is longer than the fifth article of the peduncle. Both the second and third articles bear aesthetascs. The apical cone is shorter than the apical flagellar article, but nevertheless represents the elongate type, with one short lateral sensillum.

Mandibles: left mandible with enlarged lacinia mobilis provided with only very shallow teeth. Pars incisiva as usual, hairy lobe with two penicils; one penicil between the hairy lobe and the pars molaris, which is represented by a single, densely hirsute seta. This seta seems to be not a true seta, but a tuft of hairy setae, where the basal part, on which the setae are inserted, is elongate and the setae are very short. The lacinia mobilis has the appearance of a masticatory plate. Right mandible with pars incisiva enlarged, with shallow marginal teeth; lacinia mobilis very small; pars incisiva and lacinia mobilis of the right mandible seem to form the counterpart of the masticatory surface of the left mandible. Hairy lobe of the right mandible reduced in size, bearing one penicil. One penicil between the hairy lobe and the pars molaris, which is represented by a large seta as in the left mandible. First maxilla lateral endite with lateral group of one large tooth with some structure on its inner face, and three small teeth that correspond in size to the teeth of the mesal group, one short, triangular lobe and a slender stalk, which does not exceed in length the triangular lobe. Mesal group of six teeth, one of them smaller. Whether one subapical small seta exists could not be determined with sufficient clarity. Inner endite with two stout, densely hirsute penicils and rounded laterodistal corner. Second maxilla with two subequal apical lobes; the mesal one is provided with a group of sensilla. Maxilliped endite rectangular, with one subapical seta on the caudal face and two setae on the apical margin. Frontal face with some pectinate scales, but not on the apical part. Maxilliped palp three-jointed. Proximal article with one large mesal seta; a minute vestige of a lateral seta can be seen. Second article on inner margin with distal tuft of one large and several small setae on a socket. The proximal tuft is composed of only two small setae, and approaches near to the base of the socket of the distal tuft. Lateral margin of mesal article with two setae and some long ‘hairs’ (pectinate scales). Apical article with apical tuft of setae, some irregularly placed setae on the frontal face, and one seta on the lateral margin. Pereiopod 1 with antennal brush composed of scales. Male pereiopods 1-4 with scale brushes on the ventral face of merus and carpus. Similar scale brushes or only a few scales are present on ischium and merus of most pereiopods. On male pereiopod 7, these brushes are composed of spine-shaped scales and are much more dense than on the other pereiopods. No trace of waterconducting scale rows on pereiopods 6 and 7. Dactyli with apically hirsute dactylar seta, simple, slightly curved ungual seta accompanied by a minute basal seta, short inner claw, one more seta on frontal and caudal face each, and some other setae or scales. Sternite 7 medially very narrow. Pleopod exopodites without distinct dorsolateral respiratory fields. Male pleopod 1 endopodite curved outwards, with subapical sharp process on its lateral margin. Proximal part of the endopodite (containing muscle M47) with lateral margin angulate. Pleopod 2 endopodite exceeds the exopodite, the tip of which is curved to fit endopodite 1. Exopodite 5 with medial furrow to receive endopodite 2 and field of pectinate scales on the caudal face. Exopodites 2–5 with one to three marginal setae. Uropod protopodite enlarged and flattened; outer edge angulate; the exopodite reduced in size, inserting on the medial margin of the protopodite.

Derivation of the name

Latin nebulosus (foggy), because the specimens were found in the cloud forest (selva nublada).

Remarks

The new species is distinguished from Spherarmadillo schwarzi by smaller size, margins of pleon epimera and uropod protopodites not serrated. Concerning male characters, which Schultz (1970) described for Sphe. schwarzi , the new species differs by the presence of an acute lobe on the lateral margin. Schultz’s specimens should be re-examined, to confirm the conspecificity with Spherarmadillo schwarzi .

The disposition of the noduli and the marginal row of tricorn setae implies that the position of the noduli distant from the margin represents a derived condition. The ancestral condition was a row of tricorn setae along the posterior margin of the tergites, and the pair of noduli per tergite was part of this row. When the noduli moved in a frontal direction, they left a gap in the marginal row of setae.

This species (probably also the whole genus) is remarkable for the combination of a fully pigmented body with the absence of eyes. Vandel (1958) denied the existence of pigmented oniscids without eyes, and explained their description by an observation error; in the cases that he examined, this was correct. Here, the existence of a blind, but pigmented oniscid is demonstrated for the first time.

Habitat

Cloud forest at the level of the Biological Station and above. The specimens were found in leaf litter and under stones.