Sphaeroniscus quintus, Schmidt, 2007

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 60-61

publication ID	https://doi.org/ 10.1111/j.1096-3642.2007.00286.x
persistent identifier	https://treatment.plazi.org/id/03858799-4207-FFD6-98EE-7C24AA9DF8D9
treatment provided by	Felipe
scientific name	Sphaeroniscus quintus
status	sp. nov.

Treatment

SPHAERONISCUS QUINTUS View in CoL SP. NOV.

Material examined

Type specimens: Holotype ♂, paratypes one ♀ m, four immature ♀ ( Colombia, Sasaina, leg. M. Ibáñez, 18 February 1983, BMNH 1983.535.6).

Other samples: One ♂ ( Colombia, Cundinamarca, Pacho , c. 5°N, 74°W, leg. O. Bürger, 24 March 1897, SMF ZMG 469 View Materials ) GoogleMaps .

Specimens tentatively identified as Sphaeroniscus quintus

One ♂, one ♀ (Columbia, Cundinamarca, Sibote , altitude 2800 m, leg. O. Bürger, 1897, SMF ZMG 468 View Materials )

Description ( Figs 176–181 View Figure 176 View Figure 177 View Figure 178 View Figure 179 View Figure 180 View Figure 181 )

Male 5.0 mm wide, cephalothorax width 2.36 mm. Female with marsupium c. 12 × 5.9 mm, cephalothorax width 2.80 mm, 22 ommatidia.

The coloration seems to have faded as a result of preservation, and therefore cannot be described in detail. Tergites brown, area of muscle insertions, coxal plates, pleon epimera, and also the cephalothorax pale. Second antennal fifth article with little pigment, flagellum pale. Pereiopods and pleopods not pigmented. Endoantennal conglobation. Dorsal surface smooth and shiny, with only very small tricorn setae. Noduli laterales could not be seen without dissection. Cephalothorax with frontal shield only slightly exceeding the vertex. Behind frontal shield a transverse furrow, which is bent backwards at both ends and then becomes obsolete. First coxal plate with schisma, inner lobe distinctly shorter but laterally more protruding. Anterior corner of first coxal plate delimited by a weak ridge, with striation. Second coxal plate with anterior thickened sulcus. All margins of tergites, pleon-epimera and uropod sympodites fringed with minute, hyalinous hairs or scales.

First antenna three-jointed, second article shortest. Distal article with a pair of apical aesthetascs and eight subapical aesthetascs. Second antenna with three-jointed flagellum, apical cone longer than distal article. Second and third articles with one and two aesthetascs.

Mandibles with three-cusped pars incisiva, lacinia mobilis on left mandible with two cusps, on right with two cusps, hairy lobe with one hairy seta on right and two on left mandible, pars molaris represented by a tuft of numerous hairy setae, and one hairy seta each between hairy lobe and pars molaris. Outer face of mandible with some small scale setae. First maxilla lateral endite with lateral group of four stout teeth and mesal group of six more slender teeth, five of them with cleft tips. A triangular lobe and a slender seta on the caudal face beside lateral group. Beside mesal group, a subapical, extremely small seta on caudal face. Lateral margin of lateral endite distally fringed with hairs (pectinate scales). Mesal endite of first maxilla distally rounded; one specimen has two larger and two slightly smaller penicils on both sides, another specimen has two large and one much smaller penicil on one side. A third specimen from another locality has only two penicils on one side. Second maxilla apically bilobate, mesal lobe with a distal field of presumed sensilla on the frontal face, and a slightly broader lateral lobe covered with pectinate scales. Maxilliped basis roughly rectangular, with small scale setae and scales; near insertion of palp, on caudal face, some longer scales resembling scales of water-conducting structures. Epipodite slightly hairy at its tip. Endite elongate rectangular, covered with pectinate scale and bearing a small seta on caudal face, and a penicil on frontal face, near the inner corner. Maxilliped palp proximal article with only one large seta near mesal margin, second article on mesal margin with two tufts of several equal setae, distal tuft on a long socket and with two single setae beside it; lateral margin with one slender and one broad seta. Distal article with apical tuft of numerous small setae, and three single setae on the lateral margin.

Pereiopod 1 with antennal brush composed of rather long scales on merus. Male pereiopod 7 carpus with dorsofrontal tooth-like process near distal margin. Scales resembling those of a water-conducting system could be seen only on base, near articulation with ischium. Dactylus with inner claw much shorter than outer claw, ungual seta and distally setulate dactylar seta.

Pleopod 1 and 2 exopodites with respiratory field, the latter without conspicuous structures. Lateral margin with small marginal setae. Male pleopod 1 endopodite with median subapical tubercle, some lateral subapical rugosity, and a row of 32–39 small setae along the dorsal spermatic furrow. The small setae are spiniform, except for the distalmost five, which are two to three times as long as the preceding setae, and have the tip cleft into four long ‘hairs’. Pleotelson with rounded triangular tip and concave sides. Uropod sympodite approximately as long as broad, with angular outer corner, exopodite slightly projecting beyond endopodite and sympodite. Dorsal face of uropod sympodite with a group of gland pores.

Remark

Sphaeroniscus quintus is similar in size and shape to S. frontalis , but the male pereiopod 7 and pleopod 1 endopodite indicate a closer relationship to S. pilosus . The specimens from Cundinamarca are one male, cephalothorax 1.8 mm wide, and one female, cephalothorax 1.9 mm wide. Both were covered with mould, and due to the poor preservation, it was not possible to see the important characters sufficiently clearly.

Derivation of the name

Latin quintus = the fifth.

Geographical distribution

Known only from the type locality, which could not be exactly identified.