Sphaeroniscus, GERSTACKER, 1854

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 57-59

publication ID	https://doi.org/ 10.1111/j.1096-3642.2007.00286.x
persistent identifier	https://treatment.plazi.org/id/03858799-4204-FFD0-98FC-7F36AD91FD64
treatment provided by	Felipe
scientific name	Sphaeroniscus
status

Treatment

SPHAERONISCUS GERSTÄCKER, 1854 View in CoL

Type species: Sphaeroniscus flavomaculatus Gerstäcker, 1854 (by monotypy).

Diagnosis

Eyes present, with lenses (in Sphaeroniscus gerstaeckeri only with pigment spots). Endoantennal conglobation, surface smooth. First coxal plate with schisma, anterior corner delimited by a weak ridge. Coxal plate 5 enlarged, with concave lateral margin. (convergent in N. zoiai , not in Sphaeroniscus gerstaeckeri ). Noduli laterales, as far as known, very small and located on the posterior margin of the tergites. Flagellum of second antennae with three articles. Male pereiopod 7 ischium with concavity and merus with a triangular lobe on the frontal side of the dorsodistal corner. Uropod sympodites angulate at outer corner.

KEY TO THE SPECIES OF SPHAERONISCUS View in CoL

1. Dorsal surface appears hairy or spiny because of the large tricorn setae..... Sphaeroniscus pilosus Vandel, 1972 View in CoL

1. Dorsal surface smooth........................................................................... 2

2. Coxal plate 5 with convex lateral margin; eyes represented by pigment spots without lenses............................................................................... Sphaeroniscus gerstaeckeri Vandel, 1968

2.* Coxal plate 5 with concave lateral margin; eyes with lenses present..................................... 3

3. Frontal shield exceeding vertex by about eye length; pleopod exopodites without marginal setae; uropod sympodites without dorsal gland pores................................ Sphaeroniscus flavomaculatus Gerstäcker, 1854

3.* Frontal shield exceeding vertex by less than half of eye length; pleopod exopodites with numerous small marginal setae; uropod sympodites on dorsal face with a group of gland pores..................................... 4

4. Male pereiopod 7 merus in frontal view with tubercle at dorsal margin; pleopod 1 endopodite tip with a slight swelling on the median margin, the small setae along the spermatic furrow are simple. First maxilla inner endite with two penicils.................................................. Sphaeroniscus frontalis Richardson, 1914

4.* Female pereiopod 7 merus in frontal view with tubercle below dorsal margin; pleopod 1 endopodite tip with a tubercle on the lateral margin; the small setae along the spermatic furrow are simple except for the five distalmost, which are cleft. First maxilla inner endite with number of penicils greater than two and instable (two large and one or two smaller).............................................................. Sphaeroniscus quintus sp. nov.

SPHAERONISCUS FLAVOMACULATUS GERSTÄCKER, 1854 View in CoL

Sphaeroniscus flavomaculatus Gerstäcker, 1854 View in CoL – Stuxberg (1875); Budde-Lund (1879 *); Stebbing (1893 *); Richardson (1914); Van Name (1936 *); Leistikow & Wägele (1999 *); Schmalfuss (2003 *).

Not: Sphaeroniscus flavomaculatus View in CoL – Vandel (1972) (misidentification).

Material examined

Holotype: One ♂ [ ZMB *27267 (white label) ‘ Sphaeroniscus Gerst. ’ (blue label) ‘ flavomaculatus Gerst. , Nov. Gran., Goud.’). The holotype, from which Gerstäcker’s figure had been drawn, was found in the J. F. Brandt collection, mounted on an insect pin.

Other samples: One ♂ (lacks second antennae and pigment) ( Colombia, between Bosca del Monte and Tambo, altitude 2000 m, leg. Otto Fuhrmann, USNM 43458 View Materials ) .

Description ( Figs 166–171 View Figure 166 View Figure 167 View Figure 168 View Figure 169 View Figure 170 View Figure 171 )

Male 17 × 7.6 mm. (Female unknown.) Dorsal face dark brown with pale muscle insertion spots. Coxal plates paler than tergites. With endoantennal conglobation ability. Cephalothorax frontally flat, lamina frontalis and clypeus less protruding than in most other species. Eyes composed of about 18 or 19 ommatidia. Frontal shield far exceeding the vertex. Between vertex and posterior face of the frontal shield a distinct transverse furrow, which laterally ends at some distance from eyes. Coxal plates and pleon-epimera enlarged, first coxal plate with distinct schisma on the posterior corner. Anterior corner of first coxal plate striated and delimited by a weak ridge. Lateral margin of first coxal plate bent upwards; in consequence, a broad margin of ventral surface is visible in strictly lateral view, and the dorsal face is deeply concave. Coxal plates 2–4 narrower. Coxal plates 2–7 laterally simple. Coxal plate 2 with shallow transverse sulcus near the anterior margin of the inner face. Coxal plate 5 wide, its lateral margin slightly concave. Coxal plates 5–7 with small lobes arising from the posterior margin of the leg insertions; these lobes fit with the anterior margins of following tergites. Size of coxal plates slightly decreasing from 5 to 7 (in the Oniscidea, seventh usually broadest of these three). Pleonepimeron 3 in lateral view broader than coxal plate 7. Very small noduli laterales near hind margins of tergites 2–6.

First antenna three-jointed, third article 1.5 times as long as articles 1 and 2 together, c. 20 rather small aesthetascs arranged in irregular transverse rows. Second antenna with three-jointed flagellum (apical cone broken off in the holotype), of which proximal and medial articles are equal and distal article is longer.

Mandibles with four-cusped pars incisiva, lacinia mobilis on left mandible with three cusps, on right with two cusps, hairy lobe with one hairy seta on the right and two on the left mandible, pars molaris represented by a tuft of numerous hairy setae, and one hairy seta each between the hairy lobe and the pars molaris. External face of mandible with some small scale setae. First maxilla lateral endite on distal margin 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, which appears to be furcate (probably artefact?), on the caudal face beside lateral group. Beside mesal group of tooth setae, on caudal face a small seta could not be seen with certainty. Lateral margin of lateral endite distally fringed with hairs (pectinate scales). Mesal endite of first maxilla distally rounded, with two slen- der subapical penicils. Second maxilla apically bilobate, mesal lobe with a distal field of numerous (c. 120) 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 the insertion of the palp, on the caudal face; some longer scales resemble the scales of water-conducting structures. Epipodite (apically damaged). Endite elongate rectangular, covered with pectinate scales and bearing a small seta on the caudal face and a small penicil on the frontal face, near the mesal corner. Maxilliped palp proximal article with only one large seta near the mesal margin, second article on the mesal margin with two tufts of several equal setae, the distal tuft on a long socket and with two single setae beside it; lateral margin with one slender and one broad seta. Distal article (damaged in the specimen on which the drawing is based) with apical tuft of numerous small setae, and six single setae on the lateral margin. Some pectinate scales are also found in the medioproximal region of the second article.

Pereiopod 1 with antennal brush not distinctly discernible from the scale-field. Male pereiopods 1–3 with large ventrofrontal scale-fields on carpus, pereiopod 1 also on propodus. Ventral scale-fields on pereiopods 1 and 2 ischium and on pereiopods 1–4 merus. Pereiopod 1 base frontal face enlarged. Male pereiopod 7 ischium slender, approximately 1.5 times as long as ischium 6, with dorsofrontal depression in the distal third of the article. Merus with small but sharp tubercle in dorsofrontal position near the distal margin. Dactyli with dactylar seta, some aesthetasc-like setae beside the dactylar seta, slightly curved ungual seta that is shorter than the outer claw and accompanied by a small seta, one smaller seta each on frontal and caudal faces. Inner claw 0.2 times as long as outer claw.

Pleopod 1 exopodite with distinct lateral respiratory field and outcurved distal lobe. Pleopod exopodites 2–5 with less distinctly delimited, probably respiratory fields. Exopodites 1–5 without marginal setae (the exopodites were somewhat distorted during preparation, but neither setae nor articulation holes were found). Endopodite 1 slightly and evenly bent outwards, evenly narrowed and with a row of 46 small spine-shaped setae along the spermatic furrow. Genital papilla with subapical, lateral orifices surpassed by a lobe. The lobe appears truncate, but this is probably an artefact. Endopodite 2 slender and straight (on the drawing it is shown as distorted by the preparation). Exopodites 2 and 5 with distinct hairy furrow on the medial face. Exopodite 5 with broad transverse band of several irregular rows of pectinate scales.

Pleotelson rounded-triangular, not reaching body outline, exceeded by distally angulate, truncate uropod sympodites. Uropod exopodites shorter than distal margin of sympodites. Endopodites inserted more proximally, their tips reaching body outline. Tergites smooth.

Apomorphies of Sphaeroniscus flavomaculates

1. extended frontal shield

2. pleopod exopodites without marginal setae

Remark

Beside the holotype specimen, only two authors referred to other specimens identified as Sphaeroniscus flavomaculatus . Richardson (1914) recorded the species from Colombia, referring to the second known specimen. Vandel (1968) erroneously identified a specimen of S. frontalis as S. flavomaculatus .