Colomboscia parva, Schmidt, 2007

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 33-34

COLOMBOSCIA PARVA SP. NOV.

Scleropactes andinus Vandel, 1972 pro parte.

Type specimen: One (immature?) ♂ holotype ( Colombia; Resina, village on the west slope of the east Cordillera, between Altamira and Florencia, altitude between 1800 and 2300 m, montane forest, in leaf litter, leg. H. Sturm, 8 June 1956, det. Vandel, MNHN, syntype of Scleropactes andinus ) .

Description ( Figs 76–78 )

Male; 3.0 × 1.35 mm, cephalothorax 0.76 mm wide. Coloration: dark brown with irregular pale patches and pale muscle insertion spots. Coxal plates lighter than tergites. Second antenna flagellum pale, uropod exopodites and endopodites pigmented in the proximal half, pale in the distal half. Surface not perfectly smooth, but with very shallow, nearly inconspicuous tuberculation. Cephalothorax with distinct lateral lobes. Transverse furrow laterally reaching the eyes, with medial portion slightly recurved. A weak ridge at some distance from the anterior margin of the first coxal plate; the distance is three to four times as large as the distance from the ridge parallel to the lateral margin. Eyes composed of 13 ommatidia, protruding beyond the level of the vertex, so that not all ommatidia can be seen in a strictly lateral view. Body flat in comparison to species with ‘eusphaerical’ conglobation ability; somewhat resembles the creeper type. Very small noduli could be seen on the posterior margins of coxal plates 1–4 (but this could not be confirmed on dissected and mounted material).

First antenna three-jointed, apical article with some aesthetascs. Second antenna: apical cone as long as all three flagellar articles together. Maxilliped base with large scales in the lateroproximal third and few scale setae. Epipodite without scales. Endite long, parallelsided, apically truncate with rounded corners. One seta on the caudal face, one elongate penicil on the frontal face, near the distal margin, and scales or spines on distal and medial margins of the endite. Maxilliped palp basal article with a single large seta near the medial margin, the second article on the medial margin with a proximal tuft one large and one very small seta, and two single setae beside the distal tuft, and one slender and one broad seta on the lateral margin (distal tuft of second article and distal part of apical article broken off). Apical article with one single seta on the lateral margin. Pereiopod 1 with a brush of scales on the carpus; some scales are very long, others appear to be distally fringed (propodus and dactylus broken off). Pereiopod 7 with distinct rows of scales (vestiges of the water-conducting structures) on the base and less distinct scale-rows on ischium and merus. Ischium with a shallow groove and merus with a rounded dorsofrontal lobe at the midlength. Dactyli with outer claw, inner claw of same length, stout ungual seta between the claws, and a smaller seta of half its length beside the ungual seta. Dactylar seta long, with a fringe of long setules in the distal portion. Except for these, one seta each on frontal and caudal faces and a few scales. Male genital papilla with ventral shield, more than half as long as the endopodite. The endopodite slightly bent outwards, with simple tip and a row of spine-shaped setae along the dorsal spermatic furrow. In the only known specimen, the row consists of 18 setae on the left and 16 setae on the right endopodite. Pleopod 2 endopodite exceeding the exopodite by about one-third. Pleopod exopodites without conspicuous respiratory structures. Pleopod 1 exopodite broader than long, without any visible setae or scales. Pleopod exopodites 2–5 with one small marginal seta on the outer margin, and an area of pectinate scales along the medial margin. Pleopod 5 exopodite on the caudal face with one or two rows of large pectinate scales, and the space between this row and the margin covered with smaller pectinate scales; median margin with distinct lateral furrow. Pleotelson short and apically sinuate. Uropod sympodites with narrow lateral lobe. Exopodite as long as visible portion of sympodite (in dorsal view) and half as broad as sympodite.

Remark

The only specimen known up to now was first identified as Scleropactes andinus by Vandel (1972), and later as Scleropactes gaigei Pearse , by Vandel (unpublished). As there are no spermatozoa visible in the genital papilla, it is not certain whether the specimen is adult. At present, it seems to be distinguished from Scleropactes andinus by the transverse furrow on the cephalothorax, which is medially slightly recurved, the less smooth tergal surface, and the shorter male pleopod 1 exopodite. However, more material is needed to estimate the intraspecific variation in that species.

Figures

Figure 76. Colomboscia parva sp. nov.: holotype (immature?) ♂, 3.0 × 1.35 mm, cephalothorax 0.76 mm wide (Colombia; Resina montane forest, in leaf litter, leg. H. Sturm, 8 June 1956, MNHN).

Figure 77. Colomboscia parva sp. nov.: ♂ holotype (immature?), 3.0 × 1.35 mm, maxilliped, pereiopods 1 (propodus and dactylus broken off) and 7 frontal (Colombia; Resina montane forest, in leaf litter, leg. H. Sturm, 8 June 1956, MNHN).

Figure 78. Colomboscia parva sp. nov.: ♂ holotype (immature?), 3.0 × 1.35 mm, pleopods 1–4 frontal, pleopod 4 and endopodite 1 caudal (Colombia; Resina montane forest, in leaf litter, leg. H. Sturm, 8 June 1956, MNHN).