Caecopactes minimus, Schmidt, 2007

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 25-26

publication ID	https://doi.org/ 10.1111/j.1096-3642.2007.00286.x
persistent identifier	https://treatment.plazi.org/id/03858799-4224-FFF3-9B8B-7892ABCDFF4E
treatment provided by	Felipe
scientific name	Caecopactes minimus
status	sp. nov.

Treatment

CAECOPACTES MINIMUS View in CoL SP. NOV.

Material examined

Types: One ♂ holotype and two ♀ paratypes ( Ecuador, Napo Prov., Rio Hollin , altitude c. 1000 m, leg. L. Bartolozzi, 17 February 1993, MZUF) (Map Fig. 24 View Figure 24 ) .

Description ( Figs 45–51 View Figure 45 View Figure 46 View Figure 47 View Figure 48 View Figure 49 View Figure 50 View Figure 51 )

Male 2.0 × 0.95 mm, cephalothorax width 0.71 mm. Tergites smooth, with scattered bristle-like scale setae. Each tergite with one pair of noduli laterales, which are broader than the ordinary scale setae; all noduli at the same distance from the margin. Cephalothorax with neither eyes nor lobes, the frontal face concave. First coxal plate with schisma on the hind corner, the lower lobe exceeding the upper lobe in the lateral direction, whereas the upper lobe is slightly longer posteriorly. Coxal plates 2–7 are simple, more rounded (2–4) or more angular (5–7), as it is common for conglobating Oniscidea. Sternite 7 with truncate median lobe (bent frontad in the drawing). Sternite 5 with (vestigial) female gonopores (although the specimen has male pleopods and testes). Between sternites 6 and 7, there is a paired structure of unknown function. Pleotelson short, exceeded by uropods.

First antenna three-jointed, basal article slightly longer than the approximately equally long articles 2 and 3. Distal article bearing two aesthetascs. Second antennae short and stout. Fourth and fifth articles ventrally enlarged, resulting in a nearly triangular shape. Flagellum two-jointed, distal joint approximately twice as long as basal joint, and bearing a (row of?) aesthetasc(s) and a long apical cone with one small lateral sensillum.

Right mandible with three-lobed pars incisiva, small, but three-cusped lacinia mobilis, and a lobe with one penicil basal to the lacinia. Right mandible with five-lobed pars incisiva, larger, three-cusped lacinia mobilis, and a lobe with two penicils. Both mandibles with one penicil between the lobe and the pars molaris, which is represented by a single hairy seta. First maxilla lateral endite on the distal margin with lateral group of four stronger teeth and a triangular lobe and mesal group of six setae, only two of them apically cleft (mesal endite lost during preparation). Second maxilla indistinctly bilobate, with a row of few (seven?) sensilla along the margin of the mesal lobe. Maxilliped basis with few scales and few scale setae, and a few hairs on the distolateral corner. Maxilliped palp with proximal article bearing only one seta near the mesal margin; the other articles fused. On the mesal margin with a basal group of two small setae, mesal group of one large and two (?) smaller setae on a common socket, and the apical tuft of equal-sized setae. Lateral margin with a group of one large and one slender seta and two slender setae.

Pereiopod 1 with antennal brush on carpus and propodus, on the latter consisting only of a row of setae. Male pereiopods 1–4 with ventral fields of only few scales. Dactyli with inner claw only 0.2 times as long as outer claw. Ungual seta slightly curved, not exceeding the outer claw, with a small seta beside it. One smaller seta each on frontal and caudal face. Dactylar seta slightly curved, simple, and reaching the tip of the outer claw. One or two aesthetasc-like setae beside the dactylar seta. Male pereiopod 7 ischium with a strong ventrodistal projection.

Male genital papilla with strong ventral shield exceeding by two processi, which bear the gonopores. Male pleopod 1 endopodite straight, with a row of 16 small setae along the spermatic furrow on the distal half. Proximal half enlarged, nearly as broad as the exopodite, which is more short than broad, and has no setae or hairs at all. Male pleopod 2 exopodite triangular with concave lateral margin and hairy mesal margin. Endopodite 2 twice as long as exopodite. Pleopods 3 and 4 on the mesal margin with some pectinate scales, pleopods 4 and 5 with a very small subapical seta on the lateral margin. No trace of lungs or dorsal respiratory fields could be found.

Uropods consisting of flat, enlarged sympodite, endopodite, and exopodite. The exopodite is inserted in a more distal position, but the tips of endopodite and exopodite are on the same level, somewhat exceeding the sympodite.

Biology

The specimen on which the drawing is based has two parasitic fungi, probably Laboulbeniales, one on the cephalothorax and one on the second antenna. No information on the habitat was given.

Derivation of the name

Latin minimus (the smallest, or very small).