Scleropactes pululahua, Schmidt, 2007

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 47-49

SCLEROPACTES PULULAHUA SP. NOV.

Material examined

Type specimens: Holotype ♂; paratypes four ♂, five ♀ ( Ecuador, Pichincha Prov., Pululahua volcano, altitude c. 3000 m, leg. L. Bartolozzi, 14 February 1993, MZUF).

Other samples: Six ♀ m, three ♂, seven ♀ and immatures ( Ecuador, Imbabura, road Cahuasqui-Buenos Aires , altitude 3500 m, leg. G. Onore, 10 March 1993, MZUF); one ♀, three ♂ ( Ecuador, Esmeraldas Prov., Mayronga, altitude 100 m, leg. G. Onore, 25 October 1993, MZUF) .

Description ( Figs 128–133 )

Female 7.2 × 3.5 mm, cephalothorax 1.80 mm wide, 20 or 21 ommatidia; male 6.6 × 3.0 mm, cephalothorax 1.57 mm, 18/18 ommatidia.

Tergites brown, with pale muscle insertions and a row of pale patches at the base of the coxal plates. Second antenna brown, the distal part of the fifth peduncular article and the flagellum white.

In dorsal view, the linea frontalis is medially straight and curved forwards in the region of the lateral lobes. Lateral lobes about half as long as eyes, not distinctly delimited. Frontal shield with median part forming a broad ridge between antennae, in dorsal view with slightly concave frontal face. In frontal view, linea frontalis weakly convex, lateral lobes forming slightly acute outer angles. Dark brown, with slightly brighter coxal plates and epimera. Pale patches at the base of the coxal plates and in the middle of the tergites. Noduli laterales could not be discerned from the other large tergal sensilla, which give the animal a pilose appearance, although they are distinctly weaker than in Scleropactes pilosus .

First antenna triarticulate, medial article shortest. Distal article with sharp, acute tip, two large, subapical aesthetascs and a group of c. ten smaller aesthetascs on the frontal face. Second antenna with triarticulate flagellum; apical cone longer than the distal article. Apical cone with only one free lateral sensillum (not a pair of sensilla). Medial and distal articles with a transverse row of two aesthetascs.

Left mandible with pars incisiva of four cusps, large lacinia mobilis with two cusps, hairy lobe with two hairy setae, one single hairy seta between hairy lobe and pars molaris, the latter represented by a tuft of hairy setae. Right mandible with pars molaris of four very blunt cusps and smaller lacinia mobilis, hairy lobe with one hairy seta, but no small hairs, one single hairy seta between hairy lobe and pars molaris. The latter is similar to that on left mandible. Both mandibles on the outer face with some setae. First maxilla lateral endite on distal margin with lateral group of four strong, simple tooth setae, a small triangular lobe and a slender seta, and a mesal group of six more slen- der, simple teeth. (At low magnification, the mesal group may appear to be composed of four teeth only.). Only one very small subapical, serrate seta on the caudal face beside mesal group (observed in two specimens). Distal third of lateral margin densely fringed with hairs (pectinate scales). Mesal endite bearing two stout penicils; there is a very short, obtuse-angled corner lateral of the penicils. Lateral margin distally hairy. Second maxilla distally bilobate, the lobes subequal. Both lobes hairy, mesal lobe with group of sensilla on frontal face, near margin, and two small setae between lobes. Maxilliped basis distinctly scaly in the basal and lateral parts, epipodite with few hairs. Endite approximately rectangular, longer than wide, distal part covered with acute scales; one penicil near the mediodistal corner, on the frontal face. A very small knob (probably homologous with a seta) in a more proximal position, also on the frontal face. Maxilliped palp proximal article bearing two large setae, the lateral one somewhat smaller. In holotype male, only the left maxilliped lacks the smaller lateral seta ( Fig. 129 ). Second article with distal tuft of several equal setae, and one slightly larger and more acute seta on a long socket, two equally sized setae beside the socket, and a pair of two more setae of the same size near the base of the socket. On lateral margin of second article, one broad seta and one to three slender setae. Distal article with apical tuft of equal setae, and one seta on the lateral margin. A longitudinal ridge on frontal face, as present in many Oniscidea, could not be seen.

Pereiopod 1 carpus with transverse brush of long, hair-like scales. Distal margin formed by a transverse row of tongue-shaped, hyaline scales. Propodus only with a small area with ventral spine-like scales. Male pereiopods with ventral scale-fields on merus and carpus of pereiopods 1–4. Carpus of pereiopods 2–5 on frontal face with a small, distal scale-field, decreasing in size from 2 to 5. Male pereiopod 7 ischium with concave ventral margin; on frontal face with a dorsodistal depression. Pereiopod dactyli with large outer claw, very small inner claw, dactylar seta apically double fringed, curved interungual seta with smaller seta beside it, one small seta on frontal and caudal face each, and some scales. Proximal of dactylar seta there are two aesthetasc-like setae.

Pleopods 1 and 2 with very indistinct lateral areas, which may represent vestigial respiratory fields. Male pleopod 1 exopodite broader than long, without marginal setae. Pleopod 1 endopodite slightly curved laterally, with simple tip bearing some wrinkles on the outer side. Row of small, spine-shaped setae (29 in the holotype) along the dorsal spermatic furrow. Male pleopod 2 endopodite slightly exceeding exopodite, the latter with four marginal setae. Pleopod 3 and 4 endopodites apically bilobate. Pleopod 3– 5 exopodites with two marginal setae each, and without distinct respiratory fields. Pleopod sympodites with one or two small setae. Female pleopod 1 exopodite less than half as long as wide, without marginal setae, endopodite lacking. Female pleopod 2 exopodite with one marginal seta, endopodite represented by a short cone. Uropods: distinct gland pores could not be seen. Exopodite shorter than sympodite; exopodite and endopodite reach approximately the same level.

The specimens from Mayronga are assigned to this species with some doubt. Differences are in the shape of coxal plate 4, which is narrower, and probably in the male pleopod 1 endopodite. As the specimens are also larger, the male characters could not be compared in a sensible way (see variation in Scleropactes zeteki ).

Derivation of the name

After the locus typicus, the Pululahua volcano.

Biology

Females carry eight eggs in the marsupium (N = 4). Females with marsupium were in the sample collected in March, but not in the sample collected in February. However, the total numbers are too low for conclusions to be drawn.

Remark

This species is most closely related to Scleropactes pilosus , which is similar in the pilose tergites, coloration, and morphology of the cephalothorax. Differences are in the shape of coxal plates 2–4, and the male pleopod 1 exopodite.

Figures

Figure 128. Scleropactes pululahua sp. nov.: paratype ♂, 6.5 × 3.3 mm, cephalothorax 1.82 mm wide, habitus lateral, pleon dorsal; holotype ♂, 6.6 × 3.0 mm, cephalothorax 1.57 mm wide, cephalothorax lateral, dorsal, frontal (Ecuador, Pichincha Prov., Pululahua volcano, altitude 3000 m, leg. L. Bartolozzi, 14 February 1993, MZUF).

Figure 129. Scleropactes pululahua sp. nov.: holotype ♂, 6.6 × 3.0 mm, cephalothorax 1.57 mm wide, maxilliped caudal, maxilliped distal part enlarged, frontal; paratype ♀, 3.5 mm wide, cephalothorax 1.80 mm wide, all other mouthparts, first antenna (Ecuador, Pichincha Prov., Pululahua volcano, altitude 3000 m, leg. L. Bartolozzi, 14 February 1993, MZUF).

Figure 130. Scleropactes pululahua sp. nov.: holotype ♂, 6.6 × 3.0 mm, cephalothorax 1.57 mm wide, pereiopods 1–3 frontal, uropod dorsal and ventral; paratype ♀, 3.5 mm wide, cephalothorax 1.80 mm wide, second antenna flagellum (Ecuador, Pichincha Prov., Pululahua volcano, altitude 3000 m, leg. L. Bartolozzi, 14 February 1993, MZUF).

Figure 131. Scleropactes pululahua sp. nov.: holotype ♂, 6.6 × 3.0 mm, cephalothorax 1.57 mm wide, pereiopods 4–6 frontal, pereiopod 4 dactylus frontal and caudal (Ecuador, Pichincha Prov., Pululahua volcano, altitude 3000 m, leg. L. Bartolozzi, 14 February 1993, MZUF).

Figure 132. Scleropactes pululahua sp. nov.: holotype ♂, 6.6 × 3.0 mm, cephalothorax 1.57 mm wide, pereiopod 7 frontal and caudal, second antenna ventral, sesond antenna apical cone enlarged (Ecuador, Pichincha Prov., Pululahua volcano, altitude 3000 m, leg. L. Bartolozzi, 14 February 1993, MZUF).

Figure 133. Scleropactes pululahua sp. nov.: holotype ♂, 6.6 × 3.0 mm, cephalothorax 1.57 mm wide, pleopods 1–4 frontal, pleopod 5 caudal; paratype ♀, 3.5 mm wide, cephalothorax 1.80 mm wide, pleopods 1 and 2 frontal (Ecuador, Pichincha Prov., Pululahua volcano, altitude 3000 m, leg. L. Bartolozzi, 14 February 1993, MZUF).