Spherarmadillo cavernicola, MULAIK, 1960

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 28-29

SPHERARMADILLO CAVERNICOLA MULAIK, 1960

Spherarmadillo cavernicola Mulaik, 1960 – Leistikow & Wägele (1999 *); Souza-Kury (2000 *).

Spherarmadillo schwarzi – Schultz (1984); Schmalfuss (2003 *).

Material examined

Types: Not seen.

Other samples: One ♀ m, two ♀, two ♂ ( Mexico, Tamaulipas, Rancho del Cielo , cave N. 4, altitude 1100 m, leg. P. Beron, 31 January 1982, MZUF 1441 ); one ♂, two ♀ (same data, SMNS 10094 ) .

Description ( Figs 58–64 )

Male maximum 6.4 × 2.5 mm (cephalothorax 1.55 mm wide), female with marsupium 7.1 × 3.3 mm (cephalothorax 1.85 mm wide). Eyes and pigment entirely absent. Tergal surface smooth, with scales (not shown on Fig. 59 ). Cephalothorax with frontal shield separated from vertex only by a suture. Its upper margin in frontal view is evenly convex, and in dorsal view is medially slightly recurved. First coxal plate with a schisma, the outer lobe much exceeding the inner lobe caudally, the inner lobe slightly exceeding the outer lobe laterally. All tergites with one pair of noduli laterales, at the same distance from the lateral margin, and at some distance (decreasing from one to seven) from the posterior margin. Noduli four to five times longer than the ordinary scale setae.

First antenna three-jointed; distal article is approximately six times as long as second article and 1.3 times as long as basal article. Distal article with two large distal aestethascs with narrow tips, and two transverse rows of smaller aesthetascs. Second antenna slightly longer than pereiopod 7, with thickened fifth article and a three-jointed flagellum. Distal articles of the latter are separated by a suture that is weaker than the joint between the first and second article and appears not to allow movement. Apical cone long, but shorter than the distal flagellar article, with only one (not a pair) indistinct structure which may be a (vestige of?) lateral free sensillum.

Mandibles: right mandible with pars incisiva forming a broad surface exceeded by four short cusps, small, simple lacinia mobilis. Left mandible with welldeveloped four-cusped pars incisiva, and very large lacinia mobilis with three short cusps. Hairy lobe with one hairy seta each and one hairy seta between the lobe and the simple pars molaris represented by a single, thick, hairy seta. Probably the left mandible has two hairy setae on the hairy lobe and none between lobe and pars molaris; this is not completely visible ( Fig. 60 ). Exterior part of both mandibles with some scales and few scale setae. First maxilla lateral endite on the apical margin with one large lateral tooth seta and eight smaller tooth setae, plus one seta that is about half as long and more lobe-like; as well as the latter, there seems to be a very slender and short seta, probably a vestigium of the ‘slender stalk’. All setae have simple tips, and according only to the position of the lobe-like seta, three of the smaller setae, together with the large lateral one, can be identified as the lateral group, whereas five setae form the mesal group. No small subapical setae could be seen. Distal third of the lateral margin of the lateral endite fringed with hairs (pectinate scales); the fringe is not continuous. Mesal endite of first maxilla bearing two stout penicils with dense setules, the distolateral corner bearing a small, but sharp tip. Second maxilla apically bilobate, the mesal lobe being somewhat broader than the lateral lobe and bearing a field of sensilla on the mediodistal margin. One single sensillum between lobes. Maxilliped basis on the proximal two-thirds with rather irregular scales, and some scale setae. Endite rectangular, with one long, sharp lobe in the distal margin, one seta on the lateral corner, a fringe of hairs on lateral margin, and one seta on the caudal face, in a subapical position. Maxilliped palp three-jointed, the proximal article bearing a single large setae near the medial margin, the second article with a tuft of three setae of unequal size on a long socket; at the base of a socket, two small setae thought to be homologous with the basal tuft as found, for example, in Scleropactes . One small seta beside the socket. Lateral margin of the second article with one slender and one stout seta. Distal article with an apical tuft of numerous small setae, one such seta in a subapical position on the inner margin, and one seta and a tuft of hairs (pectinate scale?) on the lateral margin. On the frontal face of the distal article there is a longitudinal fold and a small seta beside it.

Pereiopod 1 with transverse brush composed of scales on the carpus, and row of small scales or setae on the proximal portion of the ventral face of the propodus. Male pereiopods 1–3 with enlarged scales on the ventral face of the carpus. Male pereiopod 7 with elongated ischium with concave ventral margin, but no further special structures. Dactyli with outer claw, slightly shorter inner claw, a more or less curved ungual seta even shorter than both claws, and a very small seta beside the ungual seta. Dactylar seta also not reaching the tip, distally slightly enlarged, and with a fringe of setules. Beside the dactylar seta there are two aesthetasc-like setae and some scales.

None of the pleopod exopodites have obvious lungs or respiratory fields (but, at least in the dissected specimen, there is a proximal area with a diffuse structure, which might turn out to be either an artefact or something related to respiration, if fresh specimens are examined). Exopodites 2–5 have one or two marginal setae, the number differing even between the pleopods of one pair. Male pleopod 1 endopodite distally slightly curved, with a recurved lobe on the lateral face and a row of long spines along the spermatic furrow. Exopodite 1 is transverse, with a weakly developed distal lobe. Male pleopod 2 exopodite is distally elongate, and only slightly shorter than the endopodite. Male pleopod 5 exopodite distally extended to an acute lobe, with a distinct furrow along the medial margin and a transverse band of pectinate scales on the caudal (dorsal) face.

Habitat

Cave.

Geographical distribution (Map Fig. 55 )

Mexico, States Tamaulipas and San Luis Potosi ( Souza-Kury 2000) .

Remark

Spherarmadillo cavernicola was reduced to a synonym of S. schwarzi by Schultz (1984). The present investigation suggests that these are separate species. Spherarmadillo schwarzi is distinguished from S. cavernicola at least by the serrated margin of the pleon epimera and uropod sympodites.

Figures

Figure 55. Geographical distribution of Richardsoniscus portoricensis (1), Spherarmadillo cavernicola (2), Sphe. nebulosus (3), Sphe. schwarzi (4), and Troglopactes botosaneanui (5).

Figure 58. Spherarmadillo cavernicola Mulaik, 1960: ♀m, 7.1 × 3.3 mm (cephalothorax 1.85 mm), habitus lateral and pleon dorsal; ♂, 6.4 × 2.5 mm (cephalothorax 1.55 mm), cephalothorax lateral, dorsal, frontal (Mexico, Tamaulipas, Rancho del Cielo, cave N. 4, altitude 1100 m, leg. P. Beron, 31 January 1982, MZUF 1441).

Figure 59. Spherarmadillo cavernicola Mulaik, 1960: ♂, 6.4 × 2.5 mm, cephalothorax 1.55 mm, 1a tergite 1 inner face, 1b tergite 1 strictly ventral; tergites 1–7 mounted on a slide, and detail of tergite 1 showing nodulus lateralis and scale-setae (Mexico, Tamaulipas, Rancho del Cielo, cave N. 4, altitude 1100 m, leg. P. Beron, 31 January 1982, MZUF 1441).

Figure 60. Spherarmadillo cavernicola Mulaik, 1960: ♂, 6.4 × 2.5 mm, cephalothorax 1.55 mm, mouthparts and first antenna (Mexico, Tamaulipas, Rancho del Cielo, cave N. 4, altitude 1100 m, leg. P. Beron, 31 January 1982, MZUF 1441).

Figure 61. Spherarmadillo cavernicola Mulaik, 1960: ♂, 6.4 × 2.5 mm, cephalothorax 1.55 mm, pereiopods 1–3 frontal, pereiopod 6 dactylus frontal, pereiopod 2 dactylus caudal (Mexico, Tamaulipas, Rancho del Cielo, cave N. 4, altitude 1100 m, leg. P. Beron, 31 January 1982, MZUF 1441).

Figure 62. Spherarmadillo cavernicola Mulaik, 1960: ♂, 6.4 × 2.5 mm, cephalothorax 1.55 mm, pereiopods 4–6 frontal, uropods dorsal and ventral (Mexico, Tamaulipas, Rancho del Cielo, cave N. 4, altitude 1100 m, leg. P. Beron, 31 January 1982, MZUF 1441).

Figure 63. Spherarmadillo cavernicola Mulaik, 1960: ♂, 6.4 × 2.5 mm, cephalothorax 1.55 mm, second antenna ventral, flagellum of other second antenna dorsal, apical cone enlarged, pereiopod 7 frontal and caudal (Mexico, Tamaulipas, Rancho del Cielo, cave N. 4, altitude 110 m, leg. P. Beron, 31 January 1982, MZUF 1441).

Figure 64. Spherarmadillo cavernicola Mulaik, 1960: ♂, 6.4 × 2.5 mm, cephalothorax 1.55 mm, pleopods 1–5; beside pleopods 2 and 3, a detail of the opposite pleopod is given to show the difference (Mexico, Tamaulipas, Rancho del Cielo, cave N. 4, altitude 1100 m, leg. P. Beron, 31 January 1982, MZUF 1441).