Circoniscus gaigei, PEARSE, 1917

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 67-68

CIRCONISCUS GAIGEI PEARSE, 1917

Circoniscus gaigei Pearse, 1917 – Van Name (1925, 1936); Arcangeli (1927 *); Paulian de Félice (1944); Lemos de Castro (1967); Boyko (1997 *).

? Paracubaris spinosus Collinge, 1917 – syn. Van Name (1925).

Synarmadillo spinosus – Arcangeli (1927 *).

Circoniscus spinosus – Van Name (1925); Leistikow & Wägele (1999 *); Schmalfuss (2003 *).

Not: Circoniscus gaigei – Andersson (1960); Lemos de Castro (1967); Schmalfuss (1980); Souza & Lemos de Castro (1991); Schultz (1995 *); Warburg et al. (1997); Souza-Kury (1998 *); Leistikow & Wägele (1999 *).

Material examined

Types: Three ♀ m, three ♀ or immatures, fragments of one ♂ and six other specimens (syntypes of Ci. gaigei , British Guiana, Dunoon, leg. F. M. Gaige, 17 July 1914, Walker Expedition , University of Michigan, USNM 98371 ) .

Description ( Figs 204–208 )

Male 7.3 mm wide, adult females (with marsupium) 6.2–7.5 mm wide. Pigment incompletely preserved, some specimens have patches of dark pigment near the posterior margins of the tergites. Cephalothorax short, with a weak but distinct transverse furrow behind the frontal shield. Coxal plate 1 with schisma as typical for the genus, the following coxal plates simple.

Eyes composed of 26–27 ommatidia.

Pereiopods covered with scales, these distally somewhat projecting from surface. Male pereiopods with ventral brushes as follows: carpus 1 with large ventrofrontal scale-field confluent with antennacleaning brush; carpus 2–5 with ventral scale-field of decreasing extent and density; carpus 1–7 with ventral scale-fields of slightly decreasing density; ischium 1 with ventrocaudal scale-field. Male pereiopod 7 ischium and merus without any scaly lobes and base without distinct water-conducting scale-row. Dactyli with large outer claw, small inner claw, ungual seta and small seta beside it, dactylar seta with hirsute apical portion, some aesthetasc-like setae beside base of dactylar seta, one frontal and one caudal subapical simple seta and some scales.

Pleopod 1–5 exopodites with distinct, weakly wrinkled respiratory fields and small marginal setae. Male exopodite 1 with triangular distal lobe, exopodites 2–4 with medial margin hairy, and exopodite 5 apically acute, with a median furrow (to which is still attached part of endopodite 2 in the specimen from which the drawing was made). In the only male specimen of the type series, the apex of both pleopod 1 endopodites is damaged, so this character remains unknown. Male pleopod 2 endopodite longer than exopodite. Uropod sympodites angulate; the distal margin is about three times as wide as the endopodite.

Geographical distribution (Map Fig. 203 )

Guyana.

Remark

The type series contains only one male specimen. The characteristics of male pereiopod 7, as found in Circoniscus gaigei auct., are not present: the absence of these characters cannot be attributed to the possibility that the specimen is immature. In contrast, both males and females are distinctly larger than in C. gaigei auct. This implies that the type specimens of C. gaigei belong to a different species than the specimens determined as C. gaigei by subsequent authors. For the latter, the name C. ornatus ( Verhoeff, 1941) is valid (see below).

The description of Paracubaris spinosus Collinge, 1917 does not contain any useful information. The type specimens were not available for study. According to the size of the specimens (20.5 mm), it is a synonym of C. gaigei , as proposed by Arcangeli (1927), rather than a synonym of C. ornatus .

Figures

Figure 203. Geographical distribution of Circoniscus gaigei (1), Ci. hirsutus (2), Ci. incisus (3), and Ci. intermedius (4).

Figure 204. Circoniscus gaigei Pearse, 1917: ♀, 7.5 mm wide, habitus lateral and pleon dorsal; ♂, 7.3 mm wide, cephalothorax (syntypes, Guyana, Dunoon, leg. F. M. Gaige, 17 July 1914, USNM 98371).

Figure 205. Circoniscus gaigei Pearse, 1917: ♂, 7.3 mm wide, pereiopods 1–3 (syntype, Guyana, Dunoon, leg. F. M. Gaige, 17 July 1914, USNM 98371).

Figure 206. Circoniscus gaigei Pearse, 1917: ♂, 7.3 mm wide, pereiopods 4–6 (syntype, Guyana, Dunoon, leg. F. M. Gaige, 17 July 1914, USNM 98371).

Figure 207. Circoniscus gaigei Pearse, 1917: ♂, 7.3 mm wide, pereiopod 7, pleopod 5 (syntype, Guyana, Dunoon, leg. F. M. Gaige, 17 July 1914, USNM 98371).

Figure 208. Circoniscus gaigei Pearse, 1917: ♂, 7.3 mm wide, pleopods 1–4 (syntype, Guyana, Dunoon, leg. F. M. Gaige, 17 July 1914, USNM 98371).