Erigone pauperula ( Bösenberg & Strand, 1906 ), Bosenberg & Strand, 1906

Frick, Holger & Muff, Patrick, 2009, Revision of the genus Caracladus with the description of Caracladus zamoniensis spec. nov. (Araneae, Linyphiidae, Erigoninae), Zootaxa 1982, pp. 1-37 : 26-27

Erigone pauperula ( Bösenberg & Strand, 1906) nov. comb.

( Figs 60–62 ).

Caracladus pauperulus Bösenberg & Strand, 1906: 161 , plate 12, figs 257A–C.

Type material. HOLOTYPE, examined: Caracladus pauperulus Bösenberg & Strand, 1906 . Japan: 1♀ (holotype, SMF 3637-125 ) ( Bösenberg & Strand 1906).

Diagnosis. Female: The specimen was not compared with other Erigone species from Japan so that a sound diagnosis can not be provided. However, the shape of the margin of the ventral plate, seen in dorsal view has been used for species diagnoses in other Erigone species and is assumed to be typical for this species. Additionally, the postion and form of the dorsal plate, the spermatheca and the copulatory duct might also provide valuable information to recognise this species.

Males: unknown.

Description. Since the specimen is now bleached white to transparent, the colour description follows Bösenberg and Strand (1906).

Female: Total length: 1.47 mm. Cephalothorax: yellow with narrow dark brown margin and some fine, dark lines; 0.69 mm long, 0.49 mm broad. Eyes: anterior row nearly straight; posterior row slightly procurved; all eyes rather close together ( Bösenberg & Strand 1906, Fig 257C). Sternum: dark brown, with small yellow punctuations, black margin below the yellow labium; shield-shaped; 0.43 mm long, 0.34 mm broad. Labium: dark brown. Chelicerae: yellow; promargin with five big teeth; retromargin with four denticles. Legs: yellow with black hairs in rows on all segments; some macrosetae on all femora and tibiae; macrosetae and Tm I not possible to recognise. Palp: yellow. Epigyne: protruding in lateral view ( Bösenberg & Strand 1906: Figs 257B, C), transversally striated in ventral view ( Fig. 60 ), margin forming a small protuberance in the middle ( Fig. 61 ). Vulva: ventral plate much larger than dorsal plate; dorsal plate not visible in ventral view; two lobes between the dorsal and ventral plate forming the opening to the copulatory duct ( Fig. 62 ); copulatory duct sclerotised and coiled with unclear entrance to the receptacula, visible as slightly swollen part of the copulatory duct. Abdomen: dorsally brown, with dark brown dense pubescence; ventrally brown with fine yellow stripes and dots. Spinnerets: brown, brighter than the abdomen.

Males: unknown.

Distribution. Japan, no location given in the original description ( Bösenberg & Strand 1906).

Habitat and phenology. Unknown.

Remarks. Bösenberg and Strand (1906) note that the eye pattern is atypical for Caracladus but that all other characters argue for Caracladus , especially the long macrosetae on the frontal femora. We do not recognise particularly long macrosetae in neither the holotype of Erigone pauperula nov. comb. nor Caracladus avicula . The genital morphology does not fit the descriptions of the epigyne and vulva of Caracladus given above. It shows some typical characters of Erigone like the rebordered epigyne margin seen in dorsal view ( Figs 61, 62 ) and the transverse striations ventrally on the epigyne. We therefore assign this species to Erigone . However, the conformation of the vulva was very difficult to analyse because it is completely bleached. It was possible to see the form under the compound microscope, but the exact three-dimensional arrangements of the receptacula and the copulatory duct were not recognisable.

Bösenberg and Strand (1906) did not give an etymology for their species epithet “ pauperulus ”. However, it is assumed that they created a diminuitive of “pauper” that can be used as an adjective (pers. comm. Roettig) and must therefore be adjusted to agree with the genus name according to article 31.2 of the international code of zoological nomenclature (International Commission on Zoological Nomenclature 1999).

Figures

FIGURES 60 – 62. Erigone pauperula (Bösenberg & Strand, 1906) nov. comb. Female: epigyne ventral (60), vulva aboral to dorsal (61), vulva dorsal (62). Scale: 100 Μm. Specimen: Holotype, SMF 3637 - 125.