Caracladus Simon 1884
Creators: name: Frick, Holger
name: Muff, Patrick
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Caracladus

description: Caracladus Simon, 1884
Type species. Caracladus avicula (L. Koch, 1869).
Diagnosis. Males: Cephalothorax with distinct lobe facing forward, PME situated on its topmost position. This lobe bears many stout, short and few thin, long hairs anterior to the PME (Fig. 11). Simon (1884) describes this lobe as a swelling that looks like a birds head, resembling to what can be seen in Walckenaeria acuminata Blackwall, 1833. Protegulum with short and/or long papilla, radix simple without any processes other than the radical tailpiece and the embolus.
Females: Dorsal plate of epigyne totally visible in ventral view, forming a more (Fig. 26) or less (Fig. 40) distinct copulatory pouch, receptacula laterally to the dorsal plate.
Description. Males: Total length: 1.85–2.50 mm. Cephalothorax: honey brown; reticulated in all known species (unknown for C. montanus); broad oval; 0.89–1.26 mm long including the cephalic lobe; 0.61–0.83 mm wide. Cephalic lobe: in most cases very distinct, forming a neck with a swollen forward facing tip (e.g.: Fig. 9; not in C. leberti, Fig. 35); Cephalic lobe with many stout, short hairs (Fig. 12) and some slender, long hairs anterior to the PME (Fig. 11); sulcus with pit in all European species present. Eyes: PME topmost on the cephalic lobe; AME projecting forward; one long macroseta (some setae in C. leberti, Fig. 35) projecting forward between AME in most species (e.g. Fig. 54). Clypeus: directed obliquely backwards. Sternum: very fine brown pigmentation on yellow ground, darker at the margins; shield-shaped (“wappenförmig”) in all known species (unknown for C. montanus). Chelicerae: honey brown; promargin with five to six teeth, of which the 3rd and 4th are strongest; retromargin with four to six denticles; stridulatory striae imbricated in all known species (unknown for C. montanus), numerous striae, in most species very densely arranged (Fig. 13). Legs: yellow; formula 4-1-2- 3 in all known species; tibia III–IV with one proximal macroseta (0-0-1-1), sometimes also present on tibia I-II; tibial macrosetae quite robust, longer than the diameter of the tibia (Simon 1884); metatarsi I–III with one trichobothrium (Tm I: 0.50–0.63) and metatarsus IV without trichobothria in all known species. Pedipalp: patella at least two times longer than broad; tibia with one prolateral and one retrolateral trichobothrium in all known species (unknown for C. montanus); form of the prolateral tibial apophysis ranging from a small knob (Fig. 20) to a distinct triangle (Fig. 32); retrolateral tibial apophysis small (Fig. 20), big (Fig. 42) or absent (Fig. 32); paracymbium simple, basally mostly with five distinct setae (Fig. 17) (three in C. tsurusakii); tegulum with short and/or long papilla on top of protegulum (Figs 1–3, 48); suprategulum, semi circular, marginal suprategular apophysis present (Fig. 31), but often minute and shifted to the distal suprategular apophysis (Fig. 19); distal suprategular apophysis highly sclerotised, facing distally; embolic membrane slender without (Fig. 19) or with (Fig. 41) papillae, emerging close to the distal apophysis (Fig. 19); radix simple without any processes other than the radical tailpiece and the strongly sclerotised embolus, rising in the opposite end (Fig. 18). Abdomen: variable in color, often dark olive green.
Females: Total length: 1.62–2.72 mm. Cephalothorax: honey brown; reticulated; 0.75–1.08 mm long; 0.58–0.83 mm wide. Eyes: posterior row procurved in all known species; anterior row straight to slightly recurved (seen from above). Sternum: very fine brown pigmentation on yellow ground, darker at the margins; shield-shaped (“wappenförmig”) in all known species (unknown for C. montanus). Chelicerae: honey brown; promargin with five to six teeth of which the 3rd and 4th are the strongest (Simon 1884); retromargin with four to six denticles; stridulatory striae imbricated, numerous striae. Legs: yellow; formula 4-1-2-3; tibia I–IV with one dorsal proximal macroseta (1-1-1-1); tibial macrosetae quite robust, longer than diameter of tibia (Simon 1884); metatarsi I–III with one trichobothrium (Tm I: 0.48–0.63), metatarsus IV without trichobothria. Epigyne: dorsal plate fully visible in ventral view, copulatory pouch present (e.g. Fig. 26), sometimes reduced to some extent (Fig. 40); receptacula positioned lateral to dorsal plate (e.g. Fig. 26). Vulva: receptacula globular, incoming dorsally (Fig. 28), copulatory duct present in most species (C. avicula, C. leberti and C. montanus) but absent in C. zamoniensis spec. nov. and C. tsurusakii. Abdomen: variable in color, often dark olive green; tracheal system with two thick median and two thin lateral tracheae (Fig. 25).
Distribution. All European species are endemic to the Alps (Fig. 59). C. avicula and C. zamoniensis spec. nov. are restricted to areas above circa 1200 m a.s.l. (one unpublished record at 800 m), whereas C. leberti occurs below 1300 m. C. montanus was found at circa 2000 m and C. tsurusakii at circa 1200 m.
Habitat. The European species prefer litter of deciduous forests (Thaler 1973; Maurer & Hänggi 1990; Frick et al. 2006). The information on the Asian species is very limited, C. tsurusakii occurs under leaf litter (Saito 1988).
Remarks. On the Asian species only three publications are available concerning mainly the type localities, which makes a more precise ecological characterisation difficult.
C. tsurusakii and C. zamoniensis spec. nov. lack a copulatory duct. The insertion of sperm is assumed to take place through a space between the ventral and the dorsal plates, which are supposed to be pressed apart during copulation.
Characters that are invariant in all Caracladus species are not specificially mentioned in the species descriptions with the exception of C. zamoniensis spec. nov.
description: Published as part of Frick, Holger & Muff, Patrick, 2009, Revision of the genus Caracladus with the description of Caracladus zamoniensis spec. nov. (Araneae, Linyphiidae, Erigoninae), pp. 1-37 in Zootaxa 1982 on pages 4-7, DOI: 10.5281/zenodo.185321