Microcreagrella caeca caeca (Simon, 1883)

Zaragoza, Juan A. & Pérez, Toni, 2013, Hypogean pseudoscorpions (Arachnida) from Jaén province (Andalusia, Spain), with descriptions of four new species and a new synonymy, Zootaxa 3700 (2), pp. 201-225 : 222

Microcreagrella caeca caeca (Simon, 1883)

Material. Spain, Andalusia, Jaén province, Villacarrillo , Cueva de la Morciguilla (38°5′27.87″N, 3°0′5.62″W; 701 m. a.s.l.), 24.II.2013, lgt. G.E.V., 1 ♂, 1 ♀ (DEUA).

Description. Carapace, chelicerae and pedipalps brownish-red, legs and opisthosoma pale. Opisthosoma elongate, partially destroyed in female.

Carapace elongate, distinctly longer than broad, anterior margin slightly prominent, no recognizable epistome; no eyes or eye-spots; chaetotaxy: 24 setae, formula 4-6-8-6.

Tergal chaetotaxy I–XI: 9:11:11:11:12:11:11:11:11:9:6 (at least 2 TS). Manducatory process with 2 setae on each side. Male genital area with 9 setae on sternite II; sternite III with 2 medial setae behind genital opening and (3)6(3) setae on posterior margin of the sternite; genitalia with 3+3 internal setae. Sternal chaetotaxy IV–XI: (3)9(3):14:14:15:15:13:11:6(2 TS); anal cone with two dorsal and two ventral setae; pleural membrane dorsally and ventrally striate, weakly granulate in-between.

Chelicera with five setae on palm, seta gl 0.62 from base of movable finger. Galea simple, length 0.04 mm in male, 0.06 in female. Fixed finger with 5 tiny distal denticles, 10 medium or small teeth and 3 basal denticles; movable finger with 8 large teeth and 2 tiny basal denticles.

Pedipalp femur shorter than the carapace. Movable chelal finger longer than hand with pedicel. Trichobothriotaxy as illustrated by Vachon (1940b: fig. 3). Trichobothrium t bent backwards, acuminate, shorter and thicker than others on movable finger, not flattened or lanceolate; st close to t, distance b – sb 1.24× distance sb – st, sb not forming group with st - t. A row of 4 antiaxial feather-shaped setae on distal half of hand and another row of 4 on antiaxial basal half of fixed finger.

Measurements and ratios. Male. Body 1.94. Carapace 0.59/0.43 (1.4). Chelicera: palm 0.30/0.16 (1.9), movable finger 0.20. Pedipalp: femur 0.51/0.17 (3.1); patella 0.45/0.22 (2.0), pedicel 0.15; chela+ 0.86/0.29 (3.0), chela - 0.79 (2.7); hand+ 0.41 (1.4), hand - 0.34 (1.2); movable finger 0.45, ratio movable finger/hand (1.1); ratio chela+/carapace 1.5; femur/carapace 0.9; femur/movable finger 1.1; femur/patella 1.1; patella/ hand+ 1.1. Female. Carapace 0.61/0.46 (1.34). Pedipalp: femur 0.57/0.18 (3.1); 0.49/0.24 (2.0), pedicel 0.17; chela+ 0.93/0.32 (2.9), chela - 0.85/0.32 (2.6); hand+ 0.40 (1.3), hand - 0.34 1.0; movable finger 0.53, ratio movable finger/hand 1.3; ratio chela+/carapace 1.5; femur/carapace 0.9; femur/movable finger 1.1; femur/patella 1.2; patella/ hand+ 1.2.

Distribution. Portugal (Azores; Madeira; mainland), Spain (Canarias; mainland).

Remarks. The assignment of the above studied specimens to the subspecies Microcreagrina caeca caeca is based in the length of the movable chelal finger relative to the hand with pedicel, which is equal in M. caeca caeca versus shorter in the Madeiran subspecies M. caeca madeirensis (Beier 1963) . However, the lengths of the pedipalp femur and chela, and the chelal movable finger/hand are higher than in the nominate subspecies, as was also the case for the specimen described by Zaragoza (2010) from mainland Portugal.

The presence of feather-shaped setae on the pedipalp chela was argued by Zaragoza (2010) to be a characteristic for the subfamily Ideobisiinae within the family Syarinidae . A group of 4–5 such setae on the basal half of the chelal fixed finger has been mentioned by Mahnert (1976, 1993) and Zaragoza (1990, 2010) for the syarinid genera Microcreagrina Beier, 1961 and Microcreagrella , both inhabiting Macaronesian Islands and the Iberian Peninsula. An additional group 4 setae feather-shaped is also present on antiaxial distal half of chelal hand in Microcreagrella . The taxonomic importance of this characteristic remains unknown.

The genus Microcreagrella was first described from the Azores and subsequently found on Madeira and the Canary Islands. Mahnert (1980) and Zaragoza (2010) recorded its presence in mainland Portugal (Coimbra, Setúbal). The new location in Southern Spain, reported here, and unpublished data of J.A. Zaragoza extend the distribution range of the genus to a great part of mainland Portugal and to other southern Spanish provinces.