Rhacochelifer euboicus Mahnert 1977
Creators: name: Hernández-Corral, Jesús
name: Zaragoza, Juan A.
name: Micó, Estefanía
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Cheliferidae
Rhacochelifer
Rhacochelifer euboicus

description: Rhacochelifer euboicus Mahnert, 1977
Type material examined. ♂ holotype (MHNG), Greece, Euboea, Dirphys.
Non-type material examined. 7 ♂♂, 1 tritonymph (DEUA 3016), Greece, Arcadia, Mount Menalon, under bark of Abies cephalonica, 01.V.2016, leg. P. Ponel.
Diagnosis. Holotype and specimens from Arcadia: Medium-sized Rhacochelifer species without coarser granules on carapace and pedipalps. Elongated keels present on posterolateral corners of carapace and anterior tergites (usually I‒IV) in males. Hemitergites V‒X with medial setae. Pedipalpal femur 3.5‒3.7 times longer than broad, length 0.67‒0.73 mm, chela+ 3.3‒3.4 times longer than broad, length 0.99‒1.01 mm. Tarsus of leg I with distal margin slightly concave, 2.5‒2.6 times longer than deep.
Short complementary description (Ƌ). Carapacal anterior margin with 4 setae, metazone with 12 setae on posterior margin, additionally one lateromedial seta on each side. Elongated keels on posterolateral corners of carapace and anterior tergites I‒IV (I‒VI in some specimens from Arcadia) in males. Hemitergites, in addition to marginal setae, with lateral, medial and discal setae on tergites V‒X; chaetotaxy hemitergites I‒XI 5:5:6‒7:7:5‒ 9:8:8:7‒9:6:6‒7:5(2 tactile setae, length 0.07 mm), tergite XII 2 setae. Sternite X with 2 tactile setae. Trichobothria it level with ist.
Measurements (mm) and ratios. Males from Arcadia: Pedipalp: trochanter 0.34‒0.36/0.21 (1.7‒1.8), femur 0.67‒0.73/0.19‒0.20 (3.5‒3.7), patella 0.58‒0.60/0.22 (2.7‒2.8), hand+ 0.57‒0.58/0.29‒0.30 (1.9‒2.0), hand - 0.48‒ 0.50 (1.6‒1.7), movable finger 0.45‒0.46, chela+ 0.99‒1.00/0.29‒0.30 (3.3‒3.4), chela - 0.92‒0.94 (3.1‒3.2); ratio movable finger/hand+ 1.3, femur/movable finger 1.5‒1.6, femur/patella 1.2, patella/ hand+ 1.0, chela+/femur 1.4‒ 1.5. Leg I: femur+patella 0.37‒0.38/0.13 (3.0), femur 0.22‒0.23/0.13 (1.7‒1.8), patella 0.26/0.11 (2.3‒2.4), tibia 0.25‒0.26/0.12 (2.0‒2.1), tarsus 0.27/0.10‒0.11 (2.5‒2.6). Leg IV: femur+patella 0.54‒0.55/0.19‒0.20 (2.8), tibia 0.35/0.08‒0.09 (4.1‒4.2), tarsus 0.42‒0.44/0.11‒0.12 (3.7‒3.8).
Tritonymph. Specimen from Arcadia: Carapacal metazone, in addition to marginal setae, with one lateromedial seta on each side. Carapace without elongated keels on posterolateral corners of carapace and anterior tergites, 4 setae on anterior margin, 10 setae on metazone (8 posteromarginal and one lateromedial on each side). Chaetotaxy hemitergites I‒XI 5‒6:5‒6:6:6:6:6‒7:6‒7:6‒7:5‒6:6:5, tergite XII 2 setae, hemitergites VII‒XI in addition to marginal setae, with lateral, medial and discal setae. Sternite II 3 setae, III 6, hemisternites IV‒XI: 3‒ 4:4‒5:4:5:4‒5:6:3‒4:4, sternite XII 2. Both chelal fingers with 30 teeth, dental row of fixed finger shorter than that of movable finger.
Measurements (mm) and ratios. Tritonymph: Pedipalp: trochanter 0.27/0.16 (1.7), femur 0.51/0.16 (3.2), patella 0.44/0.19 (2.3), hand+ 0.57‒0.58/0.29‒0.30 (1.9‒2.0), hand - 0.48‒0.50 (1.6‒1.7), movable finger 0.45‒0.46, chela+ 0.83/0.25 (3.4), chela - 0.79 (3.2); ratio movable finger/hand+ 1.3, femur/movable finger 1.5‒1.6, femur/ patella 1.2, patella/ hand+ 1.0, chela+/femur 1.6. Leg I: femur+patella 0.30/0.11 (2.9), femur 0.17/0.10 (1.6), patella 0.21/0.10 (2.1), tibia 0.22/0.08 (2.8), tarsus 0.21/0.07 (3.2). Leg IV: femur+patella 0.43/0.17 (2.6), tibia 0.32/0.10 (3.2), tarsus 0.28/0.08 (3.4).
Remarks. Krajčovičová et al. (2017) identified as Rhacochelifer disjunctus (L. Koch, 1873) several samples from Slovakia, but examination of their fig. 3, representing the habitus of a male, shows the presence of lateral keels on the posterolateral corners of the carapace and anterior tergites. The measurements given in that paper also coincide rather well with those given for R. euboicus by Mahnert (1977a) and the present study. The setation of the posterior tergites in specimens from different locations in Slovakia has been rechecked by Katarína Krajčovičová, who confirms (in litt.) that one lateral, one medial and one discal seta are present. The presence/absence of medial setae on the posterior tergites is known to be a useful characteristic for distinguishing morphologically close species (e.g. Mahnert 1997). We conclude that the Slovakian specimens belong to R. euboicus instead of R. disjunctus. This explains also the differences in shape of spermatheca pointed out by Krajčovičová et al. (2017). This identification considerably extends the distribution of R. euboicus westwards, from Greece to Central Europe, and represents a new record for Slovakia.
description: Published as part of Hernández-Corral, Jesús, Zaragoza, Juan A. & Micó, Estefanía, 2018, New species of Pseudoscorpiones (Arachnida) from tree hollows in a Mediterranean oak forest in Spain, pp. 201-225 in Zootaxa 4497 (2) on page 213, DOI: 10.11646/zootaxa.4497.2.3, http://zenodo.org/record/1452117