Titanobochica Zaragoza & Reboleira

Reboleira, Ana Sofia P. S., Zaragoza, Juan A., Gonçalves, Fernando & Oromí, Pedro, 2010, Titanobochica, surprising discovery of a new cave-dwelling genus from southern Portugal (Arachnida: Pseudoscorpiones: Bochicidae), Zootaxa 2681, pp. 1-19 : 3-4

Titanobochica Zaragoza & Reboleira gen. nov.

Type species. Titanobochica magna Zaragoza & Reboleira sp. nov.

Terra typica. Portugal, Algarve, in caves.

Etymology. From titan, titanis, the Latin line name of the six giant sons of Gaea and Uranus in Greek mythology (common current meaning: any person or thing of enormous size or prodigious power) and Bochica , one of the most important deities of the Chibcha Indians of ancient Colombia (Judson in Mahnert 2001); gender masculine.

Diagnosis. Large cave-dwelling pseudoscorpions with extreme troglobiontic adaptations. Pleural membranes longitudinally smoothly striate. Apex of pedipalpal coxa triangular and acute, with two long setae. Carapace without epistome. Eyes absent. Chelicera usually with 4 setae on hand (seldom 5 or 6); rallum of five slender blades. Most sternites with multiple rows of setae (biseriate or triseriate). Pedipalps very slender, chelal ratio about 8.00×; without glandular tubercle on the femur; chelal fingers without accessory teeth, movable finger distinctly shorter than the fixed finger, with venom apparatus; fixed finger with the tip rounded, venedens reduced and venom apparatus absent. Trichobothrium ib in basal half of dorsum of hand; trichobothrium ist slightly proximal to est; trichobothria et and it opposite each other at apex of finger. Leg IV with femur (F)/patella (P) index F/F+P ( Muchmore 1998): about 0.15; metatarsi much shorter than tarsi; without spines on pedal tarsi; arolia shorter than claws.

Remarks. Titanobochica is placed in the family Bochicidae by virtue of the presence of a venom apparatus with a long duct in the movable chelal finger, the nodus ramosus not expanded, the apex of the pedipalpal coxa with 2 long setae and trichobothrium ib located on the dorsum of the hand. It is assigned to the subfamily Bochicinae because it has the apex of the pedipalpal coxa acute, and a low F/F+P index of leg IV, as outlined by Muchmore (1998).

Titanobochica is easily distinguishable from the other genera of Bochicidae by the multiseriate setae on the sternites and the possession of numerous microsetae on the stigmata. The only other genera of Bochicinae in which trichobothrium ist is slightly proximal of est are Bochica Chamberlin, 1930 , Troglobochica Muchmore, 1984 ( Muchmore 1984) and Spelaeobochica allodentatus Mahnert, 2001 ( Mahnert 2001) . In Antillobisium Dumitresco & Orghidan, 1977 both trichobothria are at about the same level ( Dumitresco & Orghidan 1977), whereas ist is far proximal to est in the Leucohyinae ( Muchmore 1998) . The new genus is distinguishable from Antillobisium, Bochica and Troglobochica by the number of blades and form of the cheliceral rallum. It is also clearly different to Spelaeobochica Mahnert, 2001 ( Mahnert 2001) by the basal position of trichobothrium ib on the dorsum of the hand versus distal, and the absence of accessory teeth in the chelal fingers versus presence.

The new genus resembles Troglobisium Beier, 1939 , the only representative of the family Bochicidae previously known in Europe ( Zaragoza 2004, 2007), by the large size and exceptionally slender appendages, the venom apparatus only in the movable finger and the rounded tip of the fixed chelal finger with a simple row of sclerotized denticles (J.A. Zaragoza, pers. obs. on Troglobisium specimens). Both genera are distinct by the shape of the chelal hand, which is subparallel in Troglobisium and convex paraxially in Titanobochica, the position of trichobothrium ist distal to est in Troglobisium and proximal in the new genus, cheliceral palm with four setae (occasionally five or six setae) in Titanobochica versus five in Troglobisium , cheliceral rallum with five blades in Titanobochica versus only four in Troglobisium , and in particular by the uniseriate sternal setae in Troglobisium versus multiseriate in Titanobochica.

The genus Vachonium Chamberlin, 1947 shares some features with both European genera, such as the fixed chelal finger with rounded tip and venom apparatus reduced or absent and the number and shape of the blades of the cheliceral rallum, but it differs by the higher number of setae on the cheliceral hand (about 8 versus 4–5 in the European genera), the end of the fixed chelal finger bearing some heavily sclerotized denticles in a double row versus a simple row, presence of an accessory tooth on the internal side of the fixed finger versus absent and the presence of a prominent glandular tubercle at the base of the antiaxial face of the pedipalpal femur versus absent. Paravachonium Beier, 1956 shares with Troglobisium and Titanobochica the fixed chelal finger with rounded tip and a simple row of sclerotized denticles, the absence of a glandular tubercle on pedipalpal femur and the lack of an accessory tooth paraxially on the fixed chelal finger, but the index F/F+P of leg IV is clearly higher in Paravachonium among other distinctive characters.

The new genus includes the largest species within the Bochicidae , even when compared with other “giant” genera, Antillobisium , Paravachonium , Spelaeobochica , Troglobisium , Troglohya Beier, 1956 and Vachonium , as shown in the length of parameters such as body length 6 mm versus 5 mm and chela length about 6 mm versus less than 5 mm.