Gollumjapyx Sendra & Ortuño

Sendra, Alberto, Ortuño, Vicente M., Moreno, Agustín, Montagud, Sergio & Teruel, Santiago, 2006, Gollumjapyx smeagol gen. n., sp. n., an enigmatic hypogean japygid (Diplura: Japygidae) from the eastern Iberian Peninsula, Zootaxa 1372, pp. 35-52 : 37-42

Gollumjapyx Sendra & Ortuño gen. nov.

Etymology: The name of this genus comes from joining the prefix Gollum to the suffix Japyx . Gollum is the mythological character created by J.R.R. Tolkien, the dweller of the caves located below the Misty Mountains of Middle-earth.

Description: Body elongate and restricted dorso-ventrally, unpigmented cuticle; legs, thoracic segments and urite X extremely elongate ( Figs 1 and 2a ).

Head. 53 to 55 antennomeres per antennae, manifesting 13 typical trichobothria (a clearly distal); 14 to 16 placoid sensilla over apical antonnomere, scattered in 2 groups and with at least one or two supernumerary placoid sensilla over the penultimate antennomere ( Figs 3 a, b). Buccal pieces typical from this family with all five laminae pectinate of the maxillae.

Thorax. Exceptionally elongate. Pronotum 6+6 M (5+5 M typical plus 1+1 M posterolateral) ( Fig. 4 c). Mesonotum 5+5 M typical ( Fig. 4 d). Metanotum 4+4 M (M2 absents) ( Fig. 4 e). Legs very elongate.

Abdomen. Tergite I: 0+0 M. Tergite II: 1+ 1 M. Tergites III–VII: 5+5 M and 1+ 1 m 3 ( Fig. 5 a). Tergite X with carinae distinct of subparallel margins with 4+4 M intracarinae (D) and 5+5 M carenae (L) ( Fig. 3 c and 5b). Urosternite I: 22+22 M ( Fig. 6 a). Urosternite II-VII: 28+ 28 M. Simple lateral subcoxal organs showing one or two rows of very short subequal glandular setae and a row of sensory setae ( Fig. 6 b). Median glandular organ with no apparent operculum and no pseudospori ( Fig. 6 a). Styli and exsertile vesicles typical of this family.

Cerci. ( Fig 3 c, d and 5b). Very protracted and robust with strongly sclerotized angles; slightly longer (in young specimens) or shorter (in adults) than the usually uncovered part of tergite X. Right cercus with a row of tubercles and simple denticles, with a strong sharp tooth clearly proximal; left cercus with double row of tubercles and postmedial tooth.

Affinities: Gollumjapyx gen. n. shares certain affinities with the controversial genus Burmjapyx Silvestri, 1930 . Since its description, the taxonomy of the Burmajapyx genus has undergone several difficulties. Paclt (1957) groups as Burmjapyx nine genera sharing the same model of cercal armature, a few of them have well defined characteristics and geographical distribution ( Silvestri, 1948), such as: Protjapyx Silvestri, 1948 and some species of genus Megajapyx (Verhoeff, 1904) , scattered around the Mediterranean region; Hapljapyx Silvestri, 1949 and Merojapyx Silvestri, 1948 , found in the Neotropical region; Austrajapyx Silvestri, 1949, whose species range from the Neotropical region to the Ethiopean; Xenjapyx Silvestri, 1949 , exclusive to the Ethiopean and, Henicjapyx Silvestri, 1949 from the Eastern region. Paclt (1957) grouped all the above with the true Burmjapyx and also included in this group some twenty more species, many of which belong to the heterogeneous genus Japyx Haliday, 1864 . Pagés (1961, 1977, 1994, 2000) has repeatedly noted the artificiality of Burmjapyx sensu Paclt (1957) , providing enough taxonomic evidence to return Burmjapyx to its initial taxonomic position.

Gollumjapyx shares several features with the Burmjapyx s. str., particularly in the cercal armature and, to a lesser extent, also in the antennal supernumerary placoid sensilla, which are similar in distribution and number (in some specimens) to those described by Pagés (1977) for Burmjapyx inferus (Carpenter, 1932) found at Batu Caves ( Malaysia). However, Gollumjapyx does not show a median glandular organ with setae-shaped sensilla (Silvestri’s “pseudospori”). In the new taxon, these sensilla appear on both sides of the central area. One more difference should be noted: a lack of setae with large setal socket preceding the glandular setae of the subcoxal organs, which are clearly recognisable in Burmjapyx .

Among the species of Japyx included by Paclt (1957) in Burmjapyx only Japyx goliath (Parona, 1888) from Guatemala, described again later by Silvestri (1928), manifests affinities with the new taxon. Although the type material is unknown -almost certainly disappeared-, from Silvestri’s (1928) text and illustrations a few similarities with Gollumjapyx can be observed, for instance in the number of antennomeres, the robustness of the cercal armature and the morphology of the glandular organs in the first urosternite. In the future, with new specimens, the true meaning of these affinities could be resolved. The general lengthening of the body, thorax and legs in particular, is so extraordinary as to distinguish Gollumjapyx from other known genera of the Japygidae family. This troglobite appearance with such elongate body can only be compared to the description of two hypogean species, Troglojapyx hauseri and Mixojapyx reddelli ( Muegge, 1992; Pagés, 1980); nevertheless Gollumjapyx smeagol shows a greater thinning of the body, more noticeable in the thoracic prescutum and legs. These traits suggest an adaptation of this new taxon to hypogeous life, as can be ascertained by the fact that they have been collected exclusively in caves.

Type-species: Gollumjapyx smeagol sp. n. Sendra & Ortuño

Figures

FIGURE 1. Habitus of Gollumjapyx smeagol Sendra & Ortuño sp. n. (scale: 3 mm).

FIGURE 3. Scanning electron microscope photography of Gollumjapyx smeagol Sendra & Ortuño sp. n.. a. apical antennomere; b. XXXV antennomere; c. urite X and cerci, dorsal view; d. urite X and cerci, ventral view. Terms: p, placoid sensilla; ss, short sensilla. (scales, a and b: 25 µm; c and d: 500 µm).

FIGURE 4. Gollumjapyx smeagol Sendra & Ortuño sp. n.. a. Vertex, young specimen from Avenc Mas Nou; b. Vertex, holotype; c. Pronotum, holotype; d. Mesonotum, holotype; e. Metanotum, holotype. Terms: A, S, V, M, I, P groups of large setae in vertex; M, macrochaeta thoracic. (scales: 1 mm).

FIGURE 5. Gollumjapyx smeagol Sendra & Ortuño sp. n., holotype. a. Tergites V to IX; b. Urite X and cerci, dorsal view. Term: M, macrochaeta; m, microchaeta; ls, large setae. (scale: 1 mm).

FIGURE 6. Gollumjapyx smeagol Sendra & Ortuño sp. n., paratype female from Avenc Canals pit. a. urosternite I; b. Details of sensory and glandular setae of lateral subcoxal organ. Terms: st, styli; GS, glandular setae; SS, sensory setae. (scales, a: 0.5 mm; b: 0.05 mm).

FIGURE 2. a. Gollumjapyx smeagol Sendra & Ortuño sp. n., Avenc d’en Serenge cave from Cabanes, Castellón (Spain); b. detail of the contents from the digestive tract belonging to a specimen from Avenc d’en Serenge; all the fragments belong to a male of Speleotyphlus aurouxi (Carabidae, Anillini). Terms: a, antennomeres; rgs, ring of the genital segment; ml, median lobe; p, paramere; t, tarsomeres. (scales, a: 3 mm, b: 0.3 mm).