Paraxenylla peruensis, Palacios-Vargas, José G. & Janssens, Frans, 2006

Palacios-Vargas, José G. & Janssens, Frans, 2006, Two new American species of Paraxenylla (Collembola: Hypogastruridae) and ecological notes, Zootaxa 1312, pp. 37-47 : 41-42

Paraxenylla peruensis sp. nov.

( Figs. 11–20 )

Body length (n = 5) 1,230 µm (range 1,020–1,480 µm). Body with moderate short acuminate setae (13–15 µm). Macrosetae and sensorial setae long (26–28 µm) almost two times the length of ordinary setae. Color dark blue, eye patches black.

Ratio head:antenna = 1:0.7. Antennal segment I with 7 dorsal setae. Antennal segment II with 11 setae. Antennal segment III sensory organ consists of 2 small sensilla, chop shaped, 2 longer guard setae and one external microsensillum. Antennal segment IV with four cylindrical sensilla, one smaller than others, one microsensillum, one subapical organ and a simple apical bulb. There are also several acuminate setae and some thicker curving setae with apex truncate similar to sensilla ( Fig. 11 ).

Labrum with /5,5,4 setae. 5 + 5 eyes well pigmented.

Mandible with 4–5 teeth. Maxillae with six hypertrophied fringed lamellae. Labium with a well developed internal process.

Prothorax with 5 + 5 setae (sometimes 4 + 4) ( Fig. 12 ). Dorsal chaetotaxy head and thorax in Fig. 12 . Trochanters with 5 setae, femora I, II, III with 11, 11, 10 setae respectively; tibiotarsi I, II, III with 19, 19, 18 setae respectively ( Fig. 13 ).

Tibiotarsi with clavate tenent hairs, one dorsal, one ventral­distal, two ventralproximal. Tibiotarsal setae from 11 to 25 µm, tenent hairs 40 µm. Unguis about 35 µm long, without teeth, no empodial appendix.

Dorsal chaetotaxy of abdomen in Fig. 14 , with a hyperthrichosis of the dorsal abdominal segments I to III. Ventral tube with 1 + 1 setae ( Fig. 15 ). Abdominal segment II with three ventral setae on each side ( Fig. 16 ). Tenaculum with 3 teeth on each ramus ( Fig. 17 ). Mucrodens (85 µm) with two setae ( Fig. 18 ). Female with 3 + 3 pregenital setae, 6 genital and 2 eugenital ( Fig. 19 ). Males with 3 + 3 pregenital, 6 circumgenital and 8 eugenital setae ( Fig. 20 ). Anal plate with 11 setae.

Derivatio nominis: from the country where this species was found: Peru.

Type locality: Peru: Departamento de Ica: Baha de Paracas, Reserva Nacional de Paracas. Type Material: Holotype Ψ, two paratypes ΨΨ will be send to Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima, Peru; two paratypes ΨΨ, and one paratype ♂ will kept at senior author’s collection; 2 paratypes kept at junior author's collection, 9­V­2003. All specimens collected at the beach on green algae Ulva sp. A. Catanazzi col.

Discussion: The most distinctive and easy character to separate Paraxenylla peruensis sp. nov. from the others is the presence of one smaller sensillum on Ant. IV. The tenent hairs position on tibiotarsi is a differential character, one being dorso­distal, one ventrodistal and two ventro­proximal. Among all the congeneric species this is the only one with this combination. This is the biggest species, almost 1.5 mm. The European P. affiniformis ( Stach, 1930) sensu Gama & Deharveng, 1984 measures between 750–900 µm.

Figures

FIGURES 11 – 20. Paraxenylla peruensis sp. nov. 11, Ant. I to IV; 12, dorsal chaetotaxy of head and thorax; 13, leg III; 14, Abd. chaetotaxy; 15, ventral tube; 16, ventral chaetotaxy of Abd. I to III; 17, tenaculum; 18, two different mucrodens; 19, female genital plate; 20, male genital plate.