Paraxenylla cubana, 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 : 39-41

Paraxenylla cubana sp. nov.

( Figs. 1–10 )

Body length (n = 3) 450 µm (range 430–465 µm). Body with very short acuminate setae (5 µm). Macrosetae and sensorial setae (8–10 µm) about twice the length of ordinary setae. Color light blue, eye patches dark.

Ratio head:antenna = 1:0.6. Antennal segment I with 7 dorsal setae. Antennal segment II with 11 setae. Antennal segment III sensory organ consists of 2 very small sensory rods, 2 longer guard setae and one external microsensillum. Antennal segment IV with four globular sensorial sensilla, two smaller than others, one microsensillum, one subapical organ and a simple apical bulb. There are also several acuminate setae and several thicker curving setae with apex truncate similar to sensilla ( Fig.1 ).

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

Mandible apparently without apical teeth. Maxillae with six hypertrophied fringed lamellae. Labium with a small internal process.

Prothorax with 4 + 4 setae. Dorsal chaetotaxy of head and thorax in Fig. 2 . Trochanters with five setae, femora I, II, III with 11,11, 10 setae respectively. Tibiotarsi I, II, III with 18, 18, 16 very small setae (3–5 µm) respectively, no tenent hairs developed at all. One dorsal seta on tibiotarsus and one on femur are thicker than others ( Fig. 3 ). Unguis about 10 µm long, without teeth, no empodial appendix ( Fig. 4 ).

Dorsal chaetotaxy of abdomen in Fig. 5 . Ventral tube with 1 + 1 setae ( Fig. 6 ). Abd. II with 1+1 ventral setae. Tenaculum with 2 teeth on each ramus ( Fig. 7 ). Mucrodens (20 µm) apparently with only one seta ( Fig. 8 ). Female with 3 + 3 pregenital setae, 2–3 genital and 2 eugenital ( Fig. 9 ). Male with 3 + 3 pregenital setae, 4 circumgenital and 8 eugenital ( Fig. 10 ). Anal plate with 11 setae. Anus terminal, no anal spines.

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

Type locality: Cuba: Guanacabibes.

Type Material: Holotype Ψ, two paratypes ♂♂. Kept at senior author’s collection. 1­ XII­1989, M. Díaz Azpiazu col.

Discussion: The most distinctive and easy character to separate Paraxenylla cubana sp. nov. from the others is the presence of only 2 + 2 teeth on the retinaculum, and only one dental seta. Another important character is the presence of four globular sensilla, while in the other congeneric species they are cylindrical. This is the only species with reduction of the tibiotarsal setation.

Figures

FIGURES 1 – 10. Paraxenylla cubana sp. nov. 1, Ant. I to IV with magnification of sensilla; 2, dorsal chaetotaxy of head and thorax: 3, leg III lateral view; 4, tibiotarsus III ventral view; 5, dorsal chaetotaxy of Abd. II – VI; 6, ventral tube; 7, tenaculum; 8, mucrodens; 9, female genital plate; 10 male genital plate.