Pristina armata, Schenková, Jana & Čermák, Václav, 2013

Schenková, Jana & Čermák, Václav, 2013, Description of Pristina armata n. sp. (Clitellata: Naididae: Pristininae) from a carnivorous plant (Nepenthes sp.) in Borneo, Indonesia, Zootaxa 3686 (5), pp. 587-592 : 588-589

Pristina armata n. sp.

( Figures 1 B–D, 2A–E)

Holotype. National Museum in Prague, Cat. No. P6E-3128, whole mounted sexually immature specimen ( Fig. 1 B,D, 2).

Type locality. Mentarang Hulu, district of Malinau Regency, East Kalimantan, Indonesia (1,230 m a.s.l.); the fluid of the Nepenthes sp. pitcher, which hosted six live clitellate specimens (holotype and paratypes); pH 6.6., 23 Feb 2012, leg. V. Čermák and M. Dančák.

Paratypes. Five specimens from the same Nepenthes sp. pitcher as the holotype, mounted whole into the same microscopic slide as the holotype (Cat. No. P6E-3128, Fig. 2 ), sexually immature; the larger specimens ( Fig. 1 B: specimens B, D) with giant chaetae, the smaller ones ( Fig. 1 B: specimens A, C, E) without.

Etymology. The specific name “ armata ” in Latin means armored, and refers to giant hook-like dorsal chaetae, which probably serve as a protection against predators.

Description. Very small worms, all sexually immature. Specimens with giant dorsal chaetae 647–967 μm long (holotype: 847 μm), 88–98 μm wide at VI and 61–116 μm at XII ( Fig. 2 ). Specimens without giant chaetae 458– 667 μm long and 56–83 μm wide at VI and 86–91 μm at XII. Number of segments of specimens with giant chaetae 13–20 (holotype: 15), number of segments of specimens without giant chaetae 12–17. Body wall without a noticeable pigmentation. Prostomium without proboscis, rounded and conical, short in three specimens, e.g. 21 μm long and 42 μm wide, almost as long as wide near the base in the other three specimens, e.g. 52 μm long and 51 μm wide ( Fig. 1 C). Prostomium clearly separated from the head part. No eyes. Coelomocytes present, not numerous, 10 μm in diameter. Chloragogen cells from VI, no intestinal dilatation.

Dorsal chaetae begin at II with one hair chaeta and one needle chaeta per bundle. Hair chaetae without serration (as far as it was possible to distinguish in mounted specimens), 43–124 μm long, longest at IV. Needle chaetae tiny, length 22–25 μm, diameter 1 μm, simple-pointed and slightly curved ( Fig. 2 C,D) except at IV. Giant hook-like dorsal chaetae at IV ( Figs 1 D, 2A,B), 1 per bundle, length 40–48 μm, diameter 3 μm, almost twice as long and 3x as thick as the regular needle chaetae. Giant chaetae with straight and slightly longer proximal part (holotype: 31 μm) and shorter hook-like distal part (holotype: 24 μm). Giant chaetae absent in the smallest specimens, here needles at IV minutely longer, e.g. 29 μm at IV vs. 27 μm at VI, slightly thicker and more curved in distal part (measurement of specimen A, Fig. 1 B). Ventral chaetae 19–31 μm long, bifid with teeth of equal length ( Fig. 2 E), nodules not visible at 400x magnification, all of the same shape, 2–4 (exceptionally 5) per bundle with decreasing number from head to tail region.

Figures

FIGURE 1. Pristina armata n. sp. A. Location of the type locality (circle) on the island of Borneo. B. Position of holotype and the paratypes (A – E) mounted together on one microscopic slide. C. Paratype: specimen with prostomium as wide as long, arrow: sign of future fission. D. Holotype, arrow: dorsal giant hook-like chaeta at IV and hair chaetae at II – V.

FIGURE 2. Pristina armata n. sp. A. Holotype, sexually immature, with giant dorsal chaetae. B. Dorsal giant hook-like chaeta at IV; C. Dorsal needle chaeta at V. D. Dorsal needle chaeta at VI. E. Ventral bifid chaeta at IV.