Hydrosmilodon gilliesae Thomas

Hydrosmilodon gilliesae Thomas & Péru

Hydrosmilodon gilliesae Thomas & Péru in Thomas et al., 2004: 66 (nymph).

Material. Venezuela, Edo Bolívar, Kamá river, 5º 25’ 11’’N – 61º 13’ 05’’W, 1035 m. 24/XI/2005, 3 nymphs. Tarotá stream, 5º 49’ 15’’N – 61º 25’ 04’’W, 1324 m, 18/ III /2006, 1 nymph. Parupa river, 5º 40’ 49’’N – 61º 32’ 39’’W, 1281 m, 19/ III /2006, 1 nymph. EG, AMO and MEG cols. Specimens were deposited at the MLBV (Venezuela) and IBN (Argentina).

Discussion. Hydrosmilodon gilliesae was described from the French Guiana in 2004, based solely on nymphs, and the imagos remain unknown until now. The nymphs collected in this study correspond with the original description by Thomas & Péru. The nymphs can be separated from the other species of the genus by: 1) subapical denticle of the tarsal claw much larger than the other denticles; 2) gills narrow on abdominal segments I–VII, well developed and tapered to a terminal filament on I–VI, and with main trachea not branched.

Distribution. Brazil, French Guyana, Venezuela (new country record).

Ecology. Nymphs were collected from the submerged substrates within the rivers during the rainy (November 2005) and dry (March 2006) seasons. These three sampled rivers varied in their water sizes (12 m – 40 m wide), and riparian vegetation (from partially shaded to non-shaded). They were mostly rocky rivers, with acidic waters (pH=5).