Archaebranchinecta

Distribution and ecology. Present in high-mountain (3,550 – 4,225 m a. s. l.) temporary ponds, medium to small sized, shallow, turbid or clear, with or without macrophytes, which freeze during winter and bear high levels of solar radiation (Halloy 1979). The occurrence of adult and juvenile anostracans, coexisting with the Spinicaudatan Leptestheria tucumanensis was reported by Halloy (1979) in Laguna Circular of Huaca Huasi (15 – 20 m in diameter, 0 – 70 cm deep), from February to April. In 2012, the first author examined the above mentioned FML – CRUST 01045 sample, reporting the presence of two adult males of an undetermined species, herein assigned to Archaebranchinecta. Besides, Cohen (2010, 2012) identified two other high altitude Branchinectidae from Huaca Huasi: Branchinecta brushi Hegna & Lazo-Wasem, 2010 (from a temporary pond), and B. papillata Rogers, De los Ríos & Zúñiga, 2008 (from peat-bog pools of Vega del Matadero, north of Laguna Circular).

Examined material. Samples from 4 Punenian and high-Andean temporary ponds from northwestern Argentina (Table 1, Fig. 1), deposited in the Fundación Miguel Lillo, Crustacean Collection: FML – CRUST 01148, Jujuy Province, roadside pond between Abra Pampa and Tres Cruces, colls. C. Locascio de Mitrovich and A. Villagra, April 10, 2000 (juveniles of both sexes); FML – CRUST 01092 and FML – CRUST 01149, Jujuy Province, Laguna Sayate, provincial road 79 (road 71 in label), 20 km southwest of Abra Pampa, colls. C. Locascio de Mitrovich and A. Villagra, November 8, 1999 (juveniles of both sexes); FML – CRUST 01045, Tucumán Province, Huaca Huasi, Laguna Circular, coll. S. Halloy, April 9, 1977 (two males poorly preserved). Identification. The juveniles in three samples from Jujuy were merely identified as Archaebranchinecta. The two adult males from Tucumán were also allocated to Archaebranchinecta based on the very long gonopods bearing a pair of medial projections with two processes in their non-eversible part, and the presence of prominent bulging evaginations close together in the ventral midline of the genital segments, in lateral view. Since the second antenna basal antennomere was quite distorted in both males, the diagnostic characters of the processes were hardly visible for specific identification.