Alona ossiani Sinev, 1998

(Fig 10)

Sars, 1901, 48–49, Pl. IX, fig. 1, a–d ( affinis); Daday, 1905: 171–172, Taf. X, Fig. 26–27 ( affinis); Sinev 1998: 105–110, Fig 1–4.

Type locality. Neighborhood of San Paolo, Brazil.

Type material. Holotype. Male, Zoological Museum of Oslo University, GOS slide F12324a.

Studied material. 5 parthenogenetic females from pond near Laguna Seca pond, San Josй de Gracia, Aguascalientes, 25.09.1993, AYS; 38 parthenogenetic females from Pond 4, Mesa Montoro, Calvillo, Aguascalientes, 0 5.10.1990, AYS.

Comments. Alona ossiani is a sibling-species to Palearctic Alona affinis (Leydig, 1860) . These species clearly differs by the male morphology (see Sinev, 1998), but their parthenogenetic females are not obviously distinguishable (Sinev, 2009a). According to Sinev (2009a), A. ossiani is the only species of the affinis -group known from the Americas. Specimens in our material (Figs. 10 K–M) demonstrated no significant differences from those from the type population of A. ossiani (see Sinev, 1998).

Distribution. Alona ossiani appears to be widely distributed in North and South America, but precise records of this species, with male morphology described, are sparse (Sinev, 2009a). In Aguascalientes, it is found in cold regions in two mountainous areas: Mesa Montoro mountain, over 2,500 m.a.s.l., and Laguna Seca pond in Sierra Fría mountain, at 3,100 m.a.s.l.