Aegla septentrionalis Bond-Buckup & Buckup, 1994

Bond-Buckup, Georgina, Jara, Carlos G., Buckup, Ludwig, Bueno, Alessandra A. P., Pérez-Losada, Marcos & Crandall, Keith A., 2010, Description of a new species of Aeglidae, and new records of related species from river basins in Argentina (Crustacea, Anomura), Zootaxa 2343, pp. 18-30 : 27

Aegla septentrionalis Bond-Buckup & Buckup, 1994

Diagnosis. Anterolateral spine of carapace reaching half of cornea; protogastric lobes absent; extra-orbital sinus absent; rostrum of medium length, linguiform, with little-pronounced carina on distal third; front narrow; anterior angle of ventral margin of epimera 2 unornamented; fourth thoracic sternite without ornament, flat; outer proximal margin of moveable finger of cheliped without lobe; fingers of cheliped with robust lobular tooth; palmar crest of cheliped absent; inner margin of ventral face of ischium of cheliped only with three to four nodosities. (Modified from Bond-Buckup & Buckup 1994.)

Measurements. The specimens examined showed a mean CL of 18.90 mm (n = 8 males; 5 females). Rostrum of medium length, which modifies the species diagnosis given by Bond-Buckup & Buckup (1994). PCW/FW ratio ranging from 1.81 to 1.99, mean 1.94; i.e., front narrow. AL/AW ratio ranging from 1.60 to 1.73, mean 1.68; areola subquadrate.

New records. ARGENTINA: Province of Jujuy: Arroyo Cangrejillos, basin of River Miraflores, 22º24'33"S, 65º34'14"W; 3613 m, 05.xii.2001 (UFRGS 3205, 4M, 1F); id., ib., UFRGS 3208, 11M, 6F, 6J); Yavi, northewest Argentina, 06.i.1994 (UFRGS 2431, 3M, 1F).

Former distribution. BOLIVIA: Departments of Tupiza and Tarija. ARGENTINA: Northern parts of Jujuy and Salta provinces ( Bond-Buckup & Buckup 1994).

Present distribution. BOLIVIA and ARGENTINA - Paraguay River system (Bermejo and Pilcomayo rivers).

Remarks. The locality of Cangrejillos, at an altitude of 3613 m, is the highest altitude recorded up to now for a species of aeglid.

This pre-cordilleran region is in the Bolivian altiplano, with an arid climate, strong winds, and a large moisture deficit. The species was collected in a small stream, in the middle of a site with grassy vegetation. Although the locale was uncharacteristic for an aeglid, because of the small volume of water, the population was numerous, and composed of specimens of several age classes.