Macrobrachium cortezi Rodríguez, 1982

Fig. 6 A–D

Macrobrachium cortezi Rodríguez, 1982: 383.

Material examined

Amazonas: Leticia, Corregimiento La Pedrera, La Tonina stream, 120 m asl, 6 Nov 1994, leg. M. R. Campos, 1 female, ICN-MHN-CR 2188.

Guainía: Inírida, Agujón creek, 70 m asl, 23 - 25 Mar 1998, leg. M. R. Campos, 11 males, 13 females, 7 ovigerous, 24 juveniles, ICN-MHN-CR 1691.— Pajarito creek, 70 m asl, 21 Mar 1998, leg. M. R. Campos, 11 males, 8 females, 7 ovigerous, ICN-MHN-CR 1688.— La Ceiba Community, Seje creek, 80 m asl, 18 Mar 1998, leg. M. R. Campos, 1 male, 1 ovigerous female, ICN-MHN-CR 1680.— Mañoco creek, 75 m asl, 25 Mar 1998, leg. M. R. Campos, 1 male, 4 females, 1 ovigerous, ICN-MHN-CR 1695.— Yucuta creek, 70 m asl, 24 Mar 1998, leg. M. R. Campos, 3 males, 7 females, 1 ovigerous, ICN-MHN-CR 1693.

Vaupés: Taraira, Serranía Taraira, 185 m asl, 22 Nov 1994, leg. M. R. Campos, 16 males, 21 females, 10 ovigerous, ICN-MHN-CR 1444.

Diagnosis

Rostrum nearly straight, slightly curved downward, overreaching with distal portion scaphocerite, upper margin with 10 to 12 teeth regularly spaced, including 2-4 teeth completely post orbital, lower margin 2 to 3 teeth; carapace smooth; abdomen smooth; telson terminal margin ending in sharp midpoint, flanked by two pairs of spinules, internal pair overreaching midpoint and external pair. First pair of pereopods overreaching scaphocerite with 2/3 of carpus. Second pair of pereopods elongated, similar in shape, different in size, covered with spines, which are prominent on ventral and internal surfaces; the larger pereopod overreaching scaphocerite with 1/3 to 1/4 of merus; merus 0.71 to 0.73 x carpus length, 0.56 to 0.66 x palm length; carpus 3.45 to 3.57 x as long as wide and 0.79 to 0.91 x palm length; palm subcylindrical, 3.34 to 3.81 x as long as wide, and 2.95 to 3.28 x as long as high; fingers strongly gaping when closed, 0.72 to 0.77 x palm length, prominent tooth on midcutting edge of mobile finger, followed by 3 small teeth to its base; cutting edge of fixed finger with a prominent tooth just behind of prominent tooth of mobile finger, followed by 3 small teeth to its base.

Size. The largest male TL 52.6 mm, CL 14.5 mm; the largest female TL 40.5 mm, CL 11.4 mm; 27 ovigerous females were examined: TL 26.6 to 37.0 mm, CL 6.9 to 10.5 mm, with large and few number of eggs.

Remarks

These are the first records of Macrobrachium cortezi for Colombia. This species is most similar to M. nattereri (Heller, 1862). The two can be distinguished by differences in the carapace and the size of the adult males. The anterolateral surface of the carapace in M. cortezi is smooth; whereas it is covered by spinules in M. nattereri. The total length of the adult males in M. cortezi is shorter than 52.6 mm, whereas it reaches 70 mm in M. nattereri.