Macrobrachium tenellum (Smith, 1871)

Fig. 20 A–B

Palaemon tenellus Smith, 1871: 98 .

Macrobrachium tenellum, Holthuis, 1952: 54 .— Méndez, 1981: 73.— Rodríguez, 1981: 47.— Abele & Kim, 1989: 13.— Wicksten, 1989: 13.

(For detailed synonymy refer to Holthuis, 1952).

Diagnosis

Rostrum nearly sinuous with distal portion directed upward, usually overreaching scaphocerite, upper margin with 8 to 12 teeth, including 1 tooth completely post orbital, proximal teeth separated from each other by small recess than distal ones, lower margin 4 to 7 teeth; 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 distal portion of carpus. Second pair of pereopods similar in shape and size with longitudinal row of spines, overreaching scaphocerite with distal portion of merus or with total length of carpus; merus 0.67 x carpus length; carpus 13 to 15 x as long as wide; palm elongated, cylindrical; fingers thickly pubescent, slightly shorter than palm, a tooth on 1/4 proximal in each cutting edge of fingers, followed by denticles to base of finger. The females present small and numerous eggs. The diagnosis is based on (Holthuis, 1952).

Remarks

Prahl et al. (1984) recorded the species Macrobrachium tenellum from Calima River and Aribí stream, department of Valle del Cauca, and the specimens are deposited at the CRBMUV. Only the Aribí stream specimens were found at the CRBMUV collection. After examination they were determined as M. rathbunae . Unfortunately, there are no specimens of Macrobrachium tenellum in the collections visited. The illustrations are taken from Holthuis (1952).