Macrobrachium olfersii ( Wiegmann, 1836 )

Valencia, Diego M. & Campos, Martha R., 2007, Freshwater prawns of the genus Macrobrachium Bate, 1868 (Crustacea: Decapoda: Palaemonidae) of Colombia, Zootaxa 1456, pp. 1-44 : 27-28

Macrobrachium olfersii ( Wiegmann, 1836)

Fig. 14 A–D

Palaemon olfersii Wiegmann, 1836: 150 .

Macrobrachium olfersii, Escobar, 1979: 118 .— Williams, 1984: 70.— Abele & Kim, 1989: 10.— Nizinski, 2003: 103.

Macrobrachium olfersi, Holthuis, 1952: 95 .— Martínez, 1973: 7.— Rodríguez, 1980: 120.— Rodríguez, 1981: 45, 47.— Melo, 2003: 366.

(For detailed synonymy refer to Holthuis, 1952).

Material examined.

Magdalena: Santa Marta. Buritaca, 20 m asl, 17 Nov 1998, leg. R. Casallas & A. J. Bernal, 9 males, 2 females 1 ovigerous, 1 juvenile, MLS 18.— SW, Guachaca River, 10 - 30 m asl, Dec 1993, leg. R. Contreras, 1 male, 10 juveniles, CRBMUV 93005. — Parque Nacional Natural Tayrona, Gayraca stream, 1 male, INV 771.— Parque Nacional Natural Tayrona, Nenguange, 2 males, 1 ovigerous female, INV 773, 979.— Mamatoco stream, 18 Feb 1976, 3 males, 10 females, 5 ovigerous, INV 772.— Mamatoco stream, 18 Mar 1976, leg. G. Manjarréz, 5 males, 1 ovigerous female, INV 975.

La Guajira: Riohacha. Ranchería River, 40 m asl, 7 Oct 2004, Leg. C. Castellanos, 5 males, 3 ovigerous females, ICN-MHN-CR 2209.

Diagnosis

Rostrum nearly straight, distal part slightly recurved downward, shorter than scaphocerite, as long as antennular peduncle; upper margin with 11 to 14 teeth regularly spaced, including 4-5 teeth completely post orbital, lower margin with 2 to 4 teeth; carapace smooth; abdomen smooth; telson terminal margin ending in sharp midpoint, flanked by two pairs of spinules, inner pair overreaching midpoint and external pair. First pair of pereopods overreaching scaphocerite with distal portion of carpus. Second pair of pereopods prominent, different in shape and size, covered with conspicuous spines and long setae, the larger second pereopod overreaching scaphocerite with ca. 1/4 of merus; merus 0.94 to 0.95 x carpus length, and 0.72 to 0.95 x palm length; carpus 2.45 to 2.57 x as long as wide, and 0.76 to 1.0 x palm length; palm prominent with ventral margin convex, external and internal surfaces with rows of spines and conspicuous setae, ventral margin with row of spines which are decreasing in size distally, 2.61 to 3.15 x as long as wide; fingers gaping when closed, thickly pubescent in recess, 0.91 to 1.04 x palm length, cutting edge of each finger with a tooth on midproximal portion, followed by denticles to its distal portion.

Size. The largest male TL 88.9 mm, CL 29.4 mm; the largest female TL 62.3 mm, CL 17.6 mm; 11 ovigerous females were examined: TL 36.7 to 50.0 mm, CL 9.6 to 14.9 mm, with small and numerous eggs.

Remarks

This species is closely related to Macrobrachium faustinum (De Saussure, 1857) . The two can be distinguished by differences in the second pair of pereopods in adult males. The spines of the ventral margin’s row of the palm in M. faustiunum are larger proximal and distally but smaller on the midportion; to the contrary, they diminish in size distally in M. olfersii . In addition, the spines and pubescence on the external and internal surface of the palm and on the cutting edge of the fingers are more conspicuous in M. olfersii than in M. faustiunum . Some specimens of Macrobrachium olfersii were found at INCODER collection: 4 males, the largest male was LT 72.0 mm, CL 24.4 mm. These specimens were not recorded in this article because they lack location data. They may correspond to specimens reported by Martínez (1973) and deposited at INCODER. The male of Macrobrachium olfersii , from Santa Marta, Parque Nacional Natural Tayrona, Los Cedros, department of Magdalena (ICN-MHN-CR 0532), reported by Galvis (1986) are actually M. crenulatum .

Figures

FIGURE 14. Macrobrachium olfersii (Wiegmann, 1836), male, INV 975: A, anterior part of body, lateral view; B, telson, dorsal view; C, larg second pereopod, lateral view; D, small second pereopod, lateral view.