Macrobrachium acanthurus ( 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 : 4-6

Macrobrachium acanthurus ( Wiegmann, 1836)

Fig. 1 A–C

Palaemon acanthurus Wiegmann, 1836: 150 .

Macrobrachium acanthurus, Holthuis, 1952: 45 .— Chace & Hobbs.— 1969: 89.— Chace, 1972: 20.— Martínez, 1973: 5.— Escobar, 1979: 105.— Rodríguez, 1980: 119.— Rodríguez, 1981: 45, 47.— Williams, 1984: 66.— Abele & Kim, 1989: 5.— Nizinski, 2003: 103.— Melo, 2003: 338.

(For detailed synonymy refer to Holthuis, 1952).

Material examined

Atlántico: Ciénaga El Totumo, 18 Feb 1989, 1 female, Universidad de Antioquia. Bolivar: María La Baja. 23 Apr 2001, leg. A. Celis, 1 female, 4 juveniles, Universidad de Los Andes. Córdoba: Pueblo Nuevo, Corregimiento Puerto Santo, Ciénaga El Porro, 120 m asl, 9 Jun 2004, leg. M.

R. Campos, 3 females, 19 juveniles, ICN-MHN-CR 2137. — San Bernardo del Viento, Isla Queso, sea level, 7 Jun 2004, leg. M. R. Campos, 1 male, ICN-MHN-CR 2132.

Chocó: Acandí. Acandí River, 1986, 2 males, 1 ovigerous female, INV 4613.—Monomacho stream, 15 m asl, 29 Sep 1996, leg. S. Usme, 1 female, ICN-MHN-CR 1630.

La Guajira: Riohacha. Guerrero River, 47 m asl, 27 Aug 1972, leg. P. Cala, 2 males, ICN-MHN-CR 0042.— Ranchería River, Nov 1975, 1 male, 3 females, 1 ovigerous, INV 978.— Ranchería River mouth, 40 m asl, 29 Nov 2003, leg. C. Castellanos, 2 males, 3 ovigerous females, ICN-MHN-CR 2165.— Ranchería River, 40 m asl, 6 Oct 2004, leg. P. Sánchez, 3 males, 3 females, 11 juveniles, ICN-MHN-CR 2208.— Riohacha - Maicao Highway, 50 m asl, 26 Aug 1972, leg. P. Cala, 30 males, 17 females, ICN-MHN-CR 0 0 38, 0039.— Riohacha 3 km southern, 50 m asl, 27 Aug 1972, leg. P. Cala, 2 females, ICN-MHN-CR 0040.— Riohacha 20 km southern, 50 m asl, 27 Aug 1972, leg. P. Cala, 3 males, 6 females, 2 ovigerous, ICN-MHN-CR 0 0 41.

Magdalena: Ciénaga, 21 Nov 1998, leg. R. Casallas & A. J. Bernal, 9 males, 14 females, 13 ovigerous, MLS 20, 21. — Santa Marta. Buritaca, 20 m asl, 17 Nov 1998, leg. R. Casallas & A. J. Bernal, 5 males, 6 females, 1 ovigerous, MLS 23.— Nenguange stream, Dec 1976, 2 males, 4 females, 2 ovigerous, INV 972.— Nenguange, 10 Apr 1979, leg. M. M. Criales, 1 male, INV 1444.— Parque Nacional Natural Tayrona, Los Cedros, 10 Jul 1985, leg G. Galvis, 5 males, 3 females, ICN-MHN-CR 0 627. — Pozo Colorado, 29 Aug 1972, leg J. Thomerson & P. Cala, 3 males, ICN-MHN-CR 0 0 48.

Sucre: Between Tolú and Coveñas, Ciénaga La Caimanera, 24 May 1986, leg. M. López, 1 male, 10 females, 1 ovigerous, ICN-MHN-CR 1466.— Toluviejo, Pechilín River, 60 m asl, 17 Jul 1986, leg. A. Rocha, 2 males, ICN-MHN-CR 0 646.

Diagnosis

Rostrum nearly sinuous, apex slightly curved upward, usually overreaching scaphocerite, upper margin with 8 to 12 teeth, proximal teeth with less recess between them than the distal ones, including 1-3 teeth completely post orbital, 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 elongated, prominent, similar in shape and size, overreaching scaphocerite with total length of carpus, longitudinal rows of spines from ischium to palm; merus 0.70 to 0.73 x carpus length and 0.89 to 0.96 x palm length; carpus 6.85 to 7.34 x as long as wide and 1.26 to 1.31 x palm length; palm elongated, cylindrical, 5.62 to 6.26 x as long as wide; fingers thickly pubescent, 0.75 to 0.87 x palm length, not gaping when closed, a proximal tooth on each cutting edge of fingers, and series of denticles on each base of finger.

Size. The largest male TL 126.6 mm, CL 34.5 mm; the largest female TL 121.4 mm, CL 30.3 mm; 28 ovigerous females were examined: TL 40.7 to 119.1 mm, CL 9.7 to 27.9 mm, with small and numerous eggs.

Remarks

This species is most similar to Macrobrachium rathbunae Holthuis, 1950 . The two can be distinguished by differences in the rostrum and the second pair of pereopods. The rostrum in M. acanthurus overreaches the scaphocerite, whereas it is usually shorter than the scaphocerite in M. rathbunae . The palm of the second pair of pereopods in M. acanthurus is 5.62 to 6.26 x as long as wide, and the fingers 0.75 to 0.87 x the palm length, whereas the palm is 7.76 to 9.33 x longer than wide and the fingers are 0.43 to 0.47 x the palm length in M. rathbunae . In adult females and immature males the carpus of the second pair of pereopods is usually longer than the chela length. Some specimens of Macrobrachium acanthurus were found at INCODER collection: 9 males, the largest male was TL 167.2 mm, CL 43.8 mm; 7 females, 4 of them were ovigerous, the range of the ovigerous females are: TL 62.7 to 121.1 mm, CL 15.0 to 31.3 mm. These specimens were not included in this article because they lack location data. They may correspond to specimens reported by Martínez (1973) and deposited at INCODER.

Figures

FIGURE 1. Macrobrachium acanthurus (Wiegmann, 1836), male, ICN-MHN-CR 0038: A, anterior part of body, lateral view; B, telson, dorsal view; C, second pereopod, lateral view.