Macrobrachium rosenbergii (De Man, 1879)

Hanamura, Yukio, Imai, Hideyuki, Lasasimma, Oulaytham, Souliyamath, Pany & Ito, Sayaka, 2011, Freshwater prawns of the genus Macrobrachium Bate, 1868 (Crustacea, Decapoda, Palaemonidae) from Laos, Zootaxa 3025, pp. 1-37 : 20

Macrobrachium rosenbergii (De Man, 1879)

Palaemon d’Acqueti Sunier, 1925: 117 .

Macrobrachium rosenbergii: Jayachandran 2001: 158 , figs. 11, 12: Hanamura et al. 2008: 1144, figs. 1, 2. Macrobrachium rosenbergii dacqueti: Holthuis 1995: 148 ; Cai & Ng 2002: 78; Cai et al. 2004: 582. Macrobrachium dacqueti: Wowor & Ng 2007: 326 , figs. 4, 5b–c, 6, 7b, 9, 10. Macrobrachium rosenbergii: Ng & Wowor 2011: 66 –67.

Material examined. Champasak Province. Morning market at Pakse city, 1 femele (CL 66.5 mm), 1 ovig. female (CL 58.5 mm), 12 July 2009, coll. S. Ito et al.

Remarks. Macrobrachium rosenbergii is one of the best-known freshwater prawns in the world. The identity of two distinct geographical populations (eastern and western forms) have long been a subject of taxonomic and nomenclatural controversy, although the results of morphological and DNA analyses have suggested that they could be different species (Wowor & Ng 2007, 2008). The present specimens well fit the morphological characteristics of the western form, currently as M. rosenbergii (see ICZN 2010; Ng & Wowor 2011), by having a marked rostral crest and smooth inter spine surfaces on the second pereopods as well as the absence of the posterior submedian plate on the fourth thoracic sternite (Wowor & Ng 2007).

Distribution. Macrobrachium rosenbergii is originally distributed in southern Asia ( Jayachandran 2001) and the western part of south-eastern Asia, demarcated by the Huxley’s line (de Bruyn et al. 2004; Wowor & Ng 2007; Ng & Wowor 2011), although it has occasionally been reported outside of its natural habitat as a consequence of human introduction. The presence of M. rosenbergii in southern Laos is believed to be derived from aquaculture ponds of this species in north-eastern Thailand. Recently, colonisation of this species was found in Madagascar ( Hanamura et al. 2008).