Macrobrachium olfersii Wiegmann 1836

2Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, U.K. E-mail: sammy.degrave@oum.ox.ac.uk Macrobrachium olfersii (Wiegmann, 1836)

,

popularly known as Pitu, Bristled River Shrimp and Buchura River Prawn, is a freshwater shrimp species widespread along the eastern coasts of the Americas. The species can be found from the southeastern United States, where the prawns were introduced (Holthuis & Provenzano, 1970), southwards to Rio Grande do Sul (Brazil), including numerous records in Mexico, Nicaragua, Costa Rica, Panama, Colombia, Venezuela, Guyana and Suriname (Holthuis, 1952; Williams, 1984; Melo, 2003; Valencia & Campos, 2007).

This species was described about two hundred years ago by Arend Friedrich August Wiegmann, (1836: 150), from specimens collected on the “Brazilian coast”, with no further location details. Its taxonomic history is complex with a long list of rearrangements and synonymies (see Holthuis, 1952: 95-97; references above). Due to a great many morphological variations, misidentifications and uncertainties that were detected around the relationship and the evolution of this species, members of this group are categorized as the M. olfersii complex (Rossi & Mantelatto, 2013; Rossi & Mantelatto, in prep.).

Although many of the numerous taxonomic controversies have been corrected in recent years by a combination of different analyses, the nomenclature of this species still appears troubled. In recent systematic literature treating the species, two spelling variants exist: with two “i” (olfersii, e.g. De Grave & Fransen, 2011; Rossi & Mantelatto, 2013) as an ending or only one (olfersi, e.g. Pileggi & Mantelatto, 2010; Pileggi et al., 2012).

This nomenclatorial confusion is obviously not of recent making, as numerous examples exist throughout the literature of either spelling variant, but clearly not linked to any biological discipline. We noted that the two distinct names can be found throughout different research studies with no consistent usage within the same discipline. Here we list some examples which adopted M. olfersi (- i) or M. olfersii (- ii). Studies involving physiology used - i (Augusto et al., 2007) but also - ii (Lima et al., 1997; McNamara & Torres, 1999). In reproduction aspects- i was used by Mossolin & Bueno (2002) and Magalhães et al. (2012) but - ii by Ammar et al. (2001). Morphological and development larval studies used either - i (e.g. Nazari et al., 2003; Simões-Costa et al., 2005) or - ii (e.g. Dugger & Dobkin, 1975; Anderson & Filingame, 1980; Müller et al., 2003). In ecology and general biology, - i was used by Gamba & Rodrigues (1987) and Mossolin & Bueno (2003) but – ii by Müller & Prazeres (1992) and Barros (1995), whilst in genetic, taxonomic and systematic works both - i (e.g. Villalobos, 1969; Pilleggi & Mantelatto, 2010; Pileggi et al., 2012) and - ii have been used (e.g. De Grave & Fransen, 2011; Rossi & Mantelatto, 2013).

Herein, we demonstrate that the correct spelling of the species name is Macrobrachium olfersii (Wiegmann, 1836). This species was described originally as Palaemon Olfersii by Wiegmann (1836), with the species name honouring Ignaz Franz Werner Maria von Olfers (August 30, 1793 – April 23, 1871), who was a naturalist, historian and diplomat from Germany (BBAW, 2002). In 1816, he traveled to Brazil, and sent specimens of freshwater shrimp from the coast to the zoologist Arend Friedrich August Wiegmann (June 2, 1802 – January 15, 1841), who worked at the Museum für Naturkunde, in Berlin.

The International Code of Zoological Nomenclature (ICZN, 1999), allows for two options to construct a speciesgroup name formed from personal names (Art. 31.1), if the construction is a noun in the genitive case. If the species name is formed from a personal name in Latin or from a modern personal name that is or has been latinised, it is to be formed in accordance with the rules of Latin grammar (Art. 31.1.1). Alternatively, if the species name is formed directly from a modern personal name, then it is to be formed by adding to the stem of that name - i if the personal name is that of a man (as in the present case). Both species-group names, olfersii and olfersi would be admissible under Arts. 31.1.1 and 31.1.2, although it is evident from the context of Wiegmann (1836), that the name “von Olfers” was latinised to “ olfersius ”, as the diagnosis and much of the text is written in Latin. It is therefore clear that, under Art. 32.3, the original spelling of the name, i.e. olfersii, should be preserved, as it does not require to be corrected under Art. 32.4. Further, under Art. 33.4 the alternative spelling olfersi, is deemed to be an incorrect subsequent spelling.