Genetic variability and phylogenetic aspects in species of the genus Macrobrachium

Abstract

ABSTRACT. The genus Macrobrachium includes prawns, which are widely distributed in lakes, floodplains, and rivers in tropical and subtropical regions of South America. This genus presents nearly 210 known species with great ecological and economic importance. However, few studies are related to the biology of these crustaceans. In this study, we analyzed the genetic variability and phylogenetic relationship between Macrobrachium amazonicum and Macrobrachium jelskii, which are closely related species. Additionally, they are syntopics and their taxonomy poses problems because it is difficult to differentiate between the species. We used the mitochondrial gene sequences COI and 16S rRNA to assess the genetic structure of these species in 3 populations that were collected from Tiete hydrographic basin (São Paulo State, Brazil). The interspecific Genetic variability in the genus Macrobrachium comparison of samples that were collected at the same and different locations showed a low rate of genetic variability. This similarity was attributed to the recent introduction of these species in the regions that were sampled and the habitat conditions in which they inhabit. In addition, these results may be consistent with the hypothesis that they are a single species, interspecific hybrids, or metapopulation. The dendrogram analyses did not reveal the formation of clusters, confirming the disturbances in the genetic structure of the samples that were analyzed in this study. These data are pioneers to these crustaceans, and they confirm the ecological and evolutionary problems between these Macrobrachium species.

New Record of Macrobrachium lar (Fabricius, 1798) (Crustacea: Decapoda: Palaemonidae) from Al-Hammar Marsh, Southern Iraq

“…Macrobrachium Bate, 1868 is a widely distributed and abundant macroinvertebrate genus in inland water. It has been recorded in several tropical and subtropical regions such as lakes, ponds, rivers, as well as in estuaries (Cook et al, 2002;Guerra et al, 2014). Species of Macrobrachium found in lowlands of Africa, Asia, Oceania, North, Central and South America.…”

“…Although most of the species are inhabiting freshwater environments, some can tolerate higher salinities and found near sea coasts where water is rather brackish (Wowor et al, 2009;Pileggi & Mantelatto, 2010). Update, this genus includes approximately 210 species of prawns and is considered as the largest palaemonid genus, with the greatest diversity occurring in the Indo-Pacific region and the Americas (Mantelatto et al, 2008;De Grave & Fransen, 2011;Guerra et al, 2014).…”