Uncovering a hidden diversity: a new species of freshwater shrimp Macrobrachium (Decapoda: Caridea: Palaemonidae) from Neotropical region (Brazil) revealed by morphological review and mitochondrial genes analyses

Abstract

A freshwater palaemonid shrimp from the São Francisco river basin in Brazil has been found to be a new species and is herein nominated as Macrobrachium veredensis sp. nov. It is morphologically similar to M. brasiliense (Heller, 1862), which is found in many rivers of South America. However, M. veredensis sp. nov. has a smooth carapace and few spinules on the second pereopods, while M. brasiliense has the anterolateral surface of the carapace with small spinules and the palm of the second pereopods with spines, spinules and setae. Despite their similar morphology with these subtle differences, the remarkable genetic different evidenced in DNA analysis. Molecular analyses were based on 43 sequences with 528 base pairs (bp) for 16S rDNA, and 16 new sequences with 581bp, without pseudogenes, for COI mtDNA. The nucleotide divergence between M. veredensis sp. nov. and M. brasiliense (7.0–8.5% for 16S and 11.8–12.5% for COI.), the phylogenetic topology and the haplotype network configuration and it is endemism to a region of the São Francisco river basin support the recognition of a new taxon.

Molecular phylogeny and species delimitation of the freshwater prawnMacrobrachium pilimanusspecies group, with descriptions of three new species from Thailand

“…Three standard molecular loci for Macrobrachium were selected for phylogenetic study, including the barcode regions of mitochondrial cytochrome c oxidase subunit I (COI), 16S rRNA (16S), and nuclear 18S rRNA (18S). The criteria for DNA marker selection were (1) sequences of closely related taxa for sequence comparison are available in a public database such as GenBank and BOLD ( Liu, Cai & Tzeng, 2007 ; Wowor et al, 2009 ), (2) marker is commonly used for phylogenetic tree reconstruction of genus Macrobrachium ( Rossi et al, 2020 ; Saengphan et al, 2018 ; Saengphan et al, 2019 ) and (3) a sufficient amount of variation, conserved and parsimony informative sites for multi-locus phylogenetic study ( Liu et al, 2017 ; Matzen da Silva et al, 2011 ; Pileggi & Mantelatto, 2010 ). The PCR primers used in amplification and sequencing are presented in Table 2 .…”

Peer Review #1 of "Molecular phylogeny and species delimitation of the freshwater prawn Macrobrachium pilimanus species group, with descriptions of three new species from Thailand (v0.1)"

“…Three standard molecular loci for Macrobrachium were selected for phylogenetic study, including the barcode regions of mitochondrial cytochrome c oxidase subunit I (COI), 16S rRNA (16S), and nuclear 18S rRNA (18S). The criteria for DNA marker selection were 1) sequences of closely related taxa for sequence comparison are available in a public database such as GenBank and BOLD ((Liu et al 2007;Wowor et al 2009), 2) marker is commonly used for phylogenetic tree reconstruction of genus Macrobrachium (Rossi et al 2020;Saengphan et al 2018;Saengphan et al 2019) and 3) a sufficient amount of variation, conserved and parsimony informative sites for multi-locus phylogenetic study (Liu et al 2017;Matzen da Silva et al 2011;Pileggi & Mantelatto 2010). The PCR primers used in amplification and sequencing are presented in Table 2.…”

Evidence of cryptic diversity in freshwater Macrobrachium prawns from Indochinese riverine systems revealed by DNA barcode, species delimitation and phylogenetic approaches

“…sintangense , which are consumed daily by local people as a protein resource. However, the high genetic diversity, evolutionary relationships and related biological adaptations of indigenous Macrobrachium species have only minimally been investigated in Asia; most research has focused on Neotropical American and Australian fauna [ 42 – 44 ]. In SE-Asia, the giant river prawn, M .…”

“…These include widespread species such as M. rosenbergii, M. lanchesteri, and M. sintangense, which are consumed daily by local people as a protein resource. However, the high genetic diversity, evolutionary relationships and related biological adaptations of indigenous Macrobrachium species have only minimally been investigated in Asia; most research has focused on Neotropical American and Australian fauna [42][43][44]. In SE-Asia, the giant river prawn, M. rosenbergii, is the most economically important species [41], with the most advanced breeding program in the aquaculture industry [45].…”