Fish diversity of the largest deltaic formation in the Americas - a description of the fish fauna of the Parnaíba Delta using DNA Barcoding

Abstract

Deltas are dynamic and productive systems of enormous ecological significance, encompassing unique and biologically diverse wetland habitats. Here, we present the first data on the molecular diversity of the fish fauna of the Parnaíba Delta, the largest deltaic formation of the Americas. Partial sequences (626 bp) of the mitochondrial COI gene (Cytochrome c oxidase subunit I) were used to barcode 402 individuals, representing 128 species, belonging to 98 genera, 57 families, 17 orders and two classes. The most abundant orders were the Perciformes, Siluriformes, Gobiiformes, and Pleuronectiformes. The Neighbor-Joining (NJ), Bayesian Inference (BI), and BIN analyses produced 103 molecular clusters, while the Automatic Barcode Gap Discovery (ABGD) and Maximum Likelihood (ML) approaches revealed 102 clusters. The mean conspecific, congeneric and confamilial genetic distances were 0.33%, 14.37%, and 18.60%, respectively. Intraspecific divergence ranged from 0.0% to 1.4%, and all species presented barcode gaps, with the exception of two clusters of Cathorops spixii (OTU 96 and OTU 103), which were separated by a low interspecific distance (1.2%), which overlaps the maximum intraspecific genetic distance (1.4%). The barcode data provide new insights into the fish diversity of the Parnaíba Delta, which will be important for the development of further research on this fauna.

Fish diversity in a doubly landlocked country - a description of the fish fauna of Uzbekistan using DNA barcoding

“…The gap between COI intraspecific and interspecific diversity is called the ‘barcode gap’, which is decisive for the discriminatory ability of DNA barcoding [52]. The barcode gap can be seen in our study (Table 2), as well as in many other previous studies [3, 44, 53], thereby further confirming that this approach is an effective way to distinguish between fish species.…”

Assessing fish diversity of Merbok Estuary and adjacent marine waters by DNA taxonomy: towards building comprehensive DNA barcode reference library

“…Similarly, 51 who studied the sh diversity in the Parnaíba Delta, opined that a lack of taxonomy consensus may be observed when the rate of molecular variation does not accompany recent sympatric speciation event that lead to morphological differentiation.…”

The southernmost record and an update of the geographical range of the Atlantic chupare, Styracura schmardae (Chondrichthyes: Myliobatiformes)

“…The specimen was morphologically identified based on the following diagnostic characters proposed by Stehmann et al (1978), indicated in the original description (Werner, 1904) State; see Figure 1). This area comprises estuaries, other sandy or muddy bottoms, and reef environments located on the coastlines of the Brazilian States of Pará (Barthem, 1985;Camargo & Isaac, 2001;Freitas et al, 2019b;Pinheiro & Frédou, 2004;Rodrigues-Filho et al, 2020;Santo et al, 2005;Silva et al, 2016), Maranhão (Almeida et al, 2011;Aragão et al, 2019;Guimarães-Costa et al, 2019;Lessa, 1986;Martins-Juras et al, 1987;Nunes et al, 2005Nunes et al, , 2011Rocha & Rosa, 2001;Silva et al, 2018), Piauí (Aragão et al, 2019;Guimarães-Costa et al, 2019;Mai et al, 2012;Melo et al, 2016) and…”

“…Contrasting to species that are relatively abundant in fishery captures ( e.g ., Hypanus guttatus and H. americanus ), S. schmardae was not recorded in several studies conducted in the area between the previous southernmost confirmed records (Pará State) and the one reported in the present study (easternmost Ceará State; see Figure 1). This area comprises estuaries, other sandy or muddy bottoms, and reef environments located on the coastlines of the Brazilian States of Pará (Barthem, 1985; Camargo & Isaac, 2001; Freitas et al ., 2019b; Pinheiro & Frédou, 2004; Rodrigues‐Filho et al ., 2020; Santo et al ., 2005; Silva et al ., 2016), Maranhão (Almeida et al ., 2011; Aragão et al ., 2019; Guimarães‐Costa et al ., 2019; Lessa, 1986; Martins‐Juras et al ., 1987; Nunes et al ., 2005, 2011; Rocha & Rosa, 2001; Silva et al ., 2018), Piauí (Aragão et al ., 2019; Guimarães‐Costa et al ., 2019; Mai et al ., 2012; Melo et al ., 2016) and Ceará (Araújo et al ., 2000; Basílio et al ., 2008; Freitas et al ., 2019a; Freitas & Lotufo, 2015). This indicates how uncommon or rare this species is in this region.…”