Freshwater fishes of the Parque Nacional dos Lençóis Maranhenses and adjacent areas

Abstract

We present here an embracing freshwater fish inventory of the Parque Nacional dos Lençóis Maranhenses and adjacent areas, reporting 49 fish species, 33 of which were identified accurately at the species level, representing ten orders and 25 fish families that range from obligate freshwater to estuarine organisms. This number of species is much larger than two previous studies for the park, each reporting just 12 and 33 fishes occurring on freshwater environments. Among the 49 freshwater species recorded in this study, 14 are new records for the Parque Nacional dos Lençóis Maranhenses, and just one corresponds to an introduced species. Some of the 14 new records in the Parque Nacional dos Lençóis Maranhenses, cited above, as well as some of the 16 species which we are not able to identify accurately at the species level, could include undescribed species, but more study is necessary before sorting out which species are truly undescribed, and which are already described ones. The orders reported by this survey which comprise the highest percentage of species richness, excluding introduced species, were: Characiformes, Cichliformes and Siluriformes, in the same ranking position, and Gymnotiformes, as expected for Neotropical freshwater surveys. The families with the highest number of species, excluding non-native species, were: Characidae, followed by Cichlidae, and Loricariidae. Out of the 33 species herein identified accurately at the species level, five of them are species typically found in brackish water environments, and when occurring on freshwater environments, are restricted mainly to estuaries, or, occasionally, the lower portions of the rivers. Thus, we will not address them in our biogeographical comments. From the remaining 28 species, eight did not occur in the Amazon River basin, six of them being endemic to the Maranhão-Piauí ecoregion. The remaining species herein reported also have their distribution recorded for the Amazon River basin, which shows the great influence of the Amazon basin. In the last two decades efforts to inventory the freshwater fish fauna and to taxonomically solve some groups occurring on the Maranhão state have been made. However the knowledge regarding the composition of the Maranhão freshwater fishes is still insufficient and underestimated, with several groups still lacking adequate taxonomic and systematic resolution, and with many gaps of knowledge, something that is not appropriate for our current picture of "biodiversity crisis". As well as, the other Brazilian protected areas, the PNLM fails to preserve its freshwater environment properly, since it includes only fragments of the major river systems of the area, not including and conserving the hole river drainages, mainly excluding their headwaters. Thus, its water bodies are exposed to typical human impacts.

A new cryptic species of Hyphessobrycon Durbin, 1908 (Characiformes, Characidae) from the Eastern Amazon, revealed by integrative taxonomy

“…Our results suggest a cryptic speciation in the rosy tetra clade, more specifically in a new clade here defined, the Hyphessobrycon micropterus clade, including H. caru sp. nov., H. micropterus, H. piorskii, and H. simulatus, so far only known from the Pindaré, Itapecuru, Munim, Preguiças, and São Francisco river drainages of Brazil and the coastal river basins of French Guiana and Suriname (Guimarães et al 2018;Brito et al 2019;; this study). The clade proposed here is supported by high node support values (maximum posterior probability value and 99% of bootstrap value in BI and MP, respectively).…”

First record of non-native Xiphophorus maculatus (Günther, 1866) (Cyprinodontiformes, Poeciliidae) in the state of Maranhão, northeastern Brazil

“…Despite three decades of field campaigns in the state of Maranhão which surveyed the state's ichthyofauna, X. maculatus had not been detected in any previous collections (e.g., Garavello et al 1998;Piorski 1998;Castro et al 2002;Piorski et al 2003;Pinheiro Júnior et al 2005;Soares 2005;Castro et al 2010;Barros et al 2011;Martins and Oliveira 2011;Sousa et al 2011;Fraga et al 2012;Ramos et al 2014;Ribeiro et al 2014;Matavelli et al 2015;Melo et al 2016;Piorski et al 2017;Abreu et al 2019Abreu et al , 2020Brito et al 2019Brito et al , 2020Lima et al 2019;Teixeira et al 2019;Guimarães et al 2020aGuimarães et al , 2020bGuimarães et al , 2021Oliveira et al 2020). However, from the island of São Luís, state of Maranhão, other non-native fishes have been recorded in various aquatic environments (freshwater, brackish, and marine habitats near the coast), including Butis koilomatodon (Bleeker, 1849) (Eleotridae), Omobranchus punctatus (Valenciennes, 1836) (Blenniidae), Poecilia mexicana Steindachner, 1863 (Poeciliidae), and Poecilia reticulata (Poeciliidae) (Lasso-Alcalá et al 2011;Guimarães et al 2017;Nogueira and Luvizotto-Santos 2018;Bragança et al 2019Bragança et al , 2020b.…”

“…However, this may vary depending on the niche plasticity of both the native and invasive species, as well as localized patterns of resource availability which may allow the invader to occupy a previously unexploited niche or broadening its trophic niche under competition (Dominguez et al 2021). In Maranhão there are five native poeciliid species: Poecilia (Micropoecilia) branneri Eigennman, 1894, Poecilia (Micropoecilia) sarrafae Bragança & Costa, 2011, Poecilia (Pamphorichtys) hollandi (Henn, 1916, Poecilia (Pamphorichthys) araguaiensis (Costa, 1991), and Poecilia (Poecilia) vivipara Bloch & Schneider, 1801 (Figueiredo 1997;Bragança and Costa 2011;Ramos et al 2014;Melo et al 2016;Piorski et al 2017;Brito et al 2019Brito et al , 2020Guimarães et al 2020aGuimarães et al , 2020bGuimarães et al , 2021Oliveira et al 2020), as well as diverse yet functionally similar small fish assemblages (Oliveira et al 2020). Thus, there is a possibility that a successful invasion by X. maculatus may present a threat to native species through competition.…”

Ichthyofauna of the Mata de Itamacaoca, an urban protected area from the upper Munim River basin, Northern Brazilian Cerrado

“…For example, Barros et al (2011) 69 speciesand Nascimento et al (2016) (64 species) both inventoried the fish fauna of the entire Itapecuru River basin, a of the significant coastal river basins of the Mrn and Prn. Further, Brito et al (2019 inventoried 56 species of freshwater fish from the Parque Nacional dos Lençóis Maranhenses and the adjacent areas. Therein, the Mata de Itamacaoca holds around a third of the number of the species reported in far larger systems, thus demonstrating the importance of the studied area in the protection of the fish fauna inhabiting it.…”