An inventory of Ichthyofauna of the Pindaré River drainage, Mearim River basin, Northeastern Brazil

Abstract

In the present work, we conducted an extensive long-lasting inventory of the fishes, using different collection methodologies, covering almost the entire Pindaré River drainage, one of the principal tributaries of the Mearim River basin, an area included in the Amazônia Legal region, northeastern Brazil. We reported 101 species, just three of them being non-native, demonstrating that the composition of this studied fish community is majority composed of native species. We found a predominance of species of the orders Characiformes and Siluriformes, corroborating the pattern usually found for the Neotropical fish fauna. Similar to other studies, this inventory was mainly dominated by small characids, representing 21% of the species herein recorded. When comparing the present survey with other species lists published for this region (including the States of Maranhão and Piaui), we can conclude that the freshwater fish fauna of the State of Maranhão is probably still underestimated. We reported 41 more species, and one more species than Soares (2005, 2013) and Abreu et al. (2019) recorded for the entire Mearim River basin, respectively. We believe, however, that the number of species presented by Abreu et al. (2019) is overestimated. We compared our results with all other freshwater fish species inventories performed for the hydrological units Maranhão and Parnaíba sensu Hubbert & Renno (2006). With these comparisons, we concluded that our results evidenced that a high effort was put in the inventory here presented. The two works including more species recorded from coastal river basins of the hydrological units Maranhão and Parnaíba were the works published by Ramos et al. (2014) for the Parnaíba River basin, one of the main and larger river basin of Brazil, and the compiled data published by Castro & Dourado (2011) for the Mearim, Pindaré, Pericumã, and upper Turiaçu River drainages, including 146 and 109 species, respectively. Our survey recorded only 45 less species than Ramos et al. (2014), and eight less species than Castro & Dourado (2011). However, it is essential to emphasize that the number of species presented by Castro & Dourado (2011) is probably overestimated since they did not update and check the taxonomic status of the species of their compiled data. In several cases, they considered more than one name for the same species.

Taxonomic revision of Sturisoma Swainson, 1838 (Loricariidae: Loricariinae), with descriptions of four new species

“…Sturisoma lyra (Regan, 1904). —Eigenmann, 1910:416 (reference); Miranda Ribeiro, 1918:717 (record at Juruá River); La Monte, 1935:7 (list; present at Juruá River); Gosline, 1945:109 (reference); Fowler, 1954:124 (synonym list; as present at Amazon and Paraguay rivers); lsbrücker, 1979:88;113 (reference; lectotype designation); lsbrücker 1980:94 (as valid in Sturisoma ; catalog of Loricariidae); Ortega & Vari, 1986:18 (as present in Peru; checklist); Burgess, 1989:440 (reference); Isbrücker, 2001:31,32 (as valid in Loricariidae; German version); Isbrücker, 2002:29 (as valid in Loricariidae; English version); Ferraris, 2003:347 (valid in Loricariinae; distribution; type series); Ferraris, 2007:299 (valid in Loricariinae; distribution; type series); Rapp Py‐Daniel & Ohara, 2013:292 (as present in Madeira River basin, Brazil; dorsal, lateral, and ventral images of preserved specimen; type locality; distribution; museum records; comments and remarks; record is S. reisi ); Covain et al, 2016: 514 (valid as part of Sturisoma ; phylogenetic analysis of Loricariinae; not included in phylogenetic analysis); Londoño‐Burbano, 2018:1001 (as valid in Sturisoma ; as present in Brazil; identification key of genus); Guimarães et al, 2020:8 (as present at Pindaré River drainage, Mearim River basin, Maranhão State, Brazil, as Sturisoma aff. lyra ; record is S. rostratum ); Guimarães et al, 2021:37 (as present at Mearim River basin, Maranhão State, Brazil, as Sturisoma aff.…”

“…1935), andFowler (1954) registered the species as valid and assessed records fromBoulenger (1898) and MirandaRibeiro (1911), correcting the identifications made by them. Later, designated the lectotype for the species.More recently,Guimarães et al (2020Guimarães et al ( , 2021 recorded Sturisoma aff. lyra from the Mearim River basin, record that was followed byKoerber et al (2022).…”

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

“…cryptica, Hemigrammus sp.1, and Hemigrammus sp.2), and are in the process of being described. The other four species need a more comprehensive taxonomic investigation, especially comparing with specimens from other populations from other river basins and regions, as already proposed for other fish groups occurring along the coastal river basins of the State of Maranhão by Guimarães et al (2020). The State of Maranhão (northeastern Brazil), compared to other Brazilian regions, has distinctly few studies related to its freshwater ichthyofauna, especially in taxonomic studies (Piorski, 2010, Guimarães et al 2018a, 2020.…”

CONFIRMAÇÃO DE SINONIMIA VIA DNA BARCODING DE Anomalocardia brasiliana (Gmelin, 1791) PARA Anomalocardia flexuosa (Linnaeus, 1767) NA ILHA DE UPAONAÇU, MARANHÃO, BRASIL

“…No entanto, apesar da grande importância que esta bacia apresenta, o conhecimento de sua ictiofauna ainda é limitado. A maioria dos estudos realizados para esta bacia e para os seus tributários, restringiram-se a exame de espécimes para registros taxonômicos e filogeográficos, com muitos dos táxons analisados apresentando incertezas taxonômicas (SOARES, 2005;ABREU et al, 2019;GUIMARÃES et al, 2020).…”

“…Hoplias malabaricus -100 BARROS et al, 2011;RAMOS et al, 2014;NASCIMENTO et al, 2016;ABREU et al, 2019;GUIMARÃES et al, 2020…”