Odonata of the state of Maranhão, Brazil: Wallacean shortfall and priority areas for faunistic inventories

Abstract

Environmental changes are worrying in a scenario with large knowledge gaps on species diversity and distribution. Many species may become extinct before they are known to science. Considering this scenario, the present study aims to evaluate the known distribution of the species recorded for Maranhão state in Brazilian northeast region and discuss knowledge gaps about Odonata indicating the priority areas for faunistic inventories. Using primary and secondary data together, we present convex minimum polygons of the distribution of all the species registered for the state. In addition, we created maps with the richness of species and number of records of Odonata in the Maranhão state. In primary data sample 269 specimens, represented by 17 genera and 30 species were collected. Of the 30 species collected, 17 are new records for the state of Maranhão; of these, 35.29% are geographically widespread species, occurring in practically all regions of Brazil. Considering the records in the literature, there was a 68% increase in the number of Odonata species known for Maranhão. The most unexplored region is the Cerrado of the state of Maranhão. Furthermore, the transition regions between Cerrado and Amazônia and between Cerrado and Caatinga are also unknown. All these areas are a priority for faunistic inventories.

Differences in land use modify Odonata assemblages in the Cerrado-Caatinga ecotone

“…None of the species collected during the present study are at any risk of extinction, according to the classification of the Brazilian Chico Mendes Institute for Conservation and Biodiversity (ICMBio, 2016). Unlike expected, the occurrence of species of the suborder Zygoptera (A. aepiolum, H. auripennis, T. coccinea and T. aurantinigrum), were restricted to altered streams, indicating ecological diversity within the suborder, a pattern observed in other studies (Bastos et al, 2019;Rodrigues et al, 2019Rodrigues et al, , 2016Carvalho et al, 2013a;Monteiro Júnior et al, 2013;Kalkman et al, 2007). This occurs because A. aepiolium, A. gracile, H. auripennis present the epiphytic type of oviposition, laying their eggs on the macrophytes (Rodrigues et al, 2018;Kompier, 2015), thus, areas without riparian vegetation and that develop a greater amount of aquatic macrophytes are the perfect habitats for these species (Rodrigues et al, 2018;Vilela et al, 2016).…”

“…Several ecological studies have been carried out with Odonata in Amazon biomes (Chen et al, 2017;Correa et al, 2015;Oliveira-Junior et al, 2015;Couceiro et al, 2007), there are also several others for the Cerrado (Cabette et al, 2017;Brasil et al, 2014;Juen et al, 2014), however, for the Cerrado-Caatinga ecotone there are large Hutchinsonian, Linnean and Wallacean gaps (Bastos et al, 2019;De Marco & Vianna, 2005). Thus, in the present study, we tested the hypothesis that the odonate assemblages of environments with higher habitat integrity have distinct species richness, composition, and abundance in comparison with areas that have lower habitat integrity.…”

Contradicciones de la Amazonía en el Brasil: Una nueva perspectiva

“…De los Estados que componen la llamada Amazonía Legal en Brasil, se reconocen el Acre, Amapá, Amazonas, Maranhão, Mato Grosso, Pará, Roraima, Rondônia y Tocantins que, en conjunto, atingen una superficie aproximada de 5.015.067,749 km² (501.506.774.900 ha), correspondiente a cerca de 58.9% del territorio brasileiro [21]. Siete de esos Estados, corresponden a la Región Norte de Brasil, mientras que Maranhão, hace parte de la Región Nordeste, Mato Grosso, de la Región Centro-Oeste del Brasil [22].…”

Dragonflies and Damselflies in a region of the Triângulo Mineiro, Minas Gerais: checklist and taxonomic additions

“…Many odonate species are known to be endangered with the overexploitation in many regions of the country (ICMBio 2018, Araújo et al 2020). This situation has encouraged great effort in preservation measures in the last years, including inventories in priority regions (e.g., Cerrado) and species conservation categorizations (De Marco & Viana 2005, Koroiva et al 2017, Dalzochio et al 2018a, Bastos et al 2019, Garcia Junior et al 2021, Koroiva et al 2020, Vilela et al 2020a. Despite this progress, distribution and taxonomic gaps are still frequently reported problems in the literature, even in explored regions.…”