We report the first records of Scinax ruberoculatus Ferrão, Fraga, Moravec, Kaefer & Lima, 2018 in the state of Amapá, Brazil. We provide an updated distribution map of this species, comment on its occurrence in French Guiana and Suriname, and provide morphometric and bioacoustic data for a population from the municipality of Porto Grande, Amapá, including the first description of the species’ territorial call. This record from Porto Grande extends the distribution of S. ruberoculatus approximately 1430 km northeast from its type locality and helps to better understand its actual distribution. 

The Boidae family is an ancient group of snakes widely distributed across the Neotropical region, where several biogeographic events contributed towards shaping their evolution and diversification. Most species of this family have a diploid number composed of 2n = 36; however, among Booidea families, the Boidae stands out by presenting the greatest chromosomal diversity, with 2n ranging between 36 and 44 chromosomes and an undifferentiated XY sex chromosome system. Here, we applied a comparative chromosome analysis using cross-species chromosome paintings in five species representing four Boidae genera, to decipher the evolutionary dynamics of some chromosomes in these Neotropical snakes. Our study included all diploid numbers (2n = 36, 40, and 44) known for this family and our comparative chromosomal mappings point to a strong evolutionary relationship among the genera Boa, Corallus, Eunectes, and Epicrates. The results also allowed us to propose the cytogenomic diversification that had occurred in this family: a process mediated by centric fissions, including fission events of the putative and undifferentiated XY sex chromosome system in the 2n = 44 karyotype, which is critical in solving the puzzle of the karyotype evolution of boid snakes.

We report the first collected specimen of Trachycephalus hadroceps (Duellman & Hoogmoed, 1992) from Brazil. This record, from the municipality of Porto Grande in the state of Amapá, expands the geographic distribution of this species by approximately 230 km south-southeast from the nearest previously known locality at Camopi, French Guiana. We also provide data on the advertisement call of the species.

Based on field surveys undertaken in two conservation areas, we report new distribution data of Hyalinobatrachium taylori (Goin, 1968) and H. tricolor Castroviejo-Fisher, Vilà, Ayarzagüena, Blanc & Ernst, 2011 from the state of Amapá, northern Brazil. We provide acoustic data from these new populations. These are the first records of H. taylori and H. tricolor from Amapá, extending the geographic distributions of these species by 317 km from Mitaraka and 320 km from Saut Grand Machicou, both in French Guiana, respectively.

Glass frogs (Centrolenidae) are widely distributed in the Neotropics. This study presents novel data on two centrolenid species of the genus Hyalinobatrachium Ruiz-Carranza & Lynch, 1991 collected during herpetofaunal surveys carried out in Brazilian Amazonia of the state of Amapá. Here we report the first record of Hyalinobatrachium cappellei (van Lidth de Jeude, 1904) and H. mondolfii Señaris & Ayarzagüena, 2001, extending the known distribution of H. mondolfii 264 km east and filing gaps in the distribution range of H. cappellei in eastern Amazonia.

A predation event on Chatogekko amazonicus (Sphaerodactylidae) by the wolf-spider Lycosa sp. (Lycosidae) was observed in an Amazon forest, in north Brazil.

Lithodytes lineatus (Schneider, 1799) is a medium-sized frog distributed throughout South America and found in Brazil in the Amazonia and Cerrado domains. Here we document two new records of the species in forested areas in the state of Amapá, Northern Brazil, and provide an updated distribution map for it. The record of L. lineatus in the state of Amapá extends its distribution approximately 78 km from the nearest locality, Floresta Estadual do Paru, in the municipality of Monte Alegre, state of Pará, Brazil, and help to fill information gaps.