Bioactive alkaloids from the venom of Dendrobatoidea Cope, 1865: a scoping review.

Bioactive compounds derived from secondary metabolism in animals have refined selectivity and potency for certain biological targets. The superfamily Dendrobatoidea is adapted to the dietary sequestration and secretion of toxic alkaloids, which play a role in several biological activities, and thus serve as a potential source for pharmacological and biotechnological applications. This article constitutes a scoping review to understand the trends in experimental research involving bioactive alkaloids derived from Dendrobatoidea based upon scientometric approaches. Forty-eight (48) publications were found in 30 journals in the period of 60 years, between 1962 and 2022. More than 23 structural classes of alkaloids were cited, with 27.63% for batrachotoxins, 13.64% for pyridinics, with an emphasis on epibatidine, 16.36% for pumiliotoxins, and 11.82% for histrionicotoxins. These tests included in vivo (54.9%), in vitro (39.4%), and in silico simulations (5.6%). Most compounds (54.8%) were isolated from skin extracts, whereas the remainder were obtained through molecular synthesis. Thirteen main biological activities were identified, including acetylcholinesterase inhibitors (27.59%), sodium channel inhibitors (12.07%), cardiac (12.07%), analgesic (8.62%), and neuromuscular effects (8.62%). The substances were cited as being of natural origin in the "Dendrobatidae" family, genus "Phyllobates," "Dendrobates," and seven species: Epipedobates tricolor, Phyllobates aurotaenia, Oophaga histrionica, Oophaga pumilio, Phyllobates terribilis, Epipedobates anthonyi, and Ameerega flavopicta. To date, only a few biological activities have been experimentally tested; hence, further studies on the bioprospecting of animal compounds and ecological approaches are needed.

Two names, one species: redescription and phylogenetic position of Schrankiana formosula Freitas, 1959 provides new insights into the evolutionary history of the Cosmocercidae.

Schrankiana are gastrointestinal parasites of anurans, distributed throughout Central and South America. Schrankiana formosula and Schrankiana inconspicata are some of the most commonly reported species parasitising anurans from Brazil, and the morphological differences between them are unclear. In the present study, we redescribed S. formosula based on a re-examination of type series and newly collected material from the frog Leptodactylus pentadactylus in the state of Amapá, Brazil. Additionally, we re-examined the type series of S. inconspicata, and propose it as a junior synonym of S. formosula. We provide detailed morphological and morphometric data with intraspecific variation analyses and new molecular data for S. formosula. In the present phylogeny, S. formosula formed a well-supported clade with Raillietnema sp. and Labeonema synodontisi. Based on molecular phylogenetic analyses and some morphological similarities, our findings support the hypothesis that Schrankiana is a member of the family Cosmocercidae, not Atractidae. Additionally, we provide the first ultrastructural descriptions of S. formosula, and establish the species' phylogenetic position from the Cosmocercidae.

Morphological and molecular characterization of Cosmocercoides amapari n. sp. (Nematoda: Cosmocercidae), parasitic in hylid frogs from the Brazilian Amazon.

Cosmocercoides Wilkie, 1930 are gastrointestinal parasites commonly found in amphibians and reptiles, with 4 species reported from the Neotropical region. In the present study, a new species of Cosmocercoides, namely Cosmocercoides amapari n. sp. is described using integrated approaches such as light and scanning microscopy, and DNA sequencing of the mitochondrial cytochrome c oxidase subunit 1 gene. The specimens were collected from the large intestine of 3 species of hylid frogs in Amapá, Brazil. The new species can be distinguished from its congeners by morphological traits, including the pattern of caudal papillae, absence of the gubernaculum, 2 poorly sclerotized spicules, presence of lateral alae and somatic papillae along the body. In addition, our molecular analyses and phylogenetic reconstructions strongly support the status of the new taxon, which clustered poorly with a large clade of Cosmocerca spp. Cosmocercoides amapari n. sp. is the 29th species of the genus, the 5th from the Neotropical region, the third reported in Brazil, the second described from the Amazon region and the first belonging to the Neotropical region with molecular data.

A new species of Rhabdias (Nematoda: Rhabdiasidae), a lung parasite of Pristimantis chiastonotus (Anura: Strabomantidae) from the Brazilian Amazon: description and phylogenetic analyses.

Rhabdias Stiles and Hassal, 1905 comprises approximately 90 species of parasitic lung nematodes of amphibians and reptiles that have a wide distribution, with 21 species occurring in the Neotropics. In the present study, we describe Rhabdias waiapi n. sp. found parasitizing the lungs of the anuran species Pristimantis chiastonotus from the Amazon Biome in the Amapá State, Northern Brazil. The new species is characterized by having an elongated body, expansions of the cuticular inflation in the anterior end that become more discrete along the body, an anterior end with a slight constriction at the level of the esophageal apex with four rounded subapical elevations of the body wall, six lips, four near the edge of the oral opening and two more distant lateral ones, and a gradually tapering elongated tail. In addition, molecular analyses and phylogenetic reconstructions were made, with sequences from the coding region of the mitochondrial cytochrome c oxidase subunit I gene. Those results strongly support the status of the new taxon, which formed a poorly supported clade with Rhabdias sp. 5 from Anolis brasiliensis from Northeast Brazil. Rhabdias waiapi n. sp. is the 19th species of the genus described in the Neotropics for amphibians, the 10th in Brazil, the second described from hosts of the family Strabomantidae from the Neotropical region, and the first amphibian nematode species described in the Amapá State.

Detection of Rickettsia spp. in ticks parasitizing toads (Rhinella marina) in the northern Brazilian Amazon.

This study evaluated rickettsial infection in ticks collected on toads from the northern Brazilian Amazon (Amapá state), where to our knowledge there are neither records of ticks from amphibians nor rickettsial infections in ticks. During 2016-2017, a total of 22 free-living toads were captured and identified as Rhinella marina. Overall, 12 (54.5%) toads were parasitized by a total of 97 ticks (6 males, 39 females, 31 nymphs, 21 larvae), giving a mean intensity of 8.1 ticks per infested toad. Two tick species were morphologically identified: Amblyomma rotundatum Koch (31 females, 14 nymphs), and Amblyomma dissimile Koch (6 males, 8 females, 17 nymphs). The 21 larvae were morphologically denoted as Amblyomma sp. Five toads were co-infested by A. rotundatum and A. dissimile. Morphological identifications were confirmed by nucleotide sequencing of fragments of the mitochondrial genes 16S rDNA, 12S rDNA and/or COX1. A total of 54 ticks were analyzed for the presence of rickettsial DNA. Eleven (9 females and 2 nymphs) out of 14 A. rotundatum ticks contained Rickettsia bellii. None of the 25 specimens of A. dissimile (6 males, 6 females, 13 nymphs) contained amplifiable rickettsial DNA. From 15 Amblyomma sp. larvae, a pool of 10 individuals contained Rickettsia sp. strain Colombianensi. Sequencing of the 16S rDNA amplicon derived from the positive pool yielded a sequence of A. dissimile. We detected Rickettsia sp. strain Colombianensi for the first time in Brazil. Prior records of this agent were restricted to Colombia and Honduras. In addition, we report the presence of A. rotundatum for the first time in the state of Amapá, where the only other record of A. dissimile was registered over 20 years ago.

Restoration Effects of the Riparian Forest on the Intertidal Fish Fauna in an Urban Area of the Amazon River.

Urbanization causes environmental impacts that threaten the health of aquatic communities and alter their recovery patterns. In this study, we evaluated the diversity of intertidal fish in six areas affected by urbanization (areas with native vegetation, deforested areas, and areas in process of restoration of vegetation) along an urban waterfront in the Amazon River. 20 species were identified, representing 17 genera, 14 families, and 8 orders. The different degrees of habitat degradation had a major effect on the composition of the fish fauna; the two least affected sectors were the only ones in that all 20 species were found. Eight species were recorded in the most degraded areas. The analysis revealed two well-defined groups, coinciding with the sectors in better ecological quality and degraded areas, respectively. The native vegetation has been identified as the crucial factor to the recovery and homeostasis of the studied ecosystem, justifying its legal protection and its use in the restoration and conservation of altered and threatened environments. These results reinforce the importance of maintaining the native vegetation as well as its restoration in order to benefit of the fish populations in intertidal zones impacted by alterations resulting from inadequate urbanization.

Filling the gaps on parasites of Osteocephalus: Helminth community structure of Osteocephalus cabrerai (Anura: Hylidae) from the Brazilian Amazon.

Osteocephalus cabrerai is an arboreal anuran widely distributed in South America. However, there are no parasitological studies conducted on the species, resulting in a parasite fauna completely unknown. Thus, this study aims to characterize the parasitic community structure of O. cabrerai in the municipality of Pedra Branca do Amapari, Amapá state, Amazon region, Brazil. We collected and necropsied 84 specimens of O. cabrerai to search for helminths. Parasite community structure was analyzed using helminth parasite richness, diversity, and abundance. The helminth component community of O. cabrerai comprises six nematode species: Cosmocerca parva, Cosmocerca podicipinus, Oxyascaris oxyascaris, Oswaldocruzia chabaudi, and Physaloptera sp. (larvae). Most helminth species represent the first record for the genus Osteocephalus, except Physaloptera sp. The helminth infections in the host showed a typical aggregated distribution pattern for parasites. We only found a positive correlation between the host weight and total intensity. Our bibliography revision reinforces the need for further studies on the helminth fauna of Osteocephalus spp.

Ophiotaenia karipuna n. sp. (Eucestoda: Proteocephalidae), a parasite of Erythrolamprus miliaris (Linnaeus, 1758), with redescription of Ophiotaenia arandasi (Santos and Rolas, 1973) from the Brazilian Amazon.

Ophiotaenia is the most diverse genus among proteocephalids, composed of species commonly found parasitizing snakes worldwide. However, the diversity of Ophiotaenia in the Neotropical region is still underestimated. This study describes Ophiotaenia karipuna n. sp. found parasitizing Erythrolamprus miliaris in the State of Amapá, Brazil. Additionally, we redescribe Ophiotaenia arandasi based on a re-examination of type series and newly collected material from Erythrolamprus taeniogaster in the State of Pará, Brazil. The new species differs from its congeners in the following characteristics: scolex width, number of testes, relative length of the cirrus-sac, absence of a vaginal sphincter, presence of a vestigial apical organ resembling a sucker, and relative size of the ovary in relation to the surface of the proglottid. Furthermore, we provide taxonomic information for Ophiotaenia arandasi not reported in the original description, including morphology of embryophore, uterine development, and the absence of the vaginal sphincter in the species. Ophiotaenia karipuna n. sp. represents the 21st- species described in snakes -from the Neotropical region and the first formally described in the Brazilian Amazon. Additionally, we provide the first ultrastructural analysis, a new host, and locality records for O. arandasi.

A new species of Aplectana Railliet & Henry, 1916 (Nematoda: Cosmocercidae) in the Brazilian Amazon and the taxonomic status of Aplectana longa.

Nematodes of the genus Aplectana Railliet & Henry, 1916 are common parasites of the digestive tract of amphibians and reptiles in the Neotropical region. During a parasite survey on Boana boans (Linnaeus, 1758), we found specimens of nematodes with Aplectana characteristics. We observed a set of characteristics that differs the species of our study from its congeners, and the present study describes a new species of Aplectana parasite of B. boans using light microscopy and scanning electron microscopy. Aplectana pella n. sp. has lateral alae and somatic papillae in males and females; males have equal short spicules, and the gubernaculum is absent. The arrangement of pairs of caudal papillae also differs from other species (2 precloacal,1 adcloacal, and 5 postcloacal+1 unpaired). In females, the vulva is simple, with non-prominent lips, and equatorial. This is the first record of the genus Aplectana parasitizing B. boans and the 58th species described for this genus. Additionally, we added the precloacal papillae pattern of A. delirae, and based on morphological and morphometric characteristics, we propose the reallocation of Aplectana longa to the genus Oxyascaris.

Ectoparasites infecting Mugil curema (Mugiliformes: Mugilidae) in Amapá state estuary, in the northern Brazilian coast region.

In fish, one of the most important interactions is that occur between parasite species and environment. Wild fish interactions with parasites of different taxa can result in diseases for fish and consequently damages to the fishing industry. This study investigated the ectoparasite fauna in Mugil curema (Valenciennes, 1836), in Amapá state estuary, in Brazilian coast region. The parasite prevalence was 51.4%, and a total of 282 parasites were collected among Ligophorus brasiliensis (Abdallah, Azevedo & Luque 2009), Excorallana longicornis (Lemos de Castro, 1960), larvae of Gnathia sp. and Ergasilus atafonensis (Amado & Rocha, 1995), but L. brasiliensis was the dominant parasite. The parasites presented highly aggregated dispersion, except for Gnathia sp. that had a random dispersion. There was a predominance of hosts non-parasitized and parasitized by one species. The relative condition factor did not differ between parasitized and non-parasitized fish. The body size of hosts did not influence the parasite abundance. The community of ectoparasites consisted of low species richness with low infection levels. This is the first study on parasites of fish from the coast of the State of Amapá and is the first report of Gnathia sp. for M. curema.

The tadpole of Amazophrynella teko (Anura: Bufonidae) from the eastern Amazon, Brazil.

The genus Amazophrynella Fouquet, Recoder, Teixeira, Cassimiro, Amaro, Camacho, Damasceno, Carnaval, Moritz, and Rodrigues, is represented by 12 nominal species and distributed in the Amazon region of Brazil, Bolivia, Colombia, Ecuador, Guyana, French Guiana, Peru, and Venezuela (Frost 2020). In the last eight years, ten species from this genus have been described. However, despite the wide distribution and diversity of these species, only the tadpole of Amazophrynella manaos Rojas, Carvalho, Ávila, Farias, and Hrbek from the Brazilian Amazon (Menin et al. 2014) and A. siona Rojas, Fouquet, Ron, Hernández-Ruz, Melo-Sampaio, Chaparro, Vogt, Carvalho, Pinheiro, Ávila, Farias, Gordo, and Hrbek from Ecuador have been formally described (Duellman Lynch 1969; Rojas et al. 2018). Literature about tadpole morphology, reproduction, and bioacoustics of Amazophrynella is scarce and necessary to a comprehensive taxonomic classification (Kaefer et al. 2019). Herein, we describe the tadpole of the recently described species Amazophrynella teko Rojas, Fouquet, Ron, Hernández-Ruz, Melo-Sampaio, Chaparro, Vogt, Carvalho, Pinheiro, Ávila, Farias, Gordo, and Hrbek, found in the northeastern Amazon, in the State of Amapá, Brazil, and in French Guiana.

Description of the tadpole of Dendropsophus haraldschultzi (Bokermann, 1962) (Anura: Hylidae), with comments on reproductive biology.

The genus Dendropsophus Fitzinger contains 108 recognized species (Frost 2020) distributed in nine species groups according to Faivovich et al. (2005). However, recent phylogenetic analysis recognized the presence of nonmonophyletic groups (e.g., Wiens et al. 2010; Fouquet et al. 2011; Motta et al. 2012; Jansen et al. 2019) suggesting that the relationships among species of Dendropsophus require careful revision. Species of this genus are distributed in the tropical and subtropical South America, including Trinidad, southward to northern Argentina and Uruguay and northward to Central America and tropical southern Mexico (Duellman et al. 2016; Frost 2020). Dendropsophus haraldschultzi (Bokermann) was described in the area of Santa Rita do Weill, municipality of São Paulo de Olivença, Amazonas State, Brazil. Adult individuals of D. haraldschultzi are small sized frogs (males 18-22 mm and females 22-25 mm; Rodríguez Duellman 1994) with tuberculate skin on dorsal surfaces, denser on the head. They are found near open ponds and permanent large streams or in floating meadows along the Amazon river (Bokermann 1962; Rodríguez Duellman 1994; Böning et al. 2017) and have been also found along the Amazon River Valley in the Brazilian states of Pará and Amapá (Missassi et al. 2017), and in Peru and Colombia. Bokermann (1962) and later authors (e.g., Lutz 1973) considered this species without evident taxonomic affinities. Currently, D. haraldschulzi is not assigned to any species group within the genus (Faivovich et al. 2005).

New records of hosts for Excorallana longicornis and Nerocila acuminata (Crustacea: Isopoda) in brackish fish from the coast of the State of Amapá (Brazil), with an update on the geographic distribution of Nerocila acuminata.

Fish are parasitized by several species of crustaceans, including Cymothoidae and Corallanidae. The aim of this study was to investigate the crustacean parasite fauna in Anableps anableps, Amphiarius rugispinis, Bagre bagre, Cathorops spixii, Cynoscion acoupa, Centropomus undecimalis, Macrodon ancylodon, Mugil curema, Megalops atlanticus, Pseudachenipterus nodosus, Plagioscion squamosissimus, Platystacus cotylephorus, Sciades passany, Sciades herzbergii, and Hypostomus ventrimaculata from the coast of the State of Amapá, eastern Amazon. In addition, an update on the geographic distribution of Nerocila acuminata in Brazilian Amazon is present. A total of 204 fish were examined and prevalence was 16.17%. A total of 185 Excorallana longicornis and Nerocila acuminata were collected and E. longicornis was the most frequent parasite species. The community of parasitic crustaceans in fish species from the coast of the State of Amapá consisted of two species of isopods, E. longicornis and N. acuminata, which are new records for nine host species here studied. Lastly, this is the first record of Nerocila acuminata for Brazil, besides the first report of E. longicornis for M. curema, C. acoupa, H. vetrimaculata, A. anableps, A. rugispinis, C. spixii and S. herzbergii; as well as N. acuminata for A. anableps, P. nodosus, A. rugispinis, C. spixii and M. atlanticus.

Richness and composition of anuran assemblages from an Amazonian savanna.

The Amazonian savannas occupy approximately 150,000 km2 of the Brazilian Amazon, occurring in scattered isolated patches over large areas of forest in the states of Amapá, Amazonas, Pará, Roraima and Rondônia. Despite having considerable variation in the Anuran composition between locations and between the savanna's physiognomies, a systematic and geographically wide sampling has not been performed for the savanna from Amapá yet, located in the north of Brazil, eastern Amazonia. In this perspective, a study was conducted on the richness, composition, diversity, and abundance of Anuran species in a ​​savanna area in Amapá State. For Anuran sampling, we performed 24 samples in four physiognomies (grassland savanna, scrub grassland savanna, parkland savanna, open woodland savanna) through an active and auditory search more than 20 sampling plots of 100 × 50 meters in each physiognomy. Twenty-one (21) species of frogs belonging to five families were registered: Bufonidae, Hylidae, Leptodactylidae, Microhylidae and Phyllomedusidae. Scrub grassland savanna registered a greater number of individuals regarding the species richness by physiognomy. The species rarefaction curve for the total area reached an asymptote, suggesting that the data collection effort was enough to adequately sample the species richness of the area. The Kruskal-Wallis variance analysis revealed significant differences in the species richness and diversity among the physiognomies. The Bray-Curtis similarity analysis grouped the physiognomies into three main groups: open woodland savanna, grassland savanna and scrub grassland savanna and parkland savanna. Through ordering by non-metric multidimensional scaling, the species composition from the savanna anuran assemblage resulted in a separation among three sampled physiognomies with significant differences, indicating differences in assemblage composition of the three sampled physiognomies. The local richness (21 species) corresponds to 14% of the 15 typical species that have strongly associated distribution with the Cerrado from Central Brazil, and 35.6% of 59 typical species of neighboring domains which only marginally occur in the Cerrado, representing a considerable part of frog species richness recorded in the savanna in the eastern portion of the Brazilian Amazon.

The tadpole of Elachistocleis helianneae Caramaschi, 2010 (Anura: Microhylidae).

The neotropical genus Elachistocleis Parker comprises 18 described species [including Elachistocleis ovalis (Schneider) which is considered a nomen dubium by Caramaschi (2010), with pending revision]. This genus is distributed in Central America and most of South America, from Panama and Trinidad to southern Paraguay, including central Argentina, Uruguay, Venezuela, Colombia, Bolivia, Guyana, Surinam, French Guiana, and Brazil (Marinho et al. 2018; Frost 2019). Currently, the tadpoles of ten species have been described and/or figured: Elachistocleis bicolor (Guérin-Méneville), E. cesarii (Miranda-Ribeiro), E. erythrogaster Kwet and Di-Bernardo, E. haroi Pereyra, Akmentins, Laufer and Vaira, E. muiraquitan Nunes-de-Almeida and Toledo, E. ovalis, E. panamensis (Dunn, Trapido and Evans), E. pearsei (Ruthven), E. surinamensis (Daudin), and Elachistocleis sp. (Kenny 1969; Williams & Gudynas 1987; Kwet & Di-Bernardo 1998; Duellman 2005; Lynch 2006; Rossa-Feres & Nomura 2006; Vera Candioti 2006; Magalhães et al. 2012; Pereyra et al. 2013).

The advertisement call of the Hoogmoed's harlequin toad Atelopus hoogmoedi Lescure, 1974 from northern Brazil (Anura, Bufonidae).

Harlequin toads (Atelopus) are distributed over a wide range in the Amazon Rainforest, mostly associated with streamlets in dense ombrophilous forests in lowland and sub-montane regions. Atelopus hoogmoedi Lescure, 1974a was considered as bearing full species status by Lötters et al. (2005), although until that moment this species had been assigned to a subspecies of A. pulcher (Boulenger, 1882) (Lescure 1974a, 1976) or of A. spumarius Cope, 1871 (Lescure et al. 1980; Lescure Marty 2000; Lötters et al. 2002). More recently, Noonan Gaucher (2005) subscribed to Lötters et al. (2005)'s statement that A. s. hoogmoedi should belong to a distinctive species (A. hoogmoedi), based on phylogeographic evidence. The species' range is currently restricted to the Guiana Shield of French Guiana, Suriname, Guyana, and in adjacent regions of northern Brazil (Lötters et al. 2005).

Anuran species composition of Cancão Municipal Natural Park, Municipality of Serra do Navio, Amapá state, Brazil.

In this study, the first survey of anuran species in the Cancão Municipal Natural Park is presented, a protected area of approximately 370 hectares of Amazonian forest located in the northwest center region of the state of Amapá, Brazil. The work was performed during the dry and rainy season, through active visual and auditory survey, totaling 216 man hours of sampling effort. Forty-nine species of anuran amphibians were recorded in the Cancão Municipal Natural Park, including three new records: Hyalinobatrachium iaspidiense, Pristimantis cf. ockendeni, and Scinax garbei. Three species, Hyalinobatrachium iaspidiense, Ameerega pulchripecta, and Anomaloglossus baeobatrachus, are listed as Data Deficient and one is listed as Vulnerable (Atelopus hoogmoedi) according red lists of IUCN. The rarefaction curve cumulative species did not reach an asymptote, indicating that site has potential for species that have not yet been recorded. Nine species were represented by only one individual and were considered rare in the studied environments, eight species were defined as common, and the 32 remaining species were classified as having intermediary abundance. Our data indicated that Cancão Municipal Natural Park contains a considerable portion of the anurans species richness of Amapá state, turn the area into a place of great importance for the conservation of the anurans of the Eastern Amazon.

The advertisement call of Ameerega pulchripecta (Silverstone, 1976)(Anura, Dendrobatidae).

The name Ameerega picta was once used to denote a lineage of poison frogs (Dendrobatidae) distributed throughout most of the Amazon basin (Silverstone 1976); more recently, to describe a phenetic group involving at least 18 species, Lötters et al. (2007) pointed out that some of the lineages were indeed derived from the former A. picta. Among them, the nominal species with the widest distribution is A. hahneli (Haddad & Martins 1994; Twomey & Brown 2008), also an alleged complex of poorly defined species (Grant et al. 2006; Fouquet et al. 2007; Roberts et al. 2007). The mate-recognition signal, the advertisement call, was part of the evidence used to revalidate A. hahneli as a different species from A. picta. Although the advertisement call has been described for one or few individuals of other species in the group (Haddad & Martins 1994; Costa et al. 2006; Twomey & Brown 2008; Lötters et al. 2009), namely A. flavopicta, A. braccata and A. boehmei, and A. hahneli, we still lack a formal description for A. pulchripecta, the sister taxon of A. hahneli (Twomey & Brown 2008). Its call has been qualitatively described as similar to A. hahneli's call, but "deeper-voiced" (Lötters et al. 2007).