Herpetology Notes, volume 11: 189-195 (2018) (published online on 20 February 2018) Composition and diversity of anurans from rock outcrops in the Caatinga Biome, Brazil Déborah Praciano de Castro1,3,4,*, João Fabrício Mota Rodrigues2,4, Daniel Cassiano Lima3,4 and Diva Maria Borges-Nojosa1,4 Abstract. We provide a list of anurans from an open area of Caatinga stricto sensu, state of Ceará, Brazil. Fieldwork was conducted from July 2010 to July 2011 by sampling the reproductive sites. In total, 19 frog species were recorded, distributed in 13 genera and five families. The number of species found in our study represents 34.5% of the 55 anurans registered for the state of Ceará. The recorded anurofauna is widely distributed and is typical of open areas. One of the species found in our work is more associated with the Cerrado biome (D. rubincundulus). The group of species we recorded represents a subset of the species pool of the Caatinga. Our paper contributes to the knowledge of lowland Caatinga sites outside protected areas. Keywords: amphibians, semiarid region, richness, biodiversity Introduction are found in areas occupied by this vegetation (Borges- Nojosa et al., 2010). The Caatinga, along with the Cerrado and Chaco, is Amphibians comprise one of the groups with greatest classified as a Seasonally Dry Tropical Forest and is morphological and physiological variation among considered the only biome located entirely within the vertebrates (Duellman and Trueb, 1994), covering Brazilian territory (Oliveira and Diniz-Filho, 2010). approximately 7643 species, distributed mainly in This biome is subject to a climatic regime of intense and the tropics (Frost, 2017). Among the amphibians, the irregular rainfall distributed between three to six months order Anura is the most abundant (Vieira et al., 2007), of the year, presents shallow soils with a savannah and the families Hylidae and Leptodactylidae are the vegetation, including xerophytic, shrubby, and thorny most representative in the Neotropics (Bertoluci et al., deciduous physiognomies (Oliveira and Diniz-Filho, 2007). Hylids predominate in forested environments 2010). In recent decades, natural areas of Caatinga have and leptodactylids concentrate mainly in open areas been under intense degradation, and approximately (Arzabe, 1999). 62% of zones susceptible to desertification in Brazil Heyer (1988) identified the Caatinga as one of the least known biomes of South America, with extensive areas lacking information on composition, natural history, and ecology of amphibians. Although the 1 Programa de Pós- Graduação em Ecologia e Recursos number of studies is still much lower when compared Naturais, Departamento de Biologia, Universidade Federal with Brazilian forested areas (Loebmann and Haddad., do Ceará, Campus do Pici, 60.455-970, Fortaleza- CE, Brasil 2010), there has been an increase in the number of 2 Programa de Pós-Graduação em Ecologia e Evolução, studies conducted in areas of Caatinga (e.g., Arzabe., Departamento de Ecologia, Instituto de Ciências Biológicas, 1999; Borges-Nojosa and Cascon., 2005; Garda et al., Universidade Federal de Goiás, Cx. P. 131, 74001-970, Goiânia, GO, Brasil 2013; Santana et al., 2015). 3 Universidade Estadual do Ceará, Av. Monsenhor Tabosa, CEP In this paper, we present new information on the 62500-000 Itapipoca, CE, Brasil composition and diversity of an anuran assemblage 4 Núcleo Regional de Ofiologia da UFC (NUROF-UFC), from rock outcrops in the Caatinga. Departamento de Biologia, Universidade Federal do Ceará, Campus do Pici, Bloco 905, Cep 60.440-554, Fortaleza, Materials and Methods Ceará, Brasil * Corresponding author. E-mail: [email protected] Study area.—This study was conducted at the Sítio 190 Déborah Praciano de Castro et al. Figure 1. Climatic diagram Walter and Lieth (temperature and rainfall x months), during the study period (2010-2011) for Sítio Paleontológico Lajinhas, Itapipoca, Ceará, Brazil. R environment, package climatol (R Development Core Team, 2013). Paleontológico Lajinhas (SPL; Lajinhas Paleontological • “Lagoa da Aposta” (LA) (3.41616667S/ site), in the municipality of Itapipoca, Ceará, 39.69219444W) (Fig 2B): Area of low topography, northeastern Brazil (3.41770833S/ 39.69210278W). with a maximum height of 1.5 m. It has five lentic Caatinga vegetation is predominant in the area, with and temporary ponds up to five square meters and forest and shrub species of the Cactaceae, Fabaceae small puddles on the rock surface. The vegetation and Euphorbiaceae families (Ximenes, 2008). The presents few Cactaceae and Bromeliaceae species, homogeneity of the landscape is often interrupted by and scrub vegetation, but also a massive presence of granite rock outcrops, very common in certain areas of macrophytes inside the ponds, completely covering Caatinga and locally called lajeiros (Ximenes, 2008). the surface of two of them. The study area has a hot semiarid climate with high • “Lajeiro da Jia” (LJ) (3.41594444S/ 39.69083333W) temperatures and low annual rainfall (from 600 to (Fig 2C): It has five temporary pools with a maximum 800 mm), which is concentrated from January to June, depth of 8 m, approximately. There is no scrub with the remaining months of the year being very dry vegetation on the lajeiro, but it accumulates large (Funceme, 2011) (Fig 1). amount of aquatic weeds during the rainy season. In order to improve the sampling, animals found Data collection.—Fieldwork was conducted monthly between the lajeiros were also recorded (Fig 2D). from July 2010 to July 2011, consisting of three days The abundance of each species was estimated using an per month. We conducted active and acoustic surveys active search method at the reproductive sites (Scott with three observers at each study site that were and Woodward, 1994). All individuals on the perimeter sampled during the daytime (8:00 to 12:00 am each of the water bodies were recorded, including non- day) and at night (18:00 pm to 1:00 am each day, or active ones. We used toe clipping (Ferner, 2007) to while vocalizing animals were heard), with a total effort mark all individuals. The monthly occurrence of the of 429 hrs/person. species was assessed using the method of Silveira- This study was conducted at three lajeiros (LC, LA Neto et al. (1976), which classifies the species as: and LJ, see detailed description below). The distances constant, when they are present in more than 50% between these areas are: LC/ LA= 700 m; LC/LJ = 800 of samples; accessory, those present between 25% to m; LA/LJ= 200 m (Fig 2): 50% of samples; and occasional, when found in less • “Lajeiro do Criminoso” (LC) (3.42183333S/ than 25% of the samples. Specimens were deposited 39.69422222W) (Fig 2A): The largest rocky outcrop in the Coleção de Herpetologia da Universidade in the study area, up to 10 m high. It has about 40 Federal do Ceará (CHUFC; Herpetological temporary pools of different sizes, and two ponds Collection of the Federal University of Ceará) and the with accumulated sediment, with vast vegetation species nomenclature follows Duellman et al. (2016) encrusted in sediment and rock crevices. and Frost (2017). Composition and diversity of anurans from rock outcrops, Brazil 191 Figure 2. Sampled Lajeiros in Sítio Paleontológico Lajinhas, Itapipoca, Ceará, northeastern Brazil. A: Lajeiro do Criminoso (rainy season); B- Lagoa da Aposta (rainy season); C- Lajeiro da Jia (dry season); D- Area between lajeiros (rainy season). Statistical analyzes.—To determine sampling (LJ) and the areas between lajeiros showed an equal efficiency, we constructed species richness curves number of species (11) (Table 2). The accumulation (Krebs, 1999). Species richness of the sampled area was curve suggested that more species may be found at these estimated by extrapolation of a species accumulation sites, and Chao 1 and Jackknife 1 estimated the richness curve using Jackknife 1 and Chao 1 estimators, with of the area to be between 20 - 23 species (Fig 3). 500 randomizations in the software Estimates, version The species with the highest abundances were, in 7.5 (Colwell, 2005). To analyse the relative abundance decreasing order: Pseudopaludicola mystacalis (Cope, of anurans, we built a Whittaker plot and the species 1887) (n = 603); Pleurodema diplolister (Peters, 1870) abundance distribution was fitted to four models of (n = 293); Physalaemus albifrons (Spix, 1824) (n = abundance (Broken stick, log normal, logarithmic and 135); and Scinax x-signatus (Spix, 1824) (n = 131). geometric series) (Magurran, 2011), which were tested With regard to the species abundance distribution, using a chi-square test in the program PAST (Hammer the assemblage fit best to the log-normal model (Chi- et al., 2001). square = 2.73; p= 0.43) (Fig 4). Pseudopaludicola mystacalis was the most frequent species, followed by Results Leptodactylus vastus A. Lutz, 1930, and they occurred in all sampling months and at all sampling points (P = We found 19 species distributed in 13 genera and five 100%). Considering rate of occurrence, 47% of species families: Bufonidae (2), Odontophrynidae (1), Hylidae were occasional, 21% were regarded as accessory and (6), Leptodactylidae (9) and Microhylidae (1). The 32% had a constant occurrence (Table 1). Lajeiro do Criminoso (LC) site had the highest richness (15 species). The Lagoa da Aposta (LA), Lajeiro da Jia 192 Déborah Praciano de Castro et al. Figure 3. Species accumulation curves and diversity Figure 4. Whitakker diagram for the distribution of abundance estimators for anuran