Morphological variation and taxonomy of Atractus latifrons (Günther, 1868) (Serpentes: Dipsadidae)

Abstract

As currently understood Atractus latifrons is widely distributed in South America, occurring from Suriname to the east of the Andes in Bolivia. Throughout this widespread distribution, at least three distinct color patterns were previously reported in the literature. Here, we test whether quantitative variation and qualitative distribution of morphological characters are correlated with any color pattern displayed by the species along its range. We recognize three aposematic color patterns (bicolor in monads, tricolor in dyads, and tricolor in tetrads) for A. latifrons. We found no obvious correspondence between these patterns and any character systems analyzed herein. Additionally, we redescribe the holotype of A. latifrons and report on morphological variability (meristics, morphometrics, color patterns, and hemipenis) and geographical distribution (extending its distribution to the state Roraima, Brazil) of the species.

Redescription ofAtractus punctiventrisand Description of Two NewAtractus(Serpentes: Dipsadidae) from Brazilian Amazonia

“…Data from additional specimens of Atractus previously examined can be found in Passos et al (2005), Passos et al (2007a,b), , , Passos et al (2009a,b,c,d,e), Passos et al (2010a,b,c), Passos and Lynch (2011), Passos and Prudente (2012), , Passos (2008, 2010), Passos et al (2013a,b,c,d), Almeida et al (2014), and Salazar-Valenzuela et al (2014). We prepared fully everted and almost maximally expanded hemipenes from the following specimens: IBSP 47078, MNRJ 16511, MNRJ 18035, MNRJ 24363, MPEG 17908, MPEG 23930, MUFAL 10462, and ICN 12162.…”

“…Atractus is the most species-rich snake genus in the world, with more than 140 valid species at present (Passos et al 2013a;Salazar-Valenzuela et al 2014). The genus, as currently understood, represents one of the most morphologically diverse radiations of New World snakes, having adult body size from 100 mm (Passos et al 2013b) to more than 1 m (Schargel et al 2013), and a color pattern varying from uniformly colored, banded, or striped (Savage 1960) to putative coralsnake mimetic patterns (Martins and Oliveira 1993;Almeida et al 2014). Despite renewed interest in the systematics of Atractus in the last 10 yr, the taxonomy of this genus remains in a state of flux with frequent resurrections (Passos et al 2010a), rediscoveries , synonymizations (Passos et al 2013a), and descriptions of new species (Salazar-Valenzuela et al 2014).…”

The South American false coral snake Erythrolamprus aesculapii (Serpentes: Dipsadidae) as a possible mimic of Micrurus averyi (Serpentes: Elapidae) in Central Amazonia

“…In Amazonia, where many species of Micrurus occur, snakes with different color patterns may be sympatric. Thus, there may be a wide array of potential models for other snakes to mimic; most of the potential mimics are members of Dipsadidae Bonaparte, 1838 (Martins and Oliveira 1998, Campbell and Lamar 2004, Almeida et al 2014.…”

“…This is the case of most snakes with a coral-snake pattern, independent of the sequence and length of dorsal rings. In Amazonia, not only E. aesculapii aesculapii (Figures 2, 3D), but also most Atractus latifrons (Günther, 1868) have populations with diads on the body (Almeida et al 2014(Almeida et al , 2016 that differ of all triad-and monad-patterned Micrurus with respect of the sequence of rings. Nonetheless, the scattered presence of specimens with tricolor monads and Nascimento, 1973;M.…”

Have coral snake mimics diversified more than non-mimics?

“…700 species occurring from Central to South America (Grazziotin et al 2012, Uetz andHosek 2014), and is characterized by an impressive variety of color patterns (see Martins and Oliveira 1998 for some examples). Some dipsadids have color patterns similar to those of coral snakes, and have long been suggested as cases of mimicry of New World coral snakes of the genus Micrurus and Leptomicrurus (family Elapidae; Wallace 1867, Greene and McDiarmid 1981, Sazima and Abe 1991, Savage and Slowinski 1992, Martins and Oliveira 1993, Pough 1988, Almeida et al 2014. The contrasting coloration found in dipsadid snakes always includes bright colors but is not restricted to ringed patterns.…”