On the distribution of Siphonops paulensis Boettger, 1892 (Gymnophiona: Siphonopidae): four new Brazilian state records

Siphonops paulensis Boettger, 1892 is a Neotropical siphonopid caecilian widely distributed in South America. Herein, we fill knowledge gaps in the distribution of S. paulensis mostly in northeastern Brazil, including four new state records.

The Neotropical genus Siphonops Wagler, 1828 currently includes five species: S. annulatus (Mikan, 1820), S. hardyi Boulenger, 1888, S. paulensis Boettger, 1892, S. insulanus Ihering, 1911and S. leucoderus Taylor, 1968. Among them, S. annulatus and S. paulensis exhibit very similar morphology and are widely distributed in South America (Taylor 1968;Frost 2015). Siphonops paulensis has been recorded in Argentina, Bolivia, Brazil and Paraguay (Taylor 1968;Frost 2015). In Brazil, this species can be found mainly across central and south portions of the country (Taylor 1970), but recent studies have reported a few additional records from northeastern Brazil (e.g., Loebmann and Haddad 2010;Valdujo et al. 2011;Miranda et al. 2012;Santana et al. 2015). Herein, we continue to fill knowledge gaps in the distribution of S. paulensis, mostly in northeastern Brazil.
Eighteen specimens of S. paulensis were examined by one of us ( Figure 1). Vouchers, geographic coordinates, body lengths and the number of body annuli of S. paulensis specimens are shown in Table 1.
According to Taylor (1968), S. annulatus and S. paulensis differ in the number of body annuli following the collars (78-98 in the first and 100-118 in the later) and the coloration (bluish-black to slate in the first and slate-blue to live slate or brownish to violet-brown in the latter). The taxonomic identification of all 18 specimens was made following Taylor (1968).
Four new Brazilian state records of S. paulensis are reported here (Bahia, Pará, Paraíba and Pernambuco; Figure 1). The record for Bahia is from Serra do Orobó at Ruy Barbosa municipality, whereas the nearest specimen previously collected is from Simão Dias, Sergipe State (ca. 350 km northeast; Santana et al. 2015). The northernmost record of S. paulensis in Brazil is our new record for the Pará state, at Oriximiná municipality, ca. 1,300 km north of the nearest location known for the species at Cláudia, Mato Grosso state (Faria and Mott 2011 (Schmidt and Inger 1951). The record for Pernambuco is located at Arcoverde municipality, ca. 150 km northwest from the nearest site of occurrence of the species at Murici, Alagoas state (submitted).   (Schmidt and Inger 1951) (Figure 1).
We found a misidentification rate of 66% (12 from 18) of S. paulensis specimens in seven Brazilian collections, which have raised our concerns regarding the veracity of distribution records of S. paulensis and S. annulatus in articles that do not provide meristic data (Braun and Braun 1980;Kokubum and Menin 2001;Schwartz et al. 2003;Vaz-Silva et al 2007;Cintra et al. 2009;Silva et al. 2009;Forlani et al. 2010;Faria and Mott 2011;Valdujo et al. 2011) or voucher specimens (Schwartz et al. 2003;Vaz-Silva et al. 2007;Silva et al. 2009;Lema and Martins 2011;Valdujo et al. 2011).The sympatry of these species in at least seven localities plus the discrete morphological differentiation between them reinforces our apprehension regarding their taxonomic validity and accurate identification. Dunn (1942) already reported both species sympatric at two localities (Taubaté, São Paulo state and Teresópolis, Rio de Janeiro state), and Farias and Mott (2011) at one locality (Chapada dos Guimarães National Park, Mato Grosso state). A taxonomic revision of S. annulatus and S. paulensis is urgently needed. We recommend the collection of tissue samples in order to generate further morphological and molecular data to address this question.