New records of Atractus ronnie ( Serpentes , Colubridae ) in relictual forests from the state of Ceará , Brazil , and comments on meristic and morphometric data

Atractus ronnie was recently described from Serra de Baturité, a mountainous relictual forest enclave in the semiarid Caatinga, state of Ceará, northeastern Brazil. Here we report new records of A. ronnie in two other areas of relictual forests and provide additional data on pholidosic variation. The results presented herein reinforce the need for systematic inventory surveys in the relictual forests of Ceará, since the herpetofauna remains poorly known.

Atractus ronnie (Figure 1) has recently been described on the basis of individuals from Serra de Baturité (Baturité hills), a mountainous humid forest in the semiarid Caatinga domain, state of Ceará, Brazil (Passos et al., 2007).Here we report two new records of A. ronnie in the state of Ceará and provide additional data on the pholidosic variation of this taxon.
Both areas are relictual forests and represent exceptionally humid habitat islands within the semiarid Caatinga Domain (sensu Ab 'Saber, 1977).Localized orographic rains and fog condensation favor the persistence of these relictual forests, and they experience significantly milder temperatures and increased levels of rainfall compared to the surrounding Caatinga lowlands (Vanzolini, 1981;Andrade-Lima, 1982;Carnaval and Bates, 2007).The main difference between both areas is the location of the relictual forest.This happens because the chemical morphogenesis which contributes to the formation of the humid forest occurs on the tops and slops of the hills on the Plateau of Ibiapaba, while on the Plateau of Araripe this phenomenon occurs only on the slopes of the hills (Fernandes, 1990).
Meristic data from the collected specimens agree in most aspects with the original description, although it is possible to identify certain differences (Table 1).The maximum snout vent lengths attained by specimens, especially among females, were greater (223mm in males; 391mm in females) than those seen among individuals from Serra de Baturité (220mm in males; 312mm in females).Although the ventral color pattern is uniformly creamish white in most of the specimens analyzed, as depicted in the original description, the largest specimen had small dark brown spots concentrated in the distal half of its body.
Scale counts also revealed certain differences.Ventral scales varied from 146 to 163 among females (n = 7), and from 129 to 132 among males (n = 3), against 154-160 among females and 134-144 among males in the original description.Subcaudals were very similar to the original description, although one female had 16 subcaudals, one less than the minimum observed in the population of Serra de Baturité.
Although some of the meristic data differ from the original description we believe these must be interpreted as intraspecific variations rather than to consider these populations as a distinct taxon.
The presence of A. ronnie in other areas of relictual forest in Ceará demonstrates that the species is not restricted to Serra de Baturité.The new records presented here extend the species distribution by ca.230km east and ca.350km south from the type locality, the municipality of Pacoti, state of Ceará (Figure 2).These results provide additional evidence for the need of systematic inventory surveys in order to study the diversity of the herpetofauna of the relictual forests of Ceará state, since new distribution records and new taxa continue to be published in recent years (e.g.Loebmann et al., 2007;Passos et al., 2007;Loebmann, 2008a;2008b;2008c;Ribeiro et al., 2008).

FIGURE 1 :
FIGURE 1: General view of the adult female of Atractus ronnie in life collected in the municipality of Tianguá, Plateau of Ibiapaba.Picture by Daniel Loebmann.