Apostolepis longicaudata GOMES, 1921
Can you confirm these amateur observations of Apostolepis longicaudata?
|Higher Taxa||Colubridae (Dipsadinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||Piauí Blackhead, Longhead Burrowing Snake|
|Synonym||Apostolepis longicaudata GOMES in AMARAL 1921|
Apostolepis longicaudata — DE LEMA 2002
Apostolepis longicaudata — CURCIO et al. 2011
Apostolepis longicaudata — WALLACH et al. 2014: 52
|Distribution||Brazil (Piaui, Tocantins)|
Type locality: Municipio de Santa Philomena, Estado de Piauhy, Brazil.
|Types||Holotype: IBSP 1684 (not labeled in field, destroyed by fire in 2010), an adult male from Engenheiro Dodt, municipality o Santa Filomena, state of Piauı ́, northeastern Brazil, collected by Francisco de Assis I(n)glesias between 1916 and 1918 (the ‘‘n’’ in the collector’s surname is a typographic error; the correct spelling is ‘‘Iglesias’’). Originally described in 1919, by J. Florencio Gomes, formally published by Amaral (1921a).|
|Diagnosis||Diagnosis.—A small species of Apostolepis, SVL up to 254 mm, differing from all con- geners by the following combination of char- acters: (1) snout rounded or slightly acu- minate, length of rostral visible from above slightly more than one-third its distance to frontal; (2) six supralabials; (3) preocular– nasal contact present (i.e., nasal and preocular not separated by prefrontal); (4) temporals absent (0+0), fifth and sixth supralabials in contact with parietals; (5) four infralabials contacting first pair of chin shields on each side of head; (6) ventrals 234–244 and sub- caudals 49–52 in males (females unknown); (7) dorsal head plates uniformly dark brown, except for small irregular white blotches on anteriomedial surface of prefrontals; (8) light supralabial blotch large, covering posterior margin of third and almost whole area of fourth supralabial; (9) white and black nuchal collars completely absent; (10) five dorsal stripes similar in width (as wide as, or slightly wider than, one dorsal scale row); (11) dorsum background light tan (orange-tan in life); (12) terminal scale directed backward, mostly white, possibly invaded by black pigment from the tail band at least on its dorsal surface; (13) chin and gular region immaculate cream.|
Species with five dorsal stripes that are most likely to be confused with A. longicaudata are the predominantly Amazonian species A. nigrolineata and A. quinquelineata and the Cerrado species A. nelsonjorgei, but over- lapping values of subcaudal counts are only present in A. nelsonjorgei. Nonetheless, A. longicaudata is unambiguously distinguishable from these three species by a suite of char- acters: (1) condition of the white nuchal collar: A well-developed white nuchal collar is pres- ent in A. nelsonjorgei (Lema and Renner, 2004a) and entirely lacking in A. longicaudata. Most specimens of A. nigrolineata have rudi- ments of a white nuchal collar, peculiarly ex- pressed as two well-defined pale blotches on each side of the nape (Lema and Renner, 1998:107,118). However, a few specimens have complete white collars (e.g., MPEG 16137, 17671). Lema and Renner (1998) suggest that juveniles of A. quinquelineata may have rudi- ments of a white nuchal collar. In our com- parative material, none of the specimens of this species can be considered a juvenile, but no traces of such a structure were present even in the smaller individual (e.g., MPEG 17817; SVL 5 226 mm, tail length 5 15 mm). (2) Condition of the black nuchal collar: A distinctive black nuchal collar up to two dorsal scales long is present in A. quinquelineata (Ferrarezzi, 1993; Harvey, 1999; Lema and Renner, 1998) and absent in A. longicaudata. (3) Temporal for- mulae: Usually 0+1, rarely 0+0 in A. nigroli- neata, (Ferrarezzi, 1993; Harvey, 1999; Lema and Renner, 1998), contrasting with 0+0 in all known specimens of A. longicaudata. Boulen- ger’s (1896) original description mentions no temporals in the holotype of A. quinquelineata (fifth and sixth supralabials contact parietals), but this character is apparently variable in this species, because there are specimens with 0+1 temporals. Thus, we do not recognize this character as informative for distinguishing A. quinquelineata from A. longicaudata. (4) Black caudal band: In A. quinquelineata the black caudal band is restricted to the dorsal and dor- solateral surface of the tail (Ferrarezzi, 1993; Lema and Renner, 1998), contrasting with the complete black band of A. longicaudata. (5) Width of the lateral stripe: The lateral stripes of A. quinquelineata (covering first–fourth dorsal rows) are distinctively wider than the paraver- tebral and vertebral ones (Lema and Renner, 1998), contrasting with a lateral stripe (restricted to fourth dorsal row) similar in width to the paravertebral and vertebral ones in A. longicaudata.
Five dorsal stripes are also present in Apostolepis arenaria, A. christineae, A. intermedia, A. lineata, A. serrana, A. striata, A. phillipsi and A. vittata (Harvey, 1999; Lema, 2002, 2004; Lema and Renner, 2004c, 2006; Rodrigues, 1993), but all these taxa have considerably lower subcaudal counts and differ from A. longicaudata (characters in parentheses) in sca- lation and coloration. Apostolepis arenaria has 21–31 subcaudals and distinctive white and black nuchal collars (lacking). Furthermore, this species has 168–181 ventrals, the lowest counts in the genus (Rodrigues, 1993). Apostolepis christineae has up to 29 subcaudals, a narrow black nuchal collar attaining the gular region (lacking), a strongly projecting, flattened, and acuminate snout (rounded or slightly acuminate), the rostral largely visible from above and mostly white on its dorsal surface (a small portion visible from above and mostly black on its dorsal surface), all stripes dark and cohe- sive (at least the paravertebral stripe diffuse), a black caudal band restricted to the dorsum, barely reaching the lateral margins of the sub- caudals (complete caudal band), and the white portion of the terminal scale restricted to its ventral surface (white tip and ventral surface of the termimal scale; Lema, 2002). Apostolepis intermedia is only known from the holotype, which is apparently lost (Harvey, 1999; Lema, 1993: 37). However, the original description mentions three infralabials contacting the first pair of chin shields (four), a pointed snout (rounded or slightly pointed), 217 ventrals (234–244), and 37 subcaudals (Koslowsky, 1898). Regarding A. lineata, the only objective data allowing distinction from A. longicaudata are provided by Harvey (1999: 393), who reported 24 subcaudals, and Lema and Renner (2004b), who mention a distinctly projecting snout (not projecting). Apostolepis serrana has up to 33 subcaudals, besides a distinctive black nuchal collar attaining the margins of the gular region (lacking) and an entirely white termimal scale (marked by black on the dorsal and lateral surfaces). Apostolepis striata has considerable posterior—up to three dorsal scales—and ventral extensions of the head cap, configuring a black nuchal collar that is lacking in A. longicaudata; the labial blotch covers a larger area in A. striata— third–sixth supralabials—than in A. longicaudata (third and fourth supralabials), and the only known specimen has 202 ventrals (234–244) and 26 subcaudals (Lema, 2004). Apostolepis philli- psi has narrow but distinctive white and black nuchal collars (lacking), a pointed snout, and 24 subcaudals (Harvey, 1999). Apostolepis vittata has up to 28 subcaudals, a pointed and strongly projecting snout, five supralabials (six), and only three infralabials contacting the first pair of chin shields (four; Harvey, 1999) [from CURCIO et al. 2011].
|Comment||Conservation: very rare species, known from only a few specimens.|