Micrurus obscurus (JAN, 1872)
Can you confirm these amateur observations of Micrurus obscurus?
|Higher Taxa||Elapidae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Black-neck Amazonian coral snake, Bolivian Coral Snake|
Portuguese: Chumbeguaçu, Cobra-Coral, Cobra-Coral-de-Pescoço-Amarelo, Coral, Coral-Verdadeira
|Synonym||Elaps corallinus var obscura JAN & SORDELLI 1872: plate VI|
Elaps heterozonus PETERS 1881
Elaps heterozonus BOULENGER 1896
Elaps princeps BOULENGER 1905: 456
Micrurus spixii obscura — SCHMIDT & WALKER 1943: 294
Micrurus spixii princeps — SCHMIDT 1953: 175
Micrurus spixii obscurus — SCHMIDT 1955
Micrurus spixii princeps — PETERS & OREJAS-MIRANDA 1970: 218
Micrurus spixii obscurus — PETERS & OREJAS-MIRANDA 1970: 218
Micrurus spixii obscurus — DUELLMAN 1978: 261
Micrurus spixii obscurus — WELCH 1994: 89
Micrurus spixii princeps — WELCH 1994: 89
Micrurus obscurus — HARVEY et al. 2003
Micrurus spixii obscurus — CAMPBELL & LAMAR 2004: 228
Micrurus spixii princeps — CAMPBELL & LAMAR 2004: 228
Micrurus obscurus — RIVAS et al. 2012
Micrurus obscurus — WALLACH et al. 2014: 451
Micrurus obscurus — NOGUEIRA et al. 2019
|Distribution||S/E Colombia, NW Brazil (Upper Amazon region), N Bolivia, E Ecuador, E Peru;|
Type locality: “Lima” (in error); designated to “Iquitos, Peru” by SCHMIDT 1953: 175.
princeps: NW/C Bolivia; Type locality: "Province Sara, Department Santa Cruzde la Sierra, Bolivia"
|Types||Holotype: lost, formerly MSNM, destroyed in World War II.|
Lectotype: BMNH 19188.8.131.52, a male, designated by Roze, 1989:14 [princeps]
|Diagnosis||Diagnosis: (1) Dorsal pattern of yellow, red, and black triads; (2) hemipenis and tail relatively short; (3) two supralabials entering orbit; (4) mental usually separated from chinshields by medial contact of first pair of infralabials; (5) anal scale usually divided; (6) first triad usually incomplete (if complete, the first black ring is very short and edges the parietals; a "remnant" of this ring is often evident as a row of black scales on the side of the neck): two black rings on neck, the first strongly angled anteriorly along midline; (7) dorsal surface of snout red, parietal region yellow; black band crossing frontal and supraoculars to suprala bials; (8) apices of yellow rings with more black pigment than apices of scales in red rings; (9) yellow rings longest ventrally, some black rings greatly con stricted or interrupted ventrally; (10) mental and some anterior infralabials edged in black, remaining scales of chin mostly immaculate; (11) parietals immaculate yellow or with black blotching; scales of snout moderately blotched; (12) prefrontal contacting the supralabials in about 60% of the specimens; (13) 6-9 body triads (as few as 4 in specimens outside Bolivia, Roze, 1996), 0.67—1 triads on tail; (14) yellow rings longer or only slightly shorter than exterior black rings [HARVEY et al. 2003].|
Nascimento et al. 2019 distinguished M. spixii from M. obscurus (in parenthesis) by the combination of the following characters: black cephalic cap (vs. cephalic cap absent, with red parietal region), hemipenial body with spines dispersed on the asulcate surface (vs. spines arranged in rows on the asulcate surface), capitate condition of hemipenis (vs. organ partially-capitate), narrow parietal bone with posterior angular borders (vs. enlarged parietal bone with elliptical posterior border), and relatively long venom inoculating fangs (vs. relatively short venom inoculating fangs).
Comparisons. Micrurus obscurus differs from M. spixii by having tricolor head with dark interorbital bar, white anterior ring before black ring of an incomplete triad, hemipenis non-capitate, and fangs proportionally short with respect to maxillary (vs. well-defined black cephalic cap connected to first black ring, hemipenis capitate, and venom fangs proportionally long with respect to maxillary); differs from M. diana by having absence of cephalic cap, first body triad incomplete, body triads 3–10, last triad incomplete, ventral 174–228 (vs. cephalic cap connected to first black body ring, first body triad complete, body triads 9–15, ventrals 214–116); differs from M. filiformis by having white snout with black-edged scales, relatively robust body, ventrals 197–228 and less than 11 complete body triads (vs. black snout interrupted by white transverse band, body thin, ventrals 239–329, and 10–22 complete body triads); differs from complex M. lemniscatus complex by having white snout with black-edged scales, infralabias without characteristic spots and ventrals 197–228 (vs. black snout, followed by white and black band, and inverted U-shaped spot covering infralabials; ventrals 225–263 in M. lemniscatus helleri; ventrals 225–277 in M. l. lemniscatus); differs from M. hemprichii ortoni by having divided cloacal scale and red rings composing triads (vs. entire cloacal scale and yellow rings composing triads); differs from M. nattereri and M. surinamensis by having white snout with black- bordered scales, anterior ring narrow and white before first black ring, first body triad incomplete, eyes and nostrils positioned laterally, and hemipenis short without papillate or spinulate calyces (vs. red snout with black posterior border, narrow anterior and posterior black ring as well as white rings, first body triad complete, eyes and nostrils ori- ented toward the top of head, and hemipenis short, moderately elongate with calyculated lobes and calcified spines) [Nascimento et al. 2019].
|Comment||Subspecies: M. obscurus is considered as a subspecies of M. lemniscatus by some authors.|
Synonymy after HARVEY et al. 2003 who considered spixii and obscurus as separate species. However, Campbell & Lamar 2004 rejected that, considering the differences between the populations as insufficient to be different species.
Distribution: TORRES-CARVAJAL et al. 2019 do not list M. obscurus for Ecuador but rather M. spixii, dependent on which authority is adopted. See map in Nogueira et al. 2019.
|Etymology||Latin obscurus means dark and obscure and probably alludes to the darkened head and the long black nuchal band. When describing this subspecies Jan used a darkened, large adult specimen that apparently gave the impression of an "obscurus" snake.|