Toxicocalamus nymani (LÖNNBERG, 1900)
Can you confirm these amateur observations of Toxicocalamus nymani?
|Higher Taxa||Elapidae (Hydrophiinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Loria forest snake|
|Synonym||Pseudapistocalamus nymani LÖNNBERG 1900|
Apisthocalamus nymani — BOULENGER 1908
Pseudapisthocalamus nymani – BOULENGER 1908: 249
Pseudapistocalamus nymani – DE ROOIJ 1917: 263
Pseudapistocalamus nymanni – KLEMMER 1963: 328.
Apistocalamus pratti – MCDOWELL 1967: 537 (part)
Toxicocalamus nymani — KRAUS et al. 2022: 1011
|Distribution||Papua New Guinea (southern versant of the Owen Stanley Range of Papua New Guinea, from Tapini, Central Province, in the north to Mt. Dayman, Milne Bay Province, in the south, at elevations from 620–1530 m; elevation ~4000 feet).|
Type locality: Morobe Province: Sattelberg
|Types||Holotype: BMNH 19188.8.131.52, collected by Erik Nyman in 1899.|
|Diagnosis||Diagnosis: “A modestly sized member of the T. loriae Group (maximum SVL in males 422 mm, in females 540 mm) with the following unique combination of characters: two scales covering vent; three infralabials contacting anterior genial; posterior genials entirely separated (45%) by a single intergenial or in anterior (53%) or entire (2%) contact with each other; intergenial usually widest posteriorly or centrally. Preocular approximately as long as wide and never twice as long as wide, usually contacting nasal (94%), not contacting internasal; one (4%) or two (96%) postoculars; one (1%), two (69%), three (27%), four (1%), or five (1%) posterior temporals; 178–198 ventrals in 18 males, 191–210 in 22 females, sexually dimorphic with overlap (t37 = 4.9581, p < 0.00001); 39–48 subcaudals in males, 26–37 in females, sexually dimorphic without overlap; SCR 17.5–20.7% in males, 11.6–15.8% in females, sexually dimorphic without overlap; yellow nuchal collar and yellow markings on prefrontals absent (48%), small or vaguely developed (7%), or present (45%); tail spine paler than remainder of tail; venter uniformly dark brown or dark brown with the posterior of each ventral paler brown or yellowish brown, giving a banded appearance (reported as “blackish brown, edged with light grey” within one year of preservation; Lönnberg 1900).” (Kraus et al. 2022: 1012)|
Comparisons with other species. “Toxicocalamus nymani is distinguished from T. loriae in having a single intergenial (two in T. loriae) that is widest posteriorly or centrally (widest anteriorly in T. loriae), by its short, squarish preocular (elongate, more than twice as long as high, in T. loriae), and by its dark brown or black venter (yellow with or without mid-ventral series of brown spots in T. loriae); from T. nigrescens by its smaller size (maximum SVL = 540 mm vs. 635 mm in T. nigrescens), short preocular (elongate, more than three times as long as high, in T. nigrescens), and in having two postoculars (one in T. nigrescens) and a dark brown or black venter (grey in T. nigrescens); and from T. mattisoni in having the prefrontal usually (93%) excluded from contacting the second supralabial (prefrontal and second supralabial in contact in T. mattisoni), short preocular (elongate, more than twice as long as high, in T. mattisoni), and in having two postoculars (one in T. mattisoni) and a dark brown or black venter (yellow or pale grey with grey bands across each ventral in T. mattisoni).” (Kraus et al. 2022: 1012)
Description of the lectotype. “An adult female, 435 mm SVL + 42 mm TL = 477 mm TTL. Rostral wider than tall, notched ventromedially; internasals angulate, semi- triangular, wider than long. Prefrontals distinct from preoculars, approximately square but angled posteriorly, slightly longer than wide (Fig. 1B, B’), bordered below by preocular and nasal; preoculars angulate but approximately as high as long, bordered anteriorly by nasal, below by second and third supralabials (Fig. 2C, C’, D, D’). Nasals divided by large nares, with two grooves below and partial groove above naris on right, no grooves on left, both nasals damaged. Postoculars two, irregularly pentagonal in shape, upper larger, slightly smaller than eye. Frontal shield-shaped, not fused with supraoculars, anterior margin extending slightly anterior to remainder of scale medially, lateral margins curved posteriorly; parietals approximately twice as long as wide. One elongate anterior temporal above fifth and sixth supralabials, separating latter from parietal; two posterior temporals, upper twice size of lower, with lowerabuttingposterodorsalmarginofsixthsupralabial. Supralabials six on right, seven on left due to division of sixth, third and fourth contacting eye; infralabials six, first three in contact with anterior genial. Mental small, shallow, triangular, wider than long, bordered posteriorly by first supralabials; anterior genials slightly larger than posterior genials but of approximately same length, in medial contact along their entire length; posterior genials completely separated by single elongate intergenial that is widest posteriorly; five gulars separate intergenials from first ventral in the midline; first sublabial separates posterior genial from fifth infralabial (Fig. 3B, B’). Eye relatively small; pupil round.
Dorsal scales smooth, not notched posteriorly, without apical pits, in 15-15-15 rows; ventrals 202, each approximately four times as wide as long; two scales covering vent; subcaudals 28, paired. Tail tipped by a pointed conical spine.
In preservative (114 years after collection), dorsum dark brown dorsally, paler laterally, with brown centre of each scale becoming paler yellow brown at posterior edges. Each ventral scale, including subcaudals, dark brown with paler yellow brown along posterior edges, imparting an overall impression of a dark venter banded with dark brown. Supralabials and rostral largely yellow, all with dark-brown upper margins. Head dark brown with large yellow blotch on each prefrontal and small yellow blotch in anterior part of each preocular. Incomplete yellow nuchal collar, interrupted mid-dorsally by three rows of brown dorsal scales. Chin and throat pale yellow, suffused with brown on mental and anterior portions of anterior gulars and first five infralabials. Tail spine brown, paler than remainder of dorsum. Iris black.” (Kraus et al. 2022: 1012)
Variation. “Preoculars are not in contact with the nasals in three specimens from Madang Province (AMS R25304, R25752, IRSNB 733678), in which they are separated by contact between prefrontal and second supralabial; in contact with internasals only in MCZ R-76627. Two postoculars, except one on both sides of BPBM 3397 and one on the left side of the paralectotype. Posterior temporals two (in 69% of sides), one (1%), three (27%), four (1%), or five (1%). Six supralabials, except seven on left sides of lectotype and AMS R25608, seven on both sides of BPBM 17173, and five on right side of BPBM 31257 and left side of PNGM 24716; third and fourth supralabials invariably contacting eye. Six infralabials, except five on left side of BPBM 17451 and seven on right side of BPBM 30638. Posterior genials partially (53%) or entirely (45%) separated by single intergenial, except in BPBM 30638, which lacks an intergenial and has irregular scales behind the genials. Intergenials usually widest posteriorly (68%) but may be widest centrally (26%) or occasionally anteriorly (5%).
Dorsal scales invariably in 15-15-15 rows. Ventrals 178–198 (187 ± 7) in 18 males, 191–210 (198 ± 5) in 21 females; subcaudals 39–48 (44 ± 2) in 18 males, 26–37 (30 ± 3) in 20 females; SCR 17.5–20.7% (19.1 ± 0.9%) in males, 11.6–15.8% (13.1 ± 1.1%) in females. Tail tipped by a blunt to pointed conical spine. Maximum SVL in males 422 mm, 540 mm in females, not sexually dimorphic (t31=–1.4431, p=0.0795); TLR sexually dimorphic without overlap, in males 13.3–17.9% (16.1 ± 1.3%), in females 9.2–12.9% (10.5 ± 1.0%).
Variation in head colouration is largely geographical, with yellow-spotted heads largely confined to the Huon Peninsula; the specimen from Garaina (MCZ R-152432) also has some vague pale markings on the head, which are difficult to characterize. All specimens from other areas have uniformly dark heads without yellow markings, as do six specimens from the Huon Peninsula. The Huon populations with spotted heads have a large yellow blotch on each prefrontal, a smaller one on the preocular, and a partial or complete yellow nuchal collar; they may also have yellow marks on the internasals, rostral, posterior portion of the nasal, and anterolateral portion of the parietals. Juveniles of the spotted morph (e.g., BPBM 5442, SVL=184 mm) also have yellow colouration widely distributed on the parietals, temporals, and frontals (Fig. 4C, D). These seem to darken and disappear with age in larger animals. In contrast, both adults and the smallest specimens of the dark-headed phenotype (BPBM 23669, SVL = 185 mm; PNGM 24716, SVL = 197 mm) have uniformly dark heads (Fig. 4E, F), suggesting there is no ontogenetic variation in that morph.” (Kraus et al. 2022: 1013)
|Comment||Habitat: fossorial (digging)|
Type species: Apistocalamus loriae BOULENGER 1898 is the type species of the genus Apistocalamus BOULENGER 1898: 705.
Conservation status: least concern; this is the most common Toxicocalamus species with 66% of all museum specimens belonging to this species. However, O’Shea et al. 2015 believes that this variable species represents a species complex.
Taxonomy: Strickland et al. (2016) document at least five undescribed species that all key morphologically to Toxicocalamus loriae.
|Etymology||Named after Swedish botanist Erik Nyman (1866–1900), the collector of the holotype.|
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