Varanus citrinus PAVÓN-VÁZQUEZ, ESQUERRÉ, FITCH, MARYAN, DOUGHTY, DONNELLAN & KEOGH, 2022
Can you confirm these amateur observations of Varanus citrinus?
|Higher Taxa||Varanidae, Platynota, Varanoidea, Anguimorpha, Sauria, Squamata (lizards)|
|Synonym||Varanus citrinus PAVÓN-VÁZQUEZ, ESQUERRÉ, FITCH, MARYAN, DOUGHTY, DONNELLAN & KEOGH 2022|
|Distribution||Australia (Northern Territory)|
Type locality: Barney Hill, McArthur River Station, Northern Territory, Australia, 16.4167◦ S, 136.1000◦ E, 38 m elevation.
|Types||Holotype: NTM R17430, adult male, collected by N. J. Gambold, on 8 October 1992. Paratypes (n = 7): NTM|
|Diagnosis||Diagnosis: A member of Varanus distinguished from congeners by having spinose caudal scales, the dorsal coloration consisting of an irregular dark reticulum against a pale background that gives a marbled appearance with ocelli restricted to the dorsal midline (greatly reduced in females), sexually dimorphic dorsal coloration, and a bright yellow gular region in males (Pavón-Vázquez et al. 2022).|
Comparisons: Varanus citrinus can be differentiated from most species in Varanus (except for V. acanthurus, V. insulanicus, V. ocreatus, V. primordius, and V. storri) by having spinose caudal scales (versus caudal scales smooth or weakly to strongly keeled). Distinguished from V. acanthurus, V. insulanicus, V. ocreatus, V. primordius, and V. storri by having the dorsal coloration consisting of an irregular dark reticulum against a pale background that gives a marbled appearance with ocelli restricted to the dorsal midline (pattern reduced in females; versus dorsal pattern consisting of regularly arranged ocelli/pale spots in V. acanthurus and V. storri (can be reduced); dark short transverse bars or reticulum (usually lacking ocelli, poorly formed at best) in V. insulanicus; regularly arranged reticulum usually lacking ocelli in V. ocreatus (can be reduced); and irregularly arranged dark and light brown speckles that sometimes are arranged into a reticulum in V. primordius); from V. acanthurus, V. insulanicus, V. ocreatus, and V. primordius by showing marked sexual dimorphism in dorsal color pattern (versus no consistent sexual dimorphism in dorsal color pattern in the other species); from V. ocreatus, V. primordius, V. storri, and most individuals of V. acanthurus by having a bright yellow gular region in males (versus gular region whitish or creamish); and from adult V. acanthurus, V. insulanicus, and V. ocreatus by having alternating dark and pale crossbands in the posterior portion of the tail (versus posterior portion of tail usually homogeneously dark in V. acanthurus and V. insulanicus, homogeneously pale or with longitudinally arranged dark markings in V. ocreatus). Additionally distinguishable from V. acanthurus and V. insulanicus by usually having fewer longitudinal scale rows at the level of the midbody (81–93, x = 88.5, n = 8; versus 82–110, x = 99.24, n = 99, in V. acanthurus, and 80–112, x = 94.40, n = 15, in V. insulanicus) and having dark ventral spots that end posteriorly at the level of the forelimbs (versus dark spots extending posteriorly past the vent in V. insulanicus and most V. acanthurus); additionally from V. acanthurus by having a broad pale vertebral stripe in life (versus vertebral region not noticeably paler than dorsolateral region in V. acanthurus), and narrower transverse edges on the dorsal dark reticulum (one-scale wide; versus usually two scales wide in V. acanthurus); additionally from V. insulanicus by having a relatively short tail in adults (tail length/SVL ratio 1.49–1.71, x = 1.56, n = 15; versus 1.73–1.98, x = 1.84, n = 18, in V. insulanicus); additionally from V. ocreatus by having the scales on the ventral surface of the lower hindlimbs of similar size to surrounding scales (versus scales enlarged, flattened and tightly juxtaposed in V. ocreatus); additionally from V. primordius by having more longitudinal scale rows at the level of the midbody (81–93, x = 88.5, n = 8; versus 60–66 in V. primordius) and by its larger adult size (SVL in mm 123–196, x = 157.38, n = 16; versus 85–122, x = 105.16, n = 19, in V. primordius); and additionally from V. storri by having more transverse rows of ventrals (57–66, x = 60, n = 8; versus 51–54 in V. storri) (Pavón-Vázquez et al. 2022).
Color in life: In both sexes the iris is brown and is lighter along its dorsal margin. In males, the dorsal background color ranges from light yellow to tan. The vertebral stripe is light brown or light gray. The dorsolateral region bordering the vertebral stripe is infused with either yellowish or brownish orange. The dark markings are chestnut or dark brown. The gular region posteriorly to the level of the eye is bright yellow. In females, the dorsal background color and the vertebral stripe are either light gray or light brown. The dorsolateral region bordering the vertebral stripe is infused with brownish orange. The dorsal dark markings are totally absent or greatly reduced to form a series of disconnected lines arranged in a reticulum-like pattern. The preocular and postocular dark stripes and dark spots below it are present, as are the discontinuous lines on the neck aligned with them, but the markings on the dorsal surface of the head and neck are greatly reduced. The gular region is light gray or cream, with the yellow coloration restricted to the areas immediately below the post-tympanic fold (Pavón-Vázquez et al. 2022).
|Comment||Similar species: V. acanthurus, V. insulanicus, V. ocreatus, V. primordius, V. storri|
|Etymology||Named after Latin Citrinus which means “related to lemon trees”, and refers to the bright yellow throats of males of the new species. The Latin specific epithet is treated as an adjective.|