Description

Description:

Tylototriton sparreboomi is a stout-headed and typically stout-bodied newt described from five males with a snout-vent length range of 63.20 – 68.71 mm. The head is longer than wide, but wider than the body. In the profile, the general shape is depressed and slightly oblique with a rounded snout that protrudes over the lower jaw. In the dorsal view, the snout is truncated. The nostrils are near the snout tip and aren’t visible in the dorsal view. There is a slight labial fold. The eyes are widely set. Posterior to the eye, but before the parotoid glands, there are wide, prominent, bony dorsolateral ridges that are wide, moderately protruding, and curl slightly towards each other. There is also a barely distinct mid-dorsal ridge on the head. The enlarged parotoids are directed posteriorly. A little distance posterior from the mid-dorsal ridge is a straight, high, wide, glandular, segmented crest that extends from the head to the tail. There are also a pair of distinct, round, knob-like rib nodule series on the dorsolateral portions of the body that become smaller towards the posterior. The skin on the ventrum has tubercles arranged like transverse wrinkles, but is generally smoother than the dorsum. There is a gular fold. When adpressed along the body, the fingers and toes overlap. They have four digits on their forelimbs while having five digits on their hind limbs. When the forelimb is adpressed towards the head, the fingers extend to the nostril. The thin tail is compressed laterally with an acuminated tip (Bernardes et al. 2020).

Diagnosis:

Even though T. sparreboomi looks very similar to T. pasmansi, they do have slight differences. More specifically, T. sparreboomi has a more orange-like color, narrower head, wider distance between the eyes, longer humerus, and more enlarged rib nodules. For a more complete comparison with other species please see (Bernardes et al. 2020).

Coloration:

In life, T. sparreboomi has a uniformly black/dark-brown background color from head to tail. However, they also have orange coloration on the ventral side of their digits along with an orange streak down the middle of the ventral edge of their tail. This bright orange color of the digits is also slightly visible from the dorsal view near the extremities of their digits. In preservative the body is still uniformly black/dark-brown, with the orange color on their digits and tail faded to yellow (Bernardes et al. 2020).

Variation:

Overall, individuals are consistent in morphology, however one individual in the type series has thinner rib-nodules, a more glandular vertebral ridge that is covered in tubercles, and a slightly more rounded tail tip than the holotype (Bernardes et al. 2020).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Viet Nam

View distribution map in BerkeleyMapper.

Tylototriton sparreboomi can be found in the Sin Ho District of Lai Chau Province in northern Vietnam in hardwood forests. Their upper and lower elevation limit is 1,670 meters. When specimens were collected, the air temperature was about 23 - 27°C and the humidity was about 80 - 85%. Remote sensing data indicate that they occur in areas with a mean annual temperature of 19.3°C (ranging from 11.6 - 26.1°C) and a mean annual precipitation of about 1843.7 mm (Bernardes et al. 2020).

Life History, Abundance, Activity, and Special Behaviors
Individuals were found in ponds during the day, between 9:00 - 16:30 h, but the surrounding forest, which includes shrubs and vines are also utilized as well (Bernardes et al. 2020).

They reproduce through internal fertilization and are oviparous, laying eggs aquatically (Hernandez 2016).

Trends and Threats
One of the main threats to this species is deforestation due to agriculture. However, because the specimen was collected in secondary forests, it may suggest some sort of tolerance against anthropogenic events. More research is needed to determine a concrete reason for their survival since it is possible that they returned to a “recovered” forest. Their relation to humans is also considered to be a threat to this species as the species is collected for the pet trade and traditional medicine (Bernardes et al. 2020).

Relation to Humans
They are collected/poached to be utilized in the pet trade as well as for traditional medicine. However, the most anthropogenic threat to this species is poaching (Bernardes et al. 2020).

Possible reasons for amphibian decline

General habitat alteration and loss
Intensified agriculture or grazing
Intentional mortality (over-harvesting, pet trade or collecting)

Comments

Phylogenetic Relationship:

Bayesian, Maximum Likelihood, and Maximum Parsimony analyses on ND2 mtDNA support that T. sparreboomi is a unique species but do not have enough resolution to clarify its placement in the T. asperrimus complex (Bernardes et al. 2020).

In a later study, time-calibrated Bayesian and Maximum Likelihood analyses of 12S, 16S, ND1, ND2, COI, Cytb and CR mtDNA found that T. sparreboomi is sister to the clade composed of T. pasmansi and T. asperrimus. However these same analyses with nuclear sequences did not include T. sparrebloomi and had a different topology than the mtDNA phylogenies (Dufrensnes and Hernandez 2022).

Etymology:

The origin of the species epithet is in honor of Professor Doctor Max Sparreboom, who made significant contributions to salamander biology (Bernardes et al. 2020).

References
Bernardes, M., Le, M. D., Nguyen, T. Q., Pham, C. T., Pham, A. V., Nguyen, T. T., Rödder, D., Bonkowski, M., Ziegler, T. (2020). Integrative taxonomy reveals three new taxa within the Tylototriton asperrimus complex (Caudata, Salamandridae) from Vietnam. Zookeys 935: 121–164. [link]

Dufrensnes, C., Hernandez, A. (2022). Towards completing the crocodile newts’ puzzle with all-inclusive phylogeographic resources. Zoological Journal of the Linnean Society 197(3): 620–640. [link]

Hernandez, A. (2016). Crocodile Newts: The Primitive Salamandridae of Asia (Genera Echinotriton and Tylototriton. Chimaira edition, Frankfurt. [link]

IUCN SSC Amphibian Specialist Group. (2021). Tylototriton sparreboomi. The IUCN Red List of Threatened Species 2021: e.T179066179A185517488. https://dx.doi.org/10.2305/IUCN.UK.2021-3.RLTS.T179066179A185517488.en. Accessed on 7 May 2022.

Species Account Citation: AmphibiaWeb 2023 Tylototriton sparreboomi: Sparreboom's Crocodile Newt <https://amphibiaweb.org/species/9192> University of California, Berkeley, CA, USA. Accessed Dec 3, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 3 Dec 2024.

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