Description
Ichthyophis weberi is a small caecilian, with a total length of approximately 258 mm. Eyes are in sockets and visible through the skin. Annuli are indistinguishable and the dorsal count of transverse folds is 313-329, while the ventral count is 304-322. Many folds are incomplete and three or four posterior scale rows are present in each fold. The vertebral count is 104-108 (Taylor 1920; Taylor 1968).

I. weberi has a body length about 25 times the body width (Taylor 1968). The first three or four annuli on the anterior part of the body do not meet. Otherwise, annuli meet at an angle on the venter, except for those on the posterior part of the body, which align straight across without an angle. Scales are present in each fold. At midbody there are three large rows of scales, while on the last 20% of the body there are three to four rows of scales with the fourth row sometimes incomplete (Taylor 1968). There is a relatively distinct groove extending from the tip of the lower jaw nearly to the vent, along the median ventral line of the body, although this may be an artifact of preservation. Other grooves are also used to describe the species that may be distinct or nondistinct (Taylor 1920; Taylor 1968). The head is short, oval and somewhat flattened. Nostrils visible from above. Tentacles small and conical and close to the lip, and much closer to the eye than the nostril. Snout projects slightly over the lower jaw. The distinct eyes are closer to the mouth than to the nostril. The interorbital distance is slightly greater than the length of the snout. The tentacular groove is somewhat moon-shaped and is located anterior to the orbit, near the edge of the upper jaw (Taylor 1920). Two collars are visible, with the first defined on the throat (Taylor 1968). There is a single row of teeth in the lower jaw and two rows of teeth in its upper jaw. The inner row extends further back than the outer, but not does not widen (Taylor 1920). The teeth number is as follows: premaxillary-maxillary, 25-25; prevomeropalatine, 27-27; dentary 22-22; splenials absent (Taylor 1968). The palate is high. Choanae are large and subtriangular, with the interchoanal distance more than 2.5 times the width of one choana. The tongue is flat at the anterior end, and covers the entire surface between the series of dentary teeth. C. weberi has no narial plugs (Taylor 1968). The tail is quite short, with six transverse folds. The vent has eight or nine denticulations on the sides. In males, a slightly elevated anal gland is present on either side of the vent (Taylor 1968).

Coloration: The holotype is described as yellowish brown, in preservative, with a somewhat darker shade on the median part of the body. The venter is light yellowish brown. Under a microscope the color appears as rounded yellowish dots, surrounded by a network of brown. There is a white spot on the tip of the lower jaw (Taylor 1920). The neotype is described as violet dorsally, and lighter violet with a hint of brown ventrally. The vent has a whitish mark. The snout tip is somewhat lighter than the ground color. Eyes and tentacles lack a white spot. The lower jaw is either the same shade as the skin or is slightly lighter (Taylor 1968).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Philippines

View distribution map in BerkeleyMapper.

This species is known only from the vicinity of the Malatgang River in Iwahig, on Palawan Island in the Philippines. It may be more widespread in lowland forests of Palawan. Adults are likely to be subterranean and occur in moist tropical forests (Diesmos et al. 2004).

Upon its rediscovery in 2015 by an international team of field biologists from the Palawan Centre of Sustainability, the National Museum of the Philippines, the Palawan Council for Sustainable Development, and the University of Kansas, it is thought that the Malatgan caecilian may be a dry microhabitat specialist (found away from water in dry forest floor detritus). This would explain how the caecilian has escaped detection by biologists who have searched in vain for the species in moist, riparian, or semi-aquatic microhabitats (Beijnen and Jose 2021).

Life History, Abundance, Activity, and Special Behaviors
It is presumably oviparous with terrestrial eggs and aquatic larvae (Diesmos et al. 2004).

Trends and Threats
No threats are currently known and the type locality is well protected (Diesmos et al. 2004).

Comments

The species was first described by Taylor (1920), as Ichthyophis weberi. The original holotype was lost in a museum fire during WWII. Taylor described the species again from a neotype (DSBM 21758) (Taylor 1965).

This species is in need of taxonomic review (Diesmos et al. 2004). It has sometimes been considered synonymous with Ichthyophis monochrous (Taylor 1960; Taylor 1965).

Ichthyophis weberi is named after Mr. C. M. Weber, who collected the type specimen (subsequently lost in a museum fire during WWII) and contributed greatly to the natural history collections of the Bureau of Science (Taylor 1920; Taylor 1968).

Before 2015, it had not been seen in the wild since the 1970s despite attempts. In 2015, it was rediscovered in dry forest detritus, surprising biologists and leading to new evidence of its microhabitat preference (Beijnen and Jose 2021).

References

Beijnen JV and Jose ED (2021). "Rediscovery and Range Extension of the Malatgan River Caecilian (Ichthyophis Weberi Taylor, 1920) in Palawan, Philippines." United International Journal for Research & Technology, 2(11), 87-90. [link]

Diesmos, A., Alcala, A., Brown, R., Afuang, C., Gee, G., Hampson, K., Diesmos, M. L., Mallari, A., Ong, P., Ubaldo, D., Gutierrez, B., Wilkinson, M., Gower, D., and Kupfer, A. (2004). Caudacaecilia weberi. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.1. www.iucnredlist.org. Downloaded on 17 May 2010.

Frost, D.R. 2007. Amphibian Species of the World: an Online Reference. Version 5.1 (10 October, 2007). Electronic Database accessible at American Museum of Natural History, New York, USA. Caudacaecilia weberi. Accessed on 18 May 2010.

Taylor, E. H. (1920). ''Philippine amphibia.'' The Philippine Journal of Science, 16, 213-360.

Taylor, E. H. (1960). ''On the caecilian species Ichthyophis glutinosus and Ichthyophis monochrous, with description of related species.'' University of Kansas Science Bulletin, 40, 37-120.

Taylor, E. H. (1965). ''New Asiatic and African caecilians with redescriptions of certain other species.'' University of Kansas Science Bulletin, 45, 253-302.

Taylor, E.H. (1968). The Caecilians of the World. A Taxonomic Review. University of Kansas Press, Lawrence, Kansas.

Species Account Citation: AmphibiaWeb 2021 Ichthyophis weberi: Malatgan River Caecilian <https://amphibiaweb.org/species/1971> University of California, Berkeley, CA, USA. Accessed Nov 22, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Nov 2024.

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