Description
Ichthyophis benjii is a caecilian that was described from three males and two females with total lengths in males ranging from 414 - 473 mm and the two females having total lengths of 410 mm and 459 mm. The width is greatest at the midbody width, which ranges between 14.2 - 18.0 mm in males and 15.2 - 17.6 mm in the two females. When viewed dorsally, the head appears more V-shaped than U-shaped, and is short for the body (with the total length by the head length ratio being greater than 24). The tentacular apertures are more than twice as close to the eyes as to the nares. The number of annular grooves on the dorsal surface range from 388 - 422 while on the ventrum they ranged from 383 - 423. There is a cloacal disc that is longer than wide and interrupts 5 - 6 annular grooves. There are an additional 5 - 6 annular grooves behind the disc on the short tail (Laremsanga et al. 2021). For a more complete description, please see Laremsanga et al. 2021.

DIAGNOSIS:

Within the group of striped congeners, I. benjii has a noticeably less prominent pale yellow lateral stripe above a darker ventrolateral longitudinal stripe bordering the venter on each side. It can be differentiated from Ichthyophis tricolor and Ichthyophis multicolor due to the much higher dorsal annular groove count of 385 - 422 and ventral annular groove count of 383 - 423 (Laremsanga et al. 2021).

COLORATION:

In life, the dorsum is a dark brownish-grey, the venter is reddish-grey, and the narrow irregular faint lateral stripes are a dull yellow. A thin midventral line from the anterior of the corners of the mouth across the first collar to the second nuchal groove that is pale yellow. With the exception of the areas crossing the faint lateral stripes and the venter, annular grooves appear to be mostly paler than the surrounding skin. The tip of the tail also appears pale (Laremsanga et al. 2021).

In preservation, the dorsum is brownish-grey and is more chocolate brown where the stratum corneum is absent. The tentacular papillus and snout tip are pale. The eye is surrounded by a narrow whitish ring and covered by translucent skin. There is no presence of moustache-like stripes between the snout tip and tentacular apertures. The venter is a much paler brownish-grey. Around the cloaca, there is a pale disc. The upper and lower jaws have pale lines. Beginning from right behind the corners of the mouth, I. benjii has irregular, faint, lateral yellow stripes that extend to the level of the posterior of the vent, without touching the cloacal disc. The stripe breaks at several points. Stripes are also either absent or barely visible on the ventral side of the collars and are patchy in the trunk region (Laremsanga et al. 2021).

VARIATION:

Some of the specimens were much larger than the holotype and several were less elongate. The specimen with the highest dorsal annular groove count was also the only specimen to have a ventral annular groove count larger than the dorsal count. The width of the stripe at midbody doesn’t appear to grow as fast as the width of the body and the tail appears to lengthen slower than the head during development, without correlation to total length. Specimens had 118 to 124 vertebrae (Laremsanga et al. 2021).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: India

View distribution map in BerkeleyMapper.

All specimens were collected in the Aizawl District, Mizoram, India, on the surface in a secondary forested area, between 821 and 1,233 meters above sea level (Laremsanga et al. 2021).

Life History, Abundance, Activity, and Special Behaviors
Activity on the surface seems to be nocturnal and in the months of July to October, which aligns with mid- to late monsoon season. Three specimens were collected at night and the other two appeared to be trapped in a construction zone during the night and collected in the morning. Prolonged monsoon seasons lead to longer periods where I. benjii is above ground (Laremsanga et al. 2021).

One specimen had a small freshwater shrimp in its mouth, suggesting that prey includes freshwater macroarthropods (Laremsanga et al. 2021).

Sympatric species of caecilians include Ichthyophis khumhzi, I. moustakius, and I. multicolor and sympatric frogs include Duttaphrynus melanostictus, Fejervarya multistriata, Minnervarya asmati, Megophrys serchhipii, Polypedates teraiensis, Zhangixalus suffry, and Zhangixalus smaragdinus (Laremsanga et al. 2021).

Trends and Threats
The species authority suggests that the species should be listed as Data Deficient (DD) until more is known about distribution, population statuses and ecological preferences. Prolonged monsoon seasons lead to longer periods where I. benjii is above ground and encountered by humans. Farmers in paddy fields and other local people kill I. benjii because they think the caecilians are snakes (Laremsanga et al. 2021).

Relation to Humans
Farmers in paddy fields and other local people kill I. benjii because they think the caecilians are snakes (Laremsanga et al. 2021).

Possible reasons for amphibian decline

Intentional mortality (over-harvesting, pet trade or collecting)

Comments

PHYLOGENETIC RELATIONSHIPS:

The ten species of Ichthyophis in the eight states of northeast India can be divided into a single unstriped form and nine striped forms, including I. benjii. Based on Maximum Likelihood and Bayesian analyses of 16s mtDNA I. benjii is a sister taxon to the I. multicolor, however, this relationship is not strongly supported (Laremsanga et al. 2021).

References

Lalremsanga, HT, Purkayastha, J, Biakzuala, L, Vabeiryureilai, M, Murasanga, L, Hmar, GZ. (2021). "A new striped species of Ichthyophis Fitzinger, 1826 (Amphibia: Gymnophiona: Ichthyophiidae) from Mizoram, northeast India." Amphibian & Reptile Conservation 15(2), 198–209 (e288). [link]

Species Account Citation: AmphibiaWeb 2024 Ichthyophis benjii: Benji’s Caecilian <https://amphibiaweb.org/species/9455> University of California, Berkeley, CA, USA. Accessed Dec 26, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 26 Dec 2024.

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