Monday, October 18, 2021

[Herpetology • 2021] Ichthyophis benjii • A New Striped Species of Ichthyophis Fitzinger, 1826 (Gymnophiona: Ichthyophiidae) from Mizoram, northeast India


Ichthyophis benjii  
 Lalremsanga, Purkayastha, Biakzuala, Vabeiryureilai, Muansanga & Hmar, 2021

Photos by H.T. Lalremsanga

Abstract
A new species of striped Ichthyophis is described from Mizoram State of northeast India. For its distinguishing features, Ichthyophis benjii sp. nov. has narrow (W/S >5) irregular faint lateral yellow stripes extending immediately from corner of the mouth to the level of the posterior vent, not contacting the disc, barely or not visible on the collars ventrally, patchy in the trunk region; known to attain lengths greater than 400 mm, 26 < L/W < 30; head V-shaped, short (L/H > 24); TAs (tentacular apertures) more than twice as far from nares as from eyes (TN/TE > 2); C2 (second collar) noticeably longer than C1 (frst collar). It differs from all other striped congeners, except for I. tricolor and I. multicolor, in having an indistinct pale yellowish lateral stripe that is bordered by a darker ventrolateral longitudinal stripe immediately above the pale venter on each side. It differs from I. tricolor and I. multicolor in having more AGs (annular grooves) 388–422 counted dorsally; and in having 118–124 vertebrae vs. < 120 (I. tricolor) or > 125 (I. multicolor). An analysis of mitochondrial 16s rRNA shows Ichthyophis benjii sp. nov. to be a sister taxon to I. multicolor with an uncorrected p-distance of 0.055. At present, due to the lack of data on the population status and range of distribution, we propose the species be considered as Data Defcient (DD) under the IUCN Red List criteria. 

Keywords. 16s rRNA, caecilian, conservation, Data Defcient, Ichthyophis benjii sp. nov., Indo-Burma 

 Holotype (MZMU 1479) of Ichthyophis benjii sp. nov. in life from Durtlang.
Photo by H.T. Lalremsanga.

Ichthyophis benjii sp. nov.
 
Diagnosis. Ichthyophis with narrow (W/S > 5) irregular faint lateral yellow stripes extending from immediately behind CMs to the level of the posterior of vent, not contacting the disc, barely or not visible on the collars ventrally, patchy in the trunk region; known to attain lengths greater than 400 mm, 26 < L/W < 30; head more V-shaped than U-shaped in dorsal view, short (L/H > 24); TAs more than twice as far from nares as from eyes (TN/TE > 2); without distinctive moustache-like stripes between snout tip and TAs; and C2 noticeably longer than C1. Ichthyophis benjii sp. nov. differs from all other striped congeners in having a markedly less prominent pale yellowish lateral stripe, bordered by a darker ventrolateral longitudinal stripe immediately above the pale venter on each side. It can be differentiated from I. tricolor and I. multicolor in having much higher AGs of 385–422 and 383–423 counted dorsally and ventrally, respectively.

Etymology. The species epithet “benjii” is dedicated in memory of Benjamin Lalremsanga (1988–2020, nephew of Hmar Tlawmte Lalremsanga) who used to actively assist the author(s) in their herpetofaunal surveys. 
Suggested English common name: Benji’s Caecilian

Paratypes of Ichthyophis benjii sp. nov. in life: (A) MZMU 1462 from Chhinga Veng, (B) MZMU 1481 from Tanhril, (C) MZMU 2025 from Gosen,
and (D) I. multicolor MZMU 1740 from Tuirini Bridge, Aizawl District.
Photos by H.T. Lalremsanga.


Hmar Tlawmte Lalremsanga, Jayaditya Purkayastha, Lal Biakzuala, Mathipi Vabeiryureilai, Lal Muansanga and Gospel Zothanmawia Hmar. 2021. A New Striped Species of Ichthyophis Fitzinger, 1826 (Amphibia: Gymnophiona: Ichthyophiidae) from Mizoram, northeast India. Amphibian & Reptile Conservation. 15(2) [Taxonomy Section]: 198–209 (e288).