AMPHIBIAWEB
Ichthyophis bombayensis
family: Ichthyophiidae

© 2011 Varad Giri (1 of 3)
Conservation Status (definitions)
IUCN (Red List) Status Least Concern (LC)
CITES
Other International Status None
National Status None
Regional Status None

Country distribution from AmphibiaWeb's database: India

 

View distribution map using BerkeleyMapper.

   

From the IUCN Red List Species Account:

 

Range Description

This species is distributed throughout the Western Ghats region in India (Gower et al. 2007). It has been recorded between 250 and 650 m asl.

Habitat and Ecology

The adults are subterranean and possibly partially aquatic, and are associated with the humus and decaying wood substrate of tropical wet evergreen forests, although they are also known to occur in several different disturbed and agricultural habitats (Vyas 2004; Gower et al. 2007 and references therein), such as teak plantations and garbage pits. It is oviparous with terrestrial eggs and aquatic larvae. A female from Koyana was found in a burrow near a rivulet with wet soil with an egg cluster containing 144 eggs. Once hatched the larvae move to water (Jadhav et al. 2007).

Population

There is little direct information regarding its population status.

Population Trend

unknown

Major Threats

Severe habitat destruction is a localized threat to some subpopulations of this species, but in view of the species' apparent adaptability to modified habitats and its large range it is thought that it does not affect the species as a whole (Vyas 2003, 2004). Many additional potential threats have been suggested, including the use of agrochemicals, changes in soil chemistry, collection of humus by local people, and adult mortality on roads. All of these require further investigation, and cannot be confirmed as being significant threats at present.

Conservation Actions

It has been recorded from Vansda National Park and Purna Wildlife Sanctuary, both in Gujarat, Kudremukh National Park in Karnataka, and Periyar Tiger Reserve in Kerala. Further research is required to determine its population status and to assess the potential impact of the different threat factors observed in its areas of occurrence.

Red List Status

Least Concern (LC)

Rationale

Listed as Least Concern in view of its wide distribution, tolerance of a broad range of habitats, presumed large population, and because it does not appear to be declining, therefore making it unlikely to qualify for listing in a more threatened category.

Taxonomic Notes

A recent study found that genetic diversity among unstriped, long-tailed Ichthyophis of the Western Ghats is low, supporting the hypothesis that there is only a single, widely distributed species, Ichthyophis bombayensis (Gower et al. 2007).
Gower et al. (2007) suggested that the four long tailed unstripped species of Ichthyophis of Western Ghats, namely Ichthyophis bombayensisI. malabarensisI. peninsularis and I. subterrestris, are not valid and they belong to a single widespread species Ichthyophis bombayensis. They set up a null hypothesis that there is no variation in the four said species and therefore they are the same species. They test the validity of the null hypothesis by comparing partial sequence of 16S and 12S rDNA and show that there is a remarkable genetic similarity among the species and hence the null hypothesis of no genetic variation cannot be rejected. While it is possible that the preposition made by the authors could be valid and the four said species are really not different from each other, the method used by the authors is open to question and has a statistical flaw. The philosophy of statistical hypothesis testing suggests that we test the null hypothesis against the available supporting information and reject the null hypothesis only if we have sufficient evidence to do so. In the absence of enough evidence we cannot take the risk of rejecting the null hypothesis (because we are afraid of committing the Type I error: rejection of null hypothesis when it is in fact true). However, if we deliberately give less evidence of course it is difficult to reject null hypothesis and we end up accepting the null hypothesis. This can lead to committing the Type II error (accepting null hypothesis when it is not true). What Gower et al. (2007) have done is that they have given less evidence and as a result their interpretations are subject to Type II error. It is expected that since the species are highly related to each other it is quite obvious that they are likely to have high genetic similarity. Therefore, if we really need to see if there is genetic variability among the individuals it is necessary to sequence larger DNA sequences to see any notable variations. With small partial DNA sequences with hardly 918 bp length after concatenation the authors do not give sufficient evidence to judge the validity of null hypothesis in a fair manner. Further, Gower et al. (2007) mention that there is no morphological differences but they give no analysis based on morphometric comparisons. Analysis of morphometric data available in Pillai and Ramachandran (1999) suggests that there are morphological variations among the said species. While I agree that the comparison based on data provided by Pillai and Ramachandran (1999) is not sufficient for proving that the four species are valid, we cannot reject the validity of the species using the inadequate evidence provided by Gower et al. (2007). As a result we will have to stick to old taxonomy with four valid species unless it can be proved otherwise with enough evidence (N. Dahanukar pers. comm.).

Citation

IUCN SSC Amphibian Specialist Group 2011. Ichthyophis bombayensis. The IUCN Red List of Threatened Species 2011: e.T59614A11968739. http://dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T59614A11968739.en .Downloaded on 14 November 2018

 

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