Poecilotheria hanumavilasumica
| Kingdom |
Phylum |
Class |
Order |
Family |
| ANIMALIA |
ARTHROPODA |
ARACHNIDA |
ARANEAE |
THERAPHOSIDAE |
| Scientific Name: |
Poecilotheria hanumavilasumica |
| Species Authority: |
Smith & Carpenter, 2004 |
Common Name/s:
| English |
– |
Rameshwaram Ornamental, Rameshwaram Parachute Spider |
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| Taxonomic Notes: |
In 2004, Andrew Smith discovered a new species Poecilotheria hanumavilasumica from a sacred grove of the Hanumavilasum Temple on Rameshwaram Island. This species was earlier misidentified by Simon (1885), and Annandale (1907), as Poecilotheria fasciata from the Island and later Gravely (1915) misidentified this as Poecilotheria striata from Pamban on Rameshwaram Island. |
Assessment Information
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| Red List Category & Criteria: |
Critically Endangered
B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v)
ver 3.1
|
| Year Assessed: |
2008 |
| Assessor/s |
Siliwal, M., Molur, S. & Daniel, B.A. |
| Evaluator/s: |
Spector, S. & Mason, T. (Terrestrial Invertebrates Red List Authority) |
Justification:
This Critically Endangered species is now restricted to a few tamarind, casuarina and mixed dry deciduous tree and palm plantations on the island of Rameshwaram and on the mainland close to the island. The entire estimated extent of occurrence is less than 100 km², with the actual area of occupancy being less than 6 km². The species has been recorded from eight subpopulations and less than 15 severely fragmented locations. Natural vegetation is almost completely lost. Spiders from one location were recently lost when the entire tamarind plantation of five hectares was razed for constructing government quarters. The species is CR due to restricted distribution, and continuing decline in area, quality, populations and mature individuals.
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Geographic Range
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| Range Description: |
Poecilotheria hanumavilasumica is endemic to the Ramanthapuram district, southern India. It is reported from Rameshwaram Island and Mandapam area on mainland at an altitude of less than 50 m. The extent of occurrence encompassing known and inferred distribution is around 100 km², while the area of occupancy is less than 10 km².
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| Countries: |
Native:
India (Tamil Nadu)
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| Range Map: |
(click map to view full version)
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Population
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| Population: |
Eight subpopulations in 13 severely fragmented locations. Subpopulation size varies from four individuals to 78 individuals depending upon the size of the plantation (Manju Siliwal pers. obs.). The densities are high in some tamarind plantations compared to casuarina or palm plantations.
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| Population Trend: |
Decreasing
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Habitat and Ecology
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| Habitat and Ecology: |
The species was found in plantations like tamarind, palm, coconut and casuarina. They are also frequently seen in human habitations, especially in thatch-roof houses and huts. Mature females have been observed nesting every year and the maximum number of spiderlings seen with a single mother is 52. Mortality rate amongst the spiderlings is high due to cannibalism and natural predation. The male survives for only one breeding season after maturity, rarely up to the second breeding season. Females show nest fidelity as they have been observed in the same tree holes over three years, unless they have been disturbed or physically removed.
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| Systems: |
Terrestrial |
| Major Threat(s): |
Loss of plantations due to developmental activities, small size of the habitat fragments, small population size, persecution and fragmentation are major threats. Due to increased tourism, in the course of a single year (2006) two plantations were razed of which one was observed to have at least 70 individuals. All the spiders were killed by the loggers while razing the plantation. Due to their skewed sex ratio, and the difference in maturity rates between males and females, small populations with less than 5,000 individuals have a very high probability of extinction within the next three to four decades (S. Molur and B.A. Daniel, pers. comm. from running a simulation model (Vortex)). Although not found extensively in pet trade, a few adult males and females along with subadults and juveniles were taken out of the country.
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Conservation Actions
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| Conservation Actions: |
The spiders occur in private plantations only and are not subjected to any protection laws.
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