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Talk given at ATREE, 27th April 2010 on Bioresources workshop.
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Amphibians: Amphibians: What do we know about them?What do we know about them?
Gururaja KV, Ph.D.,
Research Scientist, IISc, Bangalore
Flow of the talkFlow of the talk Introduction to Amphibians Uniqueness Systematics Research on them As Bioresources
Common sight in and around Common sight in and around your house! your house!
Duttaphrynus melanostictus Common Indian Toad
And near a lake!And near a lake!
Whom do you call amphibians?Whom do you call amphibians?
Those vertebrates that live both in water as well as land
That means ...we too?
Photo credit:http://divebarbados.net/Current%20Photos/Pictures/Green%20Turtle%201.jpghttp://www.kidcyber.com.au/IMAGES/hippoaggro_s.jpghttp://homepage.mac.com/wildlifeweb/reptile/gharial/gharial03tfk.jpg
In fact, amphibians are ...In fact, amphibians are ...
Dual lifers ...◦ Two stages in life – a tadpole stage and an adult
stage◦ From Greek, Amphi – dual, bian – life forms
What’s unique in them?What’s unique in them? Generally, aquatic and terrestrial inhabitants,
Some are arboreal, and some fussorial too
MetamorphosisMetamorphosis
They metamorphose from tadpole to adult
Life span: from 10 months to 55 years
EctothermsEctotherms
Body temperature externally maintained
Basking in SunHiding away from Sun
Skin breathersSkin breathers
AnamniotesAnamniotes
Eggs Eggs of a birdof a bird Eggs Eggs of a of a frogfrog
Ecosystem function Ecosystem function
prey and predator
So also for US ...So also for US ...
Human Welfare◦ Biocontroller of Pests◦ Skin extract – pain killer: Bufotonin, Epibatidine, Anti
microbial peptides◦ Freeze tolerance◦ Media for microbial culture◦ Delicacy!!! ◦ Indicators of change in environment◦ Culture, Rig Veda, verse 7, shloka103, ◦ Earthquake early warning system!!◦ Biogeographic linkage ...
Freezing North American Wood Frogs.flv
Factors Process(es) Climate change Temperature and precipitation patterns are altered
so as to cause disruptions in micro or macro-climatic conditions
Habitat modification
Deforestation and agriculture; drained and filled wetlands, land filling
Habitat fragmentation
Roads, introduced species, and low pH dissect habitats, creating barriers to dispersal.
Introduced species
Introduced predators, prey on/or compete with native amphibians.
UV-B radiation UV-B damages and/or kills cells, causing egg mortality, lesions, malformations and increased susceptibility to disease and low pH.
Chemical contamination
Toxins cause direct mortality of eggs and adults, mimic endocrine harmones, reduce the prey base, pesticidal effect; fluoranthene.
Acid precipitation and soil
Toxins create barriers to dispersal and cause high egg and larval mortality.
Disease Disease often causes death in amphibians (Chytridiomycosis)
Amphibians indicate …Amphibians indicate …
Common Indian toad, Duttaphrynus melanostictusup to 16cm, noctornal, terrestrial, human habitation, water bodies
Ferguson’s toad, Duttaphrynus scaberup to 5cm, noctornal, terrestrial, human habitation, water bodies
Malabar tree toad, Pedostibes tuberculosus, Endemicup to 6cm, noctornal, arboreal, forest streams
Indian burrowing frog, Sphearotheca brevicepsup to 6cm, noctornal, fussorial, human habitation, water bodies
Ornate narrow mouthed frog, Microhyla ornataup to 3cm, noctornal, semi-aquatic, human habitation, water bodies
Red narrow mouthed frog, Microhyla rubraup to 3cm, noctornal, semi-aquatic, human habitation, water bodies
Karnataka night frog, Nyctibatrachus karnatakaensis Endemicup to 9cm, noctornal, aquatic, forest streams
Castlerock night frog, Nyctibatrachus petraeus Endemicup to 5cm, noctornal, aquatic and arboreal, forest streams
Aloysius skittering frog, Euphlyctis aloysiiup to 5cm, noctornal, aquatic, human habitation, water bodies
Common skittering frog, Euphlyctis cyanophlyctisup to 6cm, noctornal, aquatic, human habitation, water bodies
Golden frog, Hylarana aurantiaca Endemicup to 5cm, noctornal, semi-aquatic, streams, paddy fields, ponds
Bronzed frog, Hylarana temporalis Endemicup to 6cm, noctornal, semi-aquatic, river, streams
Wrinkled cricket frog, Fejervarya caperataup to 4cm, noctornal, semi-aquatic, paddy fields, pools
Kudremukh cricket frog, Fejervarya kudremukhensisup to 5cm, noctornal, semi-aquatic, ponds, pools, water bodies
Reddish cricket frog, Fejervarya rufescens Endemicup to 5cm, noctornal, semi-aquatic, laterite rocks, ponds, pools
Indian bull frog, Hoplobatrachus tigerinusup to 25cm, noctornal, semi-aquatic, ponds, streams, paddy fields
Small torrent frog, Micrixalus saxicola Endemicup to 4cm, diurnal, semi-aquatic, stream/river falls
Amboli bush frog, Pseudophilautus amboli Endemicup to 3.5cm, noctornal, arboreal, shrubs, bushes, tree bark
Common tree frog, Polypedates maculatusup to 6cm, noctornal, arboreal, tree trunks, bushes, walls
Malabar gliding frog, Rhacophorus malabaricus Endemicup to 7cm, noctornal, tree trunks, shrubs, bushes
Bicolored frog, Clinotarsus curtipes Endemic south Indiaup to 6cm, nocturnal, semi-aquatic, reservoirs, streams, river
Fungoid frog, Hylarana malabarica Endemicup to 7cm, noctornal, semi-aquatic, ponds, pools, water bodies
Sahyadri minervarya frog, Minervarya sahyadris Endemicup to 3cm, noctornal, semi-aquatic, paddy fields, ponds, pools
Small leaping frog, Indirana semipalmata Endemicup to 4cm, diurnal, semi-aquatic, stream beds, leaf litter, crevices
Know a few frog friendsKnow a few frog friends
Know a few frog friends …Know a few frog friends …
Few more …Few more …
Gems from the Western GhatsGems from the Western Ghats
Few more…Few more…
Bamboo bush frog!Bamboo bush frog!
EvolutionEvolution
About 360 million years ago, late Devonian period
Triadobatrachus
Early amphibian!!!
Beelzebufo ampinga
SystematicsSystematics• Globally: 6639 species3 orders – Apoda (183species)
Caudata (597) Anura (5859)
• India: 3 orders – 309 species; Apoda (33)Caudata (1), Anura (275)
apoda
caudata
anura
BatrachologyBatrachology in Indiain India As of today 309 species, belonging to 14 families,
55 genera (4.64% of 6638 species in the world), 249 Species described from India (80.5%)
1254 authors, single species description to as many as 43 species
Since 2000, 82 new species (33%) with 47 papers on Taxonomy and taxonomy related issues, 12 on ecology, 6 on reproduction, 10 on others
So Taxonomy ‘rules’ at present Indian Batrachology!!!
Snout vent length (mm) Snout vent length (mm)
Peak
Fre
quen
cy (
kHz)
Peak
Fre
quen
cy (
kHz)
Habitat occupancy!Habitat occupancy!
Research in Research in BatrachologyBatrachology
Viviparity in caecilians
Geneophis seshachari
Gower et al., 2008. J Evol Biol. 21(5):1220-6
Other issues…Other issues…
Frog skipping tadpole stage
Gururaja and Ramachandra, 2006. Curr. Sci. 90(3):450-454
Other issues…Other issues…
Biju and Bossyut, 2003. Nature. 425: 711–714
India’s smallest frogIndia’s smallest frog
Biju et al., 2007. Current Science 93(6): 854-858.
Skin extracts and Skin extracts and pesticidalpesticidalimpacts…impacts…
1. Giri et al., 2006. doi:10.1016/j.toxicon.2006.06.0112. Sai et al., 2001. doi:10.1074/jbc.M006615200 3. Gurushankara et al., 2007. doi:10.1007/s00244-006-0015-5
Conservation and ManagementConservation and Management
Das, A., Krishnaswamy, J., Bawa, K. S., Kiran, M. C., Srinivas, V., Kumar, N. S., et al. 2006. Prioritization of conservation areas in the Western Ghats, India. Biological Conservation, 133, 16−31.
Gururaja KV, Sameer Ali and Ramachandra TV. 2008. Influence of land-use changes in river basins on diversity and distribution of amphibians. In: Environment Education for Ecosystem Conservation
Advance wishes for Advance wishes for SAVE THE FROG DAY
(APRIL 30TH 2010)
Thank you