Amphibians: Amphibians: What do we know about them?What do we know about them?

Gururaja KV, Ph.D.,

Research Scientist, IISc, Bangalore

gururajakv@gmail.com

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