Angela Campher Biodiversity & Conservation Biology University of the Western Cape Bellville 7535 2432833@uwc.ac.za

Contemporary Amphibians: Are we changing their environment ?

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“Amphibians occurs within three groups namely salamanders and newts: toads and frogs: and caecilians”-Mader (2004)

organ level of organization - body cavity containing organs

tube-in-tube body plan and have a coelom

General Characteristics of AmphibiansGeneral Characteristics of Amphibians

Have some outstanding feature that was not seen within other groups of organisms before - presence of limbs

- tongue * use to catch prey

- eyelids * functions to keep eyes moist

- ears * able to hear or pick-up sound waves

- voice * which is produced in the larynx

Within their life cycle they have both an aquatic and terrestrial life stage.

General Characteristics of AmphibiansGeneral Characteristics of Amphibians

They undergo metamorphosis - which is the process by which an organism undergoes a change in body form.

Amphibians have smooth, non-scaly, moist skin which is porous and which contains a mucus layer

The mucus layer is secreted by mucus glands within the skin, the skin has various functions namely

- water balance, respiration, temperature regulation

General Characteristics of AmphibiansGeneral Characteristics of Amphibians

Amphibians are ectotherms, this means that they are dependant upon the environment to regulate their temperature (body) - Mader (2004)

General Characteristics of AmphibiansGeneral Characteristics of Amphibians

Group 1 - Salamanders and Newts, represent earliest fossil, they have two pairs of legs-90º angle to each other

- dorsi-ventrally flattened body, elongated

- movement via sinusoidal motion

- are carnivorous, feeding on invertebrates e.g. snails

Characteristics of three groupsCharacteristics of three groups

Group 2 - Frogs and Toads, have a fused head and trunk with the absence of a tail

They have muscle padded hind legs which are long and powerful for jumping, frogs vary from toads in that it’s skin is smooth and that they have long legs.

Toads on the other hand have warty skin and snout body's, also preferring a dark and moist habitat away from water, where as frogs live by or in fresh water streams or masses.

Characteristics of three groupsCharacteristics of three groups

Group 3 - Caecilians, seems to resemble amelids owing to their long worm-like body forms.

They reach lengths of 1 metre and have folds on their skin-thus resembling segments (but it is not) .

Characteristics of three groupsCharacteristics of three groups

Their dependence on environmental conditions for body temperature regulation allow for them to occur within certain places in the world.

They are found within various Biogeographical realms e.g.

- Australia

- Afro and Neotropical

- Oceanic or Nearctic

- Palearotic and or Indomalayan Realms

Geographical DistributionGeographical Distribution

More specifically they are abundant in North and South America, Africa, Asia, Europe, Middle East, Australia and Oceania.

Amphibians do not occur in Greenland or Antarctica owing to extremely cold condition.

Their diversities are higher in the tropics.

Geographical DistributionGeographical Distribution

Amphibians are highly successful seen that they have made it possible to occupy various areas or countries world wide.

They are directly dependant upon the habitats these countries provide thus also being able to occupy various biomes.

Forests, Savannas, Shrublands, Grasslands, Aquatic habitats and Deserts are biomes which they can persist and survive in.

Within these habitats you will find them readily under rocks, stones, logs and close to fast flowing streams.

Supportive HabitatsSupportive Habitats

The largest amount of amphibians are found within wetlands or rain forests

These biomes are being readily changed and the habitats for frogs are thus being threatened and this affects the abundance and diversity of amphibians directly

Supportive HabitatsSupportive Habitats

Amphibians existed on earth 300 million years ago

They first appeared on the earth during the Devonian Period 360-408 million years ago

This was because the Devonian Period which was known as the Age of fishes, allowed for the amphibian to evolve, owing to the fact that Labe-finned fishes are believed to be ancestral to the amphibians

The Carboniferous swamp forest was the suitable habitat for primitive amphibians owing to its high water, food and trees supply

The Carboniferous Period - Age of AmphibiansThe Carboniferous Period - Age of Amphibians

Those favourable resources today have been threatened over the past few decades and have thus affected our current Amphibian populations world wide

There are 6000sp of known amphibians and their abundance's are being decreased rapidly over the past 50 years

The Carboniferous Period - Age of AmphibiansThe Carboniferous Period - Age of Amphibians

Past climates provided conditions for maximum vascular plant growth, insect population flunishment and amphibian expansion in both diversity and number

When looking at climatic conditions today, we have to realize that our climate has undergone changes over the past few decades

Proxy data and instrumental measurements of climatic variables have provided us with information about climatic conditions over millions of years ago

Climate ChangeClimate Change

There are various factors responsible for this change and these changes are affecting amphibian population abundances world wide

Climate ChangeClimate Change

There is a link between climate change and amphibian number decline owing to temperature precipitation fluctuations

Climate change is not directly responsible for this decline but it does affect the organisms variability to diseases and this will lead to a decrease in population number or death of species

Various factors plays a part in amphibian species decline, it has to be noted that some factors are more influential than others

Factors Affecting Amphibian DeclineFactors Affecting Amphibian Decline

Destruction and alteration of their natural habitats

introduction of predators into their habitats

consumption of amphibians by humans e.g. red legged frog

pollution of the water and atmosphere

climate change observed or change in climatic conditions

increased level of radiation and

transformation of landscaped

draining of wetlands

Amphibian Decline is owing to the:Amphibian Decline is owing to the:

spreading of wildlife diseases e.g. Chytridiomycosis and Ranaviral

deformation and malformation of species owing to environmental conditions

Amphibian Decline is owing to the:Amphibian Decline is owing to the:

When looking at the list of factors causing a decrease in amphibians species numbers then it is evident that most of those factors are due to human activity

Therefore yes, we are changing their environment, we are changing the natural habitats of amphibians through planting crops-agriculture and deforestation

We are either introducing other species into amphibians habitats which out compete current amphibians and or feed on them (predation)

Are we changing contemporary amphibians Are we changing contemporary amphibians environment?environment?

Because of the increase burning of fossil fuels we are raising the amount of green house gases in the atmosphere thus causing global warming

This allows for an increase in local climates, owing to the pollution of the atmosphere and the population levels in the water has now become more concentrated

Ozone also allows for increased levels of the UV-B radiation to penetrate the earth’s surface and this is harmful towards amphibians

Are we changing contemporary amphibians Are we changing contemporary amphibians environment?environment?

Swing to urbanization landscapes have been transformed and this caused a change within the amphibian environment thus affecting their development directly - wetlands were also drained for human advantage e.g. stream channelization

There is therefore a link between climate change and declines5

Are we changing contemporary amphibians Are we changing contemporary amphibians environment?environment?

There are 6000 known species of amphibian and 1/3 threatened, this is 32% of the species consisting of 1856 sp in total

43% of amphibians 2469 species are decreasing in population number

Decreases with in amphibian diversity and number is seen in cities, country sides, rainforests and wetlands

Most species declines are surprisingly seen within protected parks

The Effects on BiodiversityThe Effects on Biodiversity

Some species has gone extinct in Australia and Coasta Rica namely the Gastric breading frog (1980) and monteverde golden toad as well

Because of Amphibians dependence on their environment, owing to juvenile stage being aquatic and adult stage being terrestrial, their life as a whole is sustained by the maintenance of their habitats.

The Effects on BiodiversityThe Effects on Biodiversity

The rapid decrease in amphibians sp number has been identified and has been listed as one of the most severe issue as to date by conservationist.

Many conservationist have found methods in which to conserve the amphibian species which we do still have living today

One method used is to educate communities (human) about amphibians and how we are affecting these populations directly, thus then also allowing humans to have a direct part in the conservation of amphibians

What can we do?What can we do?

This is done through monitoring of certain areas and forming artificial natural habitats for amphibians

There are numerous Amphibian Conservation groups globally

examples are the :

PARC - Partners in Amphibians and Reptile Conservation

ACA - Amphibian Conservation Alliance

CARCWET - Canadian Amphibian and Reptile Conservation Network

What can we do?What can we do?

There are 1500000 conservation groups world wide but yet there is still a decline in amphibians occurring

This shows us the serenity of this issue

What can we do?What can we do?

ReferencesReferences www.frogs.org www.blueplanetbiomes.org/savanna www.rodford.educ/ www.parplace.org www.wokopedia.org www.animaldiversity.com