Contemporary Amphibians Are we changing their environment

Contemporary Amphibians: Are we changing their environment ? http: //tolweb. org/Living_Amphibians Angela Campher Biodiversity & Conservation Biology University of the Western Cape Bellville 7535 2432833@uwc. ac. za

General Characteristics of Amphibians q “Amphibians occurs within three groups namely salamanders and newts: toads and frogs: and caecilians”-Mader (2004) q organ level of organization - body cavity containing organs q tube-in-tube body plan and have a coelom

General Characteristics of Amphibians q 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 q Within their life cycle they have both an aquatic and terrestrial life stage.

General Characteristics of Amphibians q They undergo metamorphosis - which is the process by which an organism undergoes a change in body form. q Amphibians have smooth, non-scaly, moist skin which is porous and which contains a mucus layer q 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 Amphibians q Amphibians are ectotherms, this means that they are dependant upon the environment to regulate their temperature (body) - Mader (2004)

Characteristics of three groups q 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 groups q 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 groups q 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).

Geographical Distribution q Their dependence on environmental conditions for body temperature regulation allow for them to occur within certain places in the world. q They are found within various Biogeographical realms e. g. ¬ - Australia ¬ - Afro and Neotropical ¬ - Oceanic or Nearctic ¬ - Palearotic and or Indomalayan Realms

Geographical Distribution q More specifically they are abundant in North and South America, Africa, Asia, Europe, Middle East, Australia and Oceania. q Amphibians do not occur in Greenland or Antarctica owing to extremely cold condition. q Their diversities are higher in the tropics.

Supportive Habitats q Amphibians are highly successful seen that they have made it possible to occupy various areas or countries world wide. q They are directly dependant upon the habitats these countries provide thus also being able to occupy various biomes. q Forests, Savannas, Shrublands, Grasslands, Aquatic habitats and Deserts are biomes which they can persist and survive in. q Within these habitats you will find them readily under rocks, stones, logs and close to fast flowing streams.

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

The Carboniferous Period - Age of Amphibians q Amphibians existed on earth 300 million years ago q They first appeared on the earth during the Devonian Period 360 -408 million years ago q 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 Labefinned fishes are believed to be ancestral to the amphibians q 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 Amphibians q Those favourable resources today have been threatened over the past few decades and have thus affected our current Amphibian populations world wide q There are 6000 sp of known amphibians and their abundance's are being decreased rapidly over the past 50 years

Climate Change q Past climates provided conditions for maximum vascular plant growth, insect population flunishment and amphibian expansion in both diversity and number q When looking at climatic conditions today, we have to realize that our climate has undergone changes over the past few decades q Proxy data and instrumental measurements of climatic variables have provided us with information about climatic conditions over millions of years ago

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

Factors Affecting Amphibian Decline q There is a link between climate change and amphibian number decline owing to temperature precipitation fluctuations q 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 q Various factors plays a part in amphibian species decline, it has to be noted that some factors are more influential than others

Amphibian Decline is owing to the: ¬ 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: ¬ spreading of wildlife diseases e. g. Chytridiomycosis and Ranaviral ¬ deformation and malformation of species owing to environmental conditions

Are we changing contemporary amphibians environment? q 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 q Therefore yes, we are changing their environment, we are changing the natural habitats of amphibians through planting crops-agriculture and deforestation q 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 environment? q Because of the increase burning of fossil fuels we are raising the amount of green house gases in the atmosphere thus causing global warming q 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 q 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 environment? q 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 q There is therefore a link between climate change and declines 5

The Effects on Biodiversity q There are 6000 known species of amphibian and 1/3 threatened, this is 32% of the species consisting of 1856 sp in total q 43% of amphibians 2469 species are decreasing in population number q Decreases with in amphibian diversity and number is seen in cities, country sides, rainforests and wetlands q Most species declines are surprisingly seen within protected parks

The Effects on Biodiversity q Some species has gone extinct in Australia and Coasta Rica namely the Gastric breading frog (1980) and monteverde golden toad as well q 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.

What can we do? q 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. q Many conservationist have found methods in which to conserve the amphibian species which we do still have living today q 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? q This is done through monitoring of certain areas and forming artificial natural habitats for amphibians q There are numerous Amphibian Conservation groups globally q 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? q There are 1500000 conservation groups world wide but yet there is still a decline in amphibians occurring q This shows us the serenity of this issue

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