Some of the Carnivores include: Frogs which eat snakes, worms, insects, crustaceans, sometimes their own kind,and fish eggs. Frogs have webbed feet which makes them better swimmers which is a very good characteristic because it helps them catch prey to eat. Male frogs have vocal sacs that they use to produce their calls and both sexes have a very sense of hearing. Also Dragonflies are one of the deadliest carnivores in the pond. Dragonflies have a bullet-shaped body which helps them switch directions fast. Also, their wings help them fly and maintain their body temperature. Last but not least, dragonflies have large eyes which makes their vision good!
The Herbivores include: The Water Flea which eats algae, and the Snail who also eats algae. Did you know that snails use their mouths to scrape algae off rocks and the stems of plants? In arid regions Snails have thicker shells which helps them maintain their body moisture.
The Omnivores include: Crayfish. Crayfish in America and Europe are very much different of how the way they live. Crayfish make reproduce alot each year and this is a good thing because us humans will try to catch the Crayfish so we can eat it. This helps the other Crayfish become resistant to diseases especially Fungus. Also the Crayfish is America are able to live in dirty and polluted water but Crayfish in Europe have to live in clean water or else they will eventaully be poisoned and die. More Omnivores include: Turtles which eat fish, frogs, and algae seeds; Flatworms which eat mosquito larva.
The Decomposers include bacteria and fungi. They are everywhere in ponds and they feed on dead things.
There are other adaptations that animals have to do in lakes and ponds to stay alive. Buoyancy is on the of the problems that invertebrates and vertebrates have to face. Animals may sink sometimes in the lakes and ponds and eventually die, so they have to maintain themselves by being in a fixed position then air bubbles are used either on the inside or outside. Some of the animals that are living on the surface film use the surface tension to hold them in place so they do not sink.
http://www.lifeinfreshwater.org.uk/Web%20pages/ponds/Adaptations.htm, https://jtscience.wikispaces.com/Lakes-Ponds, http://answers.yahoo.com/question/index?qid=20090205173522AAolhs5, http://wiki.answers.com/Q/What_adaptations_does_a_dragonfly_have, http://animals.about.com/od/mollusks/ig/World-of-Snails/Snail6.htm, http://academics.smcvt.edu/dfacey/AquaticBiology/Freshwater%20Pages/CRAYFISH.html