Frog
The term ‘frog’ is very broad and covers many different species and can even be applied to toads. Frogs and toads can sometimes be difficult to tell apart. Frogs tend to be found near water, they have smooth skin and hop more than they walk. Toads have shorter legs, and dry, warty skin. Those descriptions work most of the time, but not all since there are smooth-skinned toads and frogs that live far from water. There is little real need to tell the difference between a frog and a toad, however, since they are so closely related that they are often grouped together.
Kingdom – Animalia
Phylum – Chordata
Class – Amphibia
Order – Anura
Suborders – Archaeobatrachia (Four families), Mesobatrachia (Five families), Neobatrachia (Twenty-four families)
Common Names – frog, each species has a common name
Most frogs are carnivores and will eat whatever fits into their mouths. Many eat insects, but larger species will feed on lizards, snakes, rodents, and even birds. Larger species, such as bullfrogs, can be extremely aggressive but smaller, more delicate species such as tree frogs prefer to camouflage and hide. Their lifestyles vary depending on their habitat. Frogs can be ground dwelling, mainly aquatic, or arboreal and their diet and much of their physiology will depend on that reality.
Males sing to defend territory and attract a mate and each species has a specific song. Females of most species lay their eggs directly in the water, although some will use water captured in leaves or even egg sacks hung in trees. Some species release only a few eggs each breeding period while others release thousands. The eggs form a gelatinous mass where the developing embryos can be seen as black spots in the eggs. The eggs then hatch into fully aquatic tadpoles with rounded heads, gills, and a fishlike tail. The tadpole’s metamorphosis involves growing legs, absorbing their tail, and developing lungs. A few species, such as poison frogs, will carry the eggs and tadpoles on their backs instead of leaving them to care for themselves.
Frogs have moist skin, through which they absorb oxygen to supplement their lungs. Frogs must stay moist and most are found near water sources, although there are a few rare exceptions, such as the desert dwelling Australian water-holding frog, which burrow to retain moisture. Frogs tend to come in greens and browns, to blend in with their environment. Frogs with toxins, however, advertise this fact with bright displays of reds, yellows, and blues, called aposematic coloration. Poison dart frogs are the most famous for this and they collect their poison from the beetles and ants they consume. There are no venomous frogs, but there are many that are poisonous. To be venomous, the toxins need an active delivery method such as fangs, while poisonous animals use a more passive method, with their toxins being ingested or absorbed.
Frog history probably began in the Permian period, around 265 million years ago, but the first definitive fossil dates slightly later from the Triassic. Aside from toads, frogs are most closely related to salamanders, newts, and caecilians and it is not known exactly when the divergence occurred.
While some species are invasive, many species are threatened or endangered. The absorbent nature of their skin makes them especially vulnerable to pollutants and changes in their environment. As many as forty percent of species may be endangered due to both environmental issues and a parasitic fungus, amphibian chytrid. Some species, like the Panamanian golden frog (Atelopus zeteki), exist only in captivity with all wild populations believed extinct.
References:
Peterson Field Guides Reptiles and Amphibians (Eastern/Central North America) by Roger Conant & Joseph T. Collins
No Turning Back (The Life and Death of Animal Species} Richard Ellis
North American Amphibians: Distribution and Diversity by David M. Green, Linda A. Weir , Gary S. Casper ,Michæl J. Lannoo
Amphibian Declines: The Conservation Status of United States Species by Michæl J. Lannoo
Herpetology, Fourth Edition: An Introductory Biology of Amphibians and Reptiles by Laurie J. Vitt and Janalee P. Caldwell
Safari Ltd Frog Toys:
Life Cycle of a Frog Figure Set
Incredible Creatures Red-eyed Tree Frog Figure
Incredible Creatures American Bullfrog Figure