Species
Anura
IUCN
NCBI
EOL Text
Three-chambered heart reduces mixing of blood: frog
The three-chambered heart of frogs reduces mixing of oxygenated and unoxygenated blood because of the separation of atrial inflow and outflow.
"Although anurans have a three-chambered heart, little mixing of oxygenated and unoxygenated blood occurs because of the separation of atrial inflow and outflow." (Fowler and Miller 2003:22)
Learn more about this functional adaptation.
- Fowler, ME; Miller, RE. 2003. Zoo and Wild Animal Medicine. Philadelphia: W.B. Saunders Co.
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | (c) 2008-2009 The Biomimicry Institute |
Source | http://www.asknature.org/strategy/e230cb85c99c1090794301f9a9fd64b6 |
Concentrated form reduces water requirements: frogs
The jelly mass that holds the eggs of many frogs reduces internal water requirements because it is secreted in a concentrated form, which then takes up water from the external environment.
"As far as I know, all extracellular mucuses and gels are secreted in concentrated form and then take up water--a conspicuous example is the jelly mass in which the eggs of a frog are suspended. When swollen, the mass is typically larger than the volume of the gravid female. Slime production by hagfish, according to John Gosline, provides an even more spectacular case." (Vogel 2003:444)
Learn more about this functional adaptation.
- Steven Vogel. 2003. Comparative Biomechanics: Life's Physical World. Princeton: Princeton University Press. 580 p.
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | (c) 2008-2009 The Biomimicry Institute |
Source | http://www.asknature.org/strategy/50e8b7165973fcf0dcc2ebefd40cd7a8 |
Barcode of Life Data Systems (BOLD) Stats
Specimen Records:28763
Specimens with Sequences:33511
Specimens with Barcodes:21388
Species:2618
Species With Barcodes:2449
Public Records:9310
Public Species:947
Public BINs:1794
When only living taxa are considered, a list of synapomorphies of Anura would include many of the obvious distinctive features of frogs:
- Shortened vertebral column (nine or fewer presacral vertebrae)
- Presence of a urostyle formed from developing tail vertebrae
- Absence of tail in adults
- Hindlimb longer than forelimb
- Fusion of radius and ulna into a single element
- Fusion of tibia and fibula into a single element
- Elongate ankle bones (tibiale and fibulare = astragalus and calcaneum)
- Absence of a prefrontal bone
- Fusion of separate hyobranchial elements into a hyobranchial (=hyoid) plate
- A tongue that lacks intrinsic skeletal support from the hyobranchial plate
- A tadpole, with keratinous beaks and denticles as larval mouthparts
- A single median spiracle in the larva (characteristic of Orton's Type 3 tadpole)
- Large subcutaneous lymph spaces between the skin and muscle layer
- Two protractor lentis muscles attached to lens
(Milner, 1988, 1993; Saint-Aubain, 1981; Trueb and Cloutier, 1991).
However, the existence of several early frog fossils, such as †Prosalirus and †Notobatrachus, clouds this picture, because many of these characters cannot be assessed in these fossils, either because of incompleteness of fossils or because the features are soft-tissue characters identifiable only in living taxa.
License | http://creativecommons.org/licenses/by/3.0/ |
Rights holder/Author | David Cannatella, Tree of Life web project |
Source | http://tolweb.org/Anura/16963 |
Anura is the clade of living frogs and their close fossil relatives. The name Anura refers to the lack of a tail.
License | http://creativecommons.org/licenses/by/3.0/ |
Rights holder/Author | David Cannatella, Tree of Life web project |
Source | http://tolweb.org/Anura/16963 |
IUCN Red List of Threatened Species: data deficient
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | ©1995-2013, The Regents of the University of Michigan and its licensors |
Source | http://animaldiversity.ummz.umich.edu/accounts/Anura/ |
Most people learn about the basics of frog reproduction in elementary school. Frogs lay eggs in water, and the eggs hatch into tadpoles that grow into frogs. Only about half of all frogs follow these exact steps, but there are a few rules of thumb about frog reproduction. All frogs reproduce sexually, and all hatch from eggs.
In almost all frogs, egg fertilization happens outside the female's body instead of inside. The female releases her eggs and the male releases his sperm at the same time. In order to make sure that the sperm reach the eggs, the male and female get into a mating posture called amplexus. The male climbs onto the female's back and clasps his forelegs around her middle. Frogs can stay in amplexus for hours or even days as the female releases as few as one or as many as several hundred eggs.
Sometimes, it's easy to tell male frogs from female frogs. Many species are sexually dimorphic, meaning that there are differences between the bodies and colors of males and females. But in some species, males and females are hard to tell apart. In such species, male frogs often produce a release call when clasped by another male. During mating season, researchers can use release calls to tell which frogs are male and which are female.
All frogs' eggs require moisture to develop, and most frogs abandon their eggs once they're fertilized. But not all eggs incubate underwater or without parental care. A few species carry their eggs in their vocal sacs or their abdomens. Others lay eggs in dry areas and keep the eggs moist with water or urine. Depending on the frog's species and the climate in which it typically lives, the eggs can hatch in a few days to a few weeks.
In a few species, fully formed froglets hatch from the eggs, but most of the time the frog starts its life as a tadpole. While adult frogs are carnivores, tadpoles can be vegetarians or omnivores. Some are filter feeders that eat algae, and others have teeth and can eat anything from rotting vegetation to other tadpoles. Either way, tadpoles tend to be voracious eaters -- it takes a lot of energy to complete their metamorphosis into frogs.
License | http://creativecommons.org/licenses/by/3.0/ |
Rights holder/Author | John Michael Guay, John Michael Guay |
Source | No source database. |
Red List Criteria
Year Assessed
Assessor/s
Reviewer/s
Contributor/s
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/58579 |
This taxon is known only from the non-specific type locality of "Cordofan", which is in modern-day Sudan, and not in Egypt (Baha El Din pers. comm.).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/58579 |