Columbiaspottedfrog

Columbia Spotted Frog
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Family:	Ranidae
Genus:	Rana
Species:	R. luteiventris
Binomial name
Rana luteiventris Thompson, 1913
Synonyms
Rana pretiosa luteiventris Thompson, 1913

The Columbia Spotted Frog (Rana luteiventris) is a North American species of frog. It is green to brown in color with spots on the dorsal surface. The belly and upper lip are white in color. Individuals can be distinguished from other Rana species by their shorter back legs, narrow snout and upturned eyes. Since they spend most of their time in the water, they also have more webbing in their hind feet than similar species. Although unthreatened, this animal has been studied as a model species for the effects of habitat fragmentation.

Taxonomy

Rana is a genus of frogs. Some common species associated with this genus are the Cascades Frog, Foothill Yellow-legged Frog, and the Moor Frog. Frogs of this genus are found throughout much of the world including Europe, Asia, North America, Central America, and South America.

Description

The Columbia Spotted Frog is a medium sized frog reaching lengths of up to three and a half inches. Its color ranges from a dark, olive green to light brown with irregularly-shaped black spots on its back and legs (rendering its name). Its skin texture follows suite with the rest of the Rana genus. It varies from a rough texture to a smooth texture that couple with small folds of skin along their backs. This frog inhibits a unique feature regarding its color. It has a light-colored strip that runs along the upper lip. The ventral sides of the frog are usually colored either pink or yellow but only in the adult form.

This frog is well-noted by a few of its physical characteristics as well. The frog inhibits a long, narrow snout and upturned eyes. The spotted frog is known as a very aquatic amphibian because the webbing on its feet extends all the way to the end of its longest toe.

Habitat

The Columbia Spotted Frog is widespread throughout North America. These frogs can be found ranging from Alaska and parts of British Columbia to Washington, Idaho, and parts of Wyoming, Nevada, and Utah.

The Columbia Spotted Frog is, like most other frogs, fairly aquatic. This means that their habitats are found generally near permanent bodies of water, which can include lakes, ponds, slow-moving streams, and marshes. The Spotted Frogs were found to need specific habitat characteristics within the prior-listed broader habitat characteristics. Adult spotted frogs inhabit mostly seasonally-flooded sites. This means that these frogs are more likely to be found at sites where there is a constant water source, but at certain times of the year the source increases exponentially in both the amount and level of water available.

These frogs are a constant victim to predation, which means that they need to be in an area with an abundant source of low-growing vegetation. A large part of this vegetation is usually submerged meaning that there are plants growing under the water or partly under the water. This vegetation includes many forms of algae and other aquatic plants. Moreover, the spotted frog tends not to inhabit areas where there are large amounts of grasses and sagebrush growing. These plants tend not to be as aquatic as their algae cousins; therefore, not being able to provide the frog with as good of a hiding place as do the aquatic plants. This is a primary reason for the habitat to require such low-growing, submerged, aquatic plants. The Columbia Spotted Frog rarely ventures outside of these areas characterized by the above details. However, when it is time for the spotted frog to breed, they have been known to travel outside of these areas.

Reproduction

The Columbia Spotted Frog reproduces similarly to other amphibians, but with a few unique details added. Columbia Spotted Frogs need to reproduce in areas where emergent vegetation is present. Two of the favorite types of vegetation for reproducin are reed canary grasses and cattails. The spotted frog reproduces in the same types of areas as it lives- ponds, slow-moving streams, and lakes.

The males arrive at the breeding grounds before the females. They then present to the females a chorus (type of song) to try and attract a female for mating. This song ranges from a series of clicks to long, glottal sounds.

This frog has a very unique characteristic of its reproduction. The male frog arrives at the breeding grounds before the female and establishes the oviposition site before the females become reproductively active. The oviposition is the site at which the eggs will be laid. Once the oviposition site is created, the female then begins to lay her eggs in shallow water. The male then fertilizes the eggs. The egg masses are fairly large in size ranging from zero all the way up to thirteen hundred eggs. The egg masses, once laid, absorb water and become the size of a softball. These eggs are not attached to any type of vegetation but are left free floating in said permanent water source. Soon after, the eggs hatch into little Columbia Spotted Frog tadpoles.

References

• Cossel Jr., John.1997.Rana luteiventris.Idaho Museum of Natural History. Accessed March 10, 2006
• "Rana luteiventris". IUCN Red List of Threatened Species. 2004. 2004. {{cite journal}}: Unknown parameter |assessors= ignored (help); Unknown parameter |downloaded= ignored (help) Database entry includes a range map and a brief justification of why this species is of least concern
• Hillis, D.M. & Wilcox, T.P. (2005): Phylogeny of the New World true frogs (Rana). Mol. Phylogenet. Evol. 34(2): 299–314. doi:10.1016/j.ympev.2004.10.007 PDF fulltext.
• Hillis, D. M. (2007) Constraints in naming parts of the Tree of Life. Mol. Phylogenet. Evol. 42: 331–338.

External links

• Rana luteiventris at CalPhotos