Lithobates okaloosaeFlorida Bog Frog

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Geographic Range

This is very rare species of frog. Lithobates okaloosae is found in only a small area of western Florida (Okaloosa, Santa Rosa, and Walton counties). It is "associated with small tributary streams of East Bay, Shoal, and Yellow rivers." (Moler, 1993)

Habitat

This species lives in or near shallow, nonstagnant seeps with somewhat acidic water (pH 4.1-5.5). It's also found along shallow, boggy overflows of larger seepage streams. It is often associated with black titi and Atlantic white cedar. (Moler, 1985)

  • Aquatic Biomes
  • rivers and streams

Physical Description

Males are 34.8-45.8 mm long, and females are 38.2-48.8 mm long. "The species is characterized by an unspotted dorsum, distinct dorsolateral folds that do not reach the groin, and reduced webbing of the foot". The reduced webbing distinguishes Lithobates okaloosae from all other American congeners.

"At least three phalanges of the 4th toe are free of webbing and at least two phalanges of all other toes are free".

Lithobates okaloosae has a dark green or green-brown back, a black belly and a yellow throat. It can have lighter spots on the lower jaw. (Moler, 1992)

Lithobates okaloosae tadpoles have an olive brown coloration and have buff spots on the tail. The tadpoles' ventral surfaces are marked with white spots. (Moler, 1992)

  • Sexual Dimorphism
  • female larger
  • Range length
    34.8 to 48.8 mm
    1.37 to 1.92 in

Development

Not much is known about the development of Lithobates okaloosae. In general eggs are laid near the surface of the water in thin gelatinous masses. The tadpoles overwinter, and they metamorphose during the following spring or summer. The adults remain year long in the areas used as breeding habitats. (Moler, 1992)

Reproduction

Males call through a "series of 3-21 gutteral chucks repeated at about five notes per second, but slowing audibly at the end." (Moler, 1992). The frog's calls are heard from mid-April to mid-September. We have no information on the number or pattern of matings in this species. In other species in the genus Rana, males attempt to fertilize the eggs of multiple females. Females may also exercise choice, and allow several males to fertilize their eggs. (Moler, 1992)

They deposit several hundred black eggs as a surface film (in thin gelatineous masses). Lithobates okaloosae tadpoles overwinter and metamorphose the next spring or summer. (Moler, 1992)

  • Breeding season
    Late spring through summer.

There is no parental care in this species.

  • Parental Investment
  • no parental involvement

Lifespan/Longevity

We have no information on how long these frogs live.

Behavior

We have no particular behavioral information for this species. Like all frogs it hops and swims, is mobile, but not migratory.

Home Range

We have no information on the home range size for this species.

Communication and Perception

Males of this species call to females during the breeding seasone with a series of gutteral "chucks," which they repeat at about 5 notes/sec, slowing audibly at the end. There is variation in the number of notes per call, and in intervals between cals depending on conditions. The frogs also issue single quieter notes, in response to calls coming from other nearby males.

Rana okaloosae's call is similar to Rana virgatipes. (Moler, 1985)

Food Habits

We have no information on the food habits of this species. However, it probably feeds like other species of it's genus (Rana). In this case, then adults would be predators on small animals, mostly invertebrates like insects and spider, possibly very small vertebrates, such as other tiny frogs.

If the larvae feed like other members of the genus, then they are grazing on algae, feeding on detritus, and possibly consuming some small zooplankton.

  • Animal Foods
  • amphibians
  • insects
  • terrestrial non-insect arthropods
  • zooplankton
  • Plant Foods
  • algae

Predation

Adults and tadpoles have patterns of skin coloration that are cryptic, making them less visible to predators. As with most frogs, adults will jump away from predators and hide in the water if they can. We have no information on which predators attack this species.

  • Anti-predator Adaptations
  • cryptic

Conservation Status

In "Rare and Endangered Biota of Florida," Moler describes Lithobates okaloosae as rare. This species was discovered in 1982 by Paul Moler, and has been located at only 23 sites, associated with small, cool, clear seepage streams. Three of these localities are based only on single specimens, so these sites probably don't support viable populations.

Residential developments in the areas where the frog lives convert streams into chains of lakes (through a series of dams). This poses a threat to Florida's Bog Frog habitats. So, it is important that the streams where the frogs live are protected (this can be done through the management of streamside vegetation). (Moler, 1993)

Other Comments

Not much information is available on Lithobates okaloosae, because it is limited to one small geographic location, and it is very rare. "Our knowledge of this species is currently limited to distribution, seasonality, and some aspects of larval life history" (Moler, 1992). (Moler, 1992)

Contributors

Marwa Al Nasa'a (author), University of Michigan-Ann Arbor, Kerry Yurewicz (editor), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

bog

a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

detritivore

an animal that mainly eats decomposed plants and/or animals

detritus

particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

external fertilization

fertilization takes place outside the female's body

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

freshwater

mainly lives in water that is not salty.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

saltatorial

specialized for leaping or bounding locomotion; jumps or hops.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

visual

uses sight to communicate

zooplankton

animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)

References

Ashton Jr, R., P. Sawyer Ashton. 1985. Handbook of Reptiles and Amphibians of Florida. Miami, Fl: Windward.

Moler, P. 1985. A new species of frog (Ranidae:Rana) from northwestern Florida.. Copeia, 1985(2): 379-383.

Moler, P. 1992. Florida Bog Frog. Rare and Endangered Biota of Florida, 3: 30-33.

Moler, P. 1993. Rana okaloosae Moler Florida Bog Frog. Catalogue of American Amphibians and Reptiles: 561.1-561.3.