Crawfish frog

Crawfish frog
Conservation status
Near Threatened  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Family:	Ranidae
Genus:	Lithobates
Species:	L. areolata
Binomial name
Lithobates areolata (Baird & Girard, 1852)
Synonyms
Rana circulosa Rice & Davis, 1878 Rana octoplicata Werner, 1893 Rana virescens areolata Cole & Barbour, 1906 Rana areolatus [2][3][4][5]

The crawfish frog (Lithobates areolatus)^[6] is a medium-sized species of frog native to the prairies and grasslands of the central United States.^[7] It gets its name because it inhabits the burrows of crayfish for most of the year.^[8]

Description

The crawfish frog grows from 2.2 to 3.0 in (5.6 to 7.6 cm) in length. It ranges from yellow to brown in color, with a white ventral surface. The numerous dark brown spots on its back each has a light-colored ring around it. It has a distinct skin fold on either side of its back, which are much more pronounced in males than females, and a relatively small tympanum.

Behavior

Crawfish frogs are found primarily in association with prairie or grassland habitat, though they will also make use of pastures and overgrown fields. They spend most of the year in association with a terrestrial crayfish burrow. Interestingly, this species spends a substantial amount of time active and above ground even on hot summer days, but they never stray far from their burrow which serves as an important retreat from predators, a vital source of water, an escape from grassland fires, and a means to get below the frost line during winter. Crawfish frogs feed opportunistically on insects and other small invertebrates that pass by their burrow.

The crawfish frog breeds following mild, rainy weather in mid-March throughout most of its range (breeding occurs much earlier in the southern portion of its distribution). During this time, males seek out ephemeral ponds and wetlands that lack fish and begin calling. The low-frequency call may carry over a mile, drawing females in from the surrounding area. Once the females arrive, amplexus takes place and the females deposit up to 7,000 eggs at a time in large, globular masses. The eggs hatch in about 12 days, and the tadpoles complete metamorphosis into froglets within three or four months. The newly metamorphosed juvenile frogs must quickly find a crayfish burrow to occupy to avoid predation. Crawfish frogs become sexually mature at two to three years of age and may live up to seven years or more in the wild.

Geographic range

The crawfish frog is found in former prairie regions from Indiana west to Kansas, south to Texas, and east to Mississippi, though it is believed to be locally extirpated in many regions, and remaining populations are often localized and isolated.

In 2016 a sizable population was documented in Sumter County, Alabama.^[9]

Subspecies

The two subspecies of crawfish frog (R. areolata) are:

• Southern crawfish frog, L. a. areolatus (Baird & Girard, 1852)
• Northern crawfish frog, L. a. circulosus (Davis and Rice, 1883)

Conservation status

The crawfish frog is listed as near threatened by the IUCN Red List of Threatened Species, and is listed as endangered in Iowa (where it has likely been extirpated) and Indiana. Habitat loss is the biggest threat to this species, though disease (chytridiomycosis) and competitive pressure from other anurans have also been identified as potential stresses.

Notes

1. Geoffrey Hammerson; Matthew Parris (2004). "Lithobates areolatus". IUCN Red List of Threatened Species. Version 2014.3. International Union for Conservation of Nature. Retrieved 1 February 2015.
2. Hillis & Wilcox (2005)
3. Hillis, D. M. (2007)
4. Pauly et al. (2009)
5. Frost et al. (2006)
6. Frost, Darrel R. (2014). "Lithobates areolatus (Baird and Girard, 1852)". Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History. Retrieved 1 February 2015.
7. Busby and Brecheisen (1997)
8. Hoffman et al. (2010)
9. Pillion, Dennis (2016-03-17). "New frog species found in Alabama makes state second froggiest in the nation". al.com. Retrieved 2016-03-17.

References

• Busby, W. H. & Brecheisen, W. R. (1997): Chorusing Phenology and Habitat Associations of the Crawfish Frog, Rana areolata, (Ranidae:Anura) in Kansas. The Southwestern Naturalist 42 (2):210-217.
• Engbrecht, N. J. & Lannoo, M. J. (2010): A review of the status and distribution of Crawfish Frogs (Lithobates areolatus) in Indiana. Proceedings of the Indiana Academy of Science 119:64-73.
• Frost, D. R., Grant, T., Faivovich, J., Bain, R. H., Haas, A., Haddad, C. F. B., De Sa, R. O., Channing, A., Wilkinson, M., Donnellan, S. C., Raxworthy, C. J., Campbell, J. A., Blotto, B. L., Moler, P., Drewes, R. C., Nussbaum, R. A., Lynch, J. D., Green, D. M., & Wheeler, W. C. (2006): The Amphibian Tree of Life. Bulletin of the American Museum of Natural History 297:1-291.
• Hillis, D.M., Frost, J.S.,& Wright, D.A. (1983): Phylogeny and biogeography of the Rana pipiens complex: A biochemical evaluation. Systematic Zoology 32: 132-143.
• Hillis, D.M. (1988): Systematics of the Rana pipiens complex: Puzzle and paradigm. Annual Review of Systematics and Ecology 19: 39-63.
• 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 PMID 15619443 PDF fulltext.
• Hillis, D. M. (2007) Constraints in naming parts of the Tree of Life. Mol. Phylogenet. Evol. 42: 331–338.
• Hoffman, A. S., Heemeyer J. L., Williams, P. J., Robb, J. R., Karns, D. R., Kinney, V. C., Engbrecht, N. J., & Lannoo, M. J. (2010): Strong Site Fidelity and a Variety of Imaging Techniques Reveal Around-the-Clock and Extended Activity Patterns in Crawfish Frogs (Lithobates areolatus). Bioscience 60(10):829-834.
• Kinney, V. C., Heemeyer, J. L., Pessier, A. P., & Lannoo, M. J. (2011): Seasonal pattern of Batrachochytrium dendrobatidis infection and mortality in Lithobates areolatus: Affirmation of Vredenburg’s “10,000 zoospore rule.” PLoS ONE 6(3):e16708. doi:10.1371/journal.pone.0016708.
• Kinney, V. C. (2011): Adult Survivorship and Juvenile Recruitment in Populations of Crawfish Frogs (Lithobates areolatus), with Additional Consideration of the Population Sizes of Associated Pond Breeding Species. Indiana State University (Thesis).
• Parris, J. M., & Semlitsch R. D. (1998): Asymmetric competition in larval amphibian communities: conservation implications for the northern crawfish frog, Rana areolata circulosa. Oecologia 116:219-226.
• Pauly, Greg B., Hillis, David M. & Cannatella, David C. (2009): Taxonomic freedom and the role of official lists of species names. Herpetologica 65: 115-128. PDF fulltext
• Iowa Herpetology: Crawfish Frog

External links

• Rana areolata at CalPhotos