Eleutherodactylus planirostrisGreenhouse Frog

Geographic Range

Eleutherodactylus planirostris is a small frog species native to several Caribbean islands, including Cuba, the Caymans (specifically Grand Cayman and Cayman Brac), and the Bahamas (specifically Eleuthera, Little Bahama Bank, South Bimini, and New Providence). From their origin in western Cuba (a population that is genetically distinct from populations in eastern Cuba, Jamaica, the Caymans, and the Bahamas), they have been introduced to mainland United States, Mexico, and Hawaii. Eleutherodactylus planirostris was introduced via the soil of imported tropical plants and in landscaping materials, where individuals went unnoticed because of their small size and faint advertisement call. Breeding populations have been established in Guam, and several U.S. states, including Florida, Georgia, and Alabama. There are isolated colonies found in Mississippi, Louisiana, and Texas. (Heinicke, et al., 2011; Jensen, et al., 2008; Olson, et al., 2012; Somma, 2013)

Habitat

Greenhouse frogs are widely distributed in the tropical Caribbean, predominantly in locations with a climate similar to that of Cuba, an island with a variable, tropical climate characterized by a dry season with a mean temperature of 22 °C and a wet season with a mean temperature of 29°C. Greenhouse frogs are found in both residential areas and natural habitats, with most populations residing in lowland habitats. They are usually found on the forest floor, where they hide under logs, leaf litter, debris, and in crevices along stream banks. Adults are common in moist substrates, and, in residential areas, can be found in greenhouses and gardens, and beneath mulch, boards, or stones. Because of their high tolerance for dry conditions, they can also live in the open grasslands and pastures of Jamaica, and in the grasslands, scrub habitats, and coastal areas of Florida. (Fernández, et al., 2008; Jensen, et al., 2008; Lannoo, 2005; Olson, et al., 2012; Wells, 2007)

  • Aquatic Biomes
  • rivers and streams

Physical Description

Greenhouse frogs are granular-skinned frogs that range in length from 12 to 30 mm. Individuals exhibit several background colors, including brown, reddish brown, or bronze, and two pattern phases. The recessive mottled phase has dark (brown) and light (tan) coloration, often with a faint v-shaped band on the back and a band between the eyes. The dominant, striped phase has two light, dorsolateral stripes starting at the eyes and terminating at the posterior end. The frog has a light gray or white belly with fine brown stippling and reddish eyes. Greenhouse frogs have slender fingers and toes without webbing and with small, terminal toe pads. Greenhouse frogs are sexually dimorphic. The snout-vent length (SVL) is variable among populations, but female frogs are always larger than males. In Hawaii, the mean female SVL is 22 mm while the mean male SVL is 17 mm. In Cuba and Florida, the female SVL ranges from 26.5 to 28 mm while the male SVL ranges from 17.5 to 21 mm. (Jensen, et al., 2008; Olson, et al., 2012; Somma, 2013)

  • Sexual Dimorphism
  • female larger
  • Range length
    12 to 30 mm
    0.47 to 1.18 in

Development

Fertilized greenhouse frog eggs hatch directly into tiny froglets after an in-egg development and metamorphosis period of around 2 weeks. Development may be accelerated by warmer temperatures, with hatching occurring as early as 13 days and as late as 20 days post-deposition. To hatch, eggs require 100% humidity. Hatchlings are about 9 to 11 mm long with an SVL of 4.3 to 5.7 mm. They look very similar to adults, with the addition of a reduced tail and tooth, both of which detach after hatching. Both males and females reach sexual maturity within the first year of life. (Olson, 2011; Olson, et al., 2012)

Reproduction

There is no information on the mating system of greenhouse frogs in the literature.

Greenhouse frogs breed during the spring and summer. In Cuba and Florida, they breed more during the wet season than the dry season, whereas in Hawaii, they breed almost exclusively in the wet season. Males call to females at night and when relative humidity is 84 to 100%. The call is a soft series of 4 to 5 irregular chirps with sound pressure levels of 35 to 45 decibels at 0.5 meters. Males call from under debris, from the ground, or on vegetation under 1 m from the ground. Each female lays a clutch of about 20 eggs (range: 3 to 26 eggs). Eggs are laid on the ground under moist cover such as clumps of vegetation, under debris, in leaf litter, and even in the soil of potted plants. (Jensen, et al., 2008; Kraus, et al., 1999; Lannoo, 2005; O'Neill, 2009; Olson, et al., 2012)

  • Breeding season
    Greenhouse frogs breed from April to January in Cuba and April to September in Florida.
  • Range number of offspring
    3 to 26
  • Range time to hatching
    13 to 20 days
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    1 years

No parental care is given to offspring after hatching. Hatchlings are on their own as soon as they emerge from their eggs. Females invest substantial energy into the eggs before they mate and become fertilized. (Olson, et al., 2012)

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning
    • protecting
      • female

Lifespan/Longevity

There is no information on the lifespan or longevity of greenhouse frogs in the literature.

Behavior

Greenhouse frogs are primarily nocturnal and individuals are most active during and following rains. They are especially active on warm, overcast, or rainy days. During the day, and in periods of dry weather, greenhouse frogs seek the shelter of various objects, both natural and artificial. In March, in the southern Florida Everglades, they hibernate under the loose bark of the wild tamarind (Lysiloma latisiliquum), a small shade tree common in southern Florida. (Jensen, et al., 2008; Olson, et al., 2012)

Home Range

There is no specific information on the home range of greenhouse frogs in the literature. The population density of both adult and pre-adult greenhouse frogs in a Hawaiian sample was 12,522 frogs per hectare. (Meshaka, et al., 2009; Olson, 2011)

Communication and Perception

Greenhouse frogs have a U-shaped response to light, responding more strongly to wavelengths in the red and violet areas of the visible spectrum than to intermediate wavelengths. Potential mates communicate via vocalizations. It's also likely that they perceive touch well, since that is part of the mating amplexus behavior. (Hailman and Jaeger, 1974; Olson, et al., 2012)

Food Habits

The diet of greenhouse frogs differs among populations. In Jamaica, primary animal foods are ants, beetles, and roaches. In Hawaii, primary animal foods are ants, beetles, mites, spiders, and longlegs. (Jensen, et al., 2008; Lannoo, 2005; Olson, 2011)

Greenhouse frogs eat small invertebrates, such as ants, beetles, mites, spiders, and cockroaches. (Jensen, et al., 2008; Lannoo, 2005; Olson, 2011)

  • Animal Foods
  • insects

Predation

Greenhouse frogs are eaten by a variety of carnivorous animals, including invertebrates, other frogs, lizards, snakes, birds, and mammals. Known predators include brown tree snakes (Boiga irregularis), Cuban racers (Cubophis cantherigerus), Grand Cayman racers (Cubophis caymanus), Bahamian brown racers (Cubophis vudii), Cuban tree frogs (Osteopilus septentrionalis), and ringneck snakes (Diadophis punctatus). Their cryptic coloration (dull, brown color and mottled skin pattern) helps them avoid detection by predators. (Jensen, et al., 2008; Lannoo, 2005; Olson, et al., 2012)

Greenhouse frogs are eaten by a variety of carnivorous animals, including invertebrates, other frogs, lizards, snakes, birds, and mammals. Known predators include brown tree snakes, Cuban racers, Grand Cayman racers, Bahamian brown racers, Cuban tree frogs, and ringneck snakes. They are cryptically colored to help them avoid predators. (Jensen, et al., 2008; Olson, et al., 2012)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Greenhouse frogs have little impact on the ecosystems they have been introduced to. It may be difficult to determine more subtle impacts, such as adverse effects on native insects and competition with native frogs and other animals. Greenhouse frogs could eat native arthropods, which could negatively impact native insectivorous birds that would have to compete with them for food. In Florida, for example, greenhouse frogs compete for food with lizards like Florida reef geckos and mole skinks, which are already threatened because they are habitat specialists and their habitat is rapidly disappearing. Conversely, in Hawaii, greenhouse frogs eat non-native insect species, such as Argentine ants, big-headed ants, and yellow crazy ants, that negatively affect native invertebrates. Introduction of a non-native frog species like greenhouse frogs could make the establishment and spread of other invasive species easier. They may serve as an abundant prey source for nonnative, invasive predators. In Guam, for example, greenhouse frogs could become a food source for populations of rats, mongooses, and brown tree snakes. The addition of greenhouse frogs to the ecosystem could disrupt nutrient flow through the native food web. Invertebrates eaten by greenhouse frogs play an important role in the decomposition of plant material. One study, however, found that leaf litter decomposition rates were increased and herbivory rates decreased in areas with greenhouse frogs. The frogs made nutrients more available to plants and microbes, which could give invasive plants an advantage over native species that have adapted to nutrient-poor conditions.

Greenhouse frogs are burrow symbionts of gopher tortoises (Gopherus polyphemus). They have been observed sharing ground cover with indigenous eastern narrow-mouthed toads (Gastrophryne carolinensis). In Cuba, nematodes parasitize greenhouse frogs. Overall, pathogens have a low potential for using this species as a host because viruses and diseases tend to afflict tadpole stages. (Christy, et al., 2007; Jensen, et al., 2008; Kraus, et al., 1999; Lannoo, 2005; Olson, et al., 2012; Sin, et al., 2008)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Greenhouse frogs generally go unnoticed. Some residents enjoy their soft calls and purposefully move these frogs to their gardens. (Kraus, et al., 1999; Lannoo, 2005; Olson, et al., 2012; Somma, 2013)

Economic Importance for Humans: Negative

Greenhouse frogs and their eggs are often moved inadvertently with landscape materials. Nurseries must treat infested shipments with citric acid and use various control methods to reduce the number of pests, increasing shipment costs and decreasing trade. These frogs are also a nuisance for businesses and homeowners because they may find their way into swimming pools and irrigation boxes. (Kraus, et al., 1999; Olson, et al., 2012)

  • Negative Impacts
  • household pest

Conservation Status

Greenhouse frogs are not considered threatened because populations are large and found throughout a large area. Greenhouse frogs readily adapt to human disturbed habitats.

Contributors

Stephanie Cervino (author), The College of New Jersey, Keith Pecor (editor), The College of New Jersey, Tanya Dewey (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

Neotropical

living in the southern part of the New World. In other words, Central and South America.

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.

carnivore

an animal that mainly eats meat

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.

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.

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.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

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.

native range

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

nocturnal

active during the night

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

oviparous

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

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

riparian

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

scrub forest

scrub forests develop in areas that experience dry seasons.

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

solitary

lives alone

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

References

Christy, M., A. Savidge, G. Rodda. 2007. Multiple pathways for invasion of anurans on a Pacific island. Diversity and Distributions, 13: 598-607.

Fernández, S., F. Barcala, R. Medina, D. Ortiz, H. Núñez. 2008. . Epidemiology of asthma mortality in Cuba and its relation to climate, 1989 to 2003. MEDJCC Review, 10: 24-29.

Fuller, P. 2013. "Greenhouse Frog – Point Map" (On-line). NAS program. Accessed October 23, 2013 at http://nas2.er.usgs.gov/viewer/omap.aspx?SpeciesID=61.

Hailman, J., R. Jaeger. 1974. Phototactic responses to spectrally dominant stimuli and use of colour vision by adult anuran amphibians: a comparative study. Animal Behaviour, 22: 757-795.

Heinicke, M., L. Diaz, S. Hedges. 2011. Origin of invasive Florida frogs traced to Cuba. Biology Letters, 7: 407-410.

Jensen, J., C. Camp, W. Gibbons, M. Elliot. 2008. Amphibians and Reptiles of Georgia. Athens, GA: University of Georgia Press.

Kraus, F., E. Campbell, A. Allison, T. Pratt. 1999. Eleutherodactylus frog introductions to Hawaii. Herpetological Review, 30: 21-25.

Lannoo, M. 2005. Amphibian Declines: The Conservation Status of United States Species. Sacramento: University of California Press.

Meshaka, W., J. Boundy, A. Williams. 2009. The dispersal of the Greenhouse frog, Eleutherodactylus planirostris (Anura: Eleutherodactylidae), in Louisiana, with preliminary observations on several potential exotic colonizing species. Journal of Kansas Herpetology, 32: 12-16.

O'Neill, E. 2009. "Evolutionary Consequences of the Introduction of Eleutherodactylus coqui to Hawaii" (On-line pdf). Ph.D. Thesis. Utah State University. Accessed October 23, 2013 at http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1278&context=etd.

Olson, C. 2011. "Diet, Density, and Distribution of the Introduced Greenhouse Frog, Eleutherodactylus planirostris, on the Island of Hawaii" (On-line pdf). Ph.D. Thesis. Utah State University. Accessed October 23, 2013 at http://digitalcommons.usu.edu/etd/866/.

Olson, C., K. Beard, W. Pitt. 2012. Biology and impacts of Pacific Island invasive species. 8. Eleutherodactylus planirostris, the greenhouse frog (Anura: Eleutherodactylidae). Pacific Science, 66: 255-270.

Sin, H., K. Beard, W. Pitt. 2008. An invasive frog, Eleutherodactylus coqui, increases new leaf production and leaf litter decomposition rates through nutrient cycling in Hawaii. Biological Invasions, 10: 355-345.

Somma, L. 2013. "Eleutherodactylus planirostris" (On-line). USGS Nonindigenous Aquatic Species Database. Accessed October 24, 2013 at http://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=61.

Wells, K. 2007. The Ecology and Behavior of Amphibians. Chicago: The University of Chicago Press.