Animal Diversity Web

Diversity

Genus Agalychnis is made up of 14 species in the family Phyllomedusidae. Agalychnis are slender frogs that have many different color combinations. They are small-to-medium-sized frogs that are ectothermic and exhibit bilateral symmetry. This genus includes tree frogs because they are primarily arboreal. They are predominantly green on their dorsal sides and have yellow/orange color on their ventral sides. This coloration camouflages them with leaves and other vegetation. Some species like Agalychnis lemur can have different coloration, such as exhibiting an orange dorsal side. All Agalychnis species have rather large eyes that protrude from their craniums. Their limbs are long and some have webbing between their toes. ("Amphibia Web", 2022)

Geographic Range

Agalychnis's range is limited to the Neotropical region, inhabiting areas in central and northern South America. ("Amphibia Web", 2022)

• Biogeographic Regions
• neotropical
  • native

Habitat

Agalychnis are found in the tropical forests of Central America and the northwestern regions of South America. They are arboreal animals, so they are found in tree canopies. This limits them to forests and wetlands where there is plenty of coverage from predators and ample vegetation to lay their eggs and/or seek shelter. Agalychnis are found around ponds during the mating season where they lay their eggs. These frogs rarely venture to the ground but do so for mating and spawning reasons. ("Amphibia Web", 2022; IUCN SSC Amphibian Specialist Group (IUCN SSC), 2016)

• Habitat Regions
• tropical
• terrestrial
• freshwater

• Terrestrial Biomes
• forest
• rainforest

• Aquatic Biomes
• lakes and ponds

• Wetlands
• swamp

Systematic and Taxonomic History

With our current understanding of Agalychnis, they are most closely related to genus Phyllomedusa. Agalychnis used to be known as Pachymedusa. ("Amphibia Web", 2022)

• Synonyms

  • Pachymedusa

Physical Description

Agalychnis frogs have webbing in-between each of their toes and suction disks at the ends of their digits. Body-color ranges anywhere from light green to dark green on the dorsal side. Some frogs are even able to exhibit metachrosis (i.e. Agalychnis lemur) wherein they change from a green color during the day into reddish-brown or even orangish-tan at night. On their ventral side, they can have many different yellow, white, or orange shades. Their size can range anywhere from 30mm-88mm. Their appendages are long and slender, with a slender, flattened body and a depressed head. Their eyes are rather large and protrude out of their heads, which have lower eyelids. Most of these frogs' skin, both ventrally and dorsally, is smooth but some have rough warts. Agalychnis frogs' heads are round and they have a short snout when looked at from above. ("Amphibia Web", 2022)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger

Development

• Development - Life Cycle
• metamorphosis

Reproduction

Agalychnis frogs' main source of attracting and finding mates is acoustic communication. Males have many different types of calls to attract a female. They can enforce territorial defense or make their location clear through different calls. Their aggressive calls are used to deter other males from trespassing their territory. Females can choose their mates through the differences in their mating calls. ("Amphibia Web", 2022; Cossio and Medina-Barcenas, 2020)

• Mating System
• polygynandrous (promiscuous)

Agalychnis frogs can lay anywhere from 14-67 eggs (i.e. A. spirrelli) to 47-162 eggs (i.e. A. annae) in a single clutch. Eggs then hatch into tadpoles around 6-14 days after being laid. Some species show plasticity while hatching. A. callidryas can undergo synchronous hatching when disturbed by predators or fungus. These tadpoles then develop in pools of water, where they are laid in leaves that overhang the water body. They are then independent of their parents, and the ones that survive undergo metamorphosis to transition to terrestrial life. (Cossio and Medina-Barcenas, 2020)

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous

In Agalychnis, there is little to no parental investment. After the female lays her eggs, they are left on their own to fend for themselves. ("Department of Biology", 2012; "Frogs & Co", 2021)

• Parental Investment
• no parental involvement

Lifespan/Longevity

Agalychnis frogs have been known to live as long as 4-8 years or more. ("Amphibia Web", 2022; "Frogs & Co", 2021)

Behavior

Agalychnis are primarily nocturnal frogs. Their croaks can be heard during the mating season, especially at night. These frogs exhibit many calls to attract mates and defend their territory. They can produce advertisement calls or aggressive calls. Males will fight each other to obtain a mate. They will even lay on top of females until the females have found an appropriate spot to lay their eggs. They then lay their unfertilized eggs either in leaves with a readily available source of water or leaves that overhang a body of water. Some frogs in this genus, like A. callidryas have bright red eyes that can spook predators when opened, potentially giving the frogs enough time to escape. ("Amphibia Web", 2022; Cossio and Medina-Barcenas, 2020)

• Key Behaviors
• arboreal
• nocturnal
• motile
• territorial
• social

Communication and Perception

Agalychnis frogs are social and have different croaks/calls with varying lengths or pitches to communicate location, territory, and mating rituals. They also rely on their vision to scan the environment for mates and predators. A. callidryas have also been observed to use vibration-based communication when males have territorial disputes. Specifically, one male will vibrate tree branches until the submissive male gives up that territory to the victorious male. (Cossio and Medina-Barcenas, 2020)

• Communication Channels
• visual
• acoustic

• Other Communication Modes
• choruses
• vibrations

• Perception Channels
• visual
• acoustic
• vibrations

Food Habits

Agalychnis frogs are carnivorous and feed nocturnally. They are mainly insectivorous, preying on small insects but also smaller frogs and vertebrates. Soft-bodied invertebrates like crickets, flies, and moths make up a majority of their diet. The tadpoles of Agalychnis frogs also prey on smaller insects like crickets and fruit flies. ("Amphibia Web", 2022; "Frogs & Co", 2021)

• Primary Diet
• carnivore
  • eats terrestrial vertebrates
  • insectivore

Predation

As these frogs are nocturnal, they have nocturnal predators as well. Notable predators of Agalychnis frogs are bats, snakes, and birds. Since Agalychnis frogs are arboreal and live on the leaves of trees, they are easily preyed upon by these animals, often being snatched up in an instant. However, as tadpoles, they have even more predators to worry about before they transition into their terrestrial lives. Fish are the biggest predators of Agalychnis frogs. Dragonflies and water beetles are also dangerous predators. The tadpoles' green colors do give them some camouflage, however, hiding them in the leaves of the canopy. ("Amphibia Web", 2022; Grover, 2022)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • Birds
  • Snakes
  • Monkeys
  • Water beetles
  • Dragonflies
  • Fish

Ecosystem Roles

Agalychnis frogs are biological indicators for changes within their environments. Since they have permeable skin, these frogs are easily influenced by environmental alterations earlier than most organisms. When an environment changes negatively, this effect can be seen in Agalychnis frogs almost immediately. Thus, researchers can use them to make predictions about the state of the environment that they are in. Agalychnis frogs also eat a lot of invertebrates, so they help manage insect populations and prevent the spread of disease as well. ("Amphibia Web", 2022; "Toads N Frogs", 2022)

Economic Importance for Humans: Positive

Humans can use Agalychnis frogs to determine the health status of their environments. Since they are sensitive to changes in the environment, it is easy to tell how well an ecosystem is doing by studying these frogs. Agalychnis frogs also control insect populations, which consequently reduces the spread of disease. A. callidryas is also very popular in the pet trade. Their bright colors make them a popular animal for people to want in their homes. ("Amphibia Web", 2022; IUCN SSC Amphibian Specialist Group (IUCN SSC), 2016)

• Positive Impacts
• pet trade
• controls pest population

Economic Importance for Humans: Negative

There are no known adverse effects of Agalychnis on humans.

Conservation Status

The conservation status of Agalychnis is Least Concern. However, the populations of this genus are declining. This is because of the expansion of infrastructure, logging, and agricultural activities. Agalychnis frogs populations are also declining because of their popularity in the pet trade, especially A. callidryas. This genus is also found in many protected areas of wilderness. (IUCN SSC Amphibian Specialist Group (IUCN SSC), 2016)

• IUCN Red List [Link]

  Not Evaluated

Contributors

Josh Dresen (author), Colorado State University, Audrey Bowman (editor), Colorado State University, Sydney Collins (editor), Colorado State University.

References

2022. "Amphibia Web" (On-line). Agalychnis callidryas. Accessed February 06, 2022 at https://amphibiaweb.org/species/616.

2012. "Department of Biology" (On-line). The Red-Eyed Tree Frog. Accessed February 06, 2022 at https://www.lamar.edu/arts-sciences/biology/study-abroad-belize/jungle-critters/jungle-critters-2/the-red-eyed-tree-frog.html.

2021. "Frogs & Co" (On-line). Agalychnis callidryas. Accessed February 06, 2022 at https://frogsandco.com/agalychnis-callidryas/.

2022. "ITIS" (On-line). Agalychnis Cope, 1864. Accessed March 27, 2022 at https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=208136#null.

2022. "Toads N Frogs" (On-line). Why Frogs Are Important. Accessed March 06, 2022 at https://toadsnfrogs.com/why-frogs-important/.

Cossio, R., E. Medina-Barcenas. 2020. Acoustic Repertoire and Calling Behavior of the Gliding Treefrog, Agalychnis spurrelli (Anura: Hylidae). South American Journal of Herpetology, 17/1: 71-78.

Grover, M. 2022. "Reptiles" (On-line). What Eats A Red-Eyed Tree Frog. Accessed March 06, 2022 at https://everythingreptilion.com/what-eats-a-red-eyed-tree-frog/.

IUCN SSC Amphibian Specialist Group (IUCN SSC), 2016. "Red-eyed Treefrog" (On-line). Red List. Accessed February 06, 2022 at https://www.iucnredlist.org/species/55290/3028059#habitat-ecology.

Kaiser, K., C. Boehlke, E. NAvarro-Perez, A. Vega, S. Dudgeon, J. Robertson. 2018. Local preference encoded by complex signaling: mechanisms of mate preference in the red-eyed treefrog (Agalychnis callidryas). Behavioral Ecology and Sociobiology, 72/12: 182.

Rivera-Correa, M., F. Duarte-Cubides, J. Rueda-Almonacid, J. Daza. 2013. A new red-eyed treefrog of Agalychnis (Anura: Hylidae: Phyllomedusinae) from middle Magdalena River valley of Colombia with comments on its phylogenetic position. Zootaxa, 3636/1: 85-100.

Rota, E., T. Gianfranco, M. Gilberto, G. Filippo, G. Delfino, D. Sever. 2017. .Skin of the Red Eye Tree FrogAgalychnis Calli(Hylidae,Phyllomedusinae) Contains LipidGlands of the Type Described in theGenusPhyllomedusa. The Anatomical Record, 300: 503-506.

Vilela, B., B. Lisboa, F. doNaiscimento. 2015. Reproduction of Agalychnis granulosa Cruz, 1989 (Anura: Hylidae). Journal of Natural History, 49: 709-717.

Warkentin, K. 1999. The development of behavioral defenses: a mechanistic analysis of vulnerability in red-eyed tree frog hatchlings. Behavioral Ecology, 10/3: 251-262.