The polka-dot tree frog (''Boana punctata''), also known as the dotted tree frog, is a

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

species in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Hylidae found in much of South America and also in

Trinidad and Tobago Trinidad and Tobago, officially the Republic of Trinidad and Tobago, is the southernmost island country in the Caribbean, comprising the main islands of Trinidad and Tobago, along with several List of islands of Trinidad and Tobago, smaller i ...

. It is fairly small with a snout–to– vent length of . Its natural

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s are subtropical or tropical dry forest, subtropical or tropical moist lowland forest, subtropical or tropical

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s, subtropical or tropical moist

montane forest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

, swamps, freshwater

marsh In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p More in genera ...

es, intermittent freshwater marshes, rural gardens,

urban area An urban area is a human settlement with a high population density and an infrastructure of built environment. Urban areas originate through urbanization, and researchers categorize them as cities, towns, conurbations or suburbs. In urbani ...

s, and heavily degraded former forests. It is not considered threatened by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

Pigmentation and skin fluorescence

In 2017, several polka-dot tree frogs collected in the Santa Fe Province in Argentina were the first

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

, amongst more than 6,000 species of frog, identified as naturally fluorescent. Among land-living

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

s, it had only been confirmed earlier in certain

parrot Parrots (Psittaciformes), also known as psittacines (), are birds with a strong curved beak, upright stance, and clawed feet. They are classified in four families that contain roughly 410 species in 101 genus (biology), genera, found mostly in ...

s (as opposed to fish and invertebrates where fluorescence is relatively widespread). A few months later, fluorescence was discovered in the closely related '' Boana atlantica'', and in 2019 it was discovered in the distantly related pumpkin toadlet (''Brachycephalus ephippium'') and red pumpkin toadlet (''B. pitanga''). In 2020, it was confirmed that fluorescence is relatively widespread among frogs and other amphibians. When exposed to ultra-violet light, the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

of the polka-dot tree frog emits a bright green fluorescent glow. The discovery was made accidentally when the researchers checked the skin secretions of the frog under UV light. They expected only a faint red fluorescence, because the frog skin contains biliverdin, a green tetrapyrrolic bile

pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...

responsible for its dull mottled browny-green colour. The surprising green fluorescence is attributed to hyloin compounds, mainly hyloin-L1, hyloin-L2 and hyloin-G1. These fluorescent molecules, in the dihydroisoquinolinone family and derived from the isoquinoline (a

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

ring fused to a pyridine ring), in an

alkaloid Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large varie ...

protecting mucous membrane, have been identified in the lymph tissue, skin and glandular secretions of the frog. Because it is linked to secretions from skin glands, they can also leave fluorescent markings on surfaces where they have been. The fluorescence intensity represents about 18−29% of the luminosity under twilight conditions and is suspected to play a possible role in the communication, camouflage and mating of the frog.

Gallery

File:The Polka-dot Treefrog (Hypsiboas punctatus) (15367220278).jpg File:Boana punctata (10.5852-ejt.2022.836.1919) Figure 2 (cropped).png,

Amapá Amapá (; ) is one of the 26 federative units of Brazil, states of Brazil. It is in the North Region, Brazil, North Region of Brazil. It is Federative units of Brazil#List, the second-least populous state and the eighteenth-largest state by area ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

File:Hypsiboas punctatus01a.jpg File:Hypsiboas punctatus Peru 01.JPG

References

{{Taxonbar, from1=Q58740621, from2=Q2247359 punctata Amphibians of Argentina Amphibians of Bolivia Frogs of Brazil Amphibians of Colombia Amphibians of Ecuador Amphibians of French Guiana Amphibians of Guyana Amphibians of Paraguay Amphibians of Peru Amphibians of Suriname Amphibians of Trinidad and Tobago Amphibians of Venezuela Amphibians described in 1799 Fluorescence Taxonomy articles created by Polbot