''Thaumatoneura inopinata'' is a species of

damselfly Damselflies are flying insects of the suborder Zygoptera in the order Odonata. They are similar to dragonflies (which constitute the other odonatan suborder, Epiprocta) but are usually smaller and have slimmer bodies. Most species fold the win ...

, sometimes called the cascade damselfly or giant waterfall damsel, and the only member of the genus ''Thaumatoneura''. It is unusual in flying among the falling water and spray from

waterfall A waterfall is any point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in seve ...

s in moist tropical or subtropical forests in

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

Taxonomy

''Thaumatoneura inopinata'' is a highly distinctive species, making up a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

genus (''Thaumatoneura'') and

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

(Thaumatoneurinae). It has been sometimes placed in the flatwing damselfly family

Megapodagrionidae Megapodagrionidae is a family of damselflies. They are commonly called flatwings for their habit of spreading out their wings horizontally when at rest. A 2013 phylogenetic analysis pares down this family into only three genera, and numerous ot ...

, but as a result of molecular phylogenetic studies by Dijkstra et al. in 2013, the genus ''Thaumatoneura'' is now considered one of two extant

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

in the family Thaumatoneuridae. The species was first described in 1897 by the English entomologist Robert McLachlan, but he did not know the origin of the specimen that he had bought as part of an insect collection. It later transpired that the damselfly was from the

New World The term "New World" is used to describe the majority of lands of Earth's Western Hemisphere, particularly the Americas, and sometimes Oceania."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: ...

when another specimen was brought back from Panama. The American entomologist

Philip Powell Calvert Philip Powell Calvert (January 29, 1871, in Philadelphia, PennsylvaniaCALVERT. Philip Powe ...

visited Costa Rica and researched the species. The adult insects were seen in the vicinity of waterfalls, and nymphs were found on vegetated wet rocks, but it was some time before it was certain that these were of the same species. The matter was settled when one nymph was observed transforming into an adult. As the

haemolymph Hemolymph, or haemolymph, is a fluid, similar to the blood in invertebrates, that circulates in the inside of the arthropod's body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which hemolymph ce ...

was being pumped into the wings to expand them, the wings were at first pale green with blackish veins, and with the greenish body, the insect looked like a trembling, green leaf, exactly resembling the foliage close by.

Distribution and habitat

The giant waterfall damsel is found in

and

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

. 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 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 ...

s and

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

s where it is usually found in close vicinity to waterfalls.

Description

Male giant waterfall damsels have two forms, one with entirely clear wings and the other with broad black bands across the wings. Females have clear wings with brown wing tips. In both sexes, the nodus (a notch in the leading edge of each wing) is closer to the base of the wings than is the case in most other damselfly species. When perched, the wings are held vertically above the abdomen, which allows water to drip off.

Behaviour

The giant waterfall damsel can be seen flying among the falling water and spray produced by waterfalls. The eggs are laid among the mosses and tangled roots beside the cascade which are constantly kept wet by the water. The nymphs develop among this vegetation and do not normally enter the torrent. When their development is finished and they are ready to emerge, they climb onto a rock, their skin splits and the winged adults climb out.

Status

The

International Union for Conservation of Nature 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 stat ...

used to classify this species as "

threatened A threatened species is any species (including animals, plants and fungi) which is vulnerable to extinction in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensatio ...

" but more recently it has been found at an increasing number of locations in Costa Rica and although nowhere common, it is now assessed as being sufficiently numerous to be classified as "

least concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

". The chief threats it faces is

deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...

, which alters stream habitats, and

global warming Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...

which may cause some streams and waterfalls to dry up.

References

{{Taxonbar , from1=Q2528511 , from2=Q970259 Calopterygoidea Monotypic Odonata genera Zygoptera genera Taxa named by Robert McLachlan (entomologist) Insects described in 1897 Insects of Central America Taxonomy articles created by Polbot