''Gigantometra'' is a

monotypic genus 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 "unispec ...

of water-strider bugs, containing the species ''Gigantometra gigas'': its name indicating that it is the largest species in its family

Gerridae The Gerridae are a family of insects in the order Hemiptera, commonly known as water striders, water skeeters, water scooters, water bugs, pond skaters, water skippers, or water skimmers. Consistent with the classification of the Gerridae as tr ...

. It has been found in pools of fast-flowing, subtropical and

tropical forest Tropical forests (a.k.a. jungle) are forested landscapes in tropical regions: ''i.e.'' land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds. Some tropical fores ...

streams, on

Hainan Island Hainan (, ; ) is the smallest and southernmost province of the People's Republic of China (PRC), consisting of various islands in the South China Sea. , the largest and most populous island in China,The island of Taiwan, which is slightly l ...

and highland northern

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

Description

''Gigantometra gigas'' is the largest species of water-striders, with legs having a span of about 300 mm in order to spread its relatively large body weight on the water surface.

Sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

is common throughout the Gerridae and

sexual selection Sexual selection is a mode of natural selection in which members of one biological sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of t ...

of males for large body size has been demonstrated in several species, including this one: where males are larger than females in all measured traits. This dimorphism was prominent in the leg parts, which are 10–50% longer in males than in females; males are generally more variable in size than females, especially with leg segments. It was proposed that sexual selection acts on the length of middle legs in males and explains both the increase and variance in middle leg length, with hind leg length similarly correlated.Tseng M, Rowe L (1999) Sexual dimorphism and allometry in the giant water strider ''Gigantometra gigas''. ''Can. J. Zool.''77: 923–929
ResearchGate (retrieved 14 August 2021)

References

External Links

* {{Taxonbar, from1=Q108083684, from2=Q108084978 Gerridae Gerromorpha genera Hemiptera of Asia