Gerridae
Gerridae Temporal range:
| |
---|---|
mating in Cyprus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hemiptera |
Suborder: | Heteroptera |
Superfamily: | Gerroidea |
Family: | Gerridae Leach, 1815 |
Subfamilies[1] | |
The Gerridae are a family of insects in the order
While 90% of the Gerridae are freshwater bugs, the oceanic
Description
The family Gerridae is physically characterized by having
Hydrofuge hairpiles are small,
Size
They are generally small, long-legged insects and the body length of most species is between 2 and 12 mm (0.08–0.47 in). A few are between 12 and 25 mm (0.47–0.98 in).
Antennae
Water striders have two antennae with four segments on each. Antennal segments are numbered from closest to the head to farthest. The antennae have short, stiff bristles in segment III.[8] Relative lengths of the antennae segments can help identify unique species within the family Gerridae, but in general, segment I is longer and stockier than the remaining three.[9] The four segments combined are usually no longer than the length of the water strider head.
Thorax
The
Appendages
Gerridae have front, middle, and back legs. The front legs are shortest and have preapical claws adapted to puncture prey. Preapical claws are claws that are not at the end of the leg, but rather halfway through, like
Wings
Some water striders have wings present on the dorsal side of their thorax, while other species of Gerridae do not, particularly Halobates. Water striders experience wing length polymorphism that has affected their flight ability and evolved in a phylogenetic manner where populations are either long-winged, wing-dimorphic, or short-winged.[10] Wing dimorphism consists of summer gerrid populations evolving different length wings than winter populations within the same species. Habitats with rougher waters are likely to hold gerrids with shorter wings, while habitats with calm waters are likely to hold long-winged gerrids. This is due to potential for damage of the wings and ability for dispersal.[1]
Evolution
Molecular analysis suggest an origin of the family Gerridae about 128 Million years ago (Mya) in the Cretaceous, splitting from the sister group Veliidae, with whom they share a single origin of rowing as a locomotive mechanism. According on the transcriptome-based phylogeny, Gerridae is a monophyletic group.[12]
Wing polymorphism
Wing polymorphism (i.e., the presence of multiple wing morphs in a given species) has independently evolved multiple times in Gerridae, as well as complete wing loss,[12] something that has been important for the evolution of the variety in species we see today, and dispersal of Gerridae. The existence of wing polymorphism in a given species can be explained as a particular case oogenesis-flight syndrome. Following this rationale, which is commonly applied in insects, developing short wings provides the individual with the capacity to dedicate the energy stores that would usually be used for wing and wing muscle development to increasing egg production and reproducing early, ultimately enhancing the individual's fitness.[13] The ability for one brood to have young with wings and the next not allows water striders to adapt to changing environments. Long, medium, short, and nonexistent wing forms are all necessary depending on the environment and season. Long wings allow for flight to a neighboring water body when one gets too crowded, but they can get wet and weigh a water strider down. Short wings may allow for short travel, but limit how far a gerrid can disperse. Nonexistent wings prevent a gerrid from being weighed down, but prevent dispersal.
Wing polymorphism is common in the Gerridae despite most
Nature of the ability to walk on water
Water striders are able to walk on top of water due to a combination of several factors. Water striders use the high surface tension of water and long, hydrophobic legs to help them stay above water. Gerridae species use this surface tension to their advantage through their highly adapted legs and distributed weight.
The legs of a water strider are long and slender, allowing the weight of the water strider body to be distributed over a large surface area. The legs are strong, but have flexibility that allows the water striders to keep their weight evenly distributed and flow with the water movement. Hydrofuge hairs line the body surface of the water strider. There are several thousand hairs per square millimeter, providing the water strider with a hydrofuge body that prevents wetting from waves, rain, or spray, which could inhibit their ability to keep their entire body above the water surface if the water stuck and weighed down the body.[4] This position of keeping the majority of the body above the water surface is called an epipleustonic position, which is a defining characteristic of water striders. If the body of the water strider were to accidentally become submerged, for instance by a large wave, the tiny hairs would trap air. Tiny air bubbles throughout the body act as buoyancy to bring the water strider to the surface again, while also providing air bubbles to breathe from underwater.[4] Despite their success in overcoming submergence in water, however, water striders are not as competent in oil, and experimental oil spills have suggested that oil spilled in freshwater systems can drive water strider immobility and death.[15]
The tiny hairs on the legs provide both a hydrophobic surface as well as a larger surface area to spread their weight over the water. The middle legs used for rowing have particularly well developed fringe hairs on the tibia and tarsus to help increase movement through the ability to thrust.[4] The hind pair of legs are used for steering [16] When the rowing stroke begins, the middle tarsi of gerrids are quickly pressed down and backwards to create a circular surface wave in which the crest can be used to propel a forward thrust.[4] The semicircular wave created is essential to the ability of the water strider to move rapidly since it acts as a counteracting force to push against. As a result, water striders often move at 1 meter per second or faster.[17]
Life cycle
Gerrids generally lay their eggs on submerged rocks or vegetation using a gelatinous substance as a glue. Gravid females carry between two and twenty eggs. The eggs are creamy white or translucent, but become bright orange.[17]
Gerrids go through the egg stage, five
Ecology
Habitat
Genus of family Gerridae | No. of marine species |
Brackish | Neritic | Oceanic |
---|---|---|---|---|
Asclepios | 4 | Yes | Yes | No |
Halobates group 1 | 39 | Yes | Yes | No |
Halobates group 2 | 7 | No | No | Yes |
Stenobates | 1 | No | Yes | No |
Rheumatometroides | 1 | Yes | No | No |
Rheumatobates | 6 | Yes | Yes | No |
Gerridae generally inhabit surfaces of calm waters. The majority of water striders inhabit freshwater areas, with the exception of
Diet
Gerrids are aquatic predators and feed on invertebrates, mainly spiders and insects, that fall onto the water surface.[16] Water striders are attracted to this food source by ripples produced by the struggling prey. The water strider uses its front legs as sensors for the vibrations produced by the ripples in the water. The water strider punctures the prey item's body with its proboscis, injects salivary enzymes that break down the prey's internal structures, and then sucks out the resulting fluid. Gerrids prefer living prey, though they are indiscriminate feeders when it comes to terrestrial insect type.[20] Halobates, which are found on open sea, feed off floating insects, zooplankton, and occasionally resort to cannibalism of their own nymphs.[16] Cannibalism is frequent and helps control population sizes and restrict conflicting territories. During the non-mating season when gerrids live in cooperative groups, and cannibalism rates are lower, water striders will openly share large kills with others around them. Some gerrids are collectors, feeding off sediment or deposit surface.
Predators
Gerrids, or water striders, are preyed upon largely by birds and some fish.
Parasites
Several
Dispersal
Sudden increases in salt concentration in the water of gerrid habitats can trigger migration of water striders. Water striders will move to areas of lower salt concentration, resulting in the mix of genes within
Mating behavior
Sex discrimination in some Gerridae species is determined through communication of ripple
Social behavior
Gerridae are territorial insects and make this known by their vibration patterns. Both female and male adult Gerridae hold separate territories, though usually the male territories are larger than the female.[14] During the mating season, gerrids will emit warning vibrations through the water and defend both their territory and the female in it. Even though gerridae are very conspicuous, making their presence known through repel signals, they often live in large groups.[20] These large groups usually form during the non-mating season since there is less need to compete. Instead of competing to reproduce, water striders can work together to obtain nutrition and shelter outside of the mating season. Water striders will attempt to disperse when these groups become too dense. They do so by flying away or cannibalizing.
In popular culture
- In the video game Super Mario 64, in the level Wet-Dry World, there are enemies named Skeeter that are based on water striders and their movement. The name comes from "water skeeter", an alternative name for water striders.[25]
- In the 2002 film bioterrorists to have bacteria that can spread from person to person, causing severe dehydration and instant death.[26]
See also
- Veliidae (Smaller water strider)
- Animal locomotion on the water surface
- Denny's paradox
- List of Gerridae genera
References
- ^ a b Schuh R.T., Slater J.A. (1995). True Bugs of the World (Hemiptera: Heteroptera). Classification and Natural History. Cornell University Press, Ithaca, New York, USA. 336 pp.
- ^ Lancaster, J.B.; Briers, R., eds. (2008). Aquatic insects: challenges to populations. CABI. pp. 23, 270, 284.
- ^ S2CID 86774669.
- ^ a b c d e f g Ward, J.V. (1992). Aquatic Insect Ecology: 1. Biology and habitat. New York: Wiley & Sons. pp. 74, 96, 172, 180.
- ^ .
- .
- S2CID 56016772.
- ^ a b c d Merrit, R.; Cummins, K. (1996). An Introduction to the Aquatic Insects of North America. Kendall/Hunt Pub. Co. pp. 275–282.
- ^ a b Slater, J (1995). True Bugs of the World (Hemiptera: Heteroptera). Comstock Pub. Associates. pp. 1–15.
- JSTOR 3545355.
- .
- ^ .
- JSTOR 1943013.
- ^ a b c d e f g h Koga, Hayashi. 1991. Territorial behavior of both sexes in the water strider Metrocoris histrio (Hemiptera: Gerridae) during the mating season. Journal of Insect Behavior, Volume 6 (1).
- ^ Black, Tyler (December 2019). "The effects of a simulated spill of diluted bitumen on invertebrates in a boreal lake environment". MSC Thesis.
- ^ ISBN 0-85198-782-6.
- ^ doi:10.1201/9780203507810.ch5. Archived from the original(PDF) on 2011-08-20.
- ^ Klingenberg, C. 1996. Individual Variation of Ontogenies: A Longitudinal Study of Growth and Timing. Evolution, Volume 50 (6). Evolution
- ^ S2CID 86774669.
- ^ a b c d e f Stonedahl, Lattin. 1982. The Gerridae or Water Striders of Oregon and Washington (Hemiptera:Heteroptera), Oregon State University, Pp 1-36. Gerridae
- NaCl concentrations. European Journal of Entomology, 104(3), Pp 377-383. Dispersal
- ^ Harada, T., Tabuchi, R., & Koura, J. 1997. Migratory syndrome in the water strider Aquarius paludum (Heteroptera: Gerridae) reared in high versus low nymphal densities. European Journal of Entomology, 94(4), Pp 445-452. Density and Migration
- ^ Blanckenhorn, W. 1991. "Fitness consequences of foraging success in water striders (Gerris remigis; Heptroptera; Gerridae)" Behavioral Ecology, Volume 2 (1).Foraging
- ^ a b Carcamo, Spence. 1994. Kin Discrimination and Cannibalism in Water Striders (Heteroptera: Gerridae): Another Look. Oikos Volume 70 (3).Cannibalism
- ^ "Super Mario Wiki". June 21, 2023.
- ^ "The Tuxedo". RoberEbert.com. September 27, 2002. Retrieved January 21, 2024.