Halobates

Last updated

Halobates
Temporal range: Ypresian–Present
Halobates keyanus.jpg
Halobates hayanus (zoological specimen seen from above with first leg pair not visible and remaining moved towards the rear)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Suborder: Heteroptera
Infraorder: Gerromorpha
Superfamily: Gerroidea
Family: Gerridae
Genus: Halobates
Eschscholtz, 1822
Species

More than 40, see list

Halobates or sea skaters are a genus with over 40 species of water striders. Most Halobates species are coastal and typically found in sheltered marine habitats (a habitat where a few other genera of water striders also live), but five live on the surface of the open ocean and only occur near the coast when storms blow them ashore. These are the only known truly oceanic, offshore insects. [1] [2] [3] They are found in tropical and subtropical marine habitats around the world, with a single species recorded in rivers a few kilometers upstream from the ocean. [1] Halobates are generally very common. [2]

Contents

They were first collected by Johann Friedrich von Eschscholtz, a doctor who was part of a Russian expedition aboard the Rurik between 1815 and 1818. [2] [4]

A fossil species H. ruffoi is known from 45 million year old deposits in Verona, Italy. [5]

Close relatives of the genus include Austrobates and Asclepios . [6]

Appearance

Two Halobates on the shore of Oahu, Hawaii, with upper individual facing left and lower facing right Halobates sp. (Heteroptera Gerridae), 20 August 2011, Castle Beach, Kailua (Oahu), Hawaii03.jpg
Two Halobates on the shore of Oahu, Hawaii, with upper individual facing left and lower facing right

They are small insects with a body that is up to 6.5 mm (0.26 in) long and 3 mm (0.12 in) broad, [1] and a leg span up to at least 15 mm (0.59 in). [2] They lack wings, have long antennae, short front legs used for catching prey (and, in the male, for holding the female during mating), long middle legs used for propulsion, and somewhat shorter rear legs used for steering. The nymphs resemble miniature versions of the adult. The sexes are quite similar, except that males are thinner than females and have the rear part of the body modified into genitalia, and when gravid the females may have a notably plump abdomen. The various species closely resemble each other in general appearance. [1]

Range and abundance

A group of the coastal Halobates matsumurai at the Kujuku Islands, Japan Aggregation of sea skaters.png
A group of the coastal Halobates matsumurai at the Kujūku Islands, Japan

Halobates are found in tropical and subtropical marine habitats around the world. They generally prefer temperatures of 24–28 °C (75–82 °F), are infrequent below 20 °C (68 °F) and only exceptionally recorded in waters less than 15 °C (59 °F). [1] [2] The coastal species are largely restricted to the Indo-Pacific region, with the exception of H. robustus from the Galápagos Islands. Some of these coastal species have very small ranges, often restricted to a single archipelago, while others are more widespread. They primarily occur near mangrove or other marine plants. [2] A single species, H. acherontis, has been recorded in rivers a few kilometers upstream from the ocean. [1] The absence of coastal species in the Atlantic region may in part be explained by Trochopus . That genus of veliid water striders inhabit coastal mangrove areas in the Atlantic region; the same niche inhabited by coastal Halobates in the Indian and Pacific oceans. [2]

The five offshore, pelagic species are H. micans, H. germanus, H. sericeus, H. splendens and H. sobrinus, of which the last four are found in the Indian and/or Pacific Oceans. H. micans has a circumglobal range, occurring offshore in warmer seas around the world from about 40° north to 40° south, and it is the only one found in the Atlantic Ocean, including the Caribbean. [1] [7]

Their occurrences are generally patchy, but where found they can be very common. During scientific surveys with relatively fast-moving surface nets, they are caught in more than 60% of the tows (less in slow-moving tows, likely because of their ability to avoid them). [2] Studies show that densities locally can be as high as 1 individual per 19 m2 (200 sq ft) in the oceanic species, [8] and 120 individuals per m² (11 per sq ft) in breeding aggregations of the coastal species. [1]

Behavior and predators

They are predators, with coastal species feeding mainly on land-living insects that have fallen into the water. [1] Less is known about the feeding of the oceanic species, but they appear to mostly eat zooplankton, with other recorded items being floating insects, fish eggs and larvae, and dead jellyfish. [1] [3] Small prey is caught and eaten by a single Halobates, but larger prey such as small fish may be eaten by three or four Halobates at once. Adults may cannibalize their own nymphs, and old nymphs cannibalize young nymphs, but generally they do not eat their own age class. [1] Some species prefer struggling prey over immobile prey, but in other species, it is the other way around. [1] The feeding behavior of the newly-hatched nymphs is unknown, as aquarium kept individuals refused to eat the various organisms that older captive nymphs and adults will eat (for example, dead fruit flies). This has resulted in speculations that the newly-hatched nymphs might feed on organic-rich surface film. [1] Halobates may catch aquatic prey just below the surface with their front legs, but do not dive. [1] [3] They are very fast and can reach speeds of 1 m (3.3 ft) per second. [2]

The coastal species lay their eggs close to the water surface on rocks, plants, and other structures near the shore, while the oceanic species attach their egg masses on floating objects such as cuttlebone and feathers. [1] [2] Each female lays 1–20 whitish or translucent eggs that each measure about 1 mm (0.04 in) long and half that wide. They may hatch just above or just below the surface. [2] In recent decades the oceanic species have been documented laying their eggs on floating plastic waste, which potentially may disrupt the marine food chain, as the Halobates (now with access to more surfaces for breeding) may become far more common than usual. [9] In one extreme case, a plastic gallon jug was found to be covered by 15 layers of eggs, equalling about 70,000 in total. [2]

Some species of storm petrel actively feed on Halobates, sometimes splashing the water with their feet to attract or detect sea striders. [10] Other seabirds (especially noddies) and a range of surface-feeding fish will also eat them. [1] [9]

A live specimen of the pelagic species Halobates sericeus Halobates sericeus.jpg
A live specimen of the pelagic species Halobates sericeus

Open research questions

Apart from understanding how exactly Halobates sp. came to be the only genus of insects to live on the open ocean – in spite of insects making up the majority of all animals – those animals offer unique research questions that could have applications in materials sciences. For example, it is still unknown how they can move on the water surface without slipping, but yet their legs are capable of effortlessly detaching from the surface in order to jump.

Incapable of diving or hiding, Halobates must protect themselves from ultraviolet radiation. Although it is known that the cuticle of Halobates sericeus filters more than 99.9998 percent of the UV radiation at the 280 nm wavelength, the chemical properties that confer this protection are still unknown. [11]

Related Research Articles

<span class="mw-page-title-main">Hemiptera</span> Order of insects often called true bugs

Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera.

<span class="mw-page-title-main">Reduviidae</span> Family of insects

The Reduviidae is a large cosmopolitan family of the suborder Heteroptera of the order Hemiptera. Among the Hemiptera and together with the Nabidae almost all species are terrestrial ambush predators; most other predatory Hemiptera are aquatic. The main examples of nonpredatory Reduviidae are some blood-sucking ectoparasites in the subfamily Triatominae. Though spectacular exceptions are known, most members of the family are fairly easily recognizable; they have a relatively narrow neck, sturdy build, and a formidable curved proboscis. Large specimens should be handled with caution, if at all, because they sometimes defend themselves with a very painful stab from the proboscis.

<span class="mw-page-title-main">Gerridae</span> Family of true bugs

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, water gliders, water skimmers or puddle flies. Consistent with the classification of the Gerridae as true bugs, gerrids have mouthparts evolved for piercing and sucking, and distinguish themselves by having the unusual ability to walk on water, making them pleuston (surface-living) animals. They are anatomically built to transfer their weight to be able to run on top of the water's surface. As a result, one could likely find water striders present in any pond, river, or lake. Over 1,700 species of gerrids have been described, 10% of them being marine.

<span class="mw-page-title-main">Coreidae</span> Family of insects

Coreidae is a large family of predominantly sap-sucking insects in the Hemipteran suborder Heteroptera. The name "Coreidae" derives from the genus Coreus, which derives from the Ancient Greek κόρις (kóris) meaning bedbug.

<span class="mw-page-title-main">Veliidae</span> Family of true bugs

Veliidae is a family of gregarious predatory insects in the suborder Heteroptera. They are commonly known as riffle bugs, small water striders, or broad-shouldered water striders because the segment immediately behind the head is wider than the rest of the abdomen. The genus Rhagovelia is also referred to as a ripple bug.

<i>Geocoris</i> Genus of true bugs

Geocoris is a genus of insects in the family Geocoridae. Commonly known as big-eyed bugs, the species in Geocoris are beneficial predators, but are often confused with the true chinch bug, which is a pest. There are more than 140 described species in Geocoris.

<span class="mw-page-title-main">Gerromorpha</span> Infraorder of true bugs

The Gerromorpha comprise an infraorder of insects in the "true bug" order Hemiptera. These "typical" bugs are commonly called semiaquatic bugs or shore-inhabiting bugs. The Ochteroidea (infraorder Nepomorpha are also found in shore habitat, while the Gerromorpha are actually most often encountered running around on the water surface, being kept from sinking by surface tension and their water-repellent legs. Well-known members of the Gerromorpha are the namesake Gerridae.

<span class="mw-page-title-main">Neuston</span> Organisms that live at the surface of a body of water

Neuston, also called pleuston, are organisms that live at the surface of a body of water, such as an ocean, estuary, lake, river, or pond. Neuston can live on top of the water surface or may be attached to the underside of the water surface. They may also exist in the surface microlayer that forms between the top side and the underside. Neuston have been defined as "organisms living at the air/water interface of freshwater, estuarine, and marine habitats or referring to the biota on or directly below the water’s surface layer."

<i>Gerris lacustris</i> Species of true bug

Gerris lacustris, commonly known as the common pond skater or common water strider, is a species of water strider, found across Europe.

<i>Aquarius remigis</i> Species of true bug

Aquarius remigis, known as the common water strider, is a species of aquatic bug. It was formerly known as Gerris remigis, but the subgenus Aquarius was elevated to generic rank in 1990 on the basis of phylogenetic analysis. Aquarius remigis is found throughout North America, but is most prevalent in the mid-west of the United States.

<i>Aquarius najas</i> Species of true bug

Aquarius najas, also known as the river skater, is a European species of water strider. It was formerly known as Gerris najas, but the subgenus Aquarius was elevated to generic rank in 1990 on the basis of phylogenetic analysis.

<i>Abedus</i> Genus of true bugs

Abedus is a genus of giant water bugs found in freshwater habitats in southern United States, Mexico and Central America. Sometimes called ferocious water bugs, these brown insects typically are between 2.3 and 4 cm (0.9–1.6 in) long, although A. immaculatus only is about 1.3–1.4 cm (0.51–0.55 in), making it the smallest North American belostomatid and possibly worthy of separation in its own genus. Otherwise the different Abedus species are very similar and can often only be separated with a microscope. They will bite in self-defense, which is painful but not dangerous.

<i>Notonecta undulata</i> Species of true bug

Notonecta undulata, also known by the common name grousewinged backswimmer, are from the family Notonectidae and the insect suborder Heteroptera. They are a type of hemipteran or true bug. These aquatic insects typically spend their time at the water's surface, using their abdomen and legs to cling to the underside of the surface tension. The Grousewinged backswimmer can be found in both lotic and lentic environments; however, they typically prefer small ponds and lakes where the water is slow-moving with less current. They swim upside down looking for prey. Once they stop swimming they float back up to the surface. These insects can be distinguished from water boatman or Corixidae by their segmented beak and front legs. Water boatman have highly modified front legs whereas backswimmers do not. Backswimmers are distributed across a broad range throughout North America. However, the species Notonecta undulata has only been documented and studied in southern Manitoba, Saskatchewan, Alberta and the western United States. N. undulata differs from other backswimmers by their antennae and size. They are approximately 10–12 mm long, and their antennae are 4 segmented.

<i>Lethocerus patruelis</i> Species of true bug

Lethocerus patruelis is a giant water bug in the family Belostomatidae. It is native to southeastern Europe, through Southwest Asia, to Pakistan, India and Burma. It is the largest European true bug and aquatic insect. Adult females are typically 7–8 cm (2.8–3.1 in) long, while the adult males are 6–7 cm (2.4–2.8 in).

Deraeocoris brevis is a species of predatory plant bug in the family Miridae. It is native to North America where it feeds on plant pests in apple and pear orchards.

<i>Abedus herberti</i> Species of true bug

Abedus herberti, the toe biter or ferocious water bug, is a species of giant water bug in the family Belostomatidae. It is native to streams, especially in highlands, in Arizona, New Mexico and Utah in the United States and in northwestern Mexico. Adults are typically 2 to 4 cm (0.8–1.6 in) long. The species is flightless, but may move overland between water sources. It will bite in self-defense, which is painful but not dangerous.

Gerris buenoi is a species of water strider that belongs to the family Gerridae. It was first identified in 1911 and is native to continental USA and Canada. Individuals of this species are small in size and have modified appendages, allowing them to float and "skate" along the surface of the water. G. buenoi can be found near the shoreline of freshwater ponds and small lakes, where they hunt for terrestrial insects that have fallen into the water.

<i>Halobates micans</i> Species of true bug

Halobates micans is a species of water strider in the family Gerridae. It is one of five Halobates species that live on the surface of the open ocean, only occurring near the coast when storms blow them ashore. Unlike the others that are restricted to the Indian and/or Pacific Oceans, H. micans is circumglobal, occurring offshore in warmer seas around the world. It is the only Halobates species found in the Atlantic Ocean where it ranges from about 40° north to 40° south.

<i>Hermatobates</i> Genus of true bugs

Hermatobates is a genus of wingless marine bugs placed as the sole genus in the family Hermatobatidae that are sometimes known as coral-treaders. They are quite rare and known only from coral reefs in the Indo-Pacific region. During low tide, they move over the water surface not unlike the more familiar water-striders around coral atolls and reefs and stay submerged in reef crevices during high tide.

<span class="mw-page-title-main">Ocean surface ecosystem</span>

Organisms that live freely at the ocean surface, termed neuston, include keystone organisms like the golden seaweed Sargassum that makes up the Sargasso Sea, floating barnacles, marine snails, nudibranchs, and cnidarians. Many ecologically and economically important fish species live as or rely upon neuston. Species at the surface are not distributed uniformly; the ocean's surface harbours unique neustonic communities and ecoregions found at only certain latitudes and only in specific ocean basins. But the surface is also on the front line of climate change and pollution. Life on the ocean's surface connects worlds. From shallow waters to the deep sea, the open ocean to rivers and lakes, numerous terrestrial and marine species depend on the surface ecosystem and the organisms found there.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Cheng, L. (1985). "Biology of Halobates (Heteroptera: Gerridae)". Annual Review of Entomology. 30 (5): 111–135. doi:10.1146/annurev.en.30.010185.000551. S2CID   86774669.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 Andersen N.M.; L. Cheng (2004). "The marine insect Halobates (Heteroptera: Gerridae): Biology, adaptations, distribution, and phylogeny". Oceanography and Marine Biology. Oceanography and Marine Biology: An Annual Review. Vol. 42. pp. 119–180. doi:10.1201/9780203507810. ISBN   978-0-8493-2727-8.
  3. 1 2 3 Marine Insects Archived 2009-10-03 at the Wayback Machine . Halobates Life. Retrieved on 9-09-2009.
  4. ↑ Herring, Jon L (1961). "The genus Halobates (Hemiptera: Gerridae)" (PDF). Pacific Insects. 3 (2–3): 223–305.
  5. ↑ Møller, AN; A Farma; A Minelli; G Piccoli (1994). "A fossil Halobates from the Mediterranean and the origin of sea skaters (Hemiptera, Gerridae)". Zoological Journal of the Linnean Society. 112 (4): 479–489. doi:10.1111/j.1096-3642.1994.tb00332.x.
  6. ↑ Andersen, N.; Foster, W.A. (1992). "Sea skaters of India, Sri Lanka, and the Maldives, with a new species and a revised key to Indian Ocean species of Halobates and Asclepios (Hemiptera, Gerridae)". Journal of Natural History. 26 (3): 533–553. Bibcode:1992JNatH..26..533A. doi:10.1080/00222939200770341.
  7. ↑ Cheng, L. (1975). Insecta Hemiptera: Heteroptera, Gerridae, Genus Halobates. Fich. Ident. Zooplancton 147 (PDF).
  8. ↑ Stoner, A.W.; Humphris, S.E. (1985). "Abundance and distribution of Halobates micans (Insecta : Gerridae) in the northwest Atlantic". Deep Sea Research Part A. Oceanographic Research Papers. 32 (6): 733–739. Bibcode:1985DSRA...32..733S. doi:10.1016/0198-0149(85)90076-7.
  9. 1 2 Big rise in North Pacific plastic waste BBC
  10. ↑ Cheng, L.; Spear, L.B.; Ainley, D.G. (2010). "Importance of marine insects (Heteroptera: Gerridae, Halobates spp.) as prey of eastern tropical Pacific seabirds" (PDF). Marine Ornithology. 38: 91–95.
  11. ↑ Cheng, Lanna; Mishra, Himanshu (2022-04-13). "Why did only one genus of insects, Halobates, take to the high seas?". PLOS Biology. 20 (4): e3001570. doi: 10.1371/journal.pbio.3001570 . PMC   9007337 . PMID   35417455. S2CID   248154708.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.