Distribution and Characteristics of Halobates germanus Population in the Red Sea

Mahadik, Gauri A.; Agustı́, Susana; Duarte, Carlos M.

doi:10.3389/fmars.2019.00408

Cited by 3 publications

(1 citation statement)

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“…Individuals of the species Halobates germanus White, 1883 were collected from an offshore sampling station in the Central Red Sea (22°20′32.6″N 39°05′23.6″E) during day time using a neuston net towed at 1-2 knots. H. hayanus White, 1883 individuals were collected from a mangrove ecosystem near the shore of the Central Red Sea (22°20′32.6″N 39°05′23.6″E) 77 . The number of individuals caught offshore was always low (2-8 individuals per tow), thereby restricting their inclusion to selected experiments.…”

Section: Methodsmentioning

confidence: 99%

Superhydrophobicity and size reduction enabled Halobates (Insecta: Heteroptera, Gerridae) to colonize the open ocean

Mahadik

Hernández-Sánchez

Arunachalam

et al. 2020

Sci Rep

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Despite the remarkable evolutionary success of insects at colonizing every conceivable terrestrial and aquatic habitat, only five Halobates (Heteroptera: Gerridae) species (~0.0001% of all known insect species) have succeeded at colonizing the open ocean-the largest biome on earth. this remarkable evolutionary achievement likely required unique adaptations for them to survive and thrive in the challenging oceanic environment. For the first time, we explore the morphology and behavior of an open-ocean Halobates germanus and a related coastal species H. hayanus to understand mechanisms of these adaptations. We provide direct experimental evidence based on high-speed videos which reveal that Halobates exploit their specialized and self-groomed body hair to achieve extreme water repellence, which facilitates rapid skating and plastron respiration under water. Moreover, the grooming behavior and presence of cuticular wax aids in the maintenance of superhydrophobicity. further, reductions of their body mass and size enable them to achieve impressive accelerations (~400 ms −2) and reaction times (~12 ms) to escape approaching predators or environmental threats and are crucial to their survival under harsh marine conditions. These findings might also inspire rational strategies for developing liquid-repellent surfaces for drag reduction, water desalination, and preventing bio-fouling. The proliferation of invertebrate taxa in the ocean during the Cambrian explosion eventually led to their colonization on land, where insects first appeared ~479 million years (Myr) ago 1 to eventually dominate various terrestrial ecosystems 2,3. With an estimated ~5.5 million extant species 4 , insects comprise 80% of all known metazoans, making them the dominant animals on Earth 5. Despite their successful colonization of both terrestrial and aquatic habitats, only a small number of insects (~0.5% of total species) have been found in marine environments, mostly in nearshore habitats, with only a handful of Halobates (~0.0001% of insect species) ultimately colonizing the open ocean, the largest biome on Earth 6-8. Halobates is a member of the family Gerridae, which evolved nearly 55 Myr ago 6,9. Some 48 species of Halobates are known to occur in tropical and subtropical seas and oceans that cover more than 70% of the Earth's surface. Most of these species are found in mangrove and near-shore habitats and two even live in freshwater, whereas five live on the surface of the open ocean. The fact that only a mere 0.0001% of insect species were able to colonize the largest habitat on Earth indicates that there must have been formidable environmental challenges for oceanic Halobates to overcome in order to live there. Halobates most likely evolved from an estuarine or mangrove ancestor that was washed out to the sea and became adapted to survive in the open ocean 8,10. Freshwater relatives of sea-skaters are often found on placid water bodies such as small ponds, lakes or slow-flowing streams, whereas many tropical species can be found

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Section: Methodsmentioning

confidence: 99%