Definition of mesopelagic in US English:

mesopelagic

adjective

Biology
  • (of fish and other organisms) inhabiting the intermediate depths of the sea, approximately 650–3,300 feet (200–1,000 m) below the surface.

    ‘many mesopelagic fish species have swim bladders’
    • ‘Indeed, a large number of mesopelagic animals have eyes that permanently view the upward direction for just this reason.’
    • ‘This suggests that directed bioluminescence and the transmission of bioluminescence through gut walls are more important than ambient light for detecting animals at mesopelagic depths.’
    • ‘Because the spectra at mesopelagic depths are quite narrow, light at wavelengths longer or shorter than the wavelength of peak transmission contributes very little to visibility.’
    • ‘Extensive survey data show that the max values of visual pigments of mesopelagic marine fishes are more blue-shifted than those of shallow-water species.’
    • ‘Additional comments are made below regarding the distribution of epipelagic, mesopelagic, and benthopelagic elasmobranchs and teleosts in the upwelling assemblages.’
    • ‘Indeed, the presence of bioluminescence explains several otherwise paradoxical characteristics of mesopelagic body coloration.’
    • ‘For example, pilot whales had smaller group sizes when they fed more on mesopelagic fish and less on mesopelagic cephalopods, and common dolphins had larger groups if they fed on varying types of fish.’
    • ‘Most current knowledge applies to coastal species with benthic adult stages, and it would be exciting (though challenging) to see this work extended to larvae of mesopelagic or deep-sea species.’
    • ‘These species undergo large changes in depth, many traveling from mesopelagic depths to the surface in the evening and then descending before dawn.’
    • ‘Similar events occur in the eyes of mesopelagic shrimps, such as the oplophorids.’
    • ‘Neutrally buoyant ammoniacal cephalopods in the mesopelagic are a limiting case in need of study.’
    • ‘Unfortunately measurements of absorption and scattering coefficients at mesopelagic depths in oceanic waters do not exist.’
    • ‘Rhadinesthes decimus is known primarily as a mesopelagic ocean fish living at depths around 500 m.’
    • ‘Our results indicate that mesopelagic fish pose a stronger predatory threat than invertebrates to overwintering Calanus.’
    • ‘As our understanding of large marine predators increases, the critical role of concentrations of mesopelagic cephalopods in the lives of such species as elephant seals, billfishes and tuna is becoming clear.’
    • ‘The temporal resolutions of the dark-adapted photoreceptors of several species of mesopelagic crustaceans have been described in earlier studies.’
    • ‘The assemblage is characterized by the co-occurrence of epipelagic, mesopelagic and benthopelagic taxa together with neritic taxa.’
    • ‘Tooth morphology in this selection of mesopelagic fishes is quite diverse suggesting that their feeding strategies might be diverse as well.’
    • ‘Indeed, many of the mesopelagic species range far eastward with the Gulf Stream, outside our area and into the eastern Atlantic.’
    • ‘Most mesopelagic species are either red or black and most deep-sea benthic species range from pale yellow to red.’

Pronunciation

mesopelagic

/ˌmezəpəˈlajik/