Oncaea is a genus of copepods. The genus contains bioluminescent species. Unlike other bioluminescent copepods, Oncaea have an internal (non-secreted) bioluminescence. Oncaea contains the following species:

A number of nomina dubia and species inquirendae have also been described in Oncaea:

Nomina dubia

• Oncaea neobscura Razouls, 1969
• Oncaea obscura Farran, 1908
• Oncaea parobscura Shmeleva, 1979

Species inquirendae

• Oncaea bathyalis Shmeleva, 1968
• Oncaea crassimana (Dana, 1849)
• Oncaea frosti Heron, 2002
• Oncaea gracilis (Dana, 1852)
• Oncaea obtusa (Dana, 1852)

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