noun
reef manta ray; Manta alfredi
A species of manta ray found in tropical and subtropical waters, smaller than the giant oceanic manta ray.
ダイバーはナンヨウマンタと一緒に泳ぐのを楽しみにしていた。
The divers were looking forward to swimming with the reef manta rays.
Refers to the giant oceanic manta ray (Manta birostris), which is larger and more pelagic than the reef manta ray.
From 南洋 (South Seas) + マンタ (manta), a loanword from English or Spanish.