Blue chromis

Chromis cyanea

''Chromis cyanea'', also known as Blue Reef Chromis, or just Blue Chromis is a fish from the western Atlantic Ocean that occasionally is kept in marine aquariums.
Blue Reef Chromis Sep 13, 2017. Seen in Oil Slick Leap, Bonaire. 
Body purple or bright blue, paler below, with black stripe. Black margin on spinous dorsal fin, upper and lower lobes of caudal fin and front of anal fin; no black spot at pectoral base. Adults are common above deep outer reefs and feeds in aggregations of the small zooplankton, primarily copepods .
http://www.fishbase.org/summary/Chromis-cyanea.html Blue chromis,Caribbean Netherlands,Chromis cyanea,Geotagged,Summer

Appearance

A small marine fish that reaches 15 cm in length. It is typically blue with a black margin on its back.

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Taxonomy
KingdomAnimalia
DivisionChordata
ClassActinopterygii
OrderCichliformes
FamilyPomacentridae
GenusChromis
SpeciesC. cyanea