Blackfin dartfish

The blackfin dartfish (Ptereleotris heteroptera) is a marine fish of the family Microdesmidae (dartgobies), native to reefs of the Indo-Pacific. It has a slender, pale blue-green body with a distinctive dark spot on the tail fin. It hovers in the water column above the substrate, darting into a burrow when threatened. It is a peaceful, somewhat timid fish that can be kept singly, in pairs, or in small groups where space allows. It coexists well with other calm reef fish and is safe with corals and invertebrates. A reef aquarium with a sandy bottom, rockwork with escape burrows, and a tight-fitting lid is important, as these fish are notorious jumpers. It feeds on zooplankton drifting in the current and accepts small frozen foods such as mysis and enriched brine shrimp offered frequently. Captive breeding is not commonly achieved.