🐠 Blue Gudgeon Dartfish (Ptereleotris heteroptera)
A Pale Blue-Green Body With a Distinctive Black Tail Spot • More Confident and Visible in Small Groups • A Peaceful Open-Water Hoverer
 
📋 The Blue Gudgeon Dartfish, also known as the Blacktail Goby or Blacktail Dartfish, is an elegant, elongated marine fish with a pale blue-green body that fades toward a lighter belly, topped off with a distinctive black spot right at the centre of its tail.
It comes from the reefs of Fiji and the wider Indo-Pacific, spending its time hovering in the water column just above the substrate, darting after passing zooplankton before retreating to shelter at the first sign of danger. Every Blue Gudgeon Dartfish we ship is feeding well.
This is a peaceful, fully reef-safe species, naturally quite timid and doing noticeably better in pairs or small groups introduced together, becoming visibly more confident and less secretive the larger the group. It benefits from a sandy substrate to rest near and burrow into occasionally, along with plenty of loose coral rubble and rockwork for shelter. It's also a notorious jumper, so a tightly fitted lid is essential. It reaches up to 12.7cm, so a 115L tank suits it well.
 
💡 Highlights
🎨 Distinctive Black Tail Spot: Bold marking against a pale blue-green body
🐟 Best Kept in Small Groups: Noticeably more confident and visible with 2-4 individuals
🌿 Fully Reef Safe: Won't bother fish, corals, or invertebrates
⚠️ A Notorious Jumper: A tightly fitted lid is essential
🧠 Beginner Friendly: Easy care once paired with peaceful tankmates