Dwarf Glass Goby (Phenacostethus smithi)

Dwarf Glass Goby (Phenacostethus smithi)

Delicate, ethereal, and utterly mesmerizing — the Dwarf Glass Goby is one of the most unique nano fish available in the hobby. With a near-transparent body that reveals its internal organs and a shimmering iridescent sheen, a school of Phenacostethus smithi moving through a planted aquarium is a sight unlike any other. These tiny gems catch every ray of light, flickering like living crystals as they drift through the water column.

Native to slow-moving and still freshwater habitats in Southeast Asia, the Dwarf Glass Goby is a peaceful, schooling species that thrives in well-planted nano and community tanks. Their rarity in the trade makes them a prized find for dedicated hobbyists.

Highlights

• Stunning transparency — near-clear body with visible internal structures and an iridescent shimmer
• True nano fish — reaches only 2–3 cm (under 1.5 in); ideal for small, planted aquariums
• Peaceful schooling species — best kept in groups of 8+ for natural behaviour and reduced stress
• Rare & sought-after — infrequently available; a standout addition for the serious nano enthusiast
• Mid-water swimmer — occupies the middle column, complementing bottom dwellers and surface fish

Care Guide

• Tank size: 40 L (10 gal) minimum for a small group; larger for schools of 10+
• Temperature: 22–28°C (72–82°F)
• pH: 6.5–7.5
• Water flow: Gentle — replicates their slow-moving natural habitat; avoid strong currents
• Diet: Micro foods essential — baby brine shrimp, micro worms, daphnia, and high-quality micro pellets; mouth is very small
• Tankmates: Other peaceful nano species — small rasboras, nano tetras, pygmy corydoras, freshwater shrimp (adults); avoid any fish large enough to eat them
• Décor: Dense planting with fine-leaved plants (java moss, hornwort, rotala), floating cover, and subdued lighting enhance their natural behaviour and colouration
• Water quality: Sensitive to poor water conditions — regular water changes and a mature, cycled tank are essential

The Dwarf Glass Goby rewards patient, attentive aquarists with a display of living transparency that no other fish can match. If you're curating a premium nano aquascape, this is a species that will stop visitors in their tracks.