Opal Cling Goby

Interesting Info

• The Opal Cling Goby is found in Queensland and Northern Territory coastal streams, usually close to rainforest or rocky headwaters.
• Males are especially colourful, with iridescent blue-green and opal-like flashes along their bodies, contrasted with black bands and bright fins. Females are smaller and more cryptically patterned in browns and greys.
• Their pelvic fins are fused into a suction disc, allowing them to cling tightly to rocks in fast-flowing streams.
• They are amphidromous: adults live and breed in freshwater streams, but their tiny larvae drift downstream to the sea, where they develop before returning upstream as juveniles.
• Opal Cling Gobies feed on algae and biofilm scraped from rocks, using their specialised teeth and scraping jaws.
• Their bright colours make males highly visible, especially when displaying to females during courtship.
• They prefer clear, fast-flowing, shallow streams with rocky beds and lots of sunlight, which encourages algal growth.
• Breeding usually takes place in the wet season, with males defending small territories and cleaning flat stones where females attach eggs. The males guard these eggs until they hatch.
• They are ecologically important as algae grazers, helping keep rocks clean and maintaining the balance of stream ecosystems.
• Lifespan is short, typically 1–2 years, which is common for small stream gobies.