Goby

Interesting Info

• The Goby (Sicyopus discordipinnis) is a tiny freshwater fish found only in short, coastal rainforest streams of northern Queensland, making it an Australian endemic with a very restricted range.
• Males are striking, with a dark body and brilliant neon-red stripe running along their flanks, contrasting with bluish fins. Females are more subdued, patterned in browns and greys for camouflage.
• Their pelvic fins are fused into a suction disc, which allows them to cling to rocks in strong currents.
• This species is amphidromous: adults live and spawn in freshwater, but their larvae are swept to sea, spend several months in the plankton, and return as juveniles to migrate back upstream.
• Their diet consists mainly of algae and biofilm scraped from rocks, along with small aquatic invertebrates.
• Like other Sicydiinae gobies, they are important grazers, helping to control algal growth and maintain healthy stream ecosystems.
• They prefer shallow, clear rainforest creeks with rocky beds, riffles, and fast-flowing water — habitats that depend on good rainfall and intact rainforest cover.
• Breeding is thought to occur during the wet season, when females attach eggs under rocks or in crevices, and males guard the clutch until hatching.
• Newly hatched larvae are tiny and drift downstream with floodwaters until they reach the sea. After developing in the ocean, juveniles climb back into streams, sometimes scaling small waterfalls using their suction discs.
• Unlike some cling gobies that are highly territorial, they are often described as social fish, forming small groups on rock faces in fast-flowing creeks.
• Their lifespan is usually 1–2 years, which is typical of small Sicydiinae gobies.