Catfish form part of the Order Siluriformes, which includes 24 freshwater families of catfish, and 1 coastal water family. This family, Plotosidae, is represented in Sydney by two species; the Striped Catfish and the Estuary Catfish.
The Striped Catfish (Plotosus Lineatus) school in large tight groups which move together as one ball and from a distance can look like a moving rock or log. The larger the fish get, the less they form into these tight schools. They can cause severe pain if they attack as they contain venomous spines within their dorsal and pectoral fins. We are lucky to see these schools of Striped Catfish fairly regularly in Sydney across a number of sites.