Why are ostariophysans important among freshwater fishes?

Ostariophysans are highly significant as they constitute the majority of freshwater fish species worldwide, accounting for approximately 8,000 species—nearly one-fourth of all known bony fishes. Their dominance across diverse freshwater habitats, from mountain streams to subterranean caverns, is largely attributed to two evolutionary advantages:12

• Acute Hearing: Most members of this superorder possess the Weberian apparatus, a specialized chain of bones that connects the swim bladder to the inner ear. This structure significantly enhances their perception of sound compared to other fish groups.132
• Chemical Communication: They utilize a unique warning system based on chemical secretions, which serves as an effective survival mechanism.2

Beyond their ecological success, ostariophysans—which include familiar species like minnows, carps, piranhas, and catfishes—are vital to humans as a major global food source and popular subjects for tropical aquariums.1