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Which ostariophysan species can cause painful injuries?

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knifefish — ostariophysan Knifefish, or featherback (Xenomystus nigri)

Within the superorder Ostariophysi, several species are capable of inflicting painful injuries on humans, primarily through the use of venomous spines or electrical discharges.12

Many catfishes possess hardened fin rays, or spines, in their dorsal and pectoral fins that can puncture human skin. In certain groups, these spines are associated with venom glands, which can cause significant pain when the fish is handled or stepped on. These venomous species include:23

Bullheads and madtoms (family Ictaluridae)2
Labyrinthic catfishes (family Clariidae)2
Sea catfishes (families Ariidae and Plotosidae)2

Additionally, some ostariophysans can deliver painful electrical shocks. While many freshwater fish generate electricity, the electric eel (Electrophorus electricus) and the electric catfish (Malapterurus electricus) are notable for developing sufficient voltage to stun humans.2

It is important to note that while these injuries are often painful, they are rarely fatal. Other ostariophysans, such as piranhas, possess powerful jaws and strong teeth that serve as effective weapons, though they are distinct from the venomous or electric mechanisms described above.2