Venom apparatus:
(1) 2 pectoral fin spines
(2) 1 dorsal fin spine
(3) axillary venom glands
The cartilaginous spines are extended if the fish is excited or handled.
Marine catfish tend to have a more potent toxin.
Clinical features:
(1) The venomous spine usually penetrates the skin of an unprotected hand when the fish is handled, but it can also penetrate the foot or other skin surface.
(2) There is immediate pain, stinging or throbbing at the point of penetration which then extends up the limb.
(3) Normally the pain last 30 to 60 minutes but can last up to 48 hours.
(4) Ischemia may develop in the surrounding tissues, with pallor followed by cyanosis.
(5) Marked edema may develop in the region.
(6) Muscle spasm or fasciculations may develop in the extremity.
Complications:
(1) damage to radial or ulnar artery
(2) damage to radial or ulnar nerve with a peripheral neuropathy
(3) secondary infection
(4) lymphadenopathy or lymphangitis
(5) gangrene
(6) tetanus
(7) bleeding from the puncture wound
(8) hypotension
(9) respiratory distress
