The venomous Indo-Pacific fish with venomous spines that is popular in aquariums is the lionfish. Lionfish are marine fish in the genus Pterois, recognized by their dramatic fan-like fins, bold bands, and elongated dorsal, anal, and pelvic spines.
Their spines deliver venom when pressed into a person or predator, making them different from poisonous fish that are dangerous mainly when eaten. Lionfish venom can cause intense pain, swelling, numbness, nausea, and other systemic symptoms. Serious reactions are uncommon in healthy adults, but stings can be dangerous, especially for allergic people.
Lionfish are also associated with a major marine-invasion story. Pterois volitans and Pterois miles became established in the western Atlantic, Caribbean, and parts of the Mediterranean after introduction from the aquarium trade. Triggerfish, angelfish, and clownfish may be aquarium favorites, but they do not match the question’s combination of Indo-Pacific origin, venomous spines, and the lionfish identity.