Green Spotted Puffer

The green spotted puffer is a small, brightly patterned pufferfish popular in the freshwater and brackish aquarium trade, though it is not a true freshwater species. Its vivid yellow-green back is marked with irregular black blotches, sharply set off from a clean white belly, giving it a striking two-tone appearance.

Native to brackish estuaries, mangrove creeks, and coastal rivers of South and Southeast Asia, this species requires increasing salinity as it matures, thriving best in brackish to full marine conditions as an adult despite sometimes being sold for freshwater tanks. It is a bold, intelligent, and often aggressive predator with continuously growing beak-like teeth that must be worn down on hard-shelled prey.

• Bright yellow-green back with irregular black spots and blotches
• Sharp contrast between the patterned back and pure white belly
• Golden-yellow eyes and a rounded, blunt head
• No pelvic fins; small fixed beak of fused teeth
• Compact, rounded body rarely exceeding 16 cm

Look-alikes: Ceylon puffer (Dichotomyctere fluviatilis) has a duller, more mottled brown-green pattern; figure-8 puffer (Dichotomyctere ocellatus) is smaller with looping figure-eight markings instead of scattered spots.

Green spotted puffers are native to brackish and estuarine waters across South and Southeast Asia, including river mouths, mangrove creeks, and coastal lagoons from India through Indonesia. Juveniles often occur in lower-salinity water upstream, while adults require higher salinity closer to full seawater strength to remain healthy long-term. They favor structured habitats with roots, submerged vegetation, and soft substrate where they can hunt for buried or sheltering prey. In the wild they tolerate fluctuating salinity typical of tidal estuaries but do poorly in permanently fresh water as they mature.

Green spotted puffers are active, inquisitive hunters that feed primarily on snails, crustaceans, and other hard-shelled invertebrates, using their sharp beak-like teeth to crack shells—a habit that also helps keep their ever-growing teeth worn down. They are territorial and often aggressive toward other fish, including their own species, and are typically kept singly in captivity for this reason. Like other pufferfish, they can inflate with water when threatened and contain tetrodotoxin in their tissues. In the wild they are solitary foragers over mangrove roots and estuarine substrate, using keen eyesight and smell to locate prey hidden in sediment or crevices.