Pufferfish puff up as a defense mechanism to become too large and difficult for predators to swallow, rapidly gulping water (or air if out of water) into a highly elastic, expandable stomach, which also causes their embedded spines to stick out, creating a spiny, intimidating ball. This impressive inflation can increase their size three to four times, making them unappetizing even to predators that might ignore #underwater #ocean #oceanlife #sealife #marinelife #underwaterworld #underwaterphotog