No wonder veterinarians garner such respect—they treat a plethora of patients, none of which can describe their symptoms. And aquarium veterinarians take that to the next level.

Imagine treating a pregnant seal, a wounded shark and an anorexic penguin, all in the course of a day. Aquarium veterinarians are often responsible for the health of 20 thousand animals or more—that’s a virtual town’s worth of creatures, ranging from mammals and birds to fish and invertebrates.

To appreciate the challenges, just look at anesthesia. Whereas mammals and birds inhale anesthetic from air, fish need it dissolved in the water they breathe. And as for occupational hazards, a veterinarian might avoid a shark’s mouth only to be shocked by an electric eel.

So next time you visit the aquarium, give some props to the team caring for the life aquatic.