Patricia Bartlett

Reptiles and amphibians make unique pets. They have few emotional demands, but they do have precise physical needs. And because pet reptiles and amphibians are in cages and can't seek food on their own, they depend on you for the right nourishment. Some reptiles and amphibians have considerably long lives, so be prepared for that.

Seeking a koi in top-notch health should be foremost in your mind, even ahead of color and pattern. This requirement becomes especially important if the fish must be shipped by air or ride in a vehicle for several hours to get it home. Such handling, even at its best, can quickly stress out a healthy koi for several days.

Cotton wool or cotton ball disease is a charming name for Saprolegnia — a nasty fungus that grows when bad water quality stresses your koi. Expect to find it when the water contains quantities of uneaten food and when the pond has too many koi for its size. Fungus can attack any weakened portion of a koi, from the skin to the gills.

Sometimes, being a herp owner seems to require more knowledge upfront than you might have. You can discover a lot, however, about what to expect from your herp by watching him as he feeds, sleeps, moves about his cage, and interacts with you. Becoming familiar with herp behavior is a learning curve, but it's not a steep one.

In the wild, reptiles and amphibians (collectively known as herps) tend to be wanderers, moving about during their active time. (Some herps are active at day, some at dawn and/or at dusk, and others during the night.) Herps are pretty basic creatures; when they wander, they're either looking for a spot to thermoregulate (warm up so they can have normal body function, or more rarely, where they can cool down because they're already just a bit too warm); to procreate (if it's breeding season); or to find food.

You have to use your own judgment in selecting your reptile or amphibian, no matter where you buy it. Choose one with bright eyes, an alert demeanor, and no visible injuries; and if you can see the animal eat a food item you can readily obtain, choose that one. An animal that refuses food may not be hungry, may be too stressed to eat, or may have something seriously wrong with it that you can't see.

Collectively, reptiles and amphibians are referred to as herps. That term comes from the Greek word herpes, which literally means crawling things. The term is applied equally to reptiles and amphibians. From herp comes herpetology, the study of crawling things. A person with formal training in herpetology is a herpetologist.

When you're confident that your new koi are healthy after a three-week quarantine, you can finally introduce them to their aquatic castle, whether it's an aquarium or pond. Koi can go directly from quarantine tub to pond if the pH values and temperatures are close (0.2 range for pH, and a 5 degree Fahrenheit difference for temperature).