Adam Blundell M.S.
Author’s Note- this article is not intended to encourage overzealous hobbyists to purchase rays. Rather, this article is intended to describe the husbandry requirements for committed hobbyists with a great desire to care for such wonderful animals. –Adam Blundell
Elasmobranches are fascinating creatures. They have stirred the interest of man for literally thousands of years, and are well documented for hundreds of years in cultural foods, paintings, dances, superstitions, reverence, folklore, fear, respect, and many other forms. In general the word “Shark” conjures up vivid thoughts and feelings. There lesser known kin, the Rays, are every bit as mysterious.
The rays (family Dasyatidae) number about 70 species in six genera. Some of them are not only suitable for home aquaria but can thrive in captive care. This is a big misconception in the hobby where many people think of sharks/rays as large aggressive fish that should be avoided. In fact with their relatively low collection rates they are not removed from the wild in large numbers. Note- but keep in mind many Sharks/Rays are high level predators and are therefore not in large numbers to begin with.
The requirements for many rays are not surprising. These fishes like surface area. That is bottom surface area. So providing a tank with a very long swimming area free of rockwork is important. Very important. This requirement has kept rays out of the spotlight for many years but that is changing. Just a decade ago a 125 gallon aquarium was considered large. Nowdays. you can find a hobbyist with an aquarium over 500 gallons in just about every major city. Having an aquarium 4 feet long was common, and now having a tank 10 feet long is not so rare.
Clean water is also important. Most Rays eat large food items, and produce much waste. Having biological filtration (live rock and live sand) to convert the ammonia quickly into less toxic forms is necessary. Therefore the old thought of “fish only” systems with plastic rocks and trickle filters is fading fast. Currently most advanced hobbyists are keeping Rays in reef tanks with many inhabitants and much life to consume and convert fish waste.
The third most important item for Ray care is safety. Worry not about what damage your Ray will do to your reef, worry about what damage your reef will do to your Ray. Unsuitable tank mates (described below) can damage rays. So can aquascaping. It is very important to secure all rockwork. Tumbling rocks and corals can severely injure a Ray.
Be prepared for a surprise. The average (and even above average) hobbyist views most Rays and Sharks as solitary tank inhabitants. “Oh it will eat that” is the response to just about every tank mate option. Not true. Not surprisingly they often do well with other Rays or even Sharks. But surprisingly they often do well with other reef fishes and ornamental invertebrates. Yes, you read that correctly. Many rays will eat dead fishes, or chopped up shrimp and scallops and octopus and squid… but will live in harmony with other reef fishes and invertebrates. Even smaller fishes, such as many Gobies or Anemonefishes, will do fine with Rays. Cleaning shrimp can become a meal for rays, but if put in the tank before the ray the shrimp will often live peacefully as cleaning shrimp servicing the Ray and remaining free of becoming a meal itself.
Some fishes should be avoided as tank mates for Rays. Not because they are a potential meal for the Ray, but because they will potentially prey on the Ray! Triggerfishes, Eels, and even large Angelfishes can pick on Rays and nibble on their long fleshy tails. This harassment and damage can lead to the death of the ray. Along those same lines invertebrates with large claws (i.e. some lobsters) are also to be avoided.
Proper Species for Captivity
I’m going strictly off the experience of others for this section. The information presented here are the rays I’ve personally seen doing well in captive care, and those well documented by Scott Michael.
Rays Known to do well in captivity:
While the average hobbyist and average aquarium may not be well suited for Rays, the possibility of properly caring for such animals is certainly possible. Some species are well suited for home aquaria. The growing trend for large (over 500 gallon) aquariums enables a larger number of aquarists to keep and care for rays. The key to keeping such animals is advanced planning. By developing an aquarium of the appropriate size and style a home aquarist can provide a long lasting relationship with a variety of Rays.
This article is dedicated to my dear friend Scott Michael. His love for the Elasmobranches is truly inspiring. As the world’s leading authority on the hobbyist's care of these animals he has brought much attention to them in our hobby, the industry, and to conservation efforts. Simply thanking Scott for his contributions in this field would not be enough…
References and Suggested Readings-
Michael, S., (2001) “Aquarium Sharks & Rays”, T.F.H. Publications. Neptune City, New Jersey, USA.
ADAM AND SCOTT- Pictures and Captions
Spotted Ray and Southern Ray- These rays are perfectly suited for the home aquarium. Friendly, mostly reef safe, and very beautiful for the properly designed aquarium.
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Planning Tank- Shown here an aquarist has drawn on his living room wall where the new aquarium will go. Proper planning for a ray tank is incredibly important. This aquarist made sure to design a proper system before cutting out his living room wall.
Raised Reef 3- At first site this reef tank looks like a terrible home for of all things a Bluespotted Ribbontail Ray.
Raised Reef 2- Upon closer inspection you can see that the aquascaping is actually held on a framework above the substrate.
Bluespotted 1- The raised reef allows the Bluespotted Ribbontail Ray to swim over the sandy substrate.
Raised Reef 4- A side view shows the ray coming out from under the rockwork.