One of my favorite frozen foods to feed my saltwater fish is frozen mysis shrimp. Almost every fish I have ever kept has instantly recognized the floating white morsels as a meal. I’ve offered them at the same time as flakes (which would otherwise be voraciously eaten if it wasn’t competing with the mysis shrimps), and the fish will swim around the flakes to eat the apparently more tasty mysis.
That made me wonder why this food is so interesting to the fish—which made me wonder—what in the world are mysis shrimp, anyway?
Let’s take a closer look.
There are over 72 species of Mysids. Most of them are freshwater mysids, but there are marine species as well.
We of us commonly call them “shrimps”, and most of the products we buy have the word shrimp listed on the label, but taxonomists would not consider mysids to be true shrimps.
How is that for a fun trivia fact? Especially in a hobby full of people who enjoy using the scientific names of some species.
So the next time you want to impress your aquarium friends, be sure to let them know that mysis have a thoracic pouch (wasn’t that the name of the last movie in the Jurassic Park series?)
Sorry, that was silly–anyway, mysis shrimp have a thoracic pouch (not Jurassic pouch) and they don’t have a free-swimming larval phase.
Glad we cleared that up.
Mysids naturally inhabit coastal zones across the high boreal and Arctic seas. They have also been found to inhabit freshwater northern lakes and the brackish waters of the Caspian Sea.
Some mysis shrimp species inhabit shallow waters in estuaries from the East Coast of Mexico to Florida, USA.
They are really hardy animals and can withstand a wide range of living conditions, with changing temperatures and salinities. Some species prefer the seabed, while others like to live in mid-water or among seagrass and algae.
What do Mysis shrimp eat?
Mysis shrimp are omnivorous and will feed on diatoms, plankton, and copepods. Some species will also eat detritus and algae, but since they are so small, it would take a tankful to make a meaningful contribution as members of the clean-up-crew.
Behavior and Reproduction
Females carry developing young in a marsupium-like pouch at the base of their legs and are able to carry up to 30 fry, but the usual brood is 6 – 7 young at a time.
As soon as the fry are well developed, they are released into the water, and the female prepares her pouch by filling it with a new batch of eggs.
As these shrimp normally reach adult size (1 inch) in about 3 weeks, this leads to a new generation being created every 30 days.
Use as fish food
Mysis shrimp are aquacultured—so it is possible to grow your own food.
I may actually give this a shot. But it is hard to beat the convenience of pulling frozen Mysis out of the freezer, popping out a cube or breaking off a piece of the flat and thawing it out to feed your fish. Mysis shrimp are also available as a freeze-dried product:
Fun facts recap:
- Mysids are not actual shrimps, but their great resemblance brought them the name Mysis shrimp.
- Two mysid species (Mysidopsis bahia and Mysidopsis almyra) have been used like canaries in a coal mine as environmental quality indicators to determine water toxicity across the US East Coast.
- Mysis shrimp are cannibalistic and adults would eat their young if not separated. They may also eat other adults if the shrimp density exceeds a few specimens per gallon.
- Females rear their young like marsupial mammals do (sort of…), in a pouch on their abdomens
A few questions for you:
Have you ever fed mysis shrimp to your fish? Live or frozen? If frozen—do you prefer the cubes or flat packs?