Along with good water quality, feeding your cherry (neocaridina) shrimp properly is a prime necessity for keeping a successful colony. A good diet makes your colony resilient and better able to face the rigors of living in a small glass box on your desk.
How to feed properly is actually a surprisingly big question. There are lots of opinions and approaches. To avoid cramming everything into one long post, I’ll break it down into four articles:
I. The Basics: An overview of feeding aquarium shrimp (This article)
II. How Cherry Shrimp Eat: The biology and natural feeding behavior of neocaridina shrimp
III. The Edible Aquarium: Promoting biofilm in your shrimp tank
IV. Feeding Cherry Shrimp: Primary foods and special treats (Coming soon)
Shrimp Feeding 101
It’s worth noting that the dietary needs of shrimp were little studied before our little friends made their big splash in the aquarium world, so to speak. Any talk on the subject was almost completely about shrimp BEING food.
With the rise of the shrimp hobby in Asia, Europe, and more recently the US and other parts of the world, our knowledge of shrimp—and what and how they eat—has exploded. Your aquarium is part of advancing science, if you didn’t know!
Shrimp are not Fish
Let’s start with this obvious but important truth. While many newcomers enter the hobby because they are intrigued by keep cherry shrimp, the majority of aquarists got their start with fish. If your only experience is with keeping fish, you’ll have some habits to break.
Here are some differences between fish and shrimp at mealtime:
■ Cherry shrimp don’t beg for food like many aquarium fish do. They won’t swarm the front of the aquarium whenever you pass by, and they won’t waggle adorably trying to swim through the glass to be nearer to their giant-headed food god. Shrimp are much more circumspect and dignified in their comportment … probably because they can’t see us very well.
■ Shrimp eat more slowly than fish. It takes these small crustaceans time to find their food, which they mainly locate by scent, and they tend to settle on it for a lengthy communal feast. The rule for fish is not to feed more than they can consume within two minutes; for shrimp, this figure is two HOURS.
■ Shrimp are very sensitive to spoilage. It may take two hours for your shrimp colony to finish a sizeable meal, but don’t let it stay in the tank much longer! Spoiled food will kill shrimp quickly. Even shrimp that don’t eat the tainted food will suffer as their water quality deteriorates. If perishable food still remains uneaten after four hours, remove it!
Basic Rules for Feeding Cherry Shrimp
#1 Feed frequently. Shrimp graze rather than gobble, so don’t feed too much at one time. Unless you have a seasoned, well-planted aquarium with only a few shrimp, you’ll need to feed them regularly.
Once-a-day feeding is sufficient to maintain a colony, but many hobbyists feed both morning and evening to encourage breeding and help make sure every shrimp gets something to eat.
Some breeder even feed more often than that. To sum up, feeding a light meal twice a day is a good practice … but don’t be afraid of skipping a meal now and then.
#2 Feed small amounts. Don’t feed too much—the stomach of a shrimp is about the size of their eyeball, anecdotally, so hold back. The colony should finish a meal in from one to two hours. More than this and you risk a pond snail population explosion or mass shrimp deaths from spoiled food.
#3 Don’t let food dissolve into the gravel. Because shrimp feed so slowly, pellets and other prepared foods can dissolve, break apart, and filter down into your substrate to cause all kinds of problems. The stale food rots and can poison the water; even stirring up such an ammonia-laden patch of polluted gravel can toxify the tank and trigger shrimp deaths. The thicker the substrate, the more dangerous this can be.
Here are some tips:
• Use a a bare-bottomed tank that keeps food exposed and visible on the glass; if you don’t like that look, try putting in a thin layer of gravel/sand that barely covers the bottom.
• If your substrate is over a quarter inch thick, consider feeding your shrimp in a small glass or ceramic dish. Placing a shallow dish on top of the gravel bottom will keep the shrimps’ food contained, even after it dissolves. Also, feeding in a dish is a great way to monitor exactly how much and how fast your colony is eating. (Glass petri dishes are inexpensive and work great.)
• Dropping food into the water to target a dish or other small area at the bottom of your aquarium is difficult enough to qualify as a carnival game. It’s also not a great idea to routinely stick your hand inside the water. One simple solution is to put the food in a regular drinking straw and use it to drop the food right where you want it. A glass tube mounted on the inside of the glass just above the feeding area is an even more convenient—though more costly—solution.
#4 Know Your Tank
Cherry shrimp are often considered scavengers—and they can help fulfill that role–but shrimp can indeed starve without an adequate and fairly continuous food supply. The key to happy, healthy shrimp is for them to have enough food to graze upon throughout the day.
A seasoned tank that has been in operation for several months will have had more time to build an ecosystem that supports healthy biofilm—this gives you much more leeway with feeding since shrimp can supplement their diet by “living off the landscape.”
Cherry shrimp being kept in a new, rather sterile aquarium setup will need careful feeding until sufficient biofilm grows. Twice a day feeding with some longer-lasting veggies or other special additions will see them through the lean times.
#5 Offer a Variety of Foods
Shrimp are omnivorous, which makes feeding them a bit easier. It can be a bit tricky to discern the “best” or “favorite” foods for your shrimp, so provide a mix of different foods to ensure they are getting what they need. Best results come by offering a few different kinds of prepared retail food along with regular treats like blanched veggies, rolled oats, algae wafers, etc.
The next post in this series will take a different angle on feeding: we’ll check out the cherry shrimp’s anatomy and how they feed in the wild…