Do Brine Shrimp Resort to Cannibalism? An In-Depth Look at This Strange Behavior

Brine shrimp, also known as sea monkeys or artemia, are a popular live food source for feeding aquarium fish. Their ease of breeding makes brine shrimp an extremely convenient option. However, some aquarists have noticed these tiny crustaceans will actually eat each other under certain conditions. So why do brine shrimp exhibit cannibalistic tendencies at times?

An Overview of Brine Shrimp

Brine shrimp belong to the genus Artemia with the two most common species being Artemia salina and Artemia franciscana. These small shrimp average about 8-10 mm long when mature.

Brine shrimp thrive in high salinity waters which is why they are well-suited to aquarium saltwater hatcheries. In their natural habitat they occur in inland salt lakes and coastal salt pans. The larvae exist in a dormant cyst state enabling extended dormancy periods until rehydrated to hatch.

The brine shrimp lifecycle only lasts a few weeks from larval stage to maturity. They normally feed on microalgae, yeasts, bacteria, and other tiny aquatic organisms. Brine shrimp are nutritious live feed, containing ample protein, lipids, and essential fatty acids for developing fish fry.

Reasons Why Cannibalism May Occur

In the wild, brine shrimp feed on microorganisms and do not exhibit cannibalistic tendencies. However, in controlled aquarium hatcheries, brine shrimp may turn to cannibalism for:

Overcrowding – Excessive brine shrimp density can quickly deplete nutrients needed to sustain the multiplying population. This leads to competition for limited resources, causing some shrimp to attack others.
Starvation – If larvae exhaust their yolk sac before adequate external food is provided, starvation can trigger cannibalism as a means of survival.
Life Stage Difference – Older brine shrimp that have absorbed their nutritious yolk sac may specifically target younger shrimp who still have yolk reserves.
Predatory Instinct – Inadequate food sources can bring out the natural predatory instincts of brine shrimp, leading them to consume each other
Stressors – Suboptimal salinity, temperature, pH, etc. can stress brine shrimp and potentially initiate cannibalistic tendencies.
Uneaten Shrimp – After fish feedings, uneaten living brine shrimp may go after their weakened counterparts that were nipped on by fish.

Signs Cannibalism is Occurring

If your brine shrimp population begins declining or exhibiting strange behavior, cannibalism may be at play Watch for

Presence of discarded molts or shell fragments
Damaged individuals showing loss of appendages
Direct observation of brine shrimp attacking and eating each other
Rapidly shrinking population density
Increased water turbidity from dead matter
Visible size differences indicating larger shrimp consuming smaller shrimp

Preventing Cannibalism in Brine Shrimp Cultures

While some cannibalism may be inevitable, there are ways to discourage this harmful behavior:

Avoid overcrowding hatcheries and monitor population density.
Introduce food sources like microalgae early once larvae absorb yolk sacs.
Maintain optimal temperature, salinity, pH and other conditions for brine shrimp.
Use air pumps and lighting to promote algae/infusoria growth.
Harvest brine shrimp frequently within 2-3 days before overcrowding.
Segregate younger shrimp from larger ones with partitions or nets.
When feeding fish, provide enough brine shrimp so all are rapidly consumed.

do brine shrimp eat each other

Eating LIVE brine shrimp AGAIN

FAQ

Why are my shrimp eating each other?

Eating is a necessity, shrimp in nature and in cultivation conditions will both try to meet their food needs. If it is not fulfilled then the natural nature of the shrimp can appear with its aggressiveness and will become cannibals. The main target is shrimp that are weak or smaller in size.

What eats brine shrimp eat?

Brine shrimp normally swim in an upside-down position by rhythmically beating their legs. They are consumed by birds (including flamingos, grebes, and avocets), water boatmen, fishes, and other crustaceans, and they feed primarily on green algae, which they filter from the water with their legs.

How do brine shrimp avoid predators?

Although brine shrimp grow very well under artificial conditions and in inland salt lakes, they are not found in the open ocean. This is because the brine shrimp’s only defense mechanism against predators is its habit of living in hyper-saline bodies of water.

Can you eat brine shrimp?

Because these creatures are filter eaters, almost any organic substance can be used as food as long as it’s given to them in small enough bits for absorption. The most typical brine shrimp foods you’ll find people using are wheat flour, soybean powder, whey, powdered spirulina algae, and even powdered spirulina algae.

What are the side effects of eating shrimp?

Shrimp allergy can be identified from signs and symptoms that appear after consuming shrimp or smelling it, such as itching, the appearance of red plaques on the skin, swelling in the face, especially in the eyes and mouth, and in the throat creating the feeling of a lump in the throat.

How often should brine shrimp eat?

Brine shrimp should consume food every day. These small shrimp should have a limitless amount of food since they are filter feeders. Several individuals feed the shrimp less often since there is too much food in their aquariums. Brine shrimp may survive without food for between one and three days following eating their egg yolk.

Can brine shrimps live in the ocean?

Brine shrimps are saltwater organisms, yet they can’t exist in the oceans; instead, they can only be found in inland saltwater lakes. This is due to their main line of defense against potential freshwater predators is their capacity to survive in highly salinized water.