New shrimp hiding: observe or investigate?

Hiding can occur after a move. Avoid dismantling the aquarium to find every animal, but check water, filtration and the animals you can see. There is no fixed period during which hiding is always safe. Loss of balance, several deaths or a whole group gathering at the surface warrants immediate investigation.

Observe without removing the refuge

• Look during a quiet period and under less intense light for controlled movement and grazing.
• Check the filter intake and accessible places where an animal could be trapped. Avoid trapping animals during the check itself.
• Leave existing moss, plants and wood in place. Do not add a large amount of food to lure animals out.
• Look for fish chasing shrimp or monopolising the feeding spot. Surviving adults do not establish a suitable combination for a breeding colony.

When observation is insufficient

With abnormal behaviour or uncertainty about maturity, measure ammonia, nitrite and temperature and check filtration and gas exchange. Include pH, GH, KH and conductivity when water or substrate changed. Record associations with arrival, maintenance and new products without treating timing as proof of cause. Clear water can still be unsuitable.

For repeated deaths or severe signs, use the problem route in the water guide and seek informed help with measurements and photographs. Buying replacements while the first group disappears without explanation does not help the investigation.

Species and behaviour matter

These grazing observations mainly fit dwarf shrimp such as Neocaridina. For fan shrimp, assess whether the animal can actually capture suspended particles at its feeding station. Hiding or occasionally appearing does not establish adequate nutrition. Use the checklist to follow changes without rearranging the tank every day.

Sources and scope

• LICG: Zoetwatergarnaal
• UF/IFAS: Cherry shrimp, Neocaridina davidi
• UF/IFAS: Ammonia in Aquatic Systems
• Aqueon: Freshwater shrimp, bamboo-shrimp feeding

The sources describe grazing, refuges and water quality. The distinguishing checks are editorial judgements. Hiding alone does not establish health, the cause of stress or disease.