Emergency plan: shrimp collapsing or dying suddenly

For several suddenly affected animals, loss of balance or continuing deaths, restore obvious equipment failures, support gas exchange and investigate water while seeking prompt help. Do not wait for a definite disease name. One old carcass or an empty molt first requires establishing what you actually see.

1. Stop the possible exposure. Pause a suspect additive, faulty CO2 supply or unsuitable water source. Keep product, amount and timing records. Do not add a guessed “antidote”.
2. Check filtration, aeration and temperature. Restore failed equipment, move the surface and add air where needed. Do not replace every filter medium or disturb the entire substrate simultaneously.
3. Remove confirmed carcasses and visibly decaying food. An empty molt is not a carcass. Take a photograph if possible, without delaying urgent support.
4. Measure what immediately informs action. Temperature, ammonia and nitrite, with pH for ammonia interpretation; oxygen if measurable. Record test type and units. Add source-water results, GH, KH and conductivity where differences or water replacement are relevant.
5. Correct the identified cause. For contaminated water, use suitable prepared water from a reliable source. Amount and repetition depend on severity, concentration and difference from the aquarium. Small changes are not always enough; use the water problem route and seek prompt help if uncertain.
6. Follow the effect while acting. Record behaviour, measurements and new losses. Do not wait a fixed number of hours during deterioration. Discuss suitable temporary housing and targeted investigation with an aquatic veterinarian or knowledgeable aquarium professional.

After the initial response

Recheck filtration and the measurements that were abnormal. Improvement after action provides useful information, but does not by itself prove the cause. Continue water assessment and disease investigation together where needed.

Do not add a large meal during initial assessment. Resume suitable nutrition according to uptake and water loading, considering young and filter-feeding species. A fixed multi-day fast does not fit every aquarium. Then compile the loss timeline so the underlying cause is investigated too.

Sources and scope

• UF/IFAS: Ammonia in Aquatic Systems
• UF/IFAS: Dissolved Oxygen for Fish Production
• CDC: Chlorine and chloramine in drinking water
• Merck Veterinary Manual: Management of Aquarium Fish

This order is an editorial first-response checklist based on water chemistry, gas exchange and clinical history gathering. It is not a proven treatment for every cause and uses no fish doses or universal water-change percentages.