Receiving and acclimating new Neocaridina

Evidence review: August 12, 2026

There is no experimentally validated Neocaridina recipe that says a particular GH, pH or TDS gap requires a certain number of drops per second or hours. Two direct transport experiments have tested transport duration or a dry chilling protocol, but neither compared a receiving-water transfer rate.⁷⁸ A 2026 review also found major species-specific gaps for ornamental shrimp transport physiology, including no transport-specific nitrogenous-waste thresholds in the literature it surveyed and no comparable transfer-rate data for Neocaridina.¹ The safest useful guide must separate measured facts, general aquatic-animal guidance and our protocol.

What direct transport experiments measured

A 2022 experiment assigned three conventional wet bags to each of five simulated transport durations from 24 to 120 hours. Each 15 by 30 cm bag held 125 mL of settled well water and Hydrilla and was rocked for 15 minutes every two hours. The paper lists oxygen among its materials but does not report shrimp per bag, gas volume, the oxygen-filling procedure or the gas-to-water ratio.⁷

Arrival survival differed across duration groups, but only three bags represented each duration and there was no zero-hour control. The article reports temperature, pH and dissolved oxygen at several phases, while carbon dioxide and a test-kit result labelled ammonia or NH3 appear only after transport. Those labels and methods do not establish total ammonia nitrogen, un-ionised ammonia, causation or a toxicity threshold. The percentage increments also cannot be reverse-engineered into an animal count the methods omitted.

A 2020 experiment used gradual cooling, grass and ice, and dry transport for 24 hours. The report describes 120 shrimp, four target temperatures and three replicates, but its parenthetical statement of 10 shrimp per treatment is compatible with the total only if it meant 10 per replicate. The animals were cooled in water, then layered without water in an insulated box with ice and Imperata grass at a nominal package temperature of 17 C.⁸

The article says survival at 13 and 15 C did not differ statistically, so the table does not establish one unique optimum. Its abstract labels treatment B as 13 C while giving the 15 C result, its conclusion calls 15 C best even though the results table is numerically higher at 13 C, and its weight units and 13 C weight value also conflict. The paper does not describe the recovery water, aeration, recovery denominator or any survival follow-up after the immediate response.

Before delivery

• Prepare a commissioned quarantine system, not a newly filled display tank. Use the source-separation and release guide.
• Test temperature, ammonia and nitrite before the box arrives.
• Use our latest published tank readings to prepare receiving water close to the source water when practical. Do this before delivery, not while animals wait.
• Have a clean net, container, thermometer and test kits ready.
• Dim the receiving area and keep it away from direct sun.

Record the sample, method, unit and reporting interval.

Our shipped-stock receiving protocol

Our practice This is the protocol Molt & Moss will validate during real test shipments. It is not presented as a proven biological optimum.

1. Photograph and count through the sealed bag first. This protects the live-arrival record and keeps the bag's gas exchange uninterrupted.
2. Keep a breather bag out of water. Leave it sealed, exposed to air and in a dim area at the receiving tank's room temperature while the bag approaches that temperature. A 20-minute timer does not prove temperatures match; the starting difference, bag volume and material all matter.
3. Open only when the receiving tank and net are ready. Once open, inspect promptly. Do not begin an unattended, multi-hour procedure in transport water whose ammonia, pH and oxygen have not been measured.
4. Net the shrimp into quarantine and discard the shipping water. Do not add source water, treatments or possible hitchhikers to the receiving system.
5. Observe and record. Check behaviour and survival at 1 hour, 24 hours, 48 hours and 7 days. Record a molt, hiding or reduced feeding as an observation, not a diagnosis. Use the behaviour record if movement, balance or distribution changes.

Why more drip time is not automatically safer

Aquatic animals excrete total ammonia nitrogen during transport. The fraction present as more toxic un-ionised ammonia increases as pH and temperature rise.²³ General ornamental-fish guidance therefore recommends temperature adjustment while a conventional bag remains sealed, followed by prompt net transfer and disposal of transport water.⁴ That fish guidance is a useful risk model, not a direct N. davidi experiment. Breather bags also exchange gases differently from conventional bags, so bag type matters.

A pocket TDS meter does not measure osmotic pressure or identify dissolved ions. It estimates TDS from conductivity using an assumed conversion factor.⁶ A 100 ppm difference on two meters is not evidence for a four-hour drip, and a small TDS difference does not prove the water chemistry is equivalent.

Local handoff is a different case

A short local trip in recently drawn, clean tank water does not create the same transport-water history as a multi-day shipment. Gradual mixing can be used as a house procedure when the water is clean and temperature and oxygen remain controlled. No study found in this review establishes the best duration, drip rate or target dilution for N. davidi. Measure both waters and record the actual outcome instead of treating a drop count as proof of safety.

What the first week can and cannot tell you

• Hiding can follow transfer, but hiding alone does not prove the animal is fine.
• An exuvia is translucent and hollow. A dead shrimp contains tissue. A molt soon after transfer does not by itself prove successful or failed acclimation.
• Reduced interest in prepared food can reflect grazing, disturbance or illness. Record it with behaviour and water tests rather than assigning one cause.
• A death after arrival has multiple possible causes, including transport, receiving water, pre-existing health, temperature, toxic exposure and handling. Timing alone cannot identify one.

Use the health and mortality triage guide.

Continue the source-specific quarantine record.

What the evidence does not establish

• That drip acclimation is always safer than prompt transfer.
• That two, three or five hours is optimal for a particular chemistry gap.
• That TDS is the parameter shrimp respond to fastest.
• That a low GH reading can diagnose a transfer death or failed molt.
• That every shipped bag contains a dangerous ammonia concentration.

Sources and evidence limits

1. Holroyd et al., 2026. An ecophysiological approach to improving health outcomes of ornamental shrimp during aquarium trade and transportation. Conservation Physiology 14(1): coag046. Review of the species-specific evidence gaps.
2. U.S. Environmental Protection Agency. Aquatic Life Criteria: Ammonia. Chemistry and freshwater aquatic-life guidance, not a Neocaridina transfer trial.
3. National Academies, 2018. Aquatics: Management of Animal Care and Use Programs. Ammonia equilibrium and aquatic-system management.
4. Cole et al., 1999. Shipping Practices in the Ornamental Fish Industry. USDA, NOAA and Hawaii Sea Grant manual. Its receiving protocol is for fish and is identified above as an extrapolation.
5. Kordon. Breathing Bags product instructions. Packaging operation reference, not independent physiological evidence.
6. National Institute of Standards and Technology. Conductivity meter manual. Conductivity and TDS conversion factors.
7. Santoso et al., 2022. Pengaruh Waktu Transportasi Sistem Tertutup terhadap Kelangsungan Hidup Udang Red Cherry (Neocaridina heteropoda). Clarias: Jurnal Perikanan Air Tawar 3(1): 18-27. Direct wet closed-transport duration experiment. Package density and several gas and water details limit application to our package.
8. Ismandar, Dewantoro and Rachimi, 2020. Pengaruh Suhu Pembiusan terhadap Kelangsungan Hidup Udang Red Cherry (Neocaridina denticulata sinensis) selama Transportasi Sistem Kering Suhu Rendah. Jurnal Borneo Akuatika 2(1): 1-7. Direct dry chilled transport experiment with internal unit, treatment, weight and conclusion inconsistencies and no delayed survival follow-up.