Receiving Corals via Mail Order: Assessing DOA (Dead on Arrival) and Unboxing Checklist

When welcoming corals purchased online, your immediate response upon receiving the package is a critical step that will determine survival rates afterward. By knowing the key points to check right after opening the box, you'll be able to stay calm and address any problems that arise. This article organizes the important checks to perform immediately after online-ordered corals arrive, plus strategies for identifying so-called "DOA (dead on arrival)" specimens.

First, inspect the external condition and thermal retention before opening the box

Before opening the box, start by checking whether the external packaging is damaged, showing signs of major tilting or water leakage. During summer and winter months, thermal insulation, cooling packs, or heat packs are often included, so at the unboxing stage, it's worth confirming whether these are still functioning (cooling packs not fully melted, heat packs still warm). This gives you an initial sense of how well the water temperature was maintained during transport. If shipping records (tracking numbers and dates) show that transit took longer than expected, this becomes important context for subsequent observation and assessment.

Open the individual packaging and examine the bag condition

Corals are typically packed individually in sealed bags with oxygen. Once you've removed a bag, first confirm there's no water leakage and that the bag remains fully inflated. If water levels have dropped significantly or the bag appears deflated, this points to possible seal failure—taking photos of the condition at this stage proves valuable for later assessment. Next, observe the coral through the bag without opening it. If you don't see obvious signs of tissue dissolution or skeletal material exposed and detached, the coral is usually simply contracted from shipping stress rather than showing signs of death.

How to distinguish between DOA (dead on arrival) and viable specimens

"DOA" refers to corals that are already dead upon arrival. Appearance alone—polyps not extended, coloration dulled—often cannot reliably indicate whether a coral is alive. Tissue visibly dissolving with exposed skeleton, strong foul odors, and a complete lack of response to touch are warning signs of death, but shipping stress-induced temporary contraction is also common. If you're uncertain, it's safer to proceed calmly with the acclimation process and observe for several hours to a day before making a final judgment. When in doubt, documenting photos and videos and consulting with an aquarium specialty store or your seller's support team is the safest approach.

The commonly confusing "merely weakened" condition

Darkness, vibration, and temperature fluctuations during shipping are major stressors for corals. Polyps contracted immediately after arrival or coloration appearing duller than normal don't necessarily indicate a fatal condition—as the environment stabilizes, it's common for corals to gradually recover over hours to days. Rushing to expose them to strong water flow or bright lighting can actually hinder recovery. Right after arrival, place the coral in a location with gentler water flow than usual, and take several days to gradually transition back to normal conditions.

Final checks before proceeding to acclimation

If there are no clear signs of death, proceed with standard acclimation (acclimatization) steps. Specific acclimation procedures are detailed in Coral Acclimation and Introduction Steps: The First Steps in Welcoming New Specimens, so rather than floating the bag in your tank right away, confirm the steps first. For dipping and quarantine upon introduction, Selecting Corals and Treatment Upon Arrival: Dipping and Quarantine Basics is also useful. General precautions for mail-order coral purchases are summarized in Important Things to Know When Buying Corals Online via Mail Order.

Who to contact for problems

If there's obvious damage or significant water leakage upon arrival, or if DOA is suspected, don't rely solely on your own judgment—consult with your seller's support team or a nearby aquarium specialty store. Keeping records of shipping conditions (photos of packaging, arrival time, cooling pack condition) will make subsequent communications smoother.

Avoid adding new specimens while the arrived coral acclimates

While the newly arrived coral is settling in, it's best to avoid simultaneously adding other new specimens to the same tank. When multiple new individuals are adapting to their environment at once, it becomes harder to distinguish individual behavioral changes, and if problems occur, identifying the cause becomes difficult. Adding specimens one at a time and observing for several days to a week before considering the next introduction helps you notice changes more readily.

Summary: Those first few minutes of observation are crucial

Purchasing corals online differs from selecting them in person at a store—careful assessment the moment the package arrives is essential. By methodically checking external condition, thermal retention, and individual packaging in order, and by consulting experts rather than rushing through acclimation when uncertain, you set the foundation for long-term success in keeping your corals healthy and thriving.