Don’t Get Burned: The Truth About Copepod Bottles
If you're buying live foods, here's what you need to know:
THEY ARE MICRO-ORGANISMS, NOT INVISIBLE
Yes, copepods and other live foods are microscopic organisms—but they’re not invisible. If you can’t see anything moving in the bottle with your naked eye, you're being sold saltwater. Don’t fall for it. Ask for a refund.
MISLABELLED SPECIES
We’ve received over a dozen credible reports of public-facing suppliers mislabelling copepods. The label says one thing, but what’s inside doesn’t match. This isn’t an accident, if they don’t know what they’ve put in the bottle there are likely significantly more concerns.
This is a breach of Australian Consumer Law under “misleading or deceptive conduct”. You can (and should) report it to the ACCC
Here’s how to identify them:
Cyclopoids (Apocyclops, Oithona, Dioithona)
Teardrop-shaped
Fast, twitchy swimming
Stay suspended in the water column
Hard to focus on due to size and speed
Light-sensitive – will swim away from bright light
Lifespan: 15-25 days
Tisbe (Tisbe biminiensis)
Tiny and transparent (dark if well-fed)
Stick to surfaces like glass or substrate
Rarely swim freely
Found in dense surface clusters
Light-sensitive – avoid strong light, scatter when exposed
Lifespan: 20-30 days
Tigriopus (T. californicus, T. australis)
Bright red/orange
Larger and easy to spot
Hop or dart; cling to surfaces
Swim if disturbed
Mildly light-sensitive – may react to sudden light
Lifespan: 30-40 days
Calanoids (Parvocalanus, Acartia)
Long, slender with extended antennae
Smooth, continuous swimmers
Stay in open water, avoid surfaces
Distinct T-shape when viewed from above
Strongly light-sensitive – actively avoid light
Lifespan: 5-10 days
When purchasing copepods, always test their reaction to light (the torch on your phone for example). If they do not react; or are attacted to the light then the chances are they’re not copepods. If the appearance or behavior doesn't line up with what is mentioned above it's not the species you paid for.
MISLEADING QUANTITIES
A claim like “over 3,000 copepods per bottle” is a red flag. Here's why:
A bottle packed with thousands of live copepods would crash within hours due to oxygen depletion and ammonia buildup.
Shelf life would be under 24 hours unless you’re receiving it straight from the culture room and putting them straight into a culture or a tank within a few hours.
Promotional photos and videos often don’t match what’s shipped.
This is a breach of Australian Consumer Law under “misleading or deceptive conduct”. You can (and should) report it to the ACCC
Why Adult Copepods Are a Red Flag
It’s a common misconception that bottles packed with adult copepods are the best choice. Here’s why that’s misleading:
Copepods typically live 5–20 days — in optimal conditions up to 40 days (depending on species)
They take 4–7 days to mature and begin reproducing (only females develop egg sacs or release eggs, depending on species)
Resellers usually receive pods 1–3 days after shipping, then take another 7–10 days to sell. That means adult pods are often around day 17 of their already short lifespan; nearly dead by the time they reach you. If your supplier doesn’t use express shipping, it’s even riskier.
Some suppliers sieve out adults just for bottling and keep the juveniles for themselves. They know harvesting early-stage copepods in bulk would collapse their cultures, and they know that adults are more visually appealing
A healthy bottle should be contain all generations, and preferably no adults at all, or at least adults with eggs.
Final Tip: Trust Your Eyes — and Take Action
Copepods are never invisible. If you can’t see them moving, they’re not there.
If you’ve been misled, don’t stay quiet. Ask for a refund and report the supplier to the ACCC. It’s your right — and the only way to clean up this industry.
