Live Marine Rotifers
L-type Brachionus plicatilis · 150–360 microns · 500–1,000 per mL · made-to-order weekly
Size
500–1,000 / mLFulfillment
We confirm live availability before charging. Orders placed by Tuesday 10am ET ship same week.
Built for breeders.
If you’re feeding first-feed marine larvae, you need a live food sized for their mouth opening and dense enough to fuel rapid growth. Our L-type Brachionus culture is matched to the species most commonly raised in home and commercial hatcheries.
- ✓Clownfish fry — first 14 days post-hatch
- ✓Seahorse fry — first 30+ days post-release
- ✓Mandarin fry — entire larval window
- ✓Dottybacks & angels — first-feed window
- ✓Coral spawn larvae — pelagic phase
- ✓Filter-feeding inverts — copepods, soft corals, gorgonians
Feed today. Not in three weeks.
Most live rotifer products are sold as starter cultures — you receive a low-density seed and grow it out over 14 to 21 days before you can actually feed your larvae. That timeline doesn’t work for a breeder watching a spawn approach its first-feed window.
Our packs ship from a productive parent culture at 500–1,000 rotifers per mL. Open the bag, acclimate the water, and feed directly. Use what you need; refrigerate the rest; harvest as needed across the next 5 days.
Clownfish fry will starve within 72 hours of hatch if first-feed isn’t available. A 3-week grow-out from a seed culture isn’t a buying option — it’s a scheduling commitment.
Pack date is ship date.
From culture tank to your door in 48 hours. We don’t hold inventory in a warehouse — every order is harvested fresh from a productive parent culture, tested for density and vigor, packed in phase-change insulated mailers, and shipped the same afternoon.
- TUE 7AMHarvested fresh. Adults counted at peak density.
- TUE 1PMQuality Report signed. Density, vigor, water parameters verified.
- TUE 4PMPacked and shipped. Insulated kit with phase-change cold pack.
- WEDAt your door. Refrigerate immediately. Use within 5 days.
Order by Tuesday 10am ET to ship the same week. Orders received Wed–Mon ship the following Tuesday.
Size matters for first-feed larvae.
Larval clownfish, seahorses, and mandarins have a mouth opening of approximately 400 microns at first feed. The food you offer needs to be small enough to ingest yet large enough to fuel growth. L-type Brachionus plicatilis at 150–360 microns is the textbook fit.
Small enough to ingest. Big enough to nourish.
Every bag is a document, not a guess.
A signed Certificate of Analysis ships with every order. You know the exact density, vigor rating, and batch ID of what you received. No estimates, no “target” numbers — measured before pack-out and recorded on paper.
Density declared
Measured before pack-out. Every bag, every batch.
Count verified
Total population quantified, not estimated.
Signed and dated
Traceable batch IDs on every shipment.
Choose your size.
From a single-feed test bottle to a hatchery-scale gallon bag. Density is identical across sizes — 500 to 1,000 rotifers per mL — so per-larva nutrition is the same regardless of pack volume.
4 oz
118 mL · ~60k – 120k
Single feeding / test pack
16 oz
473 mL · ~240k – 470k
Small clownfish breeder
32 oz
946 mL · ~470k – 950k
Mid-sized breeder
1 Gallon
3.8 L · ~1.9M – 3.8M
Hatchery / serious breeder
On arrival.
Rotifers are hardy but they don’t love surprises. Get them refrigerated, room-temp them before feeding, and treat them like a live culture (not a frozen food).
Open and inspect
Tilt the bag — water should look slightly cloudy or tinted. That's normal — it's the algae the rotifers feed on. Refrigerate immediately.
Feed your tank
Pour or pipette directly, or strain through a fine (~53-micron) sieve and rinse into the target tank. Turn off skimmers and strong return flow for 15–60 minutes.
Start your own culture
Add to a clean container of prepared saltwater with gentle aeration and low light. Feed live phytoplankton or rotifer feed. Harvest about 25% daily.
Storage
Refrigerator-safe for 5–7 days with the lid cracked for air exchange. Don't seal airtight. Smaller bottles handle storage better than the gallon bag.
Frequently asked.
Everything we get asked before someone places their first order.
Are these rotifers ready to feed when they arrive?+
What size rotifers are these?+
What is the density?+
How long do they keep?+
Is there a Live Arrival Guarantee?+
Can I start my own culture from these?+
When do you ship?+
What if my tank temperature is colder or warmer than the bag?+
Ready to order?
Made-to-order weekly. Tuesday harvest, Wednesday delivery. Pick your size and fulfillment in the selector at the top of this page — or email us and we’ll confirm live availability for your target arrival date.