Tisbe copepods are one of the most useful live additions you can chuck into a saltwater tank. They're tiny harpacticoid crustaceans that crawl rather than swim, so they spend their lives picking through detritus, biofilm, and algae on rocks, glass, and macroalgae. Cleaning up the tank while feeding everything from corals to wrasses.
This guide covers what they look like, what they eat, how they breed, and why a healthy Tisbe population is one of the smartest things you can have in a reef.
What are Tisbe copepods?
The species you'll usually find sold for reef tanks is Tisbe biminiensis. Adults measure roughly 0.5–1 mm, small but visible to the naked eye once you know where to look. They're benthic, meaning they live on surfaces rather than in the water column. You'll spot them most often in the refugium, on the underside of rocks, or scuttling along the back glass at lights-out.
Because they don't swim freely for long, they're far less likely to get hammered by your skimmer or filter than free-swimming species. They settle in, breed, and stick around, building a self-sustaining population if conditions are decent.
What do they eat?
Tisbe are omnivorous detritivores. They'll graze on:
- Live phytoplankton (Nannochloropsis, Tetraselmis, Isochrysis)
- Detritus and uneaten food
- Bacterial films and biofilm on rock and glass
- Decaying macroalgae
The practical effect: they convert low-value waste into high-value live food without you lifting a finger.
Reproduction and life cycle
Females carry two egg sacs, one on each side of the abdomen, with roughly 20–60 eggs per clutch depending on temperature and food supply. Eggs hatch into nauplii, which work through several naupliar and copepodite stages before reaching adulthood, usually in 9–12 days at 25°C.
Adults live about 2–4 weeks and breed continuously when fed well and left alone. A well-established culture in a refugium keeps producing without much intervention.
Nutritional value
Tisbe fed quality phytoplankton are dense in the stuff reef-keepers care about:
- EPA and DHA (omega-3 fatty acids)
- Arachidonic acid (ARA)
- Protein
- Carotenoids, the pigments behind brighter fish colour
Their soft bodies and small size make them easy to digest, which matters for juvenile fish and coral polyps that struggle with bigger prey.
Why bother adding them?
Detritus control. They eat the gunk you can't easily remove: uneaten food, mulm, decaying algae.
Live food on tap. Continuous breeding means a steady drip-feed of nutrition for mandarins, scooter blennies, pipefish, small wrasses, and filter-feeding corals.
Refugium powerhouse. Tisbe thrive among chaeto and other macroalgae. A well-stocked refugium becomes both a nutrient sink and a copepod factory.
Biodiversity. More diverse microfauna means a more stable system. Tisbe are one of the easiest ways to dial that complexity up.
How to seed and maintain a population
- Turn off skimmers and mechanical filtration for an hour or two before dosing.
- Pour the bottle straight into the refugium or onto rockwork. Lights off works best.
- Feed live phytoplankton regularly. Tisbe do best with steady food, not feast or famine.
- Don't overstock predators early on. Let the population establish for a few weeks before adding heavy pod-eaters.
- Keep parameters stable. Tisbe handle a fair range but don't love swings.
Do that and you'll have copepods working for you around the clock, cleaning, feeding, and quietly making your tank a healthier place.
