Greek lamprey

Where they come from

Greek lampreys are a rare, non-parasitic brook lamprey from a handful of cold, clear streams in Greece. They spend most of their life as burrowed larvae in fine sediments, then metamorphose into short-lived adults that spawn and die. Think shaded, spring-fed creeks with clean sand, leaf debris, and steady current.

Setting up their tank

You are basically building a chilled, high-oxygen stream with places for larvae to burrow. Temperature control is non-negotiable. Warm water wipes them out fast.

• Tank size: 75-120 cm long footprint helps create a flow lane and a quiet burrow zone. Depth matters less than floor space.
• Temperature: 8-16 C most of the year, briefly up to 18 C in summer. Use a chiller; fans are not enough.
• Flow and oxygen: Strong, even current with a river-manifold or gyre-style setup. Aim for surface agitation and no dead spots.
• Substrate: 6-10 cm of clean, rounded sand (0.5-2 mm). Add a corner of very fine sand/silt mix for larvae. Skip sharp gravel.
• Hardscape: Smooth cobbles, driftwood, and leaf litter to trap micro-foods. Leave open patches for burrowing.
• Filtration: Oversized canister or sump with heavy biological media. Put a coarse prefilter and a big sponge on intakes so larvae are not sucked in.
• Lighting: Dim to moderate. They prefer shade; bright light encourages algae and can stress newly metamorphosed adults.
• Water chemistry: Soft to moderate hardness, pH 6.8-7.6. Keep nitrates low (<10 mg/L) and avoid any ammonia spikes. Frequent small water changes.

What to feed them

Feeding depends on life stage. Larvae (ammocoetes) are filter feeders living in the sand. Adults of this species do not eat at all.

• Larvae diet: Fine particulate foods suspended in the water column. I rotate spirulina powder, chlorella, decapsulated brine shrimp powder, very fine fry foods, and a pinch of baker's yeast once a week.
• Delivery: Mix a tiny amount in tank water and dose upstream of the burrow zones. You want a gentle snow of particles drifting past, not piles on the bottom.
• Biofilm: A seasoned tank with leaf litter and mulm helps. They graze on the microscopic life that builds up there.
• Adults: After metamorphosis, they stop feeding. Focus on water quality and a stress-free environment until they spawn.

How they behave and who they get along with

Larvae spend almost all day buried with just the head exposed, usually in slower patches bordering the current. Adults hide under stones, especially at dawn and dusk. They are peaceful and ignore other fish, but most fish will not ignore them.

• Best setup: Dedicated species tank. You will actually see their natural behavior this way.
• If you must add tankmates: Small, calm, cool-water species that do not dig or peck. Avoid loaches, barbs, cichlids, and anything curious about burrowed tails.
• Intraspecific: Keep a group (6-10+) to spread any spawning energy and reduce stress. They naturally occur in clusters where conditions suit them.

Breeding tips

Hard, but not impossible with a chilled stream tank and patience. Adults need seasonal cues to ripen.

• Seasonal cycle: Give them a cool winter (8-10 C) for 8-10 weeks with short photoperiod, then a gradual spring warm-up to 12-14 C and longer days.
• Spawning site: Shallow riffle with smooth gravel and cobbles in brisk flow. They will clear a small pit using their oral discs.
• Behavior: Pairs or small groups gather in daylight in the riffle, attach to stones, and release eggs and milt into the cleaned pocket.
• After spawning: Adults are semelparous (spawn once and die). Remove bodies quickly to protect water quality.
• Raising larvae: Eggs hatch in about 2-3 weeks at cool temps. Larvae drift and then burrow in fine sand. Offer micro-particulates once you see them filter-feeding. Keep prefilters spotless.

Common problems to watch for

• Overheating: Anything over ~18 C for long stretches is risky. Sudden heat spikes kill fast. Use a chiller and a temp alarm.
• Low oxygen: Fine foods and clogged sand can strip O2. Keep strong surface agitation, clean sponges often, and avoid deep, compacted substrate.
• Silt smothering: Powder can cake over the burrow openings. Lightly turkey-baste the surface to fluff it, and reduce feeding.
• Intake injuries: Unprotected intakes will grab larvae. Every inlet needs a coarse guard plus sponge.
• Fungus on stressed adults: Any abrasions can fuzz up in cold water. Improve flow and cleanliness; salt is not a good option for lampreys.
• Legality and sourcing: Many are protected. If you cannot clearly document legal origin, do not keep them.