Spiny lanternfish
Dasyscopelus spinosus
The Spiny lanternfish exhibits a slender body, bioluminescent organs, and distinctive spines along its dorsal fin.
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About the Spiny lanternfish
This is a small oceanic lanternfish (family Myctophidae) found in tropical and subtropical waters of the Atlantic, Indian, and Pacific oceans. It is high-oceanic and mesopelagic/bathypelagic, becoming near-surface at night (nyctoepipelagic). Adults reach about 9 cm standard length and have spined ctenoid scales at the anal-fin base.
Also known as
Quick Facts
Size
9 cm SL
Temperament
Peaceful
Difficulty
Expert
Min Tank Size
180 gallons
Lifespan
unknown
Origin
Worldwide (tropical and subtropical oceans)
Diet
Carnivore - zooplankton and other small drifting animals
Water Parameters
11.8-26.3°C
8-8.4
8-12 dGH
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This species needs 11.8-26.3°C in a 180 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeWhere they come from
Spiny lanternfish (Dasyscopelus spinosus) are little mesopelagic drifters. In the wild they spend their days deep and dark, then move up toward the surface at night to hunt. That day-night commute is basically their whole lifestyle, and it explains why they can be such a headache in a bright, busy reef tank.
This is an expert-only fish for a reason: most don't handle collection and shipping well, and they rarely adapt to typical reef lighting and feeding routines. If you can't get it eating reliably in quarantine, don't "hope it turns around" in the display.
Setting up their tank
Think dim, calm, and predictable. They spook easily and they hate being blasted by light and flow. A dedicated species tank (or a very quiet fish-only system) gives you the best shot.
- Tank size: I'd treat 30-55 gallons as a practical minimum just for stability. Bigger is easier because you can keep things calmer.
- Lighting: low to moderate, with lots of shaded areas. If you run bright reef lights, give them caves and overhangs that stay dark all day.
- Flow: gentle to moderate, not a gyre ripping across open water. They do better hovering and picking, not fighting current.
- Aquascape: open midwater lanes plus rockwork they can duck into fast. They like a "ceiling" of rock to hang under.
- Cover: tight lid. Spooked lanternfish can launch.
- Water: stable marine parameters, strong biofiltration, and a skimmer. These fish often need frequent small feedings, and that can dirty water fast.
If you can, ramp lights up and down slowly. Sudden on/off flips them into panic mode. Even a cheap ramp timer helps a lot.
Quarantine is not optional here. I like a dim QT with PVC elbows, a blacked-out back and sides, and minimal "hands in the tank" time. The goal is to get them eating without them smashing themselves into glass every time you walk by.
What to feed them
They are zooplankton hunters. In practice that means small meaty foods, delivered in a way that looks alive. A lot of new imports ignore anything that just drops and sits.
- Best starters: live copepods, live enriched brine shrimp (not newborn-only forever), small live mysids if you can get them
- Frozen options once they recognize food: small mysis, Cyclops, calanus, finely chopped krill, roe/eggs, plankton blends
- How to feed: target feed in low flow, preferably at dusk or after lights out, and keep portions small but frequent
Use a red flashlight and feed after the tank is dark. You'll see a totally different fish - bolder, hunting, and actually paying attention to food.
If you have a refugium or a pod hotel that constantly leaks copepods into the display, that can be the difference between "barely hanging on" and "steady weight." I also like soaking frozen foods in a mild attractant and enriching live foods for a couple weeks until the fish is clearly putting on condition.
How they behave and who they get along with
They are shy, midwater fish that would rather avoid conflict than win it. A confident tang, wrasse, or dottyback will outcompete them at every meal and keep them pinned in a corner.
- Good tankmates: other calm, non-competitive planktivores, small peaceful fish that won't mug them at feeding time
- Bad tankmates: aggressive fish, fast eaters, anything that chases, and anything big enough to view them as a snack
- Group vs single: small groups can work if the tank is quiet and food is plentiful, but only if everyone is eating. One weak fish in a group tends to fade fast.
Feeding competition is the silent killer. A lanternfish can look "fine" during the day and still slowly starve because it never gets a real meal.
Breeding tips
Realistically, breeding spiny lanternfish in home aquariums is not a common win. They are open-water spawners, the eggs and larvae are tiny, and the larvae need specialized plankton cultures and very gentle rearing setups. If you want a project, the best "tip" I can give is to practice raising marine larvae on an easier species first, then come back to lanternfish later.
If you ever see courtship-like chasing at dusk and you keep ultra-fine mechanical filtration, check filter socks for eggs. Most of the time you'll never notice spawning because everything gets eaten or filtered.
Common problems to watch for
- Shipping stress and "just hiding": if it won't settle and eat within the first week or two, odds drop quickly
- Starvation: pinched belly, hollow behind the head, fading color, hanging in one spot and ignoring food
- Injury from spooking: scraped noses, torn fins from darting into glass or rock (often triggered by sudden lights or people rushing up)
- Parasites: flukes and protozoans show up as flashing, rapid breathing, cloudy eyes, or excess mucus
- Bloat/constipation: can happen if they finally eat but you jump straight to large frozen foods
Do not treat them like a tough damsel that can "ride it out." If you see rapid breathing, refusal to eat, or repeated panic dashes, fix the environment first (dim, calm, cover), then treat carefully in quarantine. Heavy-handed meds plus stress is a bad combo with this species.
The biggest success lever is routine: same dim periods, same feeding window (I like dusk), and low drama around the tank. Once they learn that food shows up in the same place at the same time, they get noticeably braver. Until then, go slow and keep everything gentle.
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