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 little deep-ocean lanternfish that does the classic nightly commute - hanging deeper in the day, then rising toward the surface after dark to feed. Its body is studded with light organs (photophores), and the species name 'spinosus' comes from the spiny scales around the anal-fin base. Not really an aquarium fish at all, but it is a super cool example of open-ocean life.
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
Need a heater for this species?
This species needs 11.8-26.3°C in a 180 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeCare Notes
- Plan for a dim, deepwater-style setup - lots of overhangs/caves, dark sand/rock, and very low daytime lighting; they spook hard in bright reefs and will smash their face on the glass.
- Keep temp on the cool side for a marine tank (around 68-74F / 20-23C) and don't swing it; stable salinity 1.024-1.026 and a pH around 8.0-8.3 keeps them from going downhill fast.
- They are night feeders, so feed after lights-out with pumps turned down for 10-15 minutes; tiny meaty stuff works best (enriched mysis, copepods, baby krill chopped fine, prawn roe), and frequent small meals beat one big dump.
- If it won't take frozen, start with live pods or live enriched brine to get it eating, then mix in frozen gradually; a skinny lanternfish usually means you are feeding at the wrong time, not the wrong food.
- Avoid big, pushy tankmates and anything that outcompetes at feeding time (tangs, triggers, most wrasses); think calm midwater fish and small, non-aggressive species, and watch for fin-nipping.
- Give them real open water to cruise plus shaded zones to retreat - a long tank is better than a tall one, and a tight lid helps because startled lanternfish can jump.
- Common failure mode is slow starvation and stress from bright light and constant harassment; if the belly stays pinched or it hides 24/7, back off the lighting, add cover, and increase night feedings.
- Breeding in home tanks is basically a lottery - they are pelagic spawners and larvae are tiny and hard; if you ever see eggs, you would need a separate plankton-style rearing setup and live microfoods right away.
Compatibility
Good Tankmates
- Other small, chill midwater planktivores like cardinalfish (Apogonidae) - they hang in the water column, dont bother anyone, and wont see the lanternfish as a snack
- Peaceful reef gobies (clown gobies, neon gobies, small watchman-type gobies) - they mostly mind their own business on rocks/sand while the lanternfish cruises midwater
- Small dartfish/firefish (Nemateleotris) - same vibe: gentle, hover-y, and they do well with calm tank flow and a non-bully community
- Flasher or fairy wrasses (smaller Cirrhilabrus/Paracheilinus) - active but not usually mean, and they dont have the big mouth predator thing going on
- Peaceful blennies like tailspot blenny - perches and grazes, not a hunter, and doesnt compete hard for the same food
- Small, non-territorial chromis (like green chromis) in a mellow setup - theyre fast but generally not bullies if you avoid overcrowding
Avoid
- Anything predatory with a big mouth like groupers, lionfish, frogfish/anglerfish - if it can fit a lanternfish in its mouth, it eventually will
- Aggressive dottybacks (Pseudochromis) - they can be little terrors that chase and stress timid fish until they stop coming out to eat
- Triggerfish - even the 'safer' ones tend to be too rough, too curious, and will harass small peaceful fish just because they can
- Big, territorial damsels (three-stripe/domino types) - constant chasing and pecking order drama is the opposite of what lanternfish tolerate long-term
Where 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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