Snaketooth

Where they come from

Kali kerberti is a deepwater snaketooth, the kind of midwater predator that cruises in the dark, cold layers far below the sunlit zone. Think meso- to bathypelagic depths with near-freezing water, almost no light, and a whole lot of pressure. They are built for ambush in open water, not reefs or rocky bottoms.

Setting up their tank

You are basically trying to fake deep ocean conditions without the pressure. That means cold, dark, quiet, and very stable.

• Tank size: 250-400+ liters for a single fish, with more length than height. Keep the interior simple so it does not bash its snout.
• Temperature: 4-8 C (39-46 F). You will need a serious chiller with redundancy and a controller. Insulate the sump and lines.
• Light: keep it dim. Black out three sides. Use red-spectrum night lighting if you must watch it. Sudden white light will spook it.
• Flow and gas exchange: gentle, even flow with lots of oxygen. Oversized skimmer, large biofilter, and fine bubble suppression to avoid gas bubble trauma.
• Interior: bare-bottom or dark sand. No sharp rock. Rounded PVC hide tube is fine, but they spend time midwater.
• Lid: tight, sealed lid to hold cold and humidity and to prevent leaps during startle events.
• Water: ocean-strength salinity (34-35 ppt), pH 7.8-8.1, ammonia and nitrite at zero, nitrate as low as you can keep it. Test often until the system proves stable.

What to feed them

They are fish-eaters with stretchable stomachs. In a tank, big meals cause regurgitation and fouling, so go smaller and slower.

• Start with movement: gently waft small, silvery strips of marine fish (capelin, sand lance, silversides) on feeding tongs in low red light.
• Rotate in squid strips or prawn pieces once it is taking food. Enrich with vitamins (e.g., Selcon) a couple times per week.
• Feed every 2-4 days, not daily. One or two modest items per session. Watch the belly; a slight bulge is enough.
• Remove leftovers immediately. Cold systems hide decay, but your skimmer will not.
• If it refuses dead food, try live marine ghost shrimp as a bridge, then wean back to prepared.

How they behave and who they get along with

Solitary, slow-cruising ambush predator. They hang midwater and lunge with a big mouth. Not social, not curious, and not a display fish for bright rooms.

• Tankmates: none recommended. If it fits, it is food. If it does not fit, it will still try and may injure itself.
• Lighting and foot traffic: keep the tank in a quiet, dim corner. Sudden shadows or doors slamming can trigger panicked dashes.
• Handling: use a large, soft tub rather than a net. Support the body and keep them submerged. Air exposure is rough on these guys.

Breeding tips

No captive breeding reports that I am aware of. In the wild, related deepwater fishes scatter pelagic eggs and larvae drift. Replicating seasonal cues, pressure, and space is way outside hobby reach. If breeding is your goal, pick another species.

Common problems to watch for

• Barotrauma from capture: bulging eyes, gas in tissues, loss of equilibrium. Without staged recompression, prognosis is poor.
• Light shock: frantic dashes in bright light, snout abrasions. Keep it dim and tape foam on corners.
• Refusal to feed: common the first 1-2 weeks. Try smaller pieces, lower light, less flow, and movement on tongs.
• Regurgitation after big meals: feed smaller, less oily pieces and extend time between feedings.
• Bacterial sores from net burn or bumps: at low temps, healing is slow. Work with a vet on antibiotics dosed for cold systems.
• Temperature creep: chillers drift, pumps add heat. Log temp several times a day and test your backup plan.

Bottom line from someone who has only managed this species under short-term, chilled holding: it is a specialist fish. If you have not already run a cold, dark system for other deepwater species, get miles under your belt first. There are plenty of challenging marine fish that will teach you the same skills without the heartbreak.