7 Spooky-Looking Freshwater Fish (and One Vampire Shrimp) for a Halloween Tank

Every fish tank can use a little Halloween. Here are seven freshwater fish that look like they swam out of a horror movie, plus one shrimp with the best name in the hobby. Some are easy. Some get big. We'll tell you which is which, and which ones like the current in a river tank.

1. Black ghost knifefish

Jet black, no real fins on its back, two white bands on the tail, and it swims backward as easily as forward. The name comes from beliefs in parts of South America that these fish carry the spirits of the dead. It finds its way in the dark with a weak electric field.

The catch: it gets big, often 18 inches or more in a tank, and it's nocturnal and shy. It needs a long tank, plenty of hiding tubes, and tankmates too big to eat. Not for a 55-gallon.

2. Kuhli loach

A tiny striped "eel" that looks like a snake but is completely harmless. Kuhli loaches stay around 4 inches, spend the day buried in sand or tangled in roots, and come out at night in wriggling groups.

River tank fit: good, as long as you have soft sand, a few calm spots, and keep a group of five or more. Cover every gap in the lid; they escape through holes you'd swear were too small.

3. African butterflyfish

It looks like a dead leaf with wings floating at the surface, with a big upturned mouth waiting for a bug to land. It's an ambush hunter that can leap out of the water, so a tight lid is a must.

River tank fit: poor. Butterflyfish want still, quiet water. Keep it in a calm tank with floating plants.

4. Glass catfish

You can see right through it: spine, ribs, and organs tucked up behind the head. Glass catfish school in midwater and actually like a gentle current.

River tank fit: good, if the flow isn't a firehose. Keep six or more. A lone glass catfish hides and fades.

5. Black phantom tetra

Smoky gray-black with a black shoulder patch, like a little shadow. Peaceful, hardy and inexpensive. Males flare their fins at each other but rarely do any harm.

River tank fit: fine in moderate flow, in a group of six or more.

6. Elephantnose fish

A long, trunk-like chin that it uses to probe the sand for worms, and, like the ghost knifefish, a weak electric sense. It's one of the strangest-looking fish you can buy.

The catch: it's delicate, nocturnal, picky about food and sensitive to bad water. For experienced keepers only, in a dim, quiet tank.

7. Leaf fish

The South American leaf fish looks exactly like a dead leaf drifting in the current, right down to a little "stem" on its chin. It drifts up on small fish and swallows them whole.

The catch: it eats live fish. It needs a tank of its own, or tankmates far too big to swallow.

Bonus: the vampire shrimp

The vampire shrimp (also called the African fan shrimp or viper shrimp) is a big, armored, blue-gray shrimp that can reach several inches. It doesn't suck blood. It sits in the current with its fan-shaped hands open and filters food out of the water.

River tank fit: excellent. It needs current to feed, which makes it one of the best inverts for a river tank. Give it a perch in the flow and it will sit there fanning all day. Compare it with our Amano vs. cherry shrimp guide if you're choosing a cleanup crew.

For a little Halloween look

• Dark sand, black background, driftwood and roots.
• Dim lighting, or a blue "moonlight" setting at night.
• Ghost shrimp make a good see-through companion.

Before adding anything new, quarantine it. For more fish that like flow, see our best fish for strong-current tanks.

Sources (7)

Seriously Fish: Black Ghost Knifefish · Seriously Fish: Kuhli Loach · Seriously Fish: African Butterflyfish · Seriously Fish: Glass Catfish · Seriously Fish: Black Phantom Tetra · Seriously Fish: Elephantnose Fish · Seriously Fish: Vampire Shrimp

Related: Ten Fish That Thrive Best In A River Tank Style Aquarium (Riparium)