Columbian Shark
Ariopsis seemanni
Brackish Central America
A sleek, active schooling catfish resembling a miniature shark with white-tipped fins. Often mis-sold as a freshwater oddity, juveniles demand brackish water and must gradually be transitioned to full marine salinity as adults. Provide strong currents, ample open swimming room, and beware the venomous spines located within its dorsal and pectoral fins.
Try it in the planner Opens a tank sized to its minimum with 3 fish added.
What it needs
| Item | Value | Because |
|---|---|---|
| Adult length | 30 cm | Used for the Space check: the tank must be long enough for the fish to turn round. |
| Smallest tank | 400 L, at least 150 cm long estimated | The least water and floor length this species is kept in for good, as a single fish or smallest group. |
| Extra water per added fish | 100 L estimated | What each further fish adds once the minimum is met. |
| Waste load | Class 4 of 5 estimated | How much waste an adult makes against its size. Feeds the Load check. |
| Temperature | 23 to 28 C | Stock sharing a tank need overlapping ranges. |
| pH | 7.2 to 8.4 | Compared with tankmates in the Water check. |
| Hardness | GH 10 to 25, KH 6 to 15 | Degrees of general and carbonate hardness. |
| Flow | High | Low-flow fish are stressed in a strong current. |
| Light | Moderate | Matched to the lighting class on the needs sheet. |
| Group size | At least 3, ideally 5 | Kept alone or in small numbers it hides, fades or turns on tankmates. |
| Temperament | Peaceful | Not territorial. |
| Swims in | Middle water | Fish that use different levels share a tank more easily. |
| Lifespan | About 12 years | A fish is a long commitment. |
| Experience | Some experience helps | A guide to how forgiving the species is of mistakes. |
| Jumps | Yes | Keep the tank covered. |
Tags marked estimated are judged from the size and habits of the species rather than measured, so treat them as a sensible default.
Diet and tank layout
Columbian Shark is an omnivore that swims in the middle of the tank. It is safe with plants. Give it some cover. It will eat fish small enough to swallow.
Tankmates
Works with
No close matches in the data. Check the pair tool.
Depends
Avoid
- Figure Eight Puffer
- Green Spotted Puffer
- Indian Glassy Fish
- Orange Chromide
- African Mudskipper
- Bumblebee Goby
- Knight Goby
- Spotted Archerfish
- Ceylon Puffer
- Sheepshead Minnow
- Banded Lampeye
- Banded Puffer
- Blueback Blue-Eye
- Green Panchax
- Guyana Leaffish
- Javanese Ricefish
- Queen of Siam Goby
- Shortfin Molly
- Shuttles Mudskipper
Compare any two fish on the compatibility page, or print the equipment for a stock on the needs sheet. How this is worked out: the method.