Coral Red Pencilfish (Nannostomus mortenthaleri) is an intermediate-level freshwater fish that needs at least 10 gallons and 75-82°F. A tiny pencilfish with a bright red belly and a gold stripe. It is shy and does best in a calm, planted tank with dim light, floating plants and only very gentle tankmates.
Care facts at a glance
| Scientific name | Nannostomus mortenthaleri |
|---|---|
| Family | Lebiasinidae |
| Origin | Upper Amazon basin, Peru |
| Adult size | 1.25 in |
| Minimum tank | 10 gallons |
| Temperature | 75-82°F |
| pH | 5.5-7.0 |
| Temperament | Peaceful, shy |
| Social behavior | Schooling, keep 8+ |
| Swim level | Upper to mid |
| Difficulty | Intermediate |
| Diet | Micro pellets, baby brine shrimp, tiny frozen foods |
| Typical lifespan | 2-4 years |
Quick tips
- Keep eight or more.
- Feed tiny foods; large pellets are ignored.
- Do not add to a new, unstable tank.
San Diego water
Prefers softer, more acidic water than San Diego's tap (pH roughly 7.6-8.6, hard). Most keepers blend tap with RO/DI water or use a remineralized RO/DI supply. Learn the numbers in our San Diego tap water guide.
Before you buy
Make sure your tank is cycled (how to cycle a tank), check your numbers with the water testing guide, and use the compatibility guide to check tankmates. These are general ranges; individual fish and local water vary.
Find it at Pet Zone
Pet Zone Tropical Fish is a San Diego aquarium store with two locations. Stock changes daily, so call ahead if you are after a specific species or plant. Shop online at petzonesd.com.
4160 Convoy St, San Diego, CA 92111
(858) 987-0309
Open daily, 10am-6pm
Aquascaping, planted tanks
4266 University Ave, San Diego, CA 92105
(619) 283-1812
Closed Monday; Tue-Fri 10:30am-6pm, Sat 11am-6pm, Sun 11am-4pm
Monster fish, koi