Top 5 Oddball Fish for a 10-Gallon Aquarium

If you’ve been in the aquarium hobby for a while, you have probably owned a majority of the most popular fish sold at pet store chains. Keeping oddball species is a great next step for advancing your fish keeping knowledge. Oddball fish tend to have unusual appearances, can be harder to find, and may come with complicated care requirements. If you are up for the challenge but have limited space, check out our 5 favorite oddball fish that can be kept in a 10-gallon aquarium.

1. Shell Dwellers

Neolamprologus multifasciatus or “multis” are one of the smallest African cichlids that you can keep in a 10-gallon tank. The adults range in size from 1-2 inches (2.5-5 cm) and are covered with narrow vertical stripes. While they are not the most colorful fish, their bold personalities more than make up for it. They (along with other similar species) are called “shell dwellers” because they live, breed, and raise their babies in empty snail shells. These little bulldozers are constantly rearranging their shells, digging pits in the substrate, and fiercely defending their homes. Because multis are so territorial towards other fish, we highly recommend giving them a species-only setup if you choose to keep them in a 10-gallon aquarium. The exception to the rule might be the Malaysian trumpet snail because this nocturnal invertebrate can burrow into the substrate and won’t be harmed if a multi decides to move it to the other side of the tank.

Since multis are Lake Tanganyikan cichlids, raise your pH to 7.5 or higher if needed using crushed coral or aragonite as the substrate. Most hobbyists like to breed them but they can be a little difficult to sex as juveniles, so get a group of six to ensure you have both males and females. The adults like to eat smaller fish foods like baby brine shrimp, cyclops, and mini sinking pellets. However, the fry won’t leave their shells until they’re bigger, so to increase their survival rate, make sure you feed plenty of powdered fry food and crushed flakes that can float inside their shells. If you’re looking for something a little different from your usual planted community tank, try these action-packed shell dwellers because you won’t be able to stop staring at their antics.

Neolamprologus multifasciatus or “multis”

2. Freshwater Pipefish

The African freshwater pipefish (Enneacampus ansorgii) is an advanced species that we typically only recommend for veteran fish keepers because of the time investment and specialized diet they required. As cousins of seahorses, they like to hook their tails onto objects as their heads bob around to investigate their surroundings, so provide them with lots of aquarium plants or fish tank decorations as anchor points. The difficulty comes in their food requirements since they have small mouths and like to eat tiny live foods that move, such as baby brine shrimp and daphnia. Because they are also slow eaters, use a sponge filter or other low flow filtration to prevent the food from being swept away. Most tank mates should be avoided since they will outcompete the pipefish during mealtime, but snails may be useful as clean-up crew members to pick up leftover crumbs. Due to their difficulty level, they are not readily available in the aquarium hobby, so you may need to ask your local fish store if they can order them for you.

Freshwater pipefish

3. Pea Puffer

Carinotetraodon travancoricus (also known as the dwarf puffer or pea puffer) is a 1-inch (2.5 cm) freshwater pufferfish that can sometimes be hard to keep because of their semi-aggressive nature and food preferences. Feisty males like to fight with other males to establish dominance and chase females for breeding. Some people believe it is safer to keep one by itself, while others say that a large school is preferred. For a 10-gallon aquarium, you can comfortably house a single dwarf puffer and let it establish the entire tank as its territory. However, most people don’t want to look at a predominately empty setup, so you can aim to keep one male and two or three females. Unfortunately, fish stores usually receive juveniles that are hard to sex, so you may need to get a group of six pufferfish and then return some of them as they grow older if you determine you have more than one male.

Another way to minimize fighting and provide greater enrichment is to add lots of plants, rocks, driftwood, or aquarium decorations for them to explore and hide behind. Feed them live foods like small snails and frozen foods like bloodworms and brine shrimp. To avoid nutrient deficiencies, consider adding a vitamin supplement to soak the frozen foods or try training them to eat Hikari Vibra Bites (little food sticks that look like bloodworms). For more information, read our complete care guide on pea puffers.

Pea or dwarf puffers

4. Scarlet Badis

Dario dario is a 1-inch (2.5 cm) oddball nano fish that is known for its vivid red coloration with vertical striping on the body. Like the dwarf puffer, this micropredator prefers to eat tiny live foods like microworms and frozen foods like daphnia, and the males can be quite territorial towards each other. Females are a duller, brown color and therefore are rarely sold in fish stores, so your best bet is to keep a single male or three to four of them so that the aggression is spread out. If you choose to keep just one scarlet badis, they tend to stay near the bottom of the aquarium, so you could add some peaceful tank mates like clown killifish swimming up top and pink ramshorn snails as the janitorial staff. Add lots of live aquarium plants for cover, and your 10-gallon aquarium will become a beautiful home for this stunning species.

Scarlet badis

5. Kuhli Loach

If you’ve ever thought it would be cool to own a snake but your family members don’t approve, kuhli loaches might be a good alternative. Pangio kuhlii looks like a miniature eel with vertical bands alternating between tannish-yellow and dark brown. This nocturnal bottom dweller likes to scavenge for food at night, but you can encourage them to come out more by getting a school of at least three to six kuhli loaches and providing lots of plants and little nooks to hide under. They also become braver when surrounded by peaceful tank mates that won’t bully them, such as green neon tetras, ember tetras, chili rasboras, or even cherry shrimp. For more details on how to care for them, read our article on kuhli loaches.

Kuhli loach

For more recommendations on our favorite freshwater fish and plants, check out our top 10 lists on the blog.