Opae Ula shrimp, also known as Hawaiian red shrimp, are a unique and highly sought-after species of freshwater shrimp that are native to the Hawaiian Islands. These small and colorful shrimp have gained popularity among aquarium hobbyists due to their hardiness, ease of care, and interesting behaviors. In this article, we’ll discuss the natural habitat, physical characteristics, care requirements, and other important information about keeping and caring for Opae Ula shrimp.
Scientific name: | Halocaridina Rubra |
Also known as: | Opae Ula Shrimp, Tiny red shrimp, Super shrimp, Hawaiian lava shrimp, Hawaiian red shrimp, Hawaiian volcano shrimp, Anchialine shrimp, Micro lobster, Wonder shrimp |
Origin: | Hawaii |
Size: | 0.5 inches |
Life expectancy: | Up to 20 years |
Color: | Red |
Diet: | Omnivore |
Temperament: | Peaceful |
Minimum tank size: | 5 gallons |
Temperature: | 68–80°F (20–27°C) |
pH: | 8.0–8.5 |
Hardness: | 0.0–12.0 dGH |
Care level: | Beginner |
Natural Habitat and Distribution
Opae Ula shrimp are found in freshwater ponds and streams throughout the Hawaiian Islands. They are a highly adaptable species and can be found in a wide range of environments, from lowland streams to high-altitude volcanic crater lakes. In the wild, Opae Ula shrimp live in areas with minimal current, often in brackish water environments with low salinity.
Physical Characteristics

Opae Ula shrimp are small in size, with adult specimens typically reaching a maximum length of 1 inch (2.5 cm). They have a distinctive red coloration, with a translucent body that allows their internal organs to be seen. The shrimp have two long antennae, which they use to sense their environment and locate food, and their tails end in a forked, paddle-like shape that they use to swim.
Water Parameters and Tank Setup
Opae Ula shrimp are highly adaptable and can tolerate a wide range of water parameters. In captivity, they can be kept in a small tank or even in a jar, as long as the water conditions are appropriate. The ideal temperature range for Opae Ula shrimp is 72-78°F (22-26°C), with a pH range of 7.2-8.0 and a salinity level between 1.005 and 1.015. The addition of crushed coral or aragonite sand can help maintain the pH and hardness levels.
Diet and Feeding
Opae Ula shrimp are primarily scavengers and will feed on a variety of organic matter, including algae, detritus, and small invertebrates. In the aquarium, they can be fed a variety of prepared foods, such as shrimp pellets, flakes, and algae wafers, as well as live or frozen foods, such as brine shrimp or krill. It’s important not to overfeed Opae Ula shrimp, as they are sensitive to changes in water quality.
Compatibility and Tank Mates
Opae ula shrimp are generally peaceful and can be kept with a variety of other small, non-aggressive fish and invertebrates, such as snails or small crabs. However, as mentioned earlier, it is important to choose tank mates carefully and provide ample hiding places for the shrimp to retreat to.
Here are some examples of suitable tank mates for Opae ula shrimp:
- Snails – Snails are peaceful and can help keep the tank clean by eating algae and other debris.
- Dwarf shrimp – Some species of dwarf shrimp, such as Neocaridina and Caridina, can be kept with Opae ula shrimp. However, it is important to make sure that the shrimp are of a similar size and temperament.
- Small crabs – Small crabs, such as Pom Pom crabs or Sally Lightfoot crabs, can be kept with Opae ula shrimp. However, it is important to make sure that the crabs are not aggressive and will not harm the shrimp.
- Gobies – Some species of gobies, such as the Clown Goby or the Neon Goby, can be kept with Opae ula shrimp. However, it is important to make sure that the gobies are not aggressive and will not harm the shrimp.
It is important to note that Opae ula shrimp are very small and can be easily preyed upon by larger or more aggressive tank mates. Therefore, it is important to choose tank mates carefully and provide ample hiding places for the shrimp to retreat to.
Breeding and Reproduction

Opae ula shrimp are relatively easy to breed, and they will often reproduce on their own in a well-maintained aquarium. However, if you want to maximize breeding success, there are a few steps you can take to promote breeding.
- Provide a suitable environment – Opae ula shrimp require a specific environment in order to breed successfully. This includes a brackish water environment with a pH of 7.5-8.5, a temperature between 68-84°F, and a salinity of 1.010-1.018.
- Increase food supply – Opae ula shrimp will breed more readily when there is an ample food supply. This can be accomplished by feeding the shrimp a variety of foods, such as algae wafers, brine shrimp, and crushed flakes.
- Ensure proper lighting – Opae ula shrimp are sensitive to lighting conditions, and they require a proper light cycle in order to breed successfully. Make sure to provide a light cycle of 8-10 hours per day, with a period of darkness at night.
- Provide hiding places – Opae ula shrimp will breed more readily when they have ample hiding places to retreat to. This can be accomplished by providing plenty of live rock or other decorations in the aquarium.
- Monitor water parameters – It is important to monitor water parameters closely when breeding Opae ula shrimp. Keep the water clean and well-maintained, and make sure that the pH, temperature, and salinity levels are within the appropriate range.
Opae ula shrimp will carry their eggs for several weeks before they hatch. Once the eggs hatch, the young shrimp will be able to care for themselves and will begin to feed on algae and other microorganisms in the tank. It is important to provide ample food for the young shrimp to ensure their survival.
Overall, Opae ula shrimp are relatively easy to breed and can be a rewarding addition to any brackish water aquarium. By providing a suitable environment, ample food, proper lighting, hiding places, and close monitoring of water parameters, you can increase breeding success and enjoy a thriving colony of these fascinating and unique shrimp.
Common Diseases and Health Issues
Opae ula shrimp are generally hardy and resistant to disease. However, they can still be affected by a range of common diseases and health issues, including:
- Molting problems: Like all crustaceans, opae ula shrimp periodically shed their exoskeleton in order to grow. However, this process can sometimes be hindered by poor water quality or other environmental stressors, leading to incomplete molting or difficulty shedding. If you notice your shrimp struggling to molt, you should check your water parameters and consider making adjustments to improve water quality.
- Bacterial and fungal infections: Opae ula shrimp can be susceptible to bacterial and fungal infections, especially if they have recently molted or have small cuts or abrasions on their exoskeleton. Signs of infection may include discoloration, lethargy, and decreased appetite. Treatment options may include medicated baths or antibiotic medication.
- Parasitic infestations: Opae ula shrimp can also be affected by parasitic infestations, such as copepods or mites. These tiny organisms can attach themselves to the shrimp’s exoskeleton and cause irritation, discoloration, and lethargy. Treatment options may include medicated baths or targeted removal using a magnifying glass and fine-tipped tweezers.
- Stress-related illnesses: Like all animals, opae ula shrimp can experience stress in response to changes in their environment, such as sudden fluctuations in temperature, poor water quality, or aggression from tank mates. Stress can weaken the shrimp’s immune system and make them more susceptible to disease. To minimize stress, it’s important to maintain a stable and well-maintained aquarium environment.
Care Instructions
Opae ula shrimp are relatively easy to care for, but there are some specific considerations to keep in mind when setting up and maintaining their aquarium:
- Tank size: Opae ula shrimp can be kept in relatively small aquariums, with a minimum recommended size of 2.5 gallons for a small colony of 5-10 shrimp. However, larger aquariums will provide more stable water parameters and allow for a more naturalistic environment with more hiding places and room to swim.
- Water parameters: Opae ula shrimp prefer brackish water conditions, with a salinity range of 1.010-1.015 and a pH range of 7.5-8.5. They are also tolerant of a wide range of temperatures, with a recommended range of 68-82°F. It’s important to maintain stable and consistent water parameters, as sudden changes can be stressful and harmful to the shrimp.
- Substrate and decor: Opae ula shrimp prefer a substrate of sand or small gravel, which allows them to burrow and sift for food. They also benefit from a variety of hiding places and decor, such as rocks, plants, and driftwood. However, it’s important to avoid sharp or rough materials that could damage their delicate exoskeleton.
- Feeding: Opae ula shrimp are omnivores and will feed on a variety of small organisms, such as algae, detritus, and small crustaceans. In the aquarium, they can be fed a variety of prepared foods, such as shrimp pellets or algae wafers, as well as live or frozen foods, such as brine shrimp or daphnia. It’s important not to overfeed, as excess food can lead to poor water quality and potential health issues.
- Tank mates: Opae ula shrimp are generally peaceful and can be kept with a variety of other small, non-aggressive fish and invertebrates, such as snails or small crabs. However, it is important to note that Opae ula shrimp are very small and can be easily preyed upon by larger or more aggressive tank mates. Therefore, it is important to choose tank mates carefully and provide ample hiding places for the shrimp to retreat to.
Conclusion

Opae ula shrimp are a unique and fascinating addition to any home aquarium. Their hardiness, low maintenance requirements, and ability to thrive in a variety of tank setups make them an ideal choice for both beginner and experienced aquarists.
By providing the proper tank setup, feeding, and care, you can enjoy the beauty and intrigue of these shrimp for years to come. Whether you are looking for a new centerpiece for your aquarium or simply want to add some diversity to your aquatic community, Opae ula shrimp are an excellent choice.