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Overview
Opae Ula shrimp, also known as Hawaiian red shrimp, are an uncommon species of dwarf shrimp that have been gaining popularity among aquarists due to their incredible resilience and their hardiness, which makes them the perfect no to low maintenance pet. In this article, we'll explore everything you need to know about these extraordinary shrimp, from their natural habitat and care requirements to breeding tips and setting up the perfect tank. Whether you're a seasoned aquarist or just starting out, Opae Ula shrimp are an excellent choice for those seeking a truly no to low maintenance aquatic pet.
1. Origin
Halocaridina rubra, also commonly known as Hawaiian Red Shrimp or Opae ula (meaning "red shrimp" in Hawaiian), may look a little like your typical old red cherry shrimp, but they're actually a unique, brackish-water species of dwarf shrimp that are native to the anchialine pools (natural pools in volcanic rock with brackish water and underground connection to the ocean) in the Hawaiian islands. These tiny shrimp have evolved to thrive in some of the most challenging environments, and have evolved to survive in low-oxygen environments and can tolerate wide ranges of salinity and water temperatures, making them incredibly hardy and suitable for various setups.
2. Size
They are smaller than popular dwarf shrimp species like Neocaridina Shrimp, ranging from 0.5"-1" when fully grown.
3. Lifespan
Opae ula are a surprisingly long-lived species due to their slow metabolism. On average, these shrimp typically have a lifespan between 10 and 15 years, but have been known to live for as long as 20 years in captivity.
4. Diet
Opae Ula are herbivorous and detritivorous, primarily relying on algae and biofilm as their main sources of food. Thanks to their small size and low metabolism, these shrimp require minimal food intake, having the ability to survive for extended periods, even months, without additional food, with no adverse effects on their health.
To ensure their well-being, you can supplement their diet with a small amount of algae-based food or spirulina flakes, but this should be done sparingly—once every few weeks is sufficient. It's important to exercise caution when feeding, as overfeeding can lead to excess food accumulating in the tank, which can degrade water quality and disrupt the delicate balance of the ecosystem. Therefore, it's better to err on the side of underfeeding, relying on the natural growth of algae and biofilm within the tank to sustain your shrimp.
This naturalistic feeding approach not only keeps the shrimp healthy but also helps maintain a stable and clean aquatic environment, allowing your Opae Ula to thrive with minimal intervention.
5. Differences Between Males And Females
Step-by-Step Tank Setup
Setting up an Opae Ula tank is a relatively easy process, and can be a fun activity to do over the weekend. Here's a step-by-step guide to help you create the perfect environment for your shrimp.
Step 1: Select the Tank/Jar
These shrimp aren’t high-maintenance, so they don’t need a mansion, a 1-5 gallon tank or even a simple glass jar will do the trick. We recommend going with at least 2 gallons, though, because why not give them a little elbow room? Just make sure to rinse everything thoroughly—no soap or chemicals.
Some Example Tank/Jar Options:
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Step 2: Add Substrate and Decor
We recommend using crushed coral or aragonite sand for substrate. Do make sure you place some décor in the tank, as it will help to increase the surface area for your Opae Ula's favorite food (biofilm) to potentially grow on. Adding Lava Rock will also help to create a more natural habitat for your pet shrimp.
OptionalDecorative Objects:
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Step 3: Preparing the Brackish Water
You MUST use reef/marine aquarium salt, not just table salt or “aquarium salt” as they won't have the trace minerals needed for a brackish tank.
Add around 2 tablespoons of reef/marine aquarium salt per gallon of distilled or RO (reverse osmosis) water and stir or place an air stone in the bucket to dissolve to achieve a salinity level of 1.008-1.018 SG. The ideal range we have found is 1.010-1.012 SG (specific gravity).
Use a hydrometer or refractometer to measure the salinity accurately.
Slowly pour the prepared saltwater into the tank, being careful not to disturb the substrate too much.
Step 4: Add Additional Equipment IF Needed
- Filtration
A filter isn't technically needed, but if you do want to provide some water movement or would like to establish a sturdier nitrogen cycle, a sponge filter would help this process go quicker, especially if you are setting up a much larger tank (e.g. 5 gallons or larger), but again this isn't really necessary provided you have other surfaces, such as the lava rock, that the bacteria can colonize on.
- Heater
As for an aquarium heater, unless you live in a colder climate where it often goes below 50F, installing an aquarium heater won't be necessary. However, if you want to add one in to help keep the temperatures from fluctuating, we would recommend that you set the heater to maintain a temperature between 72-82°F. While Opae Ula can tolerate a wide range of temperatures, they thrive best in a stable environment.
- Light
Light is not needed if you plan to have your tank setup in a relatively bright area, such as a window sill. Set up an LED light to provide a natural day/night cycle using a smart plug or mechanical timer outlet to allow the light to be turned on for about 8-12 hours per day.
Step 5: Cycling the Tank
Although these shrimp are very hardy, we still recommend waiting until the tank has cycled before introducing them for the best results. The easiest way to get this done is to add some Malaysian Trumpet Snails (yes, they can be kept in brackish water!) and let the tank cycle naturally for 4-6 weeks before introducing the shrimp. This process establishes beneficial bacteria that will help break down waste products.
Step 6: Introducing the Shrimp
When you’re ready to introduce your Opae Ula, float their bag in the tank for about 15-20 minutes to equalize the temperature. Slowly add small amounts of tank water to the bag over the course of an hour to acclimate them to the new water conditions. Once they've been acclimated to the new water, gently release the shrimp into the tank, making sure they are not stressed by the transition.
Step 7: Water Changes/Water Top Offs
These shrimp are the definition of “set it and forget it.” You don’t need to do water changes often, but top off the tank with fresh distilled water to replace any lost to evaporation. That’s it. Easy peasy. Our Opae Ula have been breeding in water that has not been changed, ever. However, if you feel the need to, you can perform small water changes (about 10%) every few months, using pre-mixed brackish at the same salinity as your tank.
Breeding Opae Ula Shrimp
Breeding Opae Ula is a relatively straightforward process that requires minimal intervention. The key to success in breeding Opae Ula is patience, as the breeding process is gradual. Females mature slowly and do not become gravid frequently, so it’s important to be patient and allow nature to take its course.
Unlike Neocaridina shrimp, Opae Ula undergo a larval stage before fully developing. Once the female carries eggs, it takes up to 38 days for them to hatch into larvae, known as zoeae. These larvae are extremely tiny and display characteristic behaviors such as swimming to the surface and then drifting downward or jerking upward in the water column. Despite their size, they are self-sufficient and are not disturbed by the adult shrimp.
After approximately a month, the larvae undergo metamorphosis, transforming into fully developed miniature shrimp. At this stage, they are capable of finding food and foraging alongside the adult members of the colony, seamlessly integrating into the ecosystem. This natural progression requires no special care, allowing you to observe the fascinating life cycle of these unique shrimp.
Enjoy Your Opae Ula Tank!
Setting up an Opae Ula tank is a rewarding project that brings years of enjoyment. These hardy shrimp don’t just survive—they thrive, often breeding and creating a small ecosystem right in your living room. Whether you’re watching them interact with their surroundings or simply enjoying the natural beauty of their habitat, Opae Ula shrimp are the ultimate aquatic companions for those seeking a truly low-maintenance pet. Happy shrimp keeping!
