Remarks: Opae ula, also known as Hawaiian red shrimp or volcano shrimp, are incredible examples of how adaptable some animals can be. These tiny, bright red shrimp live only in brackish pools on the Hawaiian Islands, most commonly in volcanic anchialine pools which gives them their other common name of volcano shrimp. These shallow, brackish pools have forced this species to become incredibly hardy as salinity and temperature levels fluctuate with with the tides. These levels can range anywhere from a temperature in the high 30s to the low 90s (in Fahrenheit) and salinity levels from 1.000 specific gravity all the way to 1.026 specific gravity, that is anywhere from completely fresh water to full saltwater! Not only that, wild shrimps also will sometimes have to go long periods of time without food resulting in them being able to survive on very little for years on end. While opae ula can survive these incredible extremes and through times of heavily fouled water and scarce food, this does not mean they will thrive in improper conditions in the home aquarium forever. Their hardiness has resulted in it being popular to keep these shrimps in "ecospheres" which are completely enclosed spheres with the belief they will be fully self-sustaining systems. The reality is that these systems, while they may last for a few years, are not perfect systems and will eventually crash long before the full potential of the opae ula's lifespan is carried out as they slowly die from a mixture of suffocation, starvation, and poisoning from fouling water. Instead, these shrimps should be kept in a brackish water set up with a salinity between 1.008 - 1.016 specific gravity that has been given time to cycle and accumulate at least a little bit of algae and biofilm for them to feed on. We keep our colonies at a salinity of about 1.010 - 1.012 specific gravity. As these shrimps are very hardy and low maintenance, they can typically go months without a water change. Anything is on the menu as well so they can be fed a variety of foods for aquatics along with fresh vegetables like zucchini. Due to the fact that they are so small and require brackish conditions, most tankmates are advised against though some options are nerite snails and neon blue eye rainbowfish, however these fish should only be kept with well established colonies as they will occasionally eat shrimplets. Provided the right conditions opae ula can be excellent pets with their low maintenance, bright red colors, and a lifespan of up to 20 years in captivity.
