Freshwater shrimp have become popular inhabitants of home aquariums due to their small stature and continuous activity. These invertebrates function as natural cleaners, constantly grazing on algae and biofilm, which contributes to a healthier tank environment. Their movement is distinct, often involving a slow crawl or sudden bursts of swimming, adding a different dynamic compared to fish. Selectively bred varieties display a wide spectrum of colors, making them attractive additions to planted setups.
Diversity and Natural Environments
Freshwater aquarium shrimp are largely categorized into two primary genera: Neocaridina and Caridina. Neocaridina species, including the hardy Cherry Shrimp, originate primarily from freshwater bodies in parts of Asia, such as Taiwan and China. These shrimp naturally inhabit slow-moving streams and heavily vegetated areas, and their robustness allows them to adapt to a wider range of water conditions in captivity.
Caridina species, like the delicate Crystal Red Shrimp, come from various regions in Asia, including Southeast Asia and Japan. Their natural environments are specialized, consisting of soft, slightly acidic mountain streams or clear, mineral-rich lakes. Understanding these origins is key, as the water chemistry of the natural habitat dictates the care requirements needed for each group to thrive.
Essential Aquarium Setup
A dedicated shrimp habitat should begin with a tank size of at least 5 gallons, though 10-gallon tanks are easier to keep stable. The substrate can be inert gravel or sand for Neocaridina, or specialized buffering aquarium soil for Caridina to maintain their preferred lower pH. Filtration must be gentle to protect the invertebrates, particularly shrimplets; air-driven sponge filters are ideal because they prevent the shrimp from being drawn into the mechanism.
The internal environment must be rich in structure, provided by live plants and hardscape materials like driftwood and rockwork. Aquatic mosses, such as Java moss, are beneficial as they offer extensive surface area for biofilm growth and provide safe hiding spots for vulnerable, newly molted shrimp. While many species tolerate room temperature, a heater is used to prevent sudden temperature fluctuations.
Water Quality and Maintenance
The survival of freshwater shrimp is directly linked to stable water chemistry, requiring a fully cycled aquarium to ensure zero ammonia and nitrite levels. Nitrate, the third component of the nitrogen cycle, should be kept consistently low, ideally below 10 parts per million. Water parameters vary significantly between the two main genera, and stability is more important than achieving specific numbers.
Neocaridina shrimp are more tolerant, thriving in harder, more alkaline water (pH 6.5 to 8.0). Caridina species, conversely, require softer, more acidic water (pH 5.5 to 6.5) with very low carbonate hardness (KH). Maintaining this balance requires consistent water changes, using dechlorinated tap water for Neocaridina, or remineralized reverse osmosis (RO) water for the more sensitive Caridina.
Feeding and Behavioral Needs
Freshwater shrimp are omnivorous scavengers that spend the majority of their time grazing on biofilm, a thin layer of microorganisms that grows on tank surfaces. Supplemental feeding should be infrequent—two to three times per week—to prevent overfeeding, which quickly degrades water quality. Suitable foods include specialized shrimp pellets, algae wafers, and blanched vegetables like zucchini or spinach.
Molting is the periodic shedding of the hard exoskeleton necessary for growth. Before molting, the shrimp absorbs minerals, particularly calcium, from the old shell to prepare the new one underneath. The shed exoskeleton should be left in the tank, as the shrimp may consume it to reclaim lost calcium and other nutrients needed to harden their new shell. Molting failures are symptomatic of insufficient general hardness (GH) or rapid changes in water parameters, highlighting the need for mineral stability.