How to Breed Amano Shrimps – A Complete Success Guide
To breed amano shrimps, move the newly hatched larvae from freshwater into brackish water with a salinity of 30-35 ppt. Feed them live phytoplankton until they undergo metamorphosis, then slowly transition the shrimplets back to freshwater.
Amano shrimp, scientifically known as Caridina multidentata, are among the most popular cleanup crew members in the aquarium hobby. While they are incredibly hardy as adults, learning how to breed amano shrimps is often considered a significant challenge for many keepers.
The difficulty lies in their unique life cycle, which is described as amphidromous. This means that while the adults live and mate in freshwater, their offspring require a marine or brackish environment to survive their early stages.
Without the correct salinity and microscopic food sources, the larvae will perish within days of hatching. This guide provides a detailed, expert-level roadmap to help you navigate this complex biological process and successfully raise a new generation of shrimp.
Identifying Male and Female Amano Shrimp
Before you can begin the breeding process, you must ensure you have a compatible pair. Unlike some other species, sexing Caridina multidentata is relatively straightforward once they reach maturity.
Females are significantly larger and bulkier than males, often reaching up to two inches in length. The most reliable way to identify a female is by looking at the markings along the side of her abdomen.
On a female, these markings appear as broken lines or long dashes, whereas on a male, they appear as distinct, circular dots. Additionally, mature females will develop a “saddle,” which is the mass of unfertilized eggs visible behind the head.
Visual Differences for Sexing
| Feature | Male Amano Shrimp | Female Amano Shrimp |
|---|---|---|
| Body Size | Smaller and more slender | Larger and broader abdomen |
| Side Markings | Clean, circular dots | Long, broken lines or dashes |
| Egg Carrying | Never carries eggs | Carries “berried” eggs under pleopods |
Understanding these differences is the first step in how to breed amano shrimps successfully. If you have a group of at least six shrimp, you are almost guaranteed to have a mix of both sexes.
Preparing the Breeding and Larval Tanks
Success in breeding this species requires more than just a single aquarium. You will need a dedicated setup for the adults to mate and a separate, specialized environment for the larvae to grow.
The adult tank should be a standard freshwater setup with plenty of hiding places and stable water parameters. High-quality water is essential for triggering the molting process, which is when mating typically occurs.
The second tank, often called the larval tank or zoea station, is where the real work begins. This tank does not need to be large; a 5 to 10-gallon aquarium or even a large glass jar is sufficient for the early stages.
Pro Tip: Use a small air-driven sponge filter in the adult tank, but avoid any mechanical filtration in the larval tank. Larvae are incredibly small and will be sucked into even the weakest power filters.
You must also prepare your marine salt mix in advance. Using a high-quality refractometer is vital to ensure the specific gravity remains consistent at 1.024 to 1.026, which corresponds to roughly 30-35 parts per thousand (ppt).
The Mating Process and “Berried” Females
When a female amano shrimp molts, she releases pheromones into the water that signal to the males she is ready to mate. You will often see the males swimming frantically around the tank searching for her during this time.
Once the eggs are fertilized, the female moves them to her pleopods, or swimmerets, under her tail. At this stage, she is considered “berried,” and she will carry hundreds of tiny, greenish-tan eggs for several weeks.
During the incubation period, the female constantly fans the eggs with her swimmerets to keep them oxygenated and clean. It is important to keep the water parameters stable and avoid any major changes that could stress her into dropping the eggs.
As the eggs develop, they will change color, shifting from a dark green to a lighter, translucent tan. If you look closely with a magnifying glass, you can even see the tiny black eyes of the developing larvae inside the eggs.
Step-By-Step: how to breed amano shrimps in Brackish Water
The most critical phase of how to breed amano shrimps is the transition from freshwater to brackish water. In nature, the current carries the newly hatched larvae downstream toward the ocean.
In the home aquarium, you must replicate this by moving the larvae yourself. You have two main options: moving the berried female to a hatching tank or collecting the larvae after they hatch in the main tank.
Moving the female to a separate freshwater hatching tank a few days before she releases the larvae is generally the safest method. Once the larvae are released, you must remove the female and return her to the main tank immediately.
The larvae, known as zoea, can survive in freshwater for only about 24 to 48 hours. Within this window, you must gradually or directly introduce them to the prepared salt water.
Salinity and Transition Schedule
| Stage | Salinity (ppt) | Duration |
|---|---|---|
| Hatching Phase | 0 (Freshwater) | 1-2 Days |
| Larval Growth | 30 – 35 (Marine) | 30-50 Days |
| Post-Larvae Transition | Gradual reduction to 0 | 2-5 Days |
Many successful breeders prefer a direct transfer to 35 ppt saltwater. While this seems like it would cause osmotic shock, the larvae are biologically programmed to handle this sudden change as they “reach the sea.”
Feeding the Zoea with Phytoplankton
Once the larvae are in the saltwater tank, their survival depends entirely on the availability of food. They are filter feeders and are far too small to eat crushed flakes or standard shrimp pellets.
The primary food source for amano larvae is live phytoplankton, specifically Tetraselmis or Nannochloropsis. This is often referred to as “green water” because the density of the algae turns the water a vibrant green hue.
You should aim for a light green tint in the larval tank at all times. This ensures that the zoea are constantly surrounded by microscopic nutrients, which they consume as they float through the water column.
If you cannot culture your own live algae, high-quality commercial phytoplankton concentrates can work. However, live cultures are superior as they help maintain water quality rather than adding to the organic load.
Common Mistake: Overfeeding with powdered foods is the number one cause of larval tank crashes. Stick to live algae cultures to prevent ammonia spikes that will kill the entire brood in hours.
Monitoring the larvae is fascinating; they will swim upside down and are attracted to light. You can use a small flashlight to gather them in one corner of the tank to check their health and development.
The larval stage typically lasts between 30 and 50 days, depending on the temperature and food availability. During this time, they will undergo several molts as they grow into post-larvae.
You will know they are ready to transition when they stop swimming upside down and begin to look like miniature versions of adult shrimp. At this point, they will also start crawling on the bottom and sides of the tank.
Once they have completed metamorphosis, they must be moved back to freshwater. However, unlike the initial move to saltwater, this transition must be very gradual to avoid killing the young shrimplets.
The best method is to perform 20% water changes every few hours with freshwater, slowly diluting the salinity over a period of two to three days. This allows their internal systems to adjust to the lower osmotic pressure.
Compared to breeding various freshwater species, the amano transition is much more delicate. Once they are fully acclimated to 0 ppt salinity, they can be moved into a grow-out tank or a community aquarium.
Essential Equipment for Shrimp Breeding
To increase your success rate when researching how to breed amano shrimps, having the right tools is non-negotiable. Precision is the difference between a successful brood and a total loss.
A high-quality refractometer is much more accurate than a plastic hydrometer for measuring salinity. Even a slight deviation in salt levels can halt the development of the zoea or cause a failed molt.
Lighting is also crucial for the larval tank. You need enough light to keep the phytoplankton alive and reproducing, but not so much that it causes temperature swings in the small larval vessel.
Finally, consider the behavioral differences compared to different shrimp behaviors you might have seen. Amano larvae are planktonic, meaning they drift with the current, so keeping them suspended with very gentle aeration is key.
Frequently Asked Questions About Amano Breeding
Can amano shrimp breed in pure freshwater?
No, while the adults can mate and the female can carry eggs in freshwater, the larvae will die within 48 hours if they are not moved to brackish or marine water.
How many eggs does a female amano shrimp carry?
A healthy, mature female can carry anywhere from several hundred to over a thousand eggs in a single brood.
What is the best temperature for the larval tank?
Maintaining a temperature between 72°F and 78°F (22-25°C) is ideal. Higher temperatures can speed up development but may also lead to faster bacteria growth.
Do I need to use an air stone in the larval tank?
Yes, a very gentle stream of bubbles is necessary to provide oxygen and keep the larvae and phytoplankton in suspension. Large, vigorous bubbles should be avoided.
How long do the larvae stay in the brackish water?
The larvae typically stay in the saltwater for 30 to 50 days until they transform into post-larvae shrimplets.
Final Thoughts on Raising Amano Shrimplets
Mastering how to breed amano shrimps is a rewarding challenge that sets advanced aquarists apart from the rest. It requires a blend of biology, water chemistry, and extreme patience.
While the process is significantly more involved than breeding cherry shrimp or guppies, the sight of hundreds of tiny shrimplets successfully transitioning to freshwater is an unparalleled experience.
By focusing on high-quality live food and precise salinity management, you can successfully navigate the larval stages. Remember that even professional breeders experience losses, so do not be discouraged if your first few attempts are not perfect.
With persistence and attention to detail, you will soon have a thriving population of home-bred amano shrimp to help keep your aquariums clean and beautiful.