Why Our Shrimp Changed Color in Our Fish Tank

Populating an aquarium with shrimp can make for a colorful and distinctive fish tank, however there are some things to keep in mind. Since shrimp are so small, particularly the offspring, and since other fish often feed on shrimp, the shrimp should be kept in a separate aquarium from other fish. A sponge filter should be used with a shrimp aquarium to prevent young shrimp from being sucked up the filter. Another thing to keep in mind is that shrimp can and will change color for a variety of reasons.

  1. Camouflage

    • Shrimp have been known to change colors to match their surroundings. Shrimp in a tank with a black sand bottom have been observed to be more colorful than the same shrimp in a tank with a light colored sandy bottom. Even in the wild, shrimp in a dark or colorful landscape will themselves be darker and more colorful than their relatives in a clear or light-colored environment. A brightly lit aquarium can cause a shrimp to become lighter in color.

    Diet

    • Diet can also cause shrimp to lose or change color. Many commercially available fish foods do not contain the whole range of ingredients that shrimp would consume in the wild. Although their primary diet is composed of algae, they often also consume parts of dead marine life and insects. Though such matter is consumed in very small quantities, an absence of this material from the fish diet can lead to a dulling of the shrimp's color.

    Natural Fluctuations

    • Some shrimp naturally change color and can do so quite rapidly both in the wild and in captivity. A fish such as the freshwater Singapore Flower Shrimp can quickly change colors from tan to dark brown and occasionally to a bright red. The reasons for these color changes are not entirely known. Camouflage is believed to be a part of the change. However mood or possibly mating signals may also play a part in the color changes.

    Restoring Color

    • Restoring the original color to shrimp that have become pale or faded will depend on what has caused the shrimp to lose color. Replacing light-colored pebbles at the bottom of an aquarium or turning off a bright fluorescent light will help to bring back some color to shrimp who have lost color due to their environment. For shrimp with a dietary deficiency, it may be necessary to switch to a specialized food that is designed to enhance their color with the addition of dead insect and other animal life.