The sexy anemone shrimp (Thor amboinensis
) can be found throughout a wide range, including many parts of the Indo-Pacific and Caribbean. However, specimens in the trade come almost exclusively from East Asia, including Indonesia and the Philippines. This shrimp comes from shallow tropical waters, where groups of them can be found living symbiotically with anemones or occasionally corals. Because they are comfortable in a wide range of habitats, they can be good candidates for a variety of aquariums, from lagoon tanks and refugiums all the way to high-flow coral reef environments.
Identification: The sexy anemone shrimp gets its name from its tendency to constantly move its tail back and forth suggestively. It is also known as the dancing shrimp for the same reason. It has an intricate spot-and-stripe pattern, and it can display fascinating symbiotic behaviors with other invertebrates. Thor amboinensis is capable of living within the tentacles of many anemones and corals in reef aquariums.
Aquarium requirements: Sexy shrimp only grow to about an inch, and they prefer to stay within their symbiotic host anemone. Space requirements for this species are minimal: a minimum tank size of 2 gallons would be comfortable for a single sexy shrimp. This species prefers to live in groups, so plan on one shrimp per every 2 gallons. Remember, however, that not all hosts will be suitable for such small tanks, so it is crucial to also plan for anemone and coral care when putting together a sexy-shrimp system. Also remember that large tanks might make it more difficult to observe this tiny shrimp, so a small system might actually be more preferable.
Thor amboinensis is a hardy shrimp, but as with all crustaceans, care should be taken to not rapidly change temperature or salinity. When purchasing or transferring this species, give special care to acclimation; most losses with this species occur during shipping or transfer. Temperature ranges of 72 to 82 degrees Fahrenheit are suitable, along with salinity higher than 32 parts per thousand (about 1.024 specific gravity). Good aeration and low levels of pollution are preferable, so reef tanks are often an ideal environment for this species. While iodine is an important component of good exoskeleton health in shrimp, it is usually possible to eliminate the need for iodine additives through regular water changes and providing foods for crustaceans.
Feeding: Sexy shrimp are planktivorous and will accept a variety of foods in the aquarium. Brine shrimp and Cyclops are good choices, but chopped Mysis shrimp and krill are also appreciated. Like most aquarium shrimp, T. amboinensis will also accept most dry foods, and a good flake or pellet food is probably the easiest staple diet to offer this shrimp.
Tankmates: Sexy shrimp are not aggressive with tankmates or with other sexy shrimp. They should, however, be kept away from any fish with a propensity to eat invertebrates. These tiny shrimp are among the smallest of available aquarium shrimp, and their small size can bring out the predatory nature in many otherwise well-behaved fish. Use caution with wrasses, basslets, large gobies and damselfishes that might ordinarily seem invertebrate-safe. Other crustaceans (particularly larger shrimp species) may also pose a threat. However, there are hobbyists who successfully keep sexy shrimp in diverse crustacean communities.
Breeding and propagation: Sexing this species can be quite easy, provided that you're dealing with mature specimens. Females are typically much larger than males and will often have a broken tail stripe (males have a solid stripe). The female sexy shrimp carries eggs on her abdomen and may produce a clutch every few weeks. To rear this species, set up a separate breeding tank and live foods. Larval sexy shrimp will reportedly accept newly hatched brine shrimp (Artemia) immediately, though success rates will likely improve if live rotifers are the first food offered. Despite their high rate of egg production and relative ease of culture, wild-caught sexy shrimp are not expensive, so commercial aquaculture is unlikely in the near future.
Notes: While the sexy shrimp lives with a number of anemone species in the wild, it is not always feasible to keep these anemones alive in aquaria. The mini carpet anemone (Stichodactyla tapetum), which is becoming more popular in the trade, can sometimes make an ideal host for these shrimp in a medium-sized reef tank, but it is not yet common in all markets. Fortunately, sexy shrimp will readily accept other cnidarians as a suitable host, including many popular and easy-to-keep stony corals. Large polyp stony corals, such as frogspawn (Euphyllia spp.), bubble (Plerogyra spp.), fox (Nemenzophyllia spp.) and brain (Trachyphyllia spp.) corals, can be suitable hosts for the sexy shrimp. FAMA.