Sexy Shrimp – Thor amboinensis
Have you ever wondered where the common name for the ‘Sexy Shrimp’ comes from? Or where the best spots are for finding them in North Sulawesi? In this Blog we take a look at this cute little photogenic critter and its habits in more detail.
Introducing Thor amboinensis
Thor amboinensis is the scientific name for the more commonly known ‘Sexy Shrimp’ or ‘Squat Shrimp’. Sexy shrimp are a small species of shrimp which grow to around half an inch in length (1.5cm approx.). They are found across Indonesia and they take the latter part of their scientific name from the Indonesian island of Ambon in Maluku, where they were first discovered.
Sexy shrimps have a highly distinctive coloration – they are a bright orange with white patches that are edged in an extremely fine electric blue line. The common names of ‘sexy’ and ‘squat’ come from the shrimp’s posture – it carries its fan-like tail above its head while squatting and making bobbing or dancing motions.
Sexy Shrimp and Symbiosis
Sexy shrimps are often found in numbers. They are social creatures that live in symbiosis communities (mostly) with sea anemones in North Sulawesi (they will inhabit other invertebrates such as mushroom corals if anemones are not prevalent). The sexy shrimp and its host both benefit from this shared mutual relationship. The sexy shrimp will feed on parasites that would otherwise be harmful to the anemone and the anemone not only provides the shrimp with a source of food but their stinging tentacles also offer protection from predators.
Reproduction and the Life Cycle of the Sexy Shrimp
After mating has occurred, female sexy shrimps carry their fertilized eggs under their abdomens until the time when they are ready to hatch. At the time of hatching, the shrimp is in its larvae stage – it will later undergo a metamorphosis into a juvenile, yet fully formed shrimp.
An interesting fact about sexy shrimp is that although they will inhabit multiple species of anemones and invertebrates, some experiments appear to show (but not yet scientifically proven) that juveniles are more highly attracted to the same species of anemone as their parent shrimp had inhabited!
Sexy Shrimp Dietary Habits
As discussed above, sexy shrimps will feed on parasites that become entrapped in their host anemones tentacles. If there is a shortage of parasites they will search within the anemone for other scraps. If they become desperate for food they may turn to feeding on the anemones protective mucus which changes the relationship from symbiotic to parasitism – with the sexy shrimp effectively becoming the parasite!
Best Dive Sites for Sexy Shrimp in North Sulawesi
For divers who take a Passport to Paradise with us (Bunaken/Manado, Bangka Island and Lembeh Strait), there are sexy shrimp to be found in all locations. One of our favorite sites for spotting these colorful critters is our very own House Reefs at Murex Manado, Murex Bangka and at Lembeh Resort.
Each of these North Sulawesi Resorts has a beautiful house reef which is just a step off the shore – making for very easy and accessible diving! All three of the house reefs are home to a variety of anemone species which are hot spots for sexy shrimp as well as porcelain crabs and a variety of other commensal shrimps.
Sexy Shrimp and Underwater Photography
Sexy shrimp are excellent macro photography subjects for underwater photographers. The finer details, such as the fine blue line that borders the white patches on their bodies, can be photographed beautifully. Sexy shrimp are a shy species of shrimp so patience is required to obtain a good image. Because they are most likely found around or under an anemone, it pays to watch the anemone as it sways with the current. Gaining an understanding of the movement of the anemone in accordance with any surge will help you to time your shot to when the shrimp is most visible and unobstructed by the anemones tentacles.
Tip: Because sexy shrimp are often found in communities, focus on one particular individual to get in crisp focus – this ideally will be the one that is closest to your camera lens.
Planning to Join us in North Sulawesi?
If you are planning your next dive trip and are considering staying and diving with us at Murex Manado, Murex Bangka or want to take a Passport to Paradise with us, get in touch! Let us know your travel dates and where you would like to stay and we’ll get back to you with a sample package and itinerary.
Contact our amazing reservations team here: [email protected].
Did you enjoy reading this Blog? If you are a marine life aficionado and would like to read more about the marine species found in North Sulawesi, you may enjoy reading some of the following articles: