Hitchhikers – what do they do? - NAD-Lembeh Resort
A sea cucumber or urchin might seem like something worth ignoring by most What Commensal Relationships do Emperor Shrimps Form?. Our goal for today is to answer these questions: benefits from the relationship This tiny emperor shrimp is riding along on the back of a sea cucumber. As an aside, symbiosis is actually a broad term for interactions . the emperor shrimp and medusa worm (sea cucumber) or the pearl fish and.
An easy land example of this would be a spider building its web on a tree. While the spider is benefiting from having a place to build and hide, the tree is getting nothing from this arrangement, however it is also not suffering in any way. An emperor shrimp is never spotted on its own.
It will always be hitch hiking on the back of a much larger, slow moving species of Holothurian the scientific term for sea cucumber or one of the larger species of Nudibranch, such as the Spanish Dancer Hexibranchus sanguineus. It is more common to see a single emperor shrimp on a host, but if you keep an eye on the host you may spot a second shrimp hitching a ride.
When there are two shrimps on a single host, they will often fight over who gets the best foraging turf — which is usually either around the mouth, or the anus. Should any potential predators appear, the shrimp will simply disappear underneath its host, or in other hard to reach places, such as between the branchial plumes of a dorid nudibranch.
Symbiotic Relationships by Matthew McCabe on Prezi
It not only gets protection from its giant host. The emperor shrimp will also benefit as it does not need to hunt for food — instead, as the host moves and eats, it churns up sand, and the food is practically handed to the shrimp! Although the emperor shrimp is considered a commensal shrimp, there is evidence to suggest that they will eat parasites and fungus from their hosts, which actually means that they form a mutualistic relationship where all parties involved benefit from the relationship with their host, rather than a commensal relationship.
What does an Emperor Shrimp Eat? Emperor shrimps are both carnivores and det ritovoreswhich means they survive on a diet of other animals as well as feeding on decaying organic material. When their host moves over the sea bed, they will churn up the sand, revealing a plethora of microscopic organisms both dead and alive for the emperor shrimp to feed on.
Emperor shrimp on a sea cucumber
Interestingly, they have also been observed feasting on the eggs that are released when their host sea cucumber is spawning. If you take this into account, there could be a valid argument to say that that the relationship is also slightly parasitic.
Emperor shrimps are a great example of the grey area between the different symbiotic relationships. Where can I Dive with Emperor Shrimps?
Because their hosts do not have a fixed location unlike anemone shrimp, for exampleemperor shrimps can move around the dive sites, and even leave them completely. While they can be spotted over sloping walls, such as Lekuan III, their hosts tend to live over sand and muddy flat bottoms, so you have a much better chance of spotting them while muck diving on the gentle slopes of the North Sulawesi mainland.
The majority of the time we spot them during night divesas most of their hosts are nocturnal, including almost all sea cucumber species, as well as the Spanish Dancer nudibranch. Photographing Emperor Shrimps Luckily for photographers, emperor shrimps are usually quite easy to photograph because their hosts are slow moving and not at all bothered by divers.
You may find the little shrimp tries to hide from you, but there are not so many hiding places on a sea cucumber, so if it does disappear, you just need to wait close to the host for a few minutes and it will come back out. It is important that you never try to touch either the host or the emperor shrimp, as doing so may severely harm either one — sea cucumbers have very fragile skin, and gently poking a 1cm shrimp could easily kill it.
Even if you cause it no harm, it is likely to be scared and will go deeper into hiding, which will ruin the encounter for you and the rest of your group. The porcelain crabs get a perch to sit on and protection among the arms of the soft coral, while the soft coral is unaffected. Porcelain crab on Dendronephtya soft coral Another example would be the gobies that live on many other animals in the sea, often changing colour to closely resembling their host.
It is likely that the host in most circumstances are rather unaffected by the gobies seeking shelter. Commensal goby The gobies and the porcelain crabs exemplify commensalistic interactions where one species lives on the other species, which is a true symbiosis. This was clear when we were in a slight current on Hairball, watching a box crab rip a smaller crab to pieces.
Box crabs are messy feeders, so a lot of the bits and pieces of the crab were swept down current out of reach of the box crab.
Emperor shrimp on a sea cucumber - Stock Image - Z/ - Science Photo Library
However, it was not just lost, as a couple of big flounders quickly placed themselves behind the crab and ate the morsels coming with the current, benefitting the flounders without harming the box crab. Box crab with waiting flounder Finally, one part of the pair can already be dead when the commensalistic interaction takes place. Hermit crabs, having to find shelter for their soft anterior parts, need empty shells in order to hide the unprotected part of their body.
Different snails provide these shell after the snails are dead, which means that the hermit crabs are benefitted by the presence of snails, while snails are unaffected by hermit crabs.