The blind shrimp and the macaroni goby | NAD-Lembeh Resort
This picture book for children takes a journey under the sea and tells the colorful story of a unique relationship between a shrimp born blind and a mud-sucking. There are many goby fish species that coexist with shrimp, in one of nature's most fascinating symbiotic relationships. The shrimp is blind, and builds a burrow. In the goby and pistol shrimp symbiosis, both animals benefit. The nearly blind shrimp can then retreat into the burrow to be spared from predation.
Ctenogobiops and Vanderhorstia are quite diffused all around tropical Indo-Pacific waters, but few species have been official described until now. One genus particularly loved by aquarists, Stonogobiops, includes few species all with swim bladder that allows them to hover motionless few centimeters on the top of the burrow entrance. Shrimpgobies in the wild feed on zooplankton mainly. Quite often a couple of gobies inhabits the same burrow, where the female lays the eggs.
They are territorial fish even if the territory is not very large and in the same area it's possible to find several couples. They are not very good swimmer of course, but can be very fast. House-maid Shrimp All the shrimps living in association with a goby belong to the Alpheidae family genera Alpheus or Synalpheus.
They are even called "Snapping Shrimps" or "Pistol Shrimps" for their ability to produce a loud snapping sound using their larger claw. Even if they are so small, they are one of the major sources of underwater noise. The production of this noise is one of the most amazing performances of the animal world: This bubble, producing almost decibels, can also kill small fish or other animals and preys.
A human eardrum ruptures ajust to give an idea of the power.
And, unique case in the animal world, the bubble produces a small luminescence not visible to the naked eyecalled "sonoluminescence", provoked by the bubble's superficial temperature.
Due the importance of the bigger claw in a snapping shrimp's life, in the case they lost it, the second claw grows to replace the lose one, and the missing limb will regenerate in a smaller claw.
This amazing phenomenon is called "claw symmetry" and it has been documented only once in nature. Snapping shrimps are socially monogamous and territorial, with females performing all parental care. Anyway, male and female partners share other duties like territorial defense, burrow construction, and foraging duties by returning food to the burrow, where both partners consume it.
Biography Francesco Ricciardi is a PhD in Marine Biology, with specialization on the impact of pollution on marine life, aquatic biodiversity and marine tropical ecology, including some studies on symbiosis ecology. Most of the gobies are rather small and have very little direct defence against predators. Thus, most gobies in reef areas live in close association with animals such as wire corals, branching corals and sea pens that the gobies can hide in, around or between.
Some gobies have in an amazing evolutionary process acquired the help of a group of shrimps in order to create shelter in the barren open areas. The shrimps belong to the pistol shrimps of the genus Alpheus, shrimps that often dig burrows.
The gobies, in contrast, have excellent vision, and, furthermore, have their pelvic fins extended as a pedestal. In the relationship between the shrimp and the goby, the Alpheus shrimp digs a burrow, which is used as shelter by both the shrimp and the goby. In turn, the goby spends its day outside the opening of the tunnel, resting on its extended pelvis fins, and keeping carefully watch over the immediate area, alerting the shrimp when danger comes to close, resulting in the shrimps retreat into the burrow.
Goby with partner shrimp The goby-shrimp relationship is an example of what is called an obligate mutualism. These gobies are never found without their shrimp partners, and, conversely, the partner shrimp are never found without their goby partners. Amalgamating the couples of fish and shrimp was not an easy task. If same sexes are in a small tank, it often ends in severe trouble—the shrimp are able to kill each other in an aquarium. Therefore I kept them as far apart as possible in separate tanks until I could identify the sexes of the shrimp female shrimp have a more broad abdomen and more broad pleopods.
I also kept the young gobies separated. By changing the partners in one tank, I could easily find out if two specimens would go together, which is the indication for different sexes. In the next step, I brought both couples together in the observation tank.
The blind shrimp and the macaroni goby
I kept the interior of the tank simple: The shrimp started building the burrow immediately after I introduced them in a little cup and directed them into a gap I made under a piece of live rock. Then the fish were added. It did not take longer than an hour, and the double couple was together. During the next days, the burrow grew. The shrimp transported all excavated material and pushed it outside the burrow. They used their claws to push the sand like a little bulldozer. This astonishing skill can only be performed if the goby is out to guard their safety.
When the tunnel system grew, the partner behaved differently under subterranean conditions. The narrow space in the burrow causes them to squeeze their partners against the burrow wall. The fish tend to wiggle through the burrows with force and no hesitation toward their crustacean partners. Due to the action, parts of the burrow system would often collapse. A fish buried under sand stays there without panic the shrimp can smell it and waits until the shrimp digs it out and begins to repair the burrow.
The main way into the burrow can be up to 2 feet long during the first days of excavation.
Fish and Shrimp together - Saltwater Aquarium Maintenence Specialists
Soon after, side ways are constructed, which can be as short as 2 inches. They can be driven forward and later form an exit to the surface, or they are extended to form a subterranean chamber. Repeatedly, I could observe the shrimp molting in these chambers. This happens during the night every two to four weeks. The next morning, I would find exuviae close to them, and the female was carrying eggs on her abdominal legs if the shrimp are in good condition, molting and egglaying coincide.
The shrimp cut the exuviae into pieces and transported them out of the burrow as soon as their new test hardened. Hatching of the zoea larvae seems to happen overnight, which makes sense to avoid predators as long as possible.Odd Couple - Fish and Shrimp's symbiotic relationship
The currents caused by the beating of the pleopods must pump the eggs out of the burrows, where they become a part of the plankton. The shrimp are omnivorous and collect large pieces of frozen fish positioned close to the entrance of the burrow.
They collect the food and transport it immediately into the burrow, where they feed on it.
The Symbiotic Relationship Between Gobies And Pistol Shrimp
However, outside they can also be observed eating algae growing on rocks. The shrimp directly gnaw with their mouth pieces on rock where algae is growing.
Even more fascinating was that I found parts of the algae Caulerpa racemosa inside the burrow system, though it grew more in another edge of the tank. It took some time until I could observe that the shrimp cut these algae with their claws if they get access to it. However, that can only happen when fish and shrimp are on a coexcursion outside the burrow.
In one instance, after cutting, the shrimp lost the algae due to the currents in the tank. But the unexpected happened: The goby immediately took action and grabbed the Caulerpa with its mouth.
That moment, the shrimp lost antenna contact with the fish and quickly rushed backward to the entrance. The goby transported the lost food to the entrance and spit it out into the entrance of the burrow where the shrimp was waiting.
The Symbiotic Relationship Between Gobies And Pistol Shrimp
The fish was actively feeding the shrimp! I tested this observation and pulled algae off the rocks. When the fish was in the entrance of the burrow, I threw a 1. The goby directly approached it while it was still floating in the water column, collected it and brought it to the burrow.