Marine aquariums are not only fish and corals. Among the inhabitants of coral reefs there are also other interesting, very attractive creatures that can be found in our aquarium, increasing its attractiveness. These include, among others, intriguing clams and sea urchins.
Ctenoides ales is a species of mussel that lives in the central Indo-Pacific and off the coast of Australia. It belongs to a family of large and strikingly colored bivalves with mantle tentacles. It lives in the exposed, superficial layer of ocean water, usually residing at depths of 3 to 50 meters. It is also called the disco clam. It is the only known representative of its species to have the ability to flicker (several times per second). However, it does not emit its own light, but reflects incident rays thanks to silica particles. It also has other interesting features – it has 40 eyes, can swim, and even… it also has other interesting features – it has 40 eyes, it can swim and even… change sex (it starts life as a male and ends up as a female).
Tridacna is a genus of bivalves belonging to the Tridacnidae family. In Polish, the species belonging to this genus are called przydacznia or tridacna. These beautiful, extremely colourful bivalves can be found in areas from the Indian and Pacific Oceans to the east coast of Africa. They live on coral reefs, at depths of 1 to 15 meters.
The coloration of these animals is influenced by the zooxanthellae that live on them. The most common colors are green and blue mussels. They feed mostly on symbiotic zooxanthellae (algae), so they require plenty of light. They do not tolerate strong water currents, but moderate circulation in the aquarium is necessary to supply them with the plankton they feed on. They should also be fed regularly with dedicated clam foods or SPS hard corals. Mussels of the Tridacna species are natural filter feeders, as they simultaneously filter the water while taking food, from which they also draw nutrients and trace elements.
Mespilia globulus is a relatively common yet beautiful sea urchin species found in the wild in both the Indian and Pacific Oceans. It is small – growing to about 5-6 cm. Its spines are short, not very stiff, but quite sharp (so it is not recommended to touch it with your hand). Mespilia Globulus is omnivorous, although it prefers plant food. It also eats algae – even calcareous algae, so it cleans rocks and glass in the tank well. This urchin loves to collect organic material (pebbles, shells, pieces of macro algae) and decorate itself with it, that is why marine aquarists started to call it a “garbage collector”. Despite its infamous nickname, it is probably the most beautiful aquarium sea urchin available. It has a beautiful, deep blue color (royal blue). It can be kept individually, in groups or with other species of sea urchins. It lives up to 5 years. The minimum aquarium size in which this animal can be kept is 50 liters. The water temperature should be between 22°C and 28°C with stable parameters.
Diadema setosum is a common species of echinoderm from the sea urchin family that is equipped with black spines that can reach up to half a meter in length. It inhabits the Indian Ocean (also the Red Sea and the Persian Gulf) and the Western Pacific Ocean. It breeds only in the wild, and reproduction is dependent on the phases of the moon. This species is found on coral reefs, rocks, but also in macroalgae colonies. It is mostly found in shallow waters – from 1 to 6 meters. It is omnivorous, although algae predominate in its diet. The body of this sea urchin (without spines) reaches a diameter of about 7 cm in nature, while in aquariums it is slightly less. Moreover, it has five characteristic white dots on the top.
In marine aquariums, the spines of this popular sea urchin reach a span of 20-25 cm. They are raven black, long and hollow inside. Their sharp tips are additionally equipped with venom glands. A sting results in a very painful wound and an itchy rash. Fish often hide between the spines of these sea urchins.
Diadema setosum eagerly “climbs” on rocks and penetrates the bottom of the tank looking for dead organisms and algae. It is an excellent algae eater – it scrapes algae to bare rock or glass. The minimum tank for this type of sea urchin should be at least 300 liters, as they take up a lot of space and can be a threat to other fish.
Featured photo: Wikipedia