Tuxedo urchin (Mespilia globulus) is a renowned beautiful and reef safe species of sea urchins. This species is a far better alternative to the long spine and pencil urchins because of its peaceful disposition.
Tuxedo urchin is low maintenance and forms a part of your tank’s clean-up crew — often cruising the tank and devouring algae sheets and debris it comes across.
Keep reading for everything there is to know about the Tuxedo urchin and how to care for the critter successfully in a reef aquarium.
Quick Notes about Tuxedo Urchin
||Pincushion urchin, Globe urchin, Sphere urchin, Blue Tuxedo urchin, Crown urchin, Royal urchin, Ball urchin or Decorator urchin|
|Scientific Name||Mespilia globulus|
|Tank size (minimum)||15 gallons (~60 liters)|
|Keeping||Easy – Medium|
|Average size||up to 2 inches (~5 cm)|
|Optimal Temperature||72 – 79 °C (22 – 26 °C)|
|Water type||SG = 1.021 – 1.025|
|Optimal PH||8.1 – 8.4|
|Optimal KH||8 – 12|
|Nitrate||Less than 20 ppm|
|Diet||Herbivorous / Algae|
|Life span||up to 1 – 2 years|
|Color Form||Velvety, dark blue, or black bands between rows of short, brown, or tan spines|
Tuxedo urchin, Mespilia sp., is a species of echinoderms in the family Temnopleuridae. The scientific classification of the Tuxedo urchin is as follows:
Species: Mespilia globulus
Interesting facts: About 1,000 species of sea urchins have been reported worldwide. They also belong to the same phylum as sea cucumbers, sand dollars, sea lilies, sea stars, sea biscuits, and brittle stars.
Habitat of Tuxedo Urchin
They are naturally domiciled in the tropical waters of the Indo-Pacific region throughout the Indian Ocean and the Western Atlantic Ocean from Indonesia, the Philippines, and Southern Japan.
Generally, it is found on shallow water reef areas, seagrass beds, and coral rubble at depths 0 – 200 ft (up to 60 m).
Description of Tuxedo Urchin
Like most sea urchins, Tuxedo urchins are one type of benthos that has a spherical shape adorned with several colored bands and short (up to 0.25 inches or 6 mm) movable spines.
The spines are pretty flexible and are used for locomotion. They also function as passive self-defense. However, it is not poisonous.
This sea urchin species is quite attractive and decorative. It is characterized by broad, velvety, dark blue, or black bands between rows of short, brown, or tan spines.
Note: There is also an attractive reddish variety (Mespilia cf globulus) which has blue or black bands with red-colored spines.
They have a skeleton commonly known as ‘test’. It is made from calcareous plates, round and rigid. The mouth is located near the substrate, downwards.
Tuxedo urchin is considerably small in size as it measures roughly 3 inches (7 – 8cm) in diameter when fully grown. In aquariums, the average size is often near 2 inches (5 cm).
Lifespan of Tuxedo Urchin
Currently, there is no data available on the maximum lifespan for Tuxedo urchins in the wild.
However, in captivity, their life expectancy depends on a number of factors such as water quality, poor living conditions, and shipment stress.
In the aquarium, if appropriately cared for, Tuxedo urchins can live up to 3 years. However, the average lifespan is around 1 – 2 years.
Behavior of Tuxedo Urchin
Tuxedo urchin is undoubtedly a peaceful and reef-compatible species. Despite owning numerous spines, this urchin is less likely to show aggression to other aquarium inhabitants.
These animals exhibit nocturnal foraging behavior. They are less active during the daytime, often lying across the surface of rocks or in crevices. Then at night, the urchin will emerge from its fortress to scavenge or graze on algae in the aquarium.
Tuxedo urchin is a heavy algae eater; it feeds on nuisance algae, e.g. hair algae. Other edibles include filamentous microalgae, coralline, and dried seaweed. It is not unusual to sometimes see this urchin cruising the aquarium walls and aquarium equipment in a bid to clean them up.
They eat a lot and poop even more :). Be ready for that.
In addition, Tuxedo urchin will frequently roam and pick up various items it finds lying around the tank on its head. Some of which include pebbles, algae, coral frags, snails, empty shells, etc. They use these items to camouflage against predators in the reef aquarium. If it does not carry anything, it is a sign that the urchin is sick or stressed.
- Social: Yes
- Activity: Low
- Nocturnal: Yes
- Peaceful: Yes
- Burrowers: No
Feeding Tuxedo Urchin
Algae form a huge part of the Tuxedo urchin’s diet, so it will be best to have a mature aquarium with a steady supply of fresh filamentous algae.
The urchin equally feeds debris and detritus as well as on macroalgae species — Chaetomorpha and Coralline in the reef aquarium. So, keep that in mind if you are one of those aquarists who are trying to promote Coralline algae growth.
Note: Tuxedo urchins may even eat Caulerpa algae when hungry.
Although they are great scavengers and clean up crew, you want to make sure that it is not the only food available to them. If there isn’t a plentiful supply of algae in your aquarium for your Tuxedo urchin’s nourishment, do well to practice supplemental feeding of:
- dried seaweed sheets (nori),
- thin slices of carrot, or
While at it, make efforts to keep the supplemental food away from fish and other species in your tank, else they will consume it before your urchin even gets a chance to do so.
An excellent way to minimize such occurrence is through spot feeding – hold it right under the urchin until he climbs on top of it. Another option will be to feed it in the evening, this way it will have less competition.
- Diet Type: Omnivore
- Preferences: Algae
- Feeding Frequency: 1 – 2 times a week
Are Tuxedo Urchin Reef Safe?
There is no need to worry that the Tuxedo urchins can start picking on your corals, etc. They do not eat corals, and therefore they are safe for reef tanks in that sense.
Even more, according to the study, the presence of urchins not only enhanced coral survivorship over the 180 day period but also resulted in increased coral growth rates!
That is because microherbivory can play an important role in increasing coral survival and growth.
What Tuxedos won’t usually do is move or knock off rockwork from their normal position; other sea urchins are pretty guilty of this behavior. Nonetheless, it is always recommended to glue corals to the rocks.
Note: Tuxedo urchin can even carry small and unattached zoanthids or other polyps! In nature, Zoas use this method of ‘transportation’ to spread to other areas. Do not worry, urchins do not use their spines to pierce it.
Tank Requirements and Water Parameters
This species is a good fit for various tanks, including nano tanks of 10 gallons (~40 liters). Since the Tuxedo urchin is a small-sized animal, it’s possible to house it in such small enclosures.
Anything smaller and you will definitely have feeding problems. Basically, there may not be enough algae in the tank.
Therefore, ideally, you should consider at least a 15-gallon (60 liters) tank or even larger especially if you plan to keep more than one together with other aquarium critters because they like to crawl and eat.
Water type, Temperature, Hardness, and pH:
Temperature: Tuxedo urchin is a tropical species. So, the ideal water temperature for them is between 72 – 78 °F (22 – 26 °C).
Salinity: Maintain salinity levels between 1.021 – 1.025.
Alkalinity: Between 8 – 11 dKH.
pH: Keep the pH of the aquarium water between 8.1 – 8.4.
They are nocturnal animals. Therefore, Tuxedo urchin does not have special requirements.
Lighting should be adapted to the needs of Chaetomorpha and Coralline algae in your tank.
Decorations and Hiding Places:
Tuxedo urchins need a lot of small things to be happy. Considering that they strive to put everything on themselves to disguise.
Add some empty shells, pebbles, rubble pieces, etc. After some time they will drop them when they do not want to carry them anymore.
If they cannot find suitable items to put on, then they get stressed. Being covered with things is a good indication that it is a healthy urchin.
Caring and Keeping Tuxedo Urchin
Tuxedo urchin is a low-maintenance reef aquarium candidate, and as such, the animal is relatively easy to care for. They are also safe to handle (not toxic).
As mentioned earlier, you need to ensure that the water conditions are optimal and stable to keep the urchin growing/living healthily in your reef aquarium. The lighting intensity and water flow are best kept on moderate levels. Anything above that will do more harm than good to your Tuxedo urchins.
Also, remember to carry out partial water changes (15% bi-weekly or 25% monthly) to eliminate excess nitrates in the aquarium water and the same time — replenish depleted trace elements that the urchin needs for optimal health.
Tuxedo urchin is quite sensitive to poor water conditions, so try as much as possible to maintain good water quality by engaging fervently in routine tank maintenance activities (partial water replacement, filter maintenance, etc.). Poor water conditions and non-ideal or varying parameters will negatively impact the urchin negatively; causing it to lose its spines in some cases.
Before putting Tuxedo urchin into your tank do not forget to carefully acclimate it as all invertebrates. Do it very slowly (1 – 2 hours), let them accommodate to a new environment.
Common Problems Associated with Tuxedo Urchin
Loss of spines: The urchin may lose many of its short spines due to several factors such as elevated nitrate levels above 10ppm, acclimation shock, poor handling, high-stress levels, and poor water quality. Losing spines makes them susceptible to microbial infections, and that takes a toll on their health.
Unfortunately, in most cases, it does not end well.
Prevention and solution: Therefore, make it a priority to drip-acclimate your Tuxedo urchin slowly for lengthy periods before moving it over to the display tank. During acclimation, make sure that the salinity of the water matches that of its previous environment.
Also, try as much as possible to maintain stable water parameters, keep the aquarium water clean through regular water changes, and ensure they get enough food to eat.
Solution: Manual removal. Personally, I do not know any chemical treatment that can be safe for the urchin.
Scratches: Urchins can also leave etch marks on acrylic tanks.
Solution: Keeping them in glass tanks.
Reproduction of Tuxedo Urchin
Currently, the pet industry completely depends on wild-caught species. So far, there are only several reports of successful breeding Tuxedo urchins in a reef aquarium.
That said, if it is possible, make sure to go for captive-bred specimens over wild-caught ones. The former are cultured under captive conditions, making them better adapted to living in an aquarium and more disease resistant.
The scarce information in scientific literature tells us that:
- This species carries out sexual reproduction just like most sea urchins. However, it will require a microscope to see the gender differences. For example, the male genital papilla protrudes on the body surface, forming a short cone. It rises to a height of about 110 micra.
- Tuxedo urchin becomes fully mature at diameter from 0.8 – 1 inches (2.0 to 2.5 cm)
- They are generally gonochoric and reproduce by releasing gametes (sperm and eggs) in the water. Females can release up to 270,000 oocytes (eggs).
- The results of the experiments suggest the spawning of eggs takes place not only at the full moon but also at the new moon. Therefore, the same individual may spawn twice a lunar month.
- Fertilization occurs externally. The eggs get fertilized and float in the water for months until they hatch.
- The prismatic larvae start to feed on microalgae 3 days post-fertilization.
- The embryos develop into planktotrophic larvae called echinoplateus and live for many months in the water column. However, under optimal conditions, metamorphosis occurs from 21 days post fertilization
- Afterward, they sink to the bottom using their tube feet to adhere to the ground, where they proceed to metamorphose into young urchins.
- The mean diameter of the juvenile Tuxedo urchins is around 0.06 inches (1.53 mm) 49 days post-settlement.
Tuxedo Urchin and Compatible Tankmates
Tuxedo urchin is considered reef safe and can be housed with various saltwater fish and invertebrates sold in the hobby.
You don’t have to worry much about predation from aggressive fish because the urchin uses its spines to ward them off. However, parrotfish and triggerfish are exceptions; they sometimes feast on Tuxedos despite their spiny armor.
For example, they are compatible with:
- shrimp like, Sexy Shrimp, Pederson Cleaner Shrimps, Red Fire shrimp (Lysmata debelius), Peppermint shrimp (Lysmata wurdemanni), or Skunk Cleaner (Lysmata amboinensis).
- snails like Bumble Bee Snail, Fighting Conch Snail, Cerith snails, Trochus Snails, Mexican Turbo snails, etc.
Tuxedo urchin can be kept with hermits, turbo snails, trochus snails, clownfish, goby, wrasses, zoanthids, mushrooms, and lots more.
Tuxedo urchins are lovely additions to established reef aquaria.
They do love decorating themselves. So, they will try to wear anything they can pick up that is not held down. This includes small stones, pieces of frags, shells, and even live snails!
This species does not harm corals. They need a constant supply of algae to survive.
Tuxedo urchins are very interesting creatures, they are will sure bring a lot of character and diversity to your reef aquarium but they are not ideal for everybody.