The perfect reef aquarium fish will not harm invertebrates, are bold and showy and exhibit chromaticity in a way that would make the most extravagant interior decorator drool. The fairy wrasses (genus Cirrhilabrus) meet all these qualifications. While there are dozens of species now available in the aquarium trade, the first species to show up with any regularity was a scarlet beauty known as the longfin fairy wrasse (Cirrhilabrus rubriventralis). It is an oldie but still very much a goody!
Difficulty: The longfin fairy wrasse is a hardy species that is an awesome choice for the reef aquarium. The longfin fairy wrasse will readily acclimate, accepting most of the common aquarium fare. The longfin fairy wrasse should be fed a diet of frozen foods (e.g., mysids, preparations for marine carnivores, fish eggs, flake food) at least once a day (and preferably more).
Physical description: The female longfin fairy wrasse is reddish orange overall with several lines of blue spots that sometimes coalesce into a solid line. The young and female fish also have a black spot on the top of their caudal peduncles. The male longfin fairy wrasse is “huskier” and red on its dorsum and flanks, with a white belly and blue spots on its body, dorsal, anal and caudal fins (these become more conspicuous when the male longfin fairy wrasse displays). The dorsal fin of the male longfin fairy wrasse is also adorned with two filamentous dorsal spines, and it has extremely large pelvic fins.
The species most similar to C. rubriventralis is C. joanallenae, the blackfin fairy wrasse. This species has dark blue or black pelvic fins. Some males also sport a bright yellow racing stripe down the sides of their bodies. Both species reach a maximum length of around 3 inches.
Range: The longfin fairy wrasse is known from the Red Sea and northern Indian Ocean. Most in the aquarium trade come from Sir Lanka. The longfin fairy wrasse inhabits rubble flats and slopes at depths of 10 to 140 feet. The longfin fairy wrasse occurs in loose groups that consist of a number of females and a single male.
Compatibility: The longfin fairy wrasse is not overly aggressive. Males may pick on small zooplankton-feeders, such as dartfish gobies (Tryssogobius spp.) and firefish, and squabble with other fairy wrasses (especially in limited spaces). They have also been known to spar with flasher wrasses (Paracheilinus spp.). Aggression is not likely in a larger aquarium. The rule is one male longfin fairy wrasse per aquarium with two or three female longfin fairy wrasses.
Of course, males or females can be kept without conspecifics, but a male longfin fairy wrasse without females sometimes loses its spectacular “maleness” and may actually revert back to the feminine sex! By placing a mirror on the side of the aquarium you may be able to convince a gullible male that there are conspecifics in the area, which may encourage him to maintain his masculine colors. If you add this fish to an aquarium of bullies, it will not acclimate. The usual suspects are likely to make the life of your C. rubriventralis miserable (e.g., dottybacks, pygmy angelfish, aggressive wrasses). The longfin fairy wrasse’s small size makes it a likely target for many piscivores.
Aquarium conditions: The longfin fairy wrasse will be happy in aquariums as small as 30 gallons. The longfin fairy wrasse tends to prefer the reef aquarium, where there are plenty of nooks and crannies to shelter it. It does not bury, so a sandbed is not a requirement. Acceptable water parameters for the longfin fairy wrasse are a pH of 8.1 to 8.4, specific gravity of 1.019 to 1.025 and a water temperature of 76 to 82 degrees Fahrenheit.
Care considerations: The longfin fairy wrasse is renowned for its amazing aerial displays. The longfin fairy wrasse has been known to jump from aquariums with such force that halide bulbs have been broken! Death by jumping is surely the most common cause of mortality for C. rubriventralis. Any aquariums with this wrasse will definitely need to be covered.
Breeding: The longfin fairy wrasse may spawn in home aquaria. The longfin fairy wrasse prefers taller aquariums (so that it can engage in spawning ascents). Males show-off to females by swimming rapidly into the water column — in an aquarium without a top this often leads to them jumping and hurling themselves skyward and out of their aquariums. Longfin fairy wrasse larvae are difficult to raise.