Family Labridae - Wrasses
A Diverse Family with Something for Everyone
|The harlequin tuskfish (Choerodon fasciatus) is a colorful wrasse growing to about a foot. |
The Family Labridae is a massive family of fishes (trumped only by gobies). Some of these fishes, commonly known as wrasses, are amongst the perennial favorites in the marine aquarium industry. Chances are that if you remain involved with marine aquaria for any length of time, you will eventually come to own a wrasse. Here are the basics of this diverse and extraordinary family of fishes.
Wrasses can be found throughout the Atlantic and the Indo-Pacific in both temperate and tropical seas. Many are reef-associated, and many fulfill important ecological functions within the ecosystems in which they live. Quite certainly, may wrasses have yet to be formally described, and, given color variations amongst conspecifics from different regions, not to mention hybridization, there remains plenty of disagreement as to this familys taxonomical hierarchy. An entire book could be filled with information on wrasses, and many additional volumes would then quickly become essentialas such, this article should only be construed as the briefest of overviews with a bias toward those genera most commonly seen in the aquarium industry.
A Protrusible Jaw The Common Denominator
To begin with, there are a few characteristics all wrasses share. All wrasses, for example, possess a protrusible jaw, meaning that the jaw can be extended or protruded to form a sort of tube or scoop to aid in specialized feeding. The slingjaw wrasse (Epibulus insidiator), for example, can extend its upper and lower jaw to more than half of the fishs overall length in order to create an elongate tube perfect for feeding on crustaceans (and sometimes even small fishes) amongst the nooks and crannies of the reef. Many aquarists have witnessed this feeding behavior from wrasses in their own aquaria, and many aquarists have also seen their wrasses use this anatomical characteristic in territorial interactions amongst conspecifics. This protrusable jaw is indeed a defining characteristic of the family, whose scientific nameLabridaeis, after all, derived from the Latin word for lip.
|The clown fairy wrasse ( Cirrhilabrus solorensis ) is a favorite reef-compatible wrasse that grows to 4.5 inches.|
A Varied Family
While all wrasses have some things in common such as a protrusable jaw, there are many, many more differences than similarities in this large and diverse family of fishes. Wrasses range in size from some of the largest reef-associated fishes (e.g. humphead wrasse, Cheilinus undulates) to some of the smallest (e.g. Minute wrasse, Minilabrus striatus). Some are remarkably brightly colored while other pale in comparison. Body shapes range from elongate to laterally-compressed. Most are carnivores that feed on benthic invertebrates, but there are also planktivores and even so-called cleaners that eat ectoparasites (e.g. the cleaner wrasses of the genus Labroides). Most burrow in the sand, but some build mucus cocoons in which to sleep. Most species change color and sex as they mature, but some do not. As you can see, there are many differences, making almost any aquarium a candidate for the right wrasse. Having said that, not every wrasse offered in the marine aquarium trade is a suitable aquarium fish.
Reef Compatible and Not Reef Compatible
As far as the aquarist is concerned, wrasses are generally broken down by the somewhat arbitrary distinction of reef-compatible versus not reef-compatible. In the former category, we have wrasses such as the ones from the genera Cirrhilabrus, Halichoeres, Halichoeres, Macropharyngodon, Novaculichthys, Paracheilinus, Pseudocheilinus, and Wetmorella, while in the latter category, we have wrasses such as those from the genera Anampses, Cheilinus, Choerodon, Clepticus, Coris, Gomphosus, Halichoeres, Hemigymnus, Novaculichthys, and Thalassoma. Obviously this definition of reef-compatible versus non-reef compatible (not unlike the equally arbitrary SPS versus LPS corals), has its serious limitations. Take for example that some species within the same genus (e.g. Halichoeres) are considered reef-compatible (like the melanurus wrasse, Halichoeres melanurus) while others (like the beautiful checkerboard wrasse, Halichoeres hortulanus) are not. In fact, the large genus Halichoeres is representative of much of the extant confusion regarding wrasses. In other words, while we discuss aquarium suitability by genus below, it is essential to do you species-specific research.
Aquarium Suitability The Good the Bad and the Not-so-Bad-but-Good-Only-With-Caution
Any attempt to categorize fishes as to their suitability for aquarium life is doomed to fail. Too many variables are in play when it comes to the chain of custody and the aquarists system. One persons hardy may be another persons touchy, while one persons ideal tankmate may be another persons tank terror. If we can at least agree on that score, then we can proceed with some advice that should be taken, in most cases, with the proverbial grain of salt. Having said that, let us then proceed with an overview of the wrasses commonly seen in the trade organized by how adaptive they are to captive life.
|The blue cleaner wrasse (Labroides dimidiatus) is commonly available wrasse that almost always dies in captivity.|
First the Bad. All we will say about these six genera of wrasses is steer clear unless you know exactly what you are doing (e.g. you are a researcher, public aquarium curator or very experienced aquarist).
Anampses (Tamarin wrasses)
Clepticus (Creol wrasse)
Labroides (Cleaner wrasses)
Pseudodax (Chiseltooth Wrasse)
Pseudojuloides (Pencil Wrasses)
Stethojulis (Ribbon Wrasses)
On to the goodwe can whole-heartedly endorse the use of the following genera in home marine aquaria for most aquarists that have demonstrated an ability to maintain a saltwater tank with consistent parameters over a period of time. They are:
Choerodon (Harlequin Tuskfish)
Gomphosus (Bird Wrasses)
Pseudocheilinus (Lined Wrasses)
Halichoeres (Although this is such a large genus that it is truly hard to make generalizations, but many are outstanding aquarium fishes.)
Thalassoma (Like Halichoeres, this is a large genus of these cigar-shaped wrasses, most of which do remarkably well in aquaria and are industry staples, although there are a few that fair poorly.)
Pretty Good with a Side of Caution
|The McCoskeri flasher wrasse (Paracheilinus mccoskeri ) is a favorite wrasse that only grows to three inches.|
The final group of wrasses is what might be considered pretty good for the aquarist who understands and provides for the fishs genus- (and, at times, species-) specific husbandry needs. A sentence of explanation or justification is added for each genus below.
Cirrhilabrus (The fairy or velvet wrasses are real favorites and for good reason.)
Coris (The coris wrasses do make great aquarium fishes; they just get surprisingly large.)
Epibulus (The slingjaw wrasses are a relatively new and very aptly-named wrasse that make good aquarium specimens.)
Hemigymnus (no common name)
Hologymnosus (The ringed wrasses are beautiful, if not somewhat touchy aquarium fishes.)
Macropharyngodon (The leopard wrasses are quite possibly the touchiest of this pretty good category.)
Novaculichthys (Razorfishes and rockmover wrasses have very specific habitat requirements but can make great aquarium fishes.)
Paracheilinus (Flasher Wrasses, along with the aforementioned fairy wrasses, are truly tops in terms of reef-compatible wrasses.)
Wetmorella (The possum wrassessometimes called pigmy or sharpnosed wrassesare small and secretive, but relatively hardy aquarium fishes if provided with lots of cover.)
Cheilinus (The maori or splendour wrasses simply get too big, but in a huge aquarium, they are great aquarium specimens.)
Wrasses and Conservation
While its likely that all wrasses have important functional roles to play on tropical reefs, some, such as the humphead wrasse (Cheilinus undulates ), are vital to preserving a coral-dominated reef habitat by feeding on poisonous corallivore species like the crown-of-thorns starfish (Acanthaster planci ). At present, no wrasses beyond the humphead wrasse are regulated. Dr. David Bellwood, who serves on the Grouper and Wrasse Specialist Group of the Species Survival Commission, the largest of the six volunteer Commissions of IUCN - The World Conservation Union, says of the wrasses, Generally there are no serious conservation issues; as long as populations are not overharvested the ecological impacts are likely to be minimal.
|The lunare wrasse (Thalassoma lunare ) is an aquarium favorite that grows to about 10 inches.|
In Conclusion, many wrasses make outstanding aquarium fishes with their bright colors, generally peaceful dispositions and fascinating behaviors. Many are quite hardy, or, as the venerable Robert Fenner puts it have to literally [be] beat with a stick" to knock off. Be warned, however, while generally making great tropical marine aquarium fishes, there are some wrasses that are entirely unsuitable for just about any home aquarium. Dont let the frequent availability of some of these unsuitable fool you. Do your genus- and species-specific homework before you buy, and make sure you are prepared to provide for all of the fishs needseven when that fish matures into an adult. If you follow this advice, you are sure to rewarded with a long-lived aquarium fish that will delight you and add life to your aquarium.
Published 17 June 2008. Blue Zoo Aquatics