Fish Tales by Henry C. Schultz III

Care to Go Spelunking? The Genus Liopropoma


They are hard to acquire, fairly expensive, and often reclusive. Additionally, they can put diminutive fishes and ornamental shrimps at risk of hostile attacks. So why is it that fish of the genus Liopropoma are highly sought after by seasoned aquarists? Their remarkable and beautiful coloration is one reason; their incredibly peaceful persona (except towards small fish and shrimp) is another. Finally, the irregularity with which they are collected and imported into the aquarium trade ensures that they remain eclectic additions for most aquarists. With the onset of September let me introduce the reef fish collectively known as Cave Basses.

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For all intents and purposes, this is THE fish of the genus. The Peppermint Bass, more accurately known as Liopropoma rubre, will command a high dollar in the aquarium trade. Photo courtesy of Tim McRae.

Meet the Family

Liopropoma is a member of the family Serranidae and the subfamily Liopromidae. Astute aquarists may recognize some of the other commonly available Serranids, most notably Anthias and Groupers. Ichthyologists differentiate Liopropoma from all other Serranids by the presence of a complete lateral line, a mouth containing villiform teeth throughout, yet completely lacking canine teeth, and three flat spines present on the opercle (Randall and Taylor, 1988).

Like many of the genera that Fish Tales has previously covered, the history of Liopropoma is complex; perhaps among the most complex I've discussed. To help eliminate some confusion, I'll therefore begin by noting that various species of this genus have been placed in five different described genera.

Poey (1860) was credited with the discovery of the first Liopropoma, although he named it Perca aberrans. The following year Gill created the name Liopropoma. With the erection of the name Liopropoma, no further similar species were assigned to the genus Perca. Perca, however, remains as a valid genus for freshwater perch. Unlike some of the other genera that Liopropoma species have been assigned to, it is not a synonym, junior or otherwise. In a work published in 1862 Gill reviewed Poey's work and renamed P. aberrans as Chorististium rubre. Additional species were discovered, named, and added to Chorististium on a frequent basis by such ichthyologists as Jordan and Seale (1906), Fowler and Bean (1930), Fowler (1938), Smith (1954), Starck and Courtenay (1962), and finally, Randall (1963). In addition, several genera were found to be synonyms of Chorististium, as I will discuss shortly.

Another genus, Pikea, was created by Steindachmer (1874) for the fish, Grystes lunulatus. His partner, Doderlein (1883), in some later studies named Labracopsis as a new genus and species, but Steindachmer considered Labracopis a sub-genus of Pikea. Previously, Pikea had been considered as a synonym of Liopropoma by Boulenger (1865), and this was later confirmed by Evermann (1896), though he questioned his own assessment. This assignment did not gain universal acceptance, and as the genus was considered valid and available Schultz (1958) (no relation to this author) added three more species into Pikea. Katayoma (1960) created the subfamily Liopropominae and also declared Pikea as a junior synonym of Chorististium. No discussion, however, was given for his rationale in this maneuver. Besides naming a new species that he placed in Chorististium, Randall (1963) also reviewed the Atlantic species of this genus, and in doing so, reconfirmed Katayoma's (1960) observations and no further specimens were awarded the Pikea name. Robins (1967) reviewed the original description of Liopropoma aberrans and concluded that Poey had made an error in dorsal fin counts, so he subsequently placed Chorististium into synonymy with Liopropoma. However, Robins was apparently unaware of Katayoma's work placing Pikea as a synonym of Chorististium and in the same publication named Bathyanthias as a Pikea synonym.

Another junior synonym of Liopropoma, Ypsigramma, was originally described by Schultz (1953). He went so far as to distinguish Ypsigramma from Liopropoma by the dorsal fin which is separated into two parts by a small section of scales. This is actually considered an identifying feature of several Liopropoma today, obviously including those originally referred to as Ypsigramma. Bohlke (1956) noted Schultz (1953) had made an error, in addition to his comments regarding species, about the existence of transitional stages between a single, or two separate, dorsal fins. As a result, Ypsigramma was moved into synonymy with Chorististium and no further Ypsigramma species were named.

Flagelloserranus, the final Liopropoma synonym, was a rather short-lived genus. Kotthaus (1970) described the new genus, but one year later Fourmanoir (1971) noted a post-larval Liopropoma identical to Flagelloserranus meteori. As such Flagelloserranus is a synonym of Liopropoma.

Liopropoma
aberrans
africanum
aragai
aurora
carmabi
collettei
danae
dorsoluteum
erythraeum
eukrines
fasciatum
flavidum
incomptum
japonicum
latifasciatum
lemniscatum
longilepis
lunulatum
multilineatum
pallidum
rubre
susumi
swalesi
tonstrinum

In the Wild

Unlike many of the genera I have covered in past columns, Cave Basses can be found in both the Atlantic and Pacific Oceans. Only four species, however, hail from Atlantic waters, with the remaining 23 species being well spread out across the Indo-Pacific.

The Atlantic species are most prevalent in the Caribbean, but one species, L. eukrines, has a range extending up the coast as far northward as the Carolinas. The other three species, L rubre, L. carmabi, and L. mowbrayi, are not found that far north, but are instead distributed around southern Florida and the Bahamas.

The 23 remaining species that collectively make up the Pacific branch of the genus are widespread when compared to their Atlantic cousins. Liopropoma susumi can be found in the Red Sea, along the eastern African coast, and extending across the Pacific to Samoa. This species has the largest distribution of any in the genus. No other Liopropoma species are nearly this widespread. The easternmost distribution in the Pacific belongs to L. pallidum, which has been documented in the Pitcairn Group of Islands. Located throughout Japan, as well as the Hawaiian Islands and the Ryukyu Islands, L. maculatum has the northernmost range of any species of the genus. Several species extend as far south as the northern coast of Australia, but only one species, L. susumi, has been collected from the Great Barrier Reef. Several Liopropoma species are extremely rare. For example, Liopropoma flavidum is known from only a single specimen collected from depths approaching 200 feet in the Austral Islands. Likewise, L. lunulatum is known from only a single specimen collected from Okinawa.

The Yellow-Margined Basslet, Liopropoma aurora, is known only from Hawaiian waters. Alas, you're more likely to purchase this fish at the local Hawaiian fish market as the "catch of the day" than at your local fish store. Photo courtesy of John Randall.
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Pretty, isn't it? Unfortunately, only one specimen of Liopropoma flavidum, has been captured and this is a photo of the prepared specimen. Photo courtesy of John Randall.

Except for a few species dwelling in shallow waters, collection and research of this genus have been sporadic at best. Many of the fish used for research purposes have been caught by hook and line fisherman or were discovered at local fish markets. This genus is thought to include a large population living below the normal scuba depths frequented by many researchers. While Liopropoma susumi has been collected in only six feet of water, most Liopropoma species which are collected for the hobby occur between 50 and 100 feet. This is shallow, relative to the other Cave Basses. Most of the species are edging toward 100 feet as their shallowest, and one, Liopropoma erythraeum, was collected at nearly 1000 feet. The greater depths most often maintained by some of the Cave Basses obviously account for the scarcity of individuals within the trade as well as their characteristically high retail price.

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Liopropoma africanum, or the African Basslet, takes its name from the area it hails from, the eastern coast of Africa. This is one of the few species that can be regularly found at depths less than 100 feet. Unfortunately, though, do not expect to see this beauty at your local store anytime soon. Photo courtesy of John Randall.

Liopropoma maculatum, commonly referred to as the Hanasuzuki Basslet around its native Japanese waters, cannot be purchased in the reef aquarium trade. It has been recorded from depths ranging from 300 feet down to nearly 900 feet. Photo courtesy of John Randall.
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With the given name of Cave Basses it should be a no-brainer as to what type of topography these fish prefer. Whether it is 10 feet for Liopropoma susumi or 1000 feet for L. erythraeum, they will always be associating with steep drop-offs, overhangs, small crevices, and caves. Most sightings also occur within a prominent coral reef. It is the overhead environment that these fish seek; only rarely are these fish seen in open water. If you are lucky enough to spot one while diving, get a quick look because it will often retreat immediately upon seeing you. The protection found within small crevices is the only defense Cave Basses employ.

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The Pinstriped Basslet was originally known from only the Red Sea, but when Randall (1988) reported a collection from the Tuamotu Archipelago, Liopropoma mitratum instantly became the species with the broadest (not largest) distribution of the genus. Photo courtesy of John Randall.

I was unable to locate any exact data concerning a gut analysis of this species, which makes me wonder if one has ever been documented. Small shrimp and other mobile invertebrates probably make up the bulk of their diet, but it could be assumed they will attempt to eat anything moving that's small enough to be swallowed.

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The Orange-lined Basslet is considered rare in the wild, but this aquarium photo offers a beautiful view of a fish once only known from four specimens found in 1988. Known scientifically as Liopropoma swalesi, they possess 26 - 27 gill rakers, two of which are rudimentary. The rest of the genus has 23 or less gill rakers and six or more are rudimentary (Randall, 1988). Photo courtesy of Tristan Lougher.

Smith (1971) studied the reproductive organs of the Atlantic Cave Basses. He documented these basses as being gonochoristic or non-hermaphroditic, but he also mentioned he believes they are likely evolved from hermaphroditic ancestors. DeLoach (1999) had the pleasure of witnessing a spawning pair. They are broadcast spawners and on the rare occasion when they were observed spawning, they either made a single rush while doing so, or they were frightened by the researchers and ended the ceremony early.

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Liopropoma tonstrinum, also commonly called the Red-striped Basslet, has an interesting rational behind its particular name. When translated from Latin, tonstrina means barbershop. Evidently, the red and white stripes are reminiscent of a barbershop pole. Photo courtesy of John Randall.

In the Home Aquarium

Anyone lucky enough to acquire a Cave Bass will generally have good success in keeping it. These fish are considered to be disease resistant and rather hardy. Similar to most anything else, "certain restrictions may apply," so it would be best to adhere to a few guidelines before purchasing a Cave Bass.

As their name certainly implies and as the depths at which Liopropoma species are collected dictate, these fish are not fond of bright sunlight. Brightly lit aquariums which are dominated by SPS corals are not an optimal habitat for keeping Cave basses. Although caves and crevices that create areas of low light are likely available in such an aquarium, it should be expected that these fish will remain in those areas nearly all the time. Sightings of your Cave bass will increase with decreased light levels. An actinic light phase will almost certainly provide the hobbyist with a plethora of viewing opportunities. Aquariums must also have a large amount of live rock, as it will be needed to create these lower light / no light areas. Without places to disappear into darkness Liopropoma species will never truly settle into the aquarium.

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Newly hatched fry are a delicacy that no Cave Bass can ignore. Housing an expecting Cardinalfish or any pairs of fish you hope to have spawn and a member of Liopropoma species is not recommended. Photo courtesy of Greg Rothschild.

Liopropoma species are peaceful, and their tankmates must be as well. Of all the Liopropoma species collected for the hobby, the overwhelming majority remain less than three inches long as full-grown adults. So, despite their propensity to relish small fish, the reality is (but for a few exceptions) the only fish they will eat will be newly hatched fry or young juveniles. The real concern is small, delicate shrimp, which will most often not stand a chance. They will become hunted prey in aquariums which also house Cave Basses. Other small mobile invertebrates including crabs and snails are generally left alone. Sessile invertebrates are not at risk.

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Destined to be a quick snack, delicate shrimp are best avoided in any aquarium containing Cave Basses. Photo courtesy of Greg Rothschild.

Getting these basses out into the open is tough to achieve, and the presence of large, fast, or aggressively feeding fish only compounds the problem. Once established into a peaceful aquarium Cave Basses have been known to become curious and sometimes even outgoing, so do not get the impression they will hide all the time. The biggest factor affecting quality viewing time is the tankmates. I recommend, therefore, to avoid fish fitting the above-mentioned description and instead surround them with small, peaceful fish which spend a good deal of their time in the open water. Referred to as "dither fish," they will help the basses feel comfortable in open water and will likely increase the aquarist's chances of regular sightings. Such "dither fish" would include firefish, cardinals, and flasher wrasses, among others. Finally, divers rarely find individual fish on the reefs, and it may prove essential for optimum long-term maintenance to keep it that way in the home aquarium; consider keeping at least two at a time. A full list of fish and their relative compatibility is presented below, but erring on the side of caution and selecting peaceful fish as tankmates in this instance is a good idea.

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"Dither fish" such as this Nemateleotris magnifica are a good option in aquariums containing Liopropoma species. They will help the bass feel comfortable and perhaps allow for more frequent and extended viewing. Photo courtesy of Greg Rothschild.

Compatibility chart for Liopropoma species:

Fish

Will Co-Exist

May Co-Exist

Will Not Co-Exist

Notes

Angels, Dwarf

X

 
 

Excellent choice.

Angels, Large

 

X
 

Large angels will intimidate the basses and discourage more frequent sightings.

Anthias

X
 

 

Excellent choice.

Assessors

 
X

 

Similar habitat preference - only in larger aquariums.

Basses

 

 
X

Best not to mix any basses unless they are a mated pair.

Batfish

X

 

 

Excellent choice.

Blennies

X
 

 

Excellent choice.

Boxfishes

X
 

 

Excellent choice.

Butterflies

X

 
 

Excellent choice.

Cardinals

X
 

 

Excellent choice.

Catfish

 

X
 

Large adults will attempt to consume Liopropoma species.

Comet

X

 

 

Excellent choice.

Cowfish

X
 

 

Excellent choice.

Damsels

 

X

 

Damsels are likely to harass Cave Basses.

Dottybacks

 

 
X

May attempt to consume Liopropoma species.

Dragonets

X

 

 

Excellent choice.

Drums

X
 

 

Excellent choice.

Eels

 

 
X

May attempt to consume Liopropoma species.

Filefish

X
 

 

Excellent choice.

Frogfish

 
 

X

May attempt to consume Liopropoma species.

Goatfish

 
 

X

Large adults may attempt to consume Liopropoma species.

Gobies

X
 

 

Excellent choice.

Grammas

X

 

 

Excellent choice.

Groupers

 

 

X

May attempt to consume Liopropoma species.

Hamlets

X

 

 

Excellent choice.

Hawkfish

X

 

 

Excellent choice.

Jawfish

X

 

 

Excellent choice.

Lionfish

 

 
X

May attempt to consume Liopropoma species.

Parrotfish

 

X
 

Parrotfish will intimidate the basses and discourage more frequent sightings of Liopropoma species.

Pineapple Fish

X

 

 

Excellent choice.

Pipefish

 
 

X

Pipefish are best kept in dedicated aquariums.

Puffers

 

X

 

Large adult puffers can be intimidating and may attempt to consume Liopropoma species.

Rabbitfish

X

 
 

Excellent choice.

Sand Perches

 
X

 

Large adults may attempt to consume Liopropoma species.

Scorpionfish

 
 
X

May attempt to consume Liopropoma species.

Seahorses

 
 

X

Seahorses are best kept in dedicated aquariums.

Snappers

 

 

X

May attempt to consume Liopropoma species.

Soapfishes

 

 

X

May attempt to consume Liopropoma species.

Soldierfish

 

 

X

May attempt to consume Liopropoma species.

Spinecheeks

X
 

 

Excellent choice.

Squirrelfish

 

 

X

May attempt to consume Liopropoma species.

Surgeonfish

X

 
 

Excellent choice.

Sweetlips

 

 

X

May attempt to consume Liopropoma species.

Tilefish

X

 
 

Excellent choice.

Toadfish

 
 

X

May attempt to consume Liopropoma species.

Triggerfish

 

X

 

Most triggerfish should be avoided. Odonus niger should mix well.

Waspfish

 
 

X

May attempt to consume Liopropoma species.

Wrasses

 

X

 

Most wrasses should mix well. Avoid overly large or aggressive wrasses.

Note: While many of the fish listed are good tank mates for Liopropoma species, you should research each fish individually before adding it to your aquarium. Some of the mentioned fish are better left in the ocean or for advanced aquarists.

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When provided with small "dither fish" as tankmates, views of your prized bass
like this one will become commonplace. Photo courtesy of Greg Rothschild.

Assuming you are not trying to feed them a steady diet of ornamental shrimp, you should probably concentrate on something similar. The perfect substitute is Mysid species shrimp. If this were the only food your Cave Bass was to consume, it would fare very well. It will do even better, however, with a varied diet. Enriched brine shrimp will also serve the purpose well, as will flake foods geared towards small carnivores. The real difficulty may be in actually getting the food to the fish which will likely be holed up in whichever cave it has initially chosen. If your fish ventures out more freely during the actinic phase, this is obviously the optimum time to feed it. Otherwise, using a turkey baster to blast the food behind the rockwork might be required.

Due to their limited movements and sometimes reclusive disposition, a smaller aquarium can be used. In fact, aquariums such as the industry standard 30 or 40 gallons should offer both ample space and a better chance at regular sightings. Larger aquariums will work, of course, but they offer a greater chance of losing the fish among the rockwork, not to mention the fact that many hobbyists usually cannot resist adding larger and more active fish into those larger aquariums.

Meet the Species

A large portion of the basses making their way into home aquariums are captured along the Florida coastline. The considerably shortened travel time to American hobbyists may play a factor in the overall hardiness of the genus in aquariums. Regardless, these basses are as beautiful or more beautiful than their Indo-Pacific cousins, so there really isn't a need to take on the extra burden of locating an Indo-Pacific fish and taking the risks involved with its additional shipping time and resulting stress.

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The species name for Liopropoma multilineatum translates from Latin into "many lines." Depths recorded for this species show it prefers being deeper than 100 feet, but occasionally individuals have been collected from as shallow as 80 feet. Considering its wide distribution it is possible this species may show up as a surprise for an unsuspecting fish store. Photo courtesy of John Randall.

Because collectors often collect whichever specimens they can find most easily, and hobbyists are quick to grab whichever ones are available, it would probably be improper to name one species as "the most popular" over the others. Still, it would seem the most common of the Caribbean Cave Basses is Liopropoma rubre, or the Peppermint Bass. Measuring in at roughly three inches, it is slightly larger than the nearly identical looking Candy Basslet, Liopropoma carmabi. These two species combined make up the overwhelming majority of cave basses collected. Luckily for aquarists, these two species also prefer shallower water than what is considered the norm for this genus; individuals can frequently be found shallower than 50 feet. Their preference for shallower waters makes them more suitable than their deep-water counterparts for those aquariums whose canopies are crowded with metal halide lighting. Liopropoma mowbrayi, commonly referred to as the genus namesake, Cave Bass, and the Wrasse Bass, L. eukrines are both deeper dwelling species, and as such they are not regularly collected. Additionally, these species also become about twice as large as their Atlantic brethren.

The most commonly available species of Liopropoma in the wild is L. susumi, found throughout Indonesia and the Philippines. It is bound, therefore, to occasionally turn up in the aquarium trade. The largest specimen on record is just shy of three inches, so it is another small member of the genus. Not unlike the Caribbean species regularly appearing in the hobby, L. susumi, commonly called the Meteor Perch, can occasionally be located shallower than 50 feet. It would be safe to assume any fish available in the trade were collected at the shallow end of their range.

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The most common of all Indo-Pacific Cave Basses is the Meteor Basslet,
Liopropoma susumi. Photo courtesy of John Randall.

Conclusions

The Cave Basses may be among the best fishes for a small reef aquarium. I can think of few fish I would more prefer to keep as a pair in a 40-gallon breeder style aquarium or, better yet, a 65-gallon aquarium. Their friendly disposition will allow the addition of the more easy-going gobies such as Stonogobiops, Gobiosoma, or Ptereleotris species. Just as well, for most hobbyists, it will likely be the only time they will see a live individual rather than just a photo. Finally, the beauty of these fish, like that of many of the most beautiful fish in the hobby, truly needs to be seen in person to be appreciated.



If you have any questions about this article, please visit my author forum on Reef Central.

References:

Bohlke, J. 1956. Notes on the serranid fish Chorististium rubrum (Poey) and on the status of Ypsigramma Schultz. Not. Nat., no. 29 291: 1-7, 1 fig.

DeLoach, N. 1999. Reef Fish Behavior. New World Publications. Jacksonville. 259 p.

Kotthaus, A. 1970. Flagelloserranus, a new genus of serranid fishes with descriptions of two new species (Pisces: Percomorphi). Dana Rept. 78: 1-31, 25 figs.

Lieske, E. and R. Myers. 1994. Collins Pocket Guide. Coral reef fishes. Indo-Pacific & Caribbean including the Red Sea. Haper Collins Publishers, 400 p.

Randall, J.E. 1963. Three new pecies and six new records of small serranoid fishes from Curacao and Puerto Rico. Stud. Fauna Curacao Carib. Is. 19: 77-110, 3 pls.

Randall, J.E. and Taylor, L. 1988. Review of the Indo-Pacific fishes of the serranid genus Liopropoma, with descriptions of seven new species. Indo-Pacific Fishes (16):47 p.
Page: 38.

Schultz, L.P. 1958. Three new serranid fishes, genus Pikea, from the western Atlantic. Proc. U. S. Natl. Mus. 108(3405):321-329, 2 figs.

Smith, C.L. 1971. Secondary gonochorism in the serranid genus Liopropoma. Copeia, no. 2: 316-319, 1 fig.




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Care to Go Spelunking? The Genus Liopropoma by Henry C. Schultz III - ReefKeeping.com