Today’s post is c0-contributed by Mr. Tay, a friend of ReefBuilders and one of my best fish buddies in Singapore. Mr. Tay is known online by his alias “Digiman”, and has an extensive collection of deepwater and unusual fish, many of which have been featured here before.
We love basslets, and Liopropoma is arguably one of our favourite genus of fish. We like them because they are so hard to find, so fascinating and also very rarely discussed. Liopropoma are shy, very shy. Just like their behaviour in the wild, they are full of character and are always playing hard to get with their observers.
Liopropoma isn’t something that you can buy whenever you want to, or on a whim. Most often an aquarist’s encounter with one is by surprise, when they pop up unexpectedly in a store or hidden amongst other fish at the wholesaler. Newer reefers who are unfamiliar with this genus may raise an eyebrow in curiosity and fascination. “What is this fish?” “I’ve never seen it before”. Indeed. Liopropoma don’t often show up in any numbers bigger than the number of fingers on one hand, and you’ll need a lot of luck and patience to find the species that you want.
In general, Liopropoma is a hardy and relatively disease resistant genus. They are cryptic by nature, but adapt well to home aquariums and will quickly learn to eat all kinds of prepared foods. They will however, remain very shy and stick close to the rock work for most of their lives. If you’re expecting attention seeking behaviour like those displayed by wrasses or angels, then you should be prepared to be disappointed. But if you’re looking for something with a flare for mystery, the kind that lurks in the shadows and add a sense of life to your reef structure, then Liopropoma is the perfect genus for you.
The genus can be roughly split into two main groups. Species that stay small, at around 2-3 inches, and species that get large, to around or larger than 5 inches. Regardless the species or type, all Liopropoma share the same pension for deep waters and their unrequited love for seclusion. While some species can be found in relatively shallow waters of a few meters, they usually become more common and evident the deeper you go. A large number of species are also only found in appreciable depths, some species in no less than 100 ft. With that in mind, although easy to feed and keep, they do sometimes arrive with swim bladder damage or decompression issues, resulting in the “head down” behaviour of swimming, which is sadly to say, not at all uncommon in this genus.
When planning to keep Liopropoma it is vital that suitable habitats are provided in the aquarium. Take a look at the various pictures that pepper this post. We have, to the best of our ability, chosen photos of them in the wild to give you an idea of the habitat they prefer. Notice how in every photo, the fish is surrounded by rock. Either under it, around it, near it, or within it. In the wild, these fish are hardly seen by divers or photographers. The deep reef labyrinth is a calcareous maze that these elusive and reclusive fish take refuge in. A large reef slope may seem devoid of life from afar, but within the honeycomb catacomb is a living breathing ecosystem filled with many of these elusive basslets and similar species alike.
It is vital that your aquarium have similar habitats for your Liopropoma to feel safe in, and to take refuge. Initially you may not see it at all, but given time, they will become bolder, and will peer out of their labyrinth to feed or to greet you. Another point to take note is that their propensity for the deep often have them living in very little to hardly any light. They do well in brightly lit reef tanks, but tend to show themselves more, becoming increasingly active when the lights go down or even off completely. In a dedicated dim tank set up, you can expect your Liopropoma to come out more often, but always within a fin’s length from their rock security.
One way of ensuring that you get to see your fish more often than not, is to create a specific microhabitat within your reef macrocosm. Liopropoma like hanging under large ledges, sometimes upside-down, and also enjoy weaving in and out of permeated calcareous rubble. By creating a habitat specific section within your reef, there is a high chance that your Liopropoma will hang around that area more frequently than the other sections, enabling you to see it more often. It is also equally interesting to observe this fish behaving as they would in the wild, and creating a habitat specific section will allow the fish to behave as it normally would.
If you’ve been paying attention to the pictures so far, you may be able to recognise some of these species. Liopropoma is aggressive in its distribution and have managed to conquer reefs in almost every major ocean. Many Liopropoma species such as L. swalesi, L. collettei and L. susumi are available from Indonesia, but sporadically and their appearance can be totally random. Some like L. mowbrayi, L. rubre and L. carmabi are more regular offerings from the Caribbean, and are easier to get, although much pricier.
Each of the photos in this article contains the name of the species, as well as a short description of it. Liopropoma can be variable, and this is seen in a few species where colour forms exists within the populace. For example Liopropoma multilineatum, which is pictured above and at the top, is usually pink. However, yellow forms do occur from time to time and like the one featured here, can be very beautiful indeed. Sometimes the yellow fades away in captivity and the fish takes on the regular pink appearance. It is not really clear why, but it is speculated that lighting may play a part.
Another colour changing phenomenon observed in Liopropoma occurs in the “striped” species. It is not uncommon for certain species, like the undescribed one above, to lose their striping over time in the aquarium. Liopropoma latifasciatum, another species with a horizontal black stripe, is also known to fade its stripe away in captivity. Again, not much is known as to why this happens. Speaking of undescribed species, Liopropoma is no stranger to future genus expansions.
New species of Liopropoma are being discovered now and then, and because of their cryptic and deepwater nature, will likely to continue surprising scientists and ichthyologists in the future. As mentioned earlier, the reefs are replete with a tangle of rock interstices, where a multitude of species hide away from scientists and divers. The twilight zone is especially rich with new species, being in deep waters, and unless light is intentionally shone within the reef matrix, there is very little chance a prospecting surveyor would bump into a Liopropoma.
Two “known unknowns” occur in the trade with certain regularity, and they are featured in this article with photos both in the wild, and in the aquarium. The “yellow tail sp” is currently being worked on by Dr. Luiz Rocha, and is occasionally seen in Philippine imports. Another “known unknown” is the “striped sp” seen above pictured with the “yellow tail sp”, and it resembles Liopropoma latifasciatum closely.
So far all the photos above have been of smaller, more aquarium suitable Liopropomas. We mentioned earlier that the genus is also home to larger species, attaining 5 inches and beyond in some. These are usually found in even deeper waters, some too deep to reach by conventional diving. Rebreather diving has opened up a window of opportunity for aquarists to try their hands at these exceptionally deepwater species, however even rebreather diving has its limits, and are out of reach for submersible and/or trawler depth species.
Liopropoma aberrans as above, is a wonderful rich cadmium orange and yellow that is found in the deep waters of Curacao. Very few specimens have made it to Japan, and when we visited Osaka a few years back, managed to catch a glimpse of this species. Curacao is home to a variety of deepwater Liopropomas, of which four belongs to the group of larger more predatory members. L. eukrines is the most commonly offered, while L. santi and L. olneyi are recent additions to the genus, being described only as recently as 2014.
The bigger, deeper water Liopropoma live at such soul crushing depths that an underwater submarine is usually required to capture them. For example, L. santi occurs at 241m (790ft), way too deep for any rebreather diver to penetrate. These ultra deepwater submersible caught species are very rarely offered, and when they do, which they have in the past, often fetch exorbitant amounts of money.
An example of a deepwater but rebreather accessible species is the Hawaiian endemic Liopropoma aurora. This species until very recently was hardly ever seen, but within the last couple of years have been collected in small amounts by Rufus Kimura. The beautiful peachy-orange body is adorned in a complex series of yellow spots and scrawling on the face and dorsum, while the face is decorated with a horizontal yellow mask. Like any other smaller Liopropoma, the care requirement is the same. Suitable rock habitats filled with overhangs and a web of holes is necessary for the species to feel at home. The ultra deepwater species are not as suitable for reef style tanks, and are best kept in a dedicated system with lowered temperature and very dim, to no lights.
Even deeper still, amongst the bigger Liopropomas, are species that are almost never seen alive. Liopropoma maculatum for example, is found at depths ranging from 100-400m, that’s 382-1300ft. The only time these fishes are ever seen are usually when they get trawled up from conventional deepwater food fish vessels, and are usually dead as by catch. It is not uncommon to see Liopropoma japonicum, L. lemniscatum, L. aragai and various other super deepwater Liopropoma being sold on ice, in wet markets along side other food fish for human consumption.
There you have it. A comprehensive (we hope) guide to the various Liopropoma, big and small, shallow and deep, as well as the care required to house them. The genus is big, and there are so many more species that we did not cover in this article, as well as who knows how many out there waiting to be discovered. If you’re one to get bored easily of your glass pacing angelfish, give Liopropoma a try. Their absence from your everyday view will require you to look more closely at your tank, scour at your rocks to find them. And if you ever forget that you had it in the first place, then the surprise of seeing it re-appear will be sure to delight you.