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Of the thirty four living families of catfishes, a few stand out as aquarium favorites; the armored cats of the Callichthyidae (e.g. Corydoras, Diadema), the long-whiskered pimelodids, the gorgeous Synodontis of the family Mochokidae, and the "Plecostomus" family of South and Central American sucker mouth catfishes, the Loricariidae. The Loricariids are often called upon to do "double duty" as aquarium specimens; to look nice and be a/the clean up crew removing algae and other waste. The latter role too often doesn't work out as planned.
There are some principal misunderstandings regarding the Loricariids; as basic as which species are which, what water quality they enjoy/will tolerate, providing them adequate to appropriate foods. Many species are in taxonomic limbo and numerous (at least two to three hundred) are yet to be scientifically described. Some are huge, attaining more than two feet in length, and quite aggressive/territorial; fighting back their own or other tankmates. Others, like the genera Otocinclus and Peckoltia are small (a few inches maximum) and retiring.
In "browsing" the electronic bulletin boards regarding freshwater fishes, live plants and aquariums you'll notice a great deal of interest in these "suckers"; and several references to lack of success in keeping many of them. The "formula" for Loricariid success is actually not mysterious nor any secret at all. After handling hundreds of boxes of imports of these fishes, and observing attempts at their commercial production in the Far East, I've come to the this parsimonious conclusion. As is often the case with all livestock husbandry, the principal concerns are merely selection, proper water quality, habitat and feeding.
Classification: Taxonomy, Relation With Other Groups
The Catfishes as a whole are a huge assemblage, some 34 families, 412 genera and 2,405 described species, making up the Order Siluriformes. Of these, the Sucker moth Armored Catfishes, family Loricariidae, collectively termed "plecostomus" or "Plecos" by most hobbyists, are an enormous group themselves. The largest family of catfishes, with about 80 genera and 600 plus known species, systematists subdivide the Loricariids into five subfamilies based on head shielding characters (See Nelson, 1994, Burgess, 1989, FishBase 2000). These fishes are mainly found in swift running streams and rivers but can be found in many other freshwater environments.
You know these fishes; dorso-ventrally (top to bottom) flattened, with underslung sucking mouths surrounding fleshy lips bearing reduced barbels, and spiny body armor ("loricar" means armored). Of special note are Loricariid fish eyes; those omega-shaped pupils dilate and contract in response to varying light. Most advanced fishes eyes have fixed pupils.
A few quick notes here, for comparison's sake, regarding 'other' algae eaters. The most widely sold in the west, the Chinese Algae Eater of Southeast Asia (family Gyrinocheilidae), Gyrinocheilus aymonieri. It only does a passable clean up job when small, becoming a plant (and fish) eater with age/growth. The Siamese Algae Eaters, genus Crossocheilus vie for first place however. We will deal with these minnow-like fishes (family Cyprinidae) in a separate piece. (Images: The Chinese Algae Eater, True and 'False' Siamese Algae Eaters)
Concerning the dangers of "common names", there are too numerous grievous examples of vernacular appellations having nothing to do with scientific/phylogenetic affiliations in our hobby. The Loricariids are not exempt from this confusion. The "Plecos" from the Far East, variously labeled Hong Kong or Borneo Plecostomus are better known as River Loaches, family Balitoridae (formerly Homalopteridae), and are more closely related to true Loaches (family Cobitidae) than catfishes.
Lastly, before launching into the major aquarium genera of Loricariids, a mention of "L" numbers and the group. Some time back, a few of the German hobby magazines initiated an "L number" labeling scheme to identify images of otherwise unidentified species of the family. As they are scientifically described, such numbers are retired'¦ there exists considerable confusion as to identity with this system, as the magazines have been mis-joined in their labeling with other sources. Suffice it to understand that if you're relying on such an identification source as an L-number from a magazine, book, CD-ROM, do identify the reference by name, date.
Some of the More Commonly Offered Loricariid
This is perhaps the most useful genus of Loricariids for hobbyists, due to their prodigious algae eating, leaving plants alone, and tolerating harder, alkaline water than other Loricariids. With some 54 described species and many more to come, the Bushy- or Bristle nose Plecostomus are relatively hardy and importantly, stay small (most never exceed six inches in total length). Ancistrus spp. do fine in water of near neutral pH, lower hardness and tropical temperatures. Do eat little algae in the wild or captivity'¦ need supplemental greenery daily. (Images: Ancistrus1 showing head tentacles of a male)
Genus Baryancistrus: Three species. "This genus of Plec is omnivorous rather than an algae eater, and needs catfish pellets and bloodworms alongside the usual vegetable foods. Sorry I can't be 100% certain on these, and I'd direct the owners to the Planet Catfish if they want some real experts to identify these catfish." NealeM.
Genus Farlowella, Twig Plecostomus:
Two species of rather larger "plecostomus" are bred and reared in large quantities for the aquarium trade, pond-techniques perfected at farms in Florida. Liposarcus anisitsi (Eigenmann & Kennedy 1903) is the Snow King Pleco (formerly of the genus Pterygoplichthys), to seventeen inches in length (thirty inches according to Burgess 1989), and the Leopard Pleco, Glyptoperichthys gibbiceps (Kner 1854) (formerly Pterygoplichthys gibbiceps), at about twenty inches maximum. Still these larger aquariums barely begin to measure up to some of the truly big Loricariid species. Some approach three feet in length, not a misprint. (Images: A head shot of a Snow King Pleco, a large size Leopard, and a valid member of the genus Pterygoplichthys).
A monotypic genus (all to itself), Hypancistrus zebra (Isbrucker & Nijssen 1991), is a real charmer. Though small (about three inches in length, maximum) and not much of a "cleaner upper" of algae it is still a popular Loricariid, and though still collected out of Brazil's Rio Xingu, many specimens are tank-bred and reared for the aquarium trade. (Images: An individual and group of small Zebra Pleco's)
Genus Loricaria: 11 valid species: http://fishbase.org/NomenClature/ValidNameList.cfm?criteria=SYNONYMS.SynGenus+%3D+%27loricaria%27++AND+SYNONYMS.SynSpecies+like+%27%25%25%27+&vtitle=Scientific+Names+where+genus+equals+%3Ci%3ELoricaria%3C%2Fi%3E
Just a mention of the closely related genera Parotocinclus and Hypoptopoma though rarely imported, some of these are beautifully eye-catching, and just as suitable as Otocinclus.
Of the ten described species in this genus, only two are offered in the hobby, and never cheaply. The Royal Plecostomus, Panaque nigrolineatus (Peters 1877) and Blue-eyed Panaque, Panaque suttonorum (formerly P. suttoni) are collected mainly out of Columbia for the aquarium trade, though they are found in Brazil and Ecuador as well. These fishes grow respectively to at least sixteen and nine inches in length in the wild. (Images: A juvenile and adult Royal Pleco in captivity)
Genus Peckoltia, Clown Plecostomus:
These small (3-5 inches) Loricariids are not as hardy in shipping or acclimation to captive conditions, but are sturdy enough if/when brought in well, and once they settle in'¦ and they almost always leave live plants alone. Also of note, though they are often pictured and housed together in captivity, Peckoltia species are best kept either one to a tank (even if a large system), or pairs. They're easygoing with other bottom dwellers but very aggressive toward conspecifics. (Images: three Peckoltia spp.)
Genus Pseudacanthicus, six species:
Genus Sturisoma, Royal Whiptail Plecostomus:
Hearty feeders on worms, insect larvae, crustaceans like Daphnia and Brine Shrimp and prepared foods. Some species at times sold as "Royal Farlowellas", though the genus Sturisoma's larger heads and distinctive dorsals easily distinguish them and worked tail fins. And though they look fragile, this genus' members make sturdy aquarium additions. (Image: a tank bred juvenile and adult Sturisoma in captivity).
Natural and Introduced Range
The Loricariids are entirely freshwater and of the New World, Panama to most of South America, in waters of low elevation to more than 3,000 meters, still to swift flowing.
Selection: General to Specific: Several Criteria to Consider
Pick out initially healthy stock; this is a crucial and difficult task, and no, I have no crystal ball. The majority of Suckermouth Catfishes are wild caught and imported. Some shipments of are almost 100% DOA, others the opposite. Sometimes "bad" (more than 50% lost at the get go) imports suffer very little consequent loss, whereas others are all dead for no apparent reason within a few days. A few generalizations are of service:
1) Look closely at the whole batch; every individual in the place. How do they seem? Are they full bodied; that is, not skinny? Look at their abdominal regions and their eyes. These should not be sunken in. Are the fins intact? Not frayed or whitish? All breathing? Are they alive at least? Good, go to 2).
2) Look for good color, olive brown, black and white where it should be for the species. See any with grayish white, or bloody marks, especially at the parried fin origins and belly area? If their skin is damaged, leave them all.
3) "How many do you want?" Pick out the active individuals, those cleaning up, that are moving around. Omit the skulking, immotile ones having "private parties" in tank corners.
4) How long have they been there? If they're going to die, they generally do so within a few days... from "ammonia" (or other metabolite poisoning), low oxygen, lack of feeding, poor handling in general. Wait for them to "plump up" and stabilize.
X) For you wholesalers, retailers who are receiving and holding these animals for a while (as opposed to transhippers, break-packers/jobbers): A) Do utilize acidified water and Methylene blue (for oxygen carrying ability and anti-microbial effect) in acclimation (Fenner gratuitous self-citations below). B) And make sure they're provided with some driftwood and other purposeful food. The best outfits I've seen keep some microwaved/blanched zucchini, nutritious food blocks, and defrosted frozen bloodworms in their system at all times. C) De-worm them en-masse with medicine (hobbyists can use Tetra's medicated food for parasites) applied to the food, before sending them on.
If you'll take the time to seek out and acclimate healthy Loricariids and do nothing more than provide them with an appropriate habitat, dark spaces, perhaps some live plants, and clean moving water of high oxygen tension, you will find them to be extremely hardy.
As a corollary, don't be too fastidious about scrubbing the system sterile; instead just clean the front or viewing panel(s) leaving some algal growth, mulm and bacterial populations.
Most species are nocturnal in the wild, with many of these becoming crepuscular to diurnal in captivity. Still others are not as naturally nocturnal as their sucker mouth brethren, but do appreciate cover to get out of the light and into hiding. Ideally this would be a combination of plantings, submerged wood, and other decor.
Many species (e.g. the more coastal Ancistrinines) display a wide tolerance to given standard aquarium-utilized parameters, living well in soft to hard (zip to 400+ ppm total hardness), acidic to alkaline (5.5 to 8.0) waters. Other species display less tolerance. You will need to investigate the ones you are interested in, though most do fine with less hard (<100ppm total), near neutral pH water (7.0).
They do display an objection to high concentrations of organic metabolites however. You should have no detectable ammonia, nitrite, and low nitrate (much less than 10 ppm) levels. The steps to maintaining these criteria are simple; under crowd, underfeed, properly filter, and do regular maintenance (in particular water changes) regularly. Poor water quality very often manifests itself in death due to apparent bacterial infection.
Temperature range is wide enough, 72-82 F. (21-27 C.) for most species. If summer temperatures peg out much higher, cut back on your lighting and do definitely increase/add aeration.
Should be vigorous and complete; move all the water around and through the mechanical, biological plus possibly chemical filter media a good twice plus per hour. As long as it does not disturb your plants, you can't have too much water turbulence.
Additionally, weekly water changes of 25% are recommended to keep metabolites low and the system "dynamically stable" (love those oxymoron's!).
Though these are technically armored cats, they should be handled gingerly, as little as possible, and only then with fine meshed nets or guided into specimen containers without. Avoid touching them by hand, wiping off their protective mucus and possibly getting spined by their spiny dorsal and pectoral fin spines. Instead, if you utilize them, invert the net and cats into the intended system's water and let them extricate themselves. Commercial operations do well to fashion shallow draft, rectangular nets utilizing fiberglass screen door netting for these and other similarly spiny livestock.
Some Loricariids are decidedly agonistic toward conspecifics, the clown "Plecos" (Peckoltia), and Royal types (Panaque) come to mind. Such is not the case with Otocinclus for instance; they get along with their own, other members of the genus, in fact with most everybody. There are citations that call attention to "riding" and parasitic sucking on fish tankmates by Loricariids, but rarely are these recorded as being ultimately deleterious to the host. More likely this behavior is a manifestation of food deprivation, imminent death of the fish being eaten, and a sign that you need to be supplementing their diet.
Due their intolerance of cycling metabolites and fondness for algae these fishes are best placed in well-established systems; particularly ones where there are live plants that have become firmly settled and are growing.
Most species are best-utilized one to a tank, unless you have plans for spawning them or a very large system. But there are exceptions here as well. Otocinclus should be purchased in a group (one or two per ten gallons of system is about right functionally), being social animals, and batch-processed via a dip and quarantine procedure (Fenner, 1989,94).
Most all small to medium size and aggressive fishes get along with Loricariids. Larger, more aggressive tankmates and generally agonistic species might be tempted to try picking on them; for their tanks, try the larger Loricariids.
Reproduction, Sexual Differentiation:
Sexing many Loricariids is not difficult, but takes a trained eye. In some, definitive gill cover spines and pointed genital papilla of males can be made out; in most species sexually mature males tend to be more broad in the head. Looking to the females, they are decidedly broader and rounder in appearance. When fecund and sucking onto the side of their tank, eggs can be seen with a flashlight through their vent area.
Due to mixed species shipments, the wannabe breeder is encouraged to purchase and stock a given species in as large a grouping and system as practical, and provide propitious circumstances (food, habitat, water quality) for nature to take its course.
Most species of Loricariids are recorded as male-nest building and parented; females only being tolerated if egg bearing, then driven out once they've laid their eggs. Otocinclus are listed by some authors as "egg scatterers" contrasting with most of the other egg-laying Loricariid genera. Young of the family hatch out in 4-20 days... with many folks listing baby brine and spinach as first foods. For much more on spawning accounts see the references below, particularly Burgess (1989).
Feeding/Foods/Nutrition: Types, Frequency, Amount, and Wastes
Inadequate feeding/nutrition is only second to selecting decent specimens as a source of mortality with these fishes. Three key points again; do not place Loricariids in new, or overly cleaned systems, they will perish from lack of food. Secondly, you must expressly provide foodstuffs for these suckers, (e.g. sinking pellets, greens like cooked spinach, Nori, peas) especially if keeping them in an unplanted or under-planted setting. And lastly, the "wood trick", that is, supplying your Suckermouth Catfishes with some submerged wood as a needed dietary adjunct.
Disease: Infectious, Parasitic, Nutritional, Genetic, And Social
Though they have sturdy body scutes the South American sucker mouth catfishes are barely armored against poor water quality. This shows up in their ready susceptibility to "organic pollution". For a dearth of water changes, otherwise adequate filtration, they often, too often die from bacterial-population-explosion "disease". Maintain high water quality.
On import, internal worms, mainly of the gastrointestinal tract and gill flukes can be lethal. Don't trust your livestock source to have done the job on these. During quarantine, feed your new Loricariids anti-parasitic food for a good week. Tetra "¢ makes an anti-parasite food of use here, or you can devise your own using Metronidazole/flagyl. Captive-bred specimens are of course, almost always gill and internal worm free.
The too-common infestations of ich can be quickly resolved with malachite with or without formaldehyde preparations. Be wary of utilizing too much salt, metal (copper) or insecticide (DTHP, Masoten, Dylox, Neguvon) medications on these catfishes; they succumb to these treatments more readily than the apparent cause you're treating.
The Suckermouth Catfishes are amongst the "world's most useful algae eaters" for planted and non-planted aquariums. They are largely peaceful, unobtrusive, and industrious, readily available and interesting behaviorally. Beyond these considerations the sheer diversity of this family of cats offers a lifetime of opportunities for engaging work in breeding, experimentation and fun.
If you intend to put them to good use, just keep in mind the four cardinal points offered here. Pick out healthy stock, keep water quality high and constant, provide a suitable habitat, and suitable food including some submerged wood.
Catfishes on the Internet: http://phylogeny.arizona.edu/tree/eukaryotes/animals/chordata/actinopterygii/siluriformes/siluriformes.html
Planet Catfish: http://www.planetcatfish.com/core/index.htm
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