Catfishes: A Chaotic Biodiversity that is still Waiting to be Discovered - Page 2: Families
Catfishes: A Chaotic Biodiversity that is still Waiting to be Discovered - Page 2: Families
Written by Thursday, 07 February 2002 00:00
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Callicthyidae
This family includes two of the most known subfamilies, the Callichtyinae and the Corydoradinae. Callichtyinae includes, among others, the genera Callichthys (C. callichthys), Dianema (D. longibarbis, D. urostriata), Hoplosternum (H. littorale, H. pectorale, H. thoracatum variations), while Corydoradinae includes 189 Corydoras species, some genera of the Bronchis species (Β. britskii, B. multiradiatus, B. splendens) and species of the genus Aspidoras (A. albater, A. fuscoguttatus, A. menezesi, A. pauciradiatus, A. rochai). The enormous number of Corydoras species has made the biologist classify them not by name but with a capital C, that represents the genus and a number that represents the species (C4 for instance, represents Corydoras virginiae, Miguelito Panzerwels).
Biology
Most of the members of Callichtyinae family live, feed and reproduce on the bottom or very close to the bottom, and there are only a few exceptions. They detect their prey with the help of their barbells-sensors, so we have to keep them in tanks with very fine quartz gravel or sand as a substrate. Sharp edged substratum will hurt the barbells and damage them. Damaged barbells can cause bacterial and/or parasitic infections that drive the fish to death from starvation or diseases. Lava will irritate the barbells and mouth region of catfishes, so it is not advisable to use it in tanks with these bottom dwellers. Callichthys callichthys, Dianema and Hoplosternum species are mainly nocturnal. Because of their benthic habits, they are vulnerable to chemical processes (such as anaerobic process and Nitrate (NO3¯) concentrations) that take place in the substrate region of a newly established tank, so it is better to introduce catfishes into well cycled tanks.
Feeding
In their natural habitats, catfishes feed upon benthic organisms (worms, eggs, insect larvae and aquatic creatures larvae) and dead organic material from decomposing flesh that they detect with their sensors from the substrate (bottom feeders). In captivity we should provide them foods with high concentrations of proteins not of mammalian origin. Live foods are also essential for their well being and breeding. Suitable foods for this purpose are Mysis shrimp, Daphnia, Cyclops, Microworms, black and white Mosquito larvae, Glass worms, Artemia salina etc. Dry foods, freeze-dried varieties and tablets or pellets are pleasantly accepted from them as well. Always keep in mind to dampen tablets and pellets before feeding.
Breeding
Catfishes are oviparous (lay eggs) and they spawn on the substrate, near it or under the water surface vegetation. In nature, the spawning period is usually during the rainy season, as chemical compositions of waters are different due to nutritious materials that are washed into bodies of water. During this period, there is plenty of food for adult fish and their fry and also plenty of food for their feeders (insects, for instance). In captivity we may reproduce these conditions as closely as possible.Callichthys callichthys and Hoplosternum species have a very interesting breeding behaviour that closely resembles the breeding technique of Belondidae. The males construct a bubble nest under leaves of water plants. The females deposit their clutches inside and the males fertilize them and keep nests, eggs and fry safe by chasing away any intruder. The clutch size differs from species to species and is proportional to the size of the breeders. They may vary in number from 100 to 500 eggs. The incubation period may last three to four days and is dependant upon water temperature. The larvae are not very big, so their first food must be their size (Microworms, newly hatched brine shrimp). Later, they can be fed and weaned with Cyclops, Daphnia and fine dried or freeze dried foods.
Corydoras also feature a breeding ritual. Several males chase after one heavy bodied female. The females form their pelvic fins as a basket and carry the eggs to the chosen place to deposit them. One male forms a T position with the female, stimulating her with his barbells on the ventral region. The whole thing looks rather like a comic dance with grotesque jumps.
Proportional to the size and the species, they lay 100 to 200 eggs on the substrate, driftwood, stones and aquatic plants. In a breeding tank we may see the clutch glued on the glass of the tank near the bottom. It is good to remove the parents from the breeding tank after spawning as they are not involved with incubation or any parental care, and may even eat their eggs. When we desire to breed Corydoras species in captivity it is better to keep males and females separately, feed them heavily with live foods, and when they are well conditioned we must introduce one female for 4 or more males in the breeding tank.
The most common Corydoras in community tanks are C. aeneus and C. paleatus (both plain and albino forms). Hobbyists though, prefer C. julii, C. melanistius melanistius, C. m. brevirostrum, C. rabauti (“myersi”), C. adolfoi, C. melanotaenia, C. trilineatus, C. barbatus, C. reticulatus, C. haraldshhutzi, C armatus, C. panda, C. sterbai, C. metae, C. evelynae, C. eques, C. arcuatus, C. elegans, C. pygmaeus etc. Other Corydoras and Aspidoras species are rather uncommon, if not rare, in aquaria.
Water Chemistry
The fishes of this family live in South America. The waters of this region feature a variety from the very soft and acidic black waters of Amazon and Rio Negro (2,0 dGH, pH even < 6,0), to neutral and even slightly hard and alkaline white waters (up to 25 dGH and a pH up to 8,0). They do not appreciate high temperatures, as the temperature near the bottom of the water body is cooler and they have higher dissolved Oxygen concentrations.
General Remarks
The fishes of this family are very nice tank residents. Their small and medium size, make them suitable tank mates for nearly any community tank. The bigger species grows up to 18 cm (C. callichthys), but usually they reach 12 cm (Hoplosternum species). The smaller Corydoras species grow up to 2,5 cm (C. pygmaeus) while the larger reaches nearly 12 cm (C. barbatus). It is not a good idea to house these fishes with large aggressive tank mates like Astronotus ocellatus or other large Central and South American cichlids. Other benthic species that are incompatible with these are the Asian Botia species, as their food and feeding habits are very similar so there would be much competition between them. Their helpfulness as garbage controllers and scavengers and their cute schooling behaviour (never house, for instance, less than 6 to 8 Corydoras per tank) and their oddities have made them a must for community tanks.
Loricariidae
This family includes at least 7 subfamilies with over 130 genera. The most known and popular are: Ancistrinae, Hypoptopomatinae, Hypostominae and Loricariinae. The subfamily Ancistrinae includes Ancistrus, Acanthicus, Baryacinstrus, Chaetostoma, Dekeyseria, Lasiancistrus, Leporacanthicus, Lithoxus, Hemiancistrus, Hypancistrus, Panaque, Pecoltia, Pseudacanthicus, etc. Members of the subfamily Hypoptopomatinae are the species of the genera Hypoptopoma, Microlepidogaster, Otocinclus, Otothyris, Parotocinclus etc. Hypostominae subfamily includes the genera Cochliodon, Glyptoperichthys, Hypostomus, Liposarcus, Monistiancistrus, Pterygoplichthys etc. And in the subfamily Loricariinae belong species of the genera Farlowella, Loricaria, Ricola, Rineloricaria, Sturisoma, Sturisomatichthys, Lamontichthys etc.
Because of the extremely large number of Loricariid species, their classification is being made by the capital letter L and a number that follows. L represents the family and the number represents the species (for instance L 015 represents Pecoltia vittata, known as Rio Xingu Pecoltia). German systematic biologist used, until recently, LDA numbers (“DAS AQUARIUM” publications) and Brazilian exporters TR numbers, so the confusion was major. During the last few years only L numbers and sometimes LDA numbers are used so their taxonomy became simpler.
Biology
The members of the family are oviparous (lay eggs). They live in “black” waters as well as in “white” ones in the river systems of South America (Amazon basin, Rio Purus, Rio Negro, Orinoco, etc.). Many of them live in very soft (up to 2,0 dGH) and acidic (pH even low as 5,0) waters, several others in neutral waters and some others in slightly to moderately hard (10 – 12 dGH) and slightly acidic waters (pH 7,5). Their natural biotopes are cool, fast flowing waters rich in dissolved Oxygen, while some prefer warmer and still water bodies. Many prefer the submersed root formations of aquatic or water friendly tropical trees and driftwood that enhances the water with tannic and humid acids and colour. Some, like the Ancistrus dolichopterus, make their nests in caves of sunken bogwood, while others use crevices of stones, as Hypancistrus zebra does; and some others dig their nests in the mud of riverbanks as male Liposarcus anisitsi do. During the dry season, these kinds of nests they may be found above the water level, but the moisture keeps the animals wet and safe from drying out. The accurate recognition of the species helps us to provide them the suitable water parameters and the right aquascape for their well being and breeding in captivity. The size of these species differs, so we may find very small species 4 cm and under (Otocinclus affinis), while some others can reach 45 cm (Glyptoperichthys gibbiceps) and some others may grow over 50 cm as the Liposarcus multiradiatus .
Feeding
Feeding habits of these animals are as diverse as their origin and environments. There are completely herbivorous species (vegetarians) that prefer algae, fruits from the rain forest trees; omnivorous species that utilize whatever is abundant at any season and is considered food and some carnivorous species (flesh eaters) that eat worms, small crustaceans, plankton and invertebrates. As was said above, the recognition of any particular species we want to keep is very important, as feeding them is dependant on the accurate recognition of the species. In captivity, we must provide herbivorous species with green foods such as algae, spinach, spirulina, zucchini and broccoli, while we must feed the carnivores foods rich in proteins; live foods as Whiteworms, black mosquito larvae, Artemia salina, Daphnia, Cyclops etc. and high quality freeze dried or dried foods. Pellets and tablets must be moistened before are given and, because most of the species are nocturnal, it is advised to be fed right after the tank’s lights goes off. The presence of driftwood, mopani or bogwoods is essential in the tank, as they love to chew wood either for constructing nests or even for digestion, as greens are hard foods to be digested (same thing as with chickens that swallow little pebbles).
Breeding
Spawning some of these species might be very easy (as Ancistrus dolichopterus or Sturisoma species), as long as the animals receive appropriate food, aquascaping and water chemistry. A. dolichopterus is a prolific spawner in a neutral to moderately alkaline (pH 7,0 – 8,3) and moderate to very hard (anything from 6,0 to 50 dGH) water (from personal observations). They demand clean, fast moving, slightly cool (not more than 26° C for spawning stimulation and no more than 24° C for keeping and growing them) water. They also need driftwood with holes, which the male will dig out and size as it likes and utilize them as its spawning site and for egg and fry deposit. They prefer vertical deep holes away from the current, and it is better not to have more than 3 females per male as the females become rather aggressive and competitive among themselves when attempting to enter the male’s spawning site. Because they do not harm their fry, it is common to see adults with several generations of fry (newly free swimmers to semi adult fish) in the same tank. The male accepts ripe females into the nest only for depositing the eggs, and then they are chased away. A male can mate with two different females at about the same time (when one leaves the nest after depositing its eggs, the other enters and deposits its own). The fry are quite large when they abandon the nest and eat microorganisms from the substrate, but they accept live foods; and artificial foods are very easily taken, as well. They have a regular growth rate and if they are fed heavily and we are performing frequent partial water changes (15% daily) they grow rather fast (personal observations). They love spinach and spirulina tablets, but they prefer half - boiled zucchini and broccoli. There is sexual dimorphism as males develop a dense tuft of long horn-like fleshy bush on the front of their heads, but females do not.
General Remarks
The members of the subfamily are the most appreciated between aquarists. The most popular are the species of the genus Ancistrus (A. dolichopterus, A. sp. cf. temminckii etc.), several species of the genus Chaetostoma (for instance Chaetostoma leucomelas), and species of the genus Peckoltia (Peckoltia vittata – known as L015). Some hobbyists prefer the larger species of this genus as Panaque nigrolineatus, P. suttonorum and others. Among the members of the subfamily Hypoptopomatinae more common are the small species of the genus Otocinclus (as O. affinis, O. vittatus, O. flexilis etc.). The dedicated aquarists prefer more rare species like LDA 023 - Otocinclus species or Venezuelan Peckoltia and Hypoptopoma species.
Hypostominae
Many very popular species belong to this subfamily, and are common in many aquaria, like the species of the genus Glyptoperichthys. They also lay eggs and they are rather omnivorous, although they take a good care of the algae in community tanks with large cichlids. Hypostomus plecostomus are very common (in their regular, xanthic and albino form) and Pterygoplichthys gibbiceps are a must for big tanks. They do not harm plants – as a rule with exceptions, of course – but their large size make them clumsy in planted tanks, while swimming between them, when they are trying to find a good place to rest or while they are “redecorating” their tanks according their own desires. Although they are nocturnal, they easily get adapted in diurnal action when they feel safe in their tank. In this case, they will swim up to the surface to consume flakes with other surface feeder fishes. They may reach a length of 50 cm. Hobbyists prefer rarer species such as Glyptoperichthys species cf. lituratus, Hypostomus regani, Liposarcus anisitsi (Snow king pleco), Cochliodon cochliodon. They accept any kind of foods (live, frozen, freeze dried, tablets, pellets, flakes and fresh fruits and vegetables). There are not many things known about their reproduction, but they possibly have the same demands and techniques as the members of the Ancistrinae and the Loricariinae subfamilies’ species.
Loricariinae
This subfamily includes very many species. Among these species, some are very popular in the aquaristic community. The most abundant in home aquaria are the members of the genera Sturisoma (as S. aureum), Farlowella (as F. acus, F. gracilis), Rineloricaria (as R. lanceolata, R. teffeana, R. microlepidogaster, R. fallax). The most beautiful of them are Rineloricaria heteroptera, R. morrowi, Sturisomatichthys leightoni, Lamontichthys filamentosa and they are preferred by hobbyists. There is sexual dimorphism and the males protect the nests (if they use nests) and their eggs. The species of the genus Sturisoma (like S. aureum) spawn on open surfaces while many species of the genus Rineloricaria (as R. fallax) use holes and burrows of sunken driftwood as spawning places. They prefer cool water and the incubation period last for about a week in 24° C. They may produce 40 – 200 eggs (depend on the species and size). The color and the shape of their eggs vary from yellowish round to brown yellow ellipsoid eggs. The fry can be fed on live foods although they’ll prefer awfwuchs. They love peas, spinach, zucchini, broccoli, moistened spirulina tablets or even flakes. They are very beautiful and interesting fish species. They fit in any planted (not heavily planted) tank, as long as there are no extreme water parameters, their tank mates are peaceful, and the water temperature is between 23° C and 26° C. They also like chewing on wood, so some pieces of driftwood, mopani or bogwood must be added in their tank.
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