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South American Cichlids: Part 2, Giants, Pikes and Dwarfs
The acaras and eartheaters looked at in the first part of this series are adaptable fish that adapt well to robust community tanks and place relatively modest demands on the aquarist. The cichlids discussed this time round are significantly more challenging. Unlike blue or port acaras, which might be considered fish eminently suitable for the beginner, these fish are best kept by more advanced aquarists. They require excellent water quality and in many cases careful management of water chemistry as well.
The most popular genus of big South American cichlids are Astronotus, in particular the oscar Astronotus ocellatus. The second species in the genus is Astronotus crassipinnis, a fish that is similar in size and shape but distinguished by its basically black body colour and white vertical banding. Both species are large, comparatively peaceful outside of breeding, and make excellent residents for large community tanks.
Astronotus generally, and tank-bred oscars especially, have proven to be very adaptable with regard to water chemistry, and will do quite well in hard, alkaline water. What does matter is water quality though; these fish are notoriously messy feeders, and this puts a huge strain on the filter. Choose a generous filtration system for these fish that delivers at least 6 times the volume of the tank in turnover per hour. Do not overstock the tank and perform regular water changes (ideally daily, and certainly not less often than weekly). High levels of nitrate are particularly dangerous because they appear to be a triggering factor behind the Hexamita/Hole-in-the-Head infections that oscars are prone to. Treating these diseases is difficult, so prevention rather than cure should be the aim.
Wild oscars feed on a variety of prey including small fish but also armoured prey such as snails, crayfish and crabs. To break through the shells of such prey, oscars have very strong jaws. In captivity oscars will eat a wide variety of foods including chunky seafood, whole prawns, snails, cichlid pellets, and even tinned peas. Laboratory work has show that oscars are prone to disease when not provided with enough Vitamin C, so in aquaria it is important that they are given good-quality pellet foods on a regular basis to ensure adequate nutrition. Oscars have a reputation for becoming fussy feeders when given one sort of food every single day, so always take care to vary the diet by offering different food items throughout the week.
Species of Cichla are surprisingly good aquarium residents, despite being very large, very predatory and very active. Cichla temensis for example gets to as much as 100 cm in length, making it a strong candidate for the "largest cichlid on Earth" monicker. The more commonly traded species is Cichla ocellaris, a species that typically gets to about 50-60 cm. Despite their size, Cichla are not particularly aggressive outside of spawning, and wild fish at least live in groups. In aquaria they may be kept singly or in small groups depending on the size of the tank. They also combine well with non-aggressive tankmates too big to be eaten, including stingrays, oscars, clown loaches, tigerfish and so on.
All Cichla are piscivores in the wild, eating a wide variety of prey including other cichlids. Their hunting method is distinctive: rather than being ambush predators like most other predatory cichlids, they are pursuit predators, swimming fast enough that they can outrun any potential prey. In captivity they are very adaptable and will take a wide variety of live and frozen foods including river shrimps, earthworms, crickets, lancefish and chunky seafood. They will also take carnivore pellets.
Cichla species are found in the Amazon, Orinoco and other major river systems in tropical South America. They are mostly found in freshwater but Cichla ocellaris at least is found in brackish water as well.
The third big cichlid widely kept are the severum cichlids, Heros spp. There are several species known as well as tank-bred "golden" forms. Severums get to about 20 cm in length, making them a bit too big for the average community tank. But they are relatively peaceful fish and work well in large community tanks with species of comparable size. Unlike the other big cichlids mentioned so far, severums are omnivores and feed on fruits, plant leaves and algae as well as invertebrates of various types. They consequently need a varied diet to do well, and optimal condition and colouration will be obtained with a diet rich in crustaceans and plant material. Cooked spinach and tinned peas are particular favourites, though severums will also graze on cheap aquatic plants such as Elodea.
The standard severum is likely a hybrid Heros of some sort. Other species in the trade include Heros appendiculatus, Heros notatus, and the "true" Heros severus. Heros appendiculatus is noted for its red pelvic and anal fins and the incomplete black bars on the flanks. A variety known as the 'Rotkeil' form has much stronger red colouration and is among the most attractive fish in the hobby. Heros notatus has very weak banding on the body and is covered with hundreds of small black spots. It is a very smart-looking fish, but sadly rather uncommon in the trade. True Heros severus have strong black vertical bands on the body when young, but even when it matures the last band that runs from the anal fin to the dorsal fin should remain clear. There are a variety of colour morphs, including a brassy green form and one with a more golden background colouration.
Maintenance of tank-bred severums is not particularly difficult. They are adaptable to a range of water chemistry conditions, and do fine in hard and alkaline water. Soft and acidic conditions are preferred though, and probably essential for spawning wild-caught fish. Aim for pH 6.0-7.5, hardness 5-15 degrees dH when keeping severums. Severums get along well with mid-sized characins and non-aggressive cichlids (such as acaras). They generally ignore catfish, and severums can make excellent midwater additions to tanks where loricariid and pimelodid catfish are otherwise the prime focus of the aquarium.
Among the most specialised of all the South American cichlids are the pike cichlids, Batrachops and Crenicichla. Both genera share a similar elongate body shape and large, deeply-cleft mouth. Like their namesakes, pike cichlids are predators that feed primarily on small fish as well as large invertebrates such as river shrimps and insect larvae. Most pike cichlids are fairly large, around 30 cm being typical for things like Crenicichla sp. "Xingu 1" and Crenicichla saxatilis, but there are some dwarf species such as Crenicichla compressiceps that only get to about 10 cm in length and make better choices for aquarists that have less space available. Many species are very vividly coloured, and coupled with their interesting shape and habits has ensured that they are very popular among aquarists.
In terms of social behaviour, pike cichlids are territorial but shy. Compared with most other cichlids they are not very outgoing, and tend to hide away most of the time. Obviously pike cichlids cannot be kept in community tanks with substantially smaller fish, but they make good community residents when kept with fish of similar size including large characins and barbs, armoured catfish, and clown loaches. Do not underestimate the size of their gape though: these fish have huge mouths and can swallow remarkably large prey! Keeping them other cichlids tends to be inconsistent in results though; pike cichlids are territorial and often squabble with other cichlids over access to caves and nesting sites.
Feeding pike cichlids can be tricky, wild-caught specimens especially much preferring live foods over anything else. River shrimps and earthworms make ideal foods for pike cichlids, being nutritious, inexpensive, and very safe to use. As is ever the case with predatory fish, avoid using cheap "feeder fish" because of the health risks involved. If you must use live fish as food, breed your own livebearers such as guppies or mosquitofish to avoid the problems with fat and thiaminase that come from using cyprinids such as goldfish and minnows. Once settled in, pike cichlids will eat a variety of foods including chunky seafood and frozen foods.
Pike cichlids are not particularly hardy, and need an aquarium with excellent water quality and ideally the right water chemistry. Most pike cichlids will only thrive when maintained in soft (5-10 degrees dH), slightly acidic water (pH 6-7) conditions. While tank-bred fish may acclimatise to hard, alkaline water conditions, do not assume that wild-caught fish will do so. As is often the case with predatory cichlids, feeding these fish the high protein diet they prefer results in dangerous levels of nitrate, so water should be changed on a regular basis, at least 50% per week. The filter needs to provide turnover of not less than 6 times the volume of the tank per hour. When exposed to poor water quality for extended periods these cichlids are very prone to Hexamita and hole-in-the-head infections. Slightly complicating matters is the fact pike cichlids need warmer than average conditions, around 25-30 degrees C in most cases. As water gets warmer, its oxygen content decreases, so it is important not to overstock a tank containing these fish. Because feeding and maintaining them isn't as simple as it is for more generalised cichlids, pike cichlids are best kept by experienced aquarists who understand the basics of water chemistry and water quality management.
The dwarf cichlids of South America are much appreciated by aquarists for their bright colours and interesting breeding behaviours. On the plus side, their small size makes them easy to house in relatively small quarters. Few do any serious digging, and while some can be aggressive towards other benthic fish (such as Corydoras) they generally combine well with tetras, hatchetfish and other small fishes of the middle and upper levels of the tank. The chief downside to dwarf cichlids is their relative lack of hardiness: these fish very sensitive to dissolved metabolites including nitrate, and demand clean, well-maintained aquaria for long term success. South American cichlids are also rather more fussy about water chemistry than the their West African cousins, so while kribs can be expected to adapt to most water conditions, Mikrogeophagus ramirezi and many Apistogramma will need soft, acid water conditions to do well.
Mikrogeophagus ramirezi is known as the ram cichlid in the hobby and is the most widely traded South American dwarf cichlid. It is a very beautiful fish with vivid colours, but unfortunately is also among the least robust of all the dwarf cichlids. Two problems in particular need to be dealt with before the aquarist can expect to keep them alive for more than a few months. Firstly, soft, acidic water conditions are absolutely essential. Aim for a pH between 5 and 6 and a general hardness less than 10 degrees dH (and ideally around 3-5 degrees dH). The second thing these cichlids need is warmth: around 28-30 degrees C being optimal. This is a lot warmer than most other South American community fish like, and is for example well above the tolerances of neon tetras and most Corydoras. So choose tankmates with care, or better yet, keep these lovely cichlids in an aquarium of their own.
Ram cichlids are not easy to sex, though males typically have longer dorsal fins and tend to be a little bigger than the females. Given appropriate environmental conditions they spawn willingly. In hard water the eggs will not develop properly. The fry, once they emerge, are tiny and need smaller live foods than is the case with things like kribs. Infusoria and microworms are generally used for the first week, after which brine shrimp nauplii can be used. Ram cichlids are challenging to keep and breed, so despite their widespread sale, less experienced aquarists will find other South American dwarf cichlids altogether more rewarding, even if they might be more difficult to find or more expensive to buy.
For the hobbyist after a more adaptable, easier to care for species, it is hard to fault the cockatoo dwarf cichlid Apistogramma cacatuoides. Although they do well in slightly soft and acidic water, they will also live and breed quite happily in neutral, even slightly basic, moderately hard water (pH 6-7.5, 5-15 degrees dH). They are also content to be maintained at normal aquarium temperatures around 25 degrees C. This makes them much easier to keep, and unlike ram cichlids, Apistogramma cacatuoides can be recommended as a good community fish provided its small size and need for good water quality is accommodated.
As is generally the case with Apistogramma, males and females are strongly dimorphic. Males have beautifully marked fins, the dorsal and tail fins in particular being covered in bright red and black markings, almost like a fancy guppy. Females are also attractive in their way, with a yellow body marked with black stripes on the body and fins. There's a lot of variation in this species, so take your time to find some really nice breeding stock! Apistogramma tend to be harem spawners, so keep one male to multiple females if you want to see their normal behavioural repertoire.
There are plenty of other Apistogramma in the trade. Some are easier to keep and breed than others. Apistogramma borellii is known as the umbrella dwarf cichlid and is similar to Apistogramma cacatuoides in terms of maintenance. Males have brilliant sky blue colouration on their otherwise golden-yellow bodies and fins. Apistogramma hongsloi is another lovely species, the males being yellow in front, red on the flanks, and blue patches on the flanks and fins. Apistogramma hongsloi is unusual in being a true pair-forming species rather than a harem spawning species. Most Apistogramma are around 5 cm in length, though males tend to be a bit bigger than females.
Probably the best species for beginners is the golden-eye cichlid Nannacara anomala. In breeding condition the males bright blue on the face, flanks and fins. Females are less strongly coloured, usually greenish-yellow with a prominent dark band running along the midline of the flanks. When shepherding their fry, females develop a striking pattern of dark black stripes and vertical bars. Both sexes get to about 6 cm.
While peaceful towards other aquarium fish, the males can be waspish towards one another and are very arduous suitors. For that reason, it's a good idea to keep two or more females per male. If they must be kept in a pair, don't overcrowd them, and make sure there are plenty of plants and caves for the females. Nannacara anomala is otherwise a lovely addition to the community tank and an excellent species for the aquarist looking to spawn dwarf cichlids. Breeding behaviour is similar to Apistogramma, with males defending a large territory containing the nests of several females. Females look after the eggs and fry on their own, usually very diligently.
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