[Ebook] The New Guide to Aquarium Fish – Ciclilids – Cichlid Behaviour and Its Management

Ciclilids

Qchlids (family Cichlidae) originate primarily in tropical America and Africa, with a few species in the Middle East and Asia. They are mainly freshwater fishes, though a few species require or tolerate brackish conditions. Size – adult Standard Length (SL) – ranges from 2 cm to 91 cm (3/4 in to 36 in) with a similar diversity in form, diet, and behaviour. Some species are very colourful and are thus attractive aquarium occupants. Many aquarists are, however, attracted by their interesting behaviour, character, and apparent intelligence; large specimens in particular can become genuine pets.

Cichlids can be divided into a number of more or less discrete groups, based largely on geographical distribution, but also habitat, size, diet, and behaviour. Before discussing the major groups, however, we must present an overview of “cichlid psychology” — how they behave, and, more important, why. A thorough understanding of this is essential to their successful maintenance.

Cichlid Behaviour and Its Management

All cichlids practise brood care, guarding both eggs and young. This ensures a high survival rate, so clutch size is small compared to that in egg-scattering fishes, which rely on sheer numbers of eggs for genetic survival.

Cichlids have two brood-care strategies: substrate brooding and mouthbrooding. In the former, (normally) adhesive eggs are laid on a “spawning substrate”, for example a stone, plant, or piece of wood; then guarded against predators, kept clean by regular “mouthing”, and fanned with the pectoral fins to ensure a constant supply of oxygenated water. Both parents may share these duties, or one (usually the female) may concentrate on tending the eggs while the other guards the breeding territory. When the larvae hatch they are often placed in a pre-dug nursery pit, and sometimes moved at regular intervals to new pits. Once freeswimming, the fry may be escorted around in search of food, or allowed to forage, independently but under supervision, in the breeding territory. Brood care usually continues until the parents are ready to spawn again (which may be from 10 days to several months, depending on the species).

This strategy is often known as “substrate spawning”, and is further divided into “open brooding” and “cave brooding”, according to the location of the spawning substrate. It requires a strong pair bond which may last for a single spawning episode, a breeding season, or life. In some species a male may bond with several females (“harem polygyny”), each holding her own breeding territory within his “super territory”.

Mouthbrooding, by contrast, protects the eggs and young in the mouth of one or both parents until they are old enough or large enough to stand a good chance of survival alone. Mouthing and fanning are replaced by the drawing of clean, oxygenated water through the mouth by gill action. This, coupled with a reduction in or cessation of food intake, imposes a considerable physical strain on the parent(s).

The majority of mouthbrooders belong to one of the two main lineages of African Cichlids, the haplochromines, in which eggs and fry are incubated by the female alone (maternal mouthbrooding). Upon release, normally after about three weeks, he fry are often abandoned. Males do not bond with females, but hold spawning territories, often centred on laboriously constructed “nests”, from which they display to potential temporary partners. Frequently males hold adjacent territories and competefor females (“arena breeding”). The non-adhesive eggs are laid in the nest. Sometimes they are fertilized before collection by the female, but in many species males have ocelli, the colour and size of eggs (“eggspots”), on the analfin, and in trying to collect these the female ingests sperm, released from the nearby vent, to fertilize the real eggs that are already in her mouth.

In tilapiines, the other African lineage, brooding may be maternal, paternal or biparental, the last usually involving a pair bond and shared territory, as in substrate brooding. Brood care may continue after release, with fry returning to the mouth or being guarded like substrate-brooder young. Some species have eggspots, while others have evolved different egg dummies such as “genital tassels” and egg-like tips to the pelvic fins. Many tilapiines are, however, substrate-brooders, and where mouth-brooding has evolved it often appears less advanced than in the haplochromines.

Mouthbrooding has also arisen, quite independently, in some American Cichlids but is far less common.

Breeding may be seasonal or continuous. The former is the norm in bodies of water affected dramatically by climatic change, and is often triggered by the onset of the rains and a concomitant increase in food supply and available territory (flooded areas). Piscivorous species may spawn later when their food supply is augmented by fry of other fishes! Some species raise more than one brood during a breeding season, often with the same partner. The pair bond commonly dissolves at the end of the breeding season, with a new partner being selected next time.

Continuous breeding is normally found where changes in the climate have less effect, for example in large lakes. Overpopulation is prevented by cyclical fluctuation in food supply and breeding success; when the food supply is good females produce large clutches, but the resulting population explosion depletes the food supply and reduces breeding success until the food supply recovers. In cap-nvhy constant abundant food may lead to unnaturally frequent and/or large clutches and excessive physical drain on the female, with gill strain a serious danger in mouthbrooders.

Most cichlids can be induced to breed in captivity (some need little persuasion), but it must be understood that in some species there is a downside to their breeding behaviour. This has given the entire family an often undeserved reputation for being difficult, destructive, aggressive, and so on. The worst problems can be avoided by understanding the reasons for their actions and taking their behavioural (as well as physical) needs into account.

Digging is a natural and instinctive part of cichlid behaviour, and attempts to curb it, for example by having no substrate, are cruel. “Aquascaping”, sometimes with uprooting of plants, is often a necessary preliminary to breeding – the construction of nursery pits or nests. Large cichlids may try to remove intrusive decor and equipment by brute force – and worse still, succeed! In general, the larger the species, the greater the extent, and likelihood, of disruption.

Plants can be protected by planting in pots, or between rocks and/or pebbles; or omitted. Equipment can be fixed in place, and heavy, immovable, decor used. The environment should be tailored to natural behaviour – you will never achieve the reverse!

A fish which needs to hold a private territory to attract a mate (mouthbrooders) or raise a family (substrate brooders) will quite justifiably regard tankmates as competitors, intruders, or potential fry-predators, and do its best to eliminate such threats. Even if the aquarist is aware of the need for an exclusive territory, he rarely comprehends the amount of space required by substrate brooders.

Although some small species are content, in nature as well as captivity, with an area 30-40 cm (12-15 in) in diameter, many others occupy an area the size of a good-sized room in the wild, and while they are obliging enough to make do with territorial male extends to the female. In nature a female can simply swim away from a malewhen she does not wish to breed.

To stay is to indicate interest. In the aquarium she cannot swim away, the male assumes she wants to breed, and when she rejects his courtship he attacks her like any intruder – but she has nowhere to go, and may be killed. So, unless the tank is rather longer than natural territorial diameter, care must be exercised with sexually mature adults; the problem can often be solved by using a clear divider to separate them until the female responds to the male’s display.

Where aggression between the sexes is likely, or absence of sexual dimorphism makes sexing impossible, it is best to grow on six to eight juveniles together and let them pair naturally. This makes for greater compatibility. “Spare” fishes can be rehomed.

Even with a compatible and bonded pair, perhaps with eggs or fry, the male may suddenly turn on the female if they are alone in the aquarium. His prime instinct is to defend his territory and family against intruders, but if there are no actual enemies to repel, this may be turned upon the only suitably sized fish available – the female. This can be avoided by placing the tank adjacent to one containing fishes large enough to pose a threat, or by partitioning off part of the breeding tank with a clear divider to accommodate a “target fish”. Target fishes must, however, always have adequate living space, and never be exposed to actual aggressive contact.

The novice cichlid breeder is often devastated when hitherto parents suddenly eat their young. In the wild fry gradually wander further and further afield until eventually they become independent. Often there is not room for this to happen in the aquarium; the parents tolerate the youngsters until either the latter grow large enough to represent competition, or the urge to breed again renders them a potential threat to the intended brood. Fry must be removed before this stage if they are to be grown on.

With arena-breeding mouthbrooders, where territory is not needed for fry-guarding, territoriality can be turned on itself by crowding, so no male can claim a significant area except when his motivation peaks in the presence of a “ripe” female. Often these fishes cannot be kept alone in single pairs as the male then harasses the female to death in his attempts to persuade her to spawn; again her presence implies willingness. In the crowded mouthbrooder community, however, males have plenty of distractions and females can “hide” among the other fishes. Such an aquarium is a hive of activity, and it is generally best to move brooding females to individual small brooding tanks until fry release.

Territoriality is usually greatest towards conspecifics, as they are the chief competitors for suitable habitat, mates, and breeding space. Next come other cichlids, especially those of similar size and appearance – often members of  the same genus-. Non-cichlids are often a threat only to the brood, but not to the chance to breed, and are ignored if they keep their distance.

Care must be exercised in introducing new fishes to any tank in which a cichlid holds territory; again conspecifics and similar species are most likely to fare badly. “New” fishes include former residents which have been absent for -a period – for example while brooding. They will have become strangers and have lost their position in the tank hierarchy.

By now you must be wondering if cichlids are worth the hassle, but this doubt will evaporate the first time you see a pair with young, or watch a mouthbrooder  release her fry. Many a confirmed fish-hating partner has softened at the sight!

Moreover many species can be kept and bred without problem in a general community. We trust, however, it is quite clear that you must always research behaviour as well as environmental requirements before making any purchase.