Cichlid fish, pronounced “sick-lid,” represent a large family of freshwater, bony fish with a remarkable diversity and specialization. While the exact number of species is unknown, it’s thought that well over 1,000 exist in the Cichlidae family today. Vivid, vibrant, and varied, cichlids include angelfishes, Oscars, discus, green terror, yellow lab, firemouth, blood red parrot, humphead, and convict. A common member of the Cichlid family is the tilapia. The cichlidae family is just one of the 482 families of fishes. Being colorful, fairly easy to maintain, and interesting to observe makes cichlids popular with aquarium enthusiasts.
Diversity and Distribution
Cichlids exhibit a remarkable degree of specialization, with each species adapting to its environment in its own unique way. They are found in almost every possible body of freshwater within their geographic range including rivers, lakes, swamps, and even ditches and puddles. They are not found at high elevations and generally require water warmer than about 68 degrees Fahrenheit (20 degrees Centigrade). Cichlids are found in the Americas, from southern Texas down to Argentina in South America. They are found throughout Africa and parts of the Middle East. There are cichlids on the island of Madagascar, on the island of Sri Lanka, and along the southern coast of India.
Diet and Habitat
Cichlids can be herbivorous, feeding on algae and plants; carnivorous, preying on small wildlife, other fishes, and insect larvae; or detritivores, eating all types of organic material. The cichlids are very specific in habitat choice: some live only among the rocks, others in open water, others along sandy beaches.
Aquaculture and Behavior
Tilapia (a type of cichlid) are an important food source for many people around the world. Cichlidae are known to be very territorial, especially in aquariums. They show more aggressive behavior toward members of different species than toward their own, however, they are most aggressive toward those that have similar lifestyles (habitats, diets, coloration, etc.).
Parental Care
All cichlids provide parental care in one form or another. This is not the norm for fishes-most fish do not provide parental care, and of those that do, it is typically the male that provides the parental care (in contrast to mammals or birds where the female is often the primary caregiver). Many cichlids are mouth-brooders. In these varieties, a female lays her eggs near a male, he fertilizes them, then she picks them up in her mouth and swims away. The female incubates and hatches her eggs in her mouth. Many male cichlids have “anal fin egg-spots” that loosely mimic the mouth-brooder females’ eggs. This signal was once thought to encourage the female to stimulate the area to maximize the male’s fertilization of her eggs. But recent studies have indicated that the presence or absence of these egg-spots does not impact fertilization rates. Some are substrate-spawners, where a female lays a string of eggs and the male fertilizes them.
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There are no live-bearing cichlids, though there are a number of other fish families that give birth to live young. Activity can be diurnal or nocturnal, depending on the species. Cichlids display numerous complex behaviors in feeding, reproduction, and parental care.
Threats to Cichlids
Threats to various cichlids include overfishing by the local fishers of Lake Malawi, due to the high human population. Water pollution from agricultural runoff is also a threat, because it results in the degradation of the fishes’ habitat. About two-thirds of endemic cichlids (about 300 species), especially bottom-feeders, have become endangered or extinct.
Convict Cichlids: A Closer Look
Convict cichlids are a widespread, well-known species within this unique group. Convict cichlids are both popular aquarium pets and fascinating scientific research subjects - they’re also a problematic invasive species. Do your research before you decide to bring one home. The scientific name for convict cichlids is Cichlasoma nigrofasciatus. You may also see it written as Amatitlania nigrofasciatus, an alternate name for the genus. They go by several other common names too - like zebra cichlids and zebra chanchitos.
Convict cichlids are only one example of the many thousands of species of cichlids. Scientists struggle to estimate the exact number of genera and species in the Cichlidaea family. People discover new ones all the time, while others go extinct before anyone can identify them. Convict cichlids have a distinct look and unique behaviors compared to other cichlid species. They’re very easy to grow, breed, and maintain in an aquarium. These factors are some of the main reasons that they’re popular both as pets and for use in scientific research. These fish have been popular in the aquarium trade since the 1930s.
Habitat and Distribution of Convict Cichlids
Each cichlid species is typically found in a very small area. This is usually just one lake or river. They’re all freshwater species but some also do well in brackish areas. You can find cichlids in habitats like these in a handful of regions around the world, including: South America, Central America, Africa - the region with the greatest species diversity even though cichlids only live in a handful of isolated lakes, Cuba, India, Sri Lanka.
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The convict cichlid has a wider range than most cichlid species. Their natural habitat includes waterways along both coasts of Central America - from Guatemala to Honduras and El Salvador. This makes them a tropical cichlid species. These fish live in rivers, creeks, and lakes. They may outcompete native fish for resources and upset the balance of local ecosystems. waterways.
The aquarium trade is the main reason that these fish are distributed throughout the world. distribution, it’s safe to say that more than one pet owner has prematurely flushed a convict cichlid down the drain.
Physical Characteristics
Two main physical features distinguish cichlids from other types of fish. First, all cichlids only have one nostril opening on each side of their head - not the two holes that similar fish possess. Second, the line that runs along the length of their torso, called the lateral line, is broken into two parts. Comparable non-cichlid species have one continuous lateral line.
On top of these distinguishing characteristics, all cichlid species have a core set of physical features. This includes their: Fin positions, Scale composition, Pharyngeal jaw - an extra set of teeth in the throat. Apart from these basic features, cichlids are as different as can be in terms of their sizes, colors, shapes, and behaviors.
Traditional convict cichlids have black and white stripes across their bodies. Yellow and black striped varieties also exist in the aquarium trade. The typical convict cichlid size depends on the sex. Males are usually larger than females. Males can grow to be over 4 inches, but a more reasonable average for both sexes is about 3.5 inches long.
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We don’t have good data on the average convict cichlid lifespan out in nature. In captivity, many cichlids live for at least 10 years. Be prepared for a long-term commitment before deciding to keep convict cichlids in your home aquarium.
Diet and Feeding Habits
Convict cichlids are omnivores. This means that they eat both plants and animals in their natural environments. This includes: Crustaceans, Insects, Small fish, Worms, Aquatic plants. These fish aren't picky. They quickly adapt to local food supplies when they enter new environments. In an aquarium setting, you can buy a wide variety of commercial flakes and pellets that are formulated for cichlids. Expect to feed your tank once or twice a day.
One fun fact about the convict cichlid diet is that researchers have used it to demonstrate early altruistic behavior in the species. Altruistic behavior is the kind that benefits the community as a whole instead of just the individual that’s involved in the decision. For example, male convict cichlids were far more likely to request food for unknown females as well as themselves - instead of just for themselves - when given the choice between the two options in a controlled experiment.
CONVICT CICHLID CARE GUIDE
Aquarium Setup
Convict cichlids do best when kept in pairs. Your fish will be much happier and healthier with another convict cichlid around. But before you bring your new pets home, get your aquarium set up and ready to go.
Your basic convict cichlid aquarium should involve:
- At least a 30-gallon tank for two convict cichlids - some experimental setups keep mated pairs in 75-gallon tanks
- A water pH between 6.6 and 7.8
- A temperature that’s maintained somewhere between their native range of 68 degrees Fahrenheit to about 84 degrees Fahrenheit - one experiment found that convict cichlids grew the best when they were kept at 79 degrees Fahrenheit, and another had no trouble keeping them alive at 68 degrees Fahrenheit
- Clay pots and rocks provide places to hide and lay eggs
- A light source - scientific setups maintain the fish with 12 hours of light and 12 hours of darkness each day
- A good filtration system
Change your water regularly to help maintain these conditions. You can monitor your tank's environment with equipment like thermometers and chemical test strips. Even slight changes in pH and temperature can affect these tropical fish. For example, varying the temperature can influence the sex ratio of young convict cichlids.
Sourcing and General Care
Once you’ve decided that you want to raise convict cichlids, you’ll need to find a good source. You can always try local pet stores or contact an ornamental fish hatchery if you’re looking for a lot of these fish. In general, convict cichlids are one of the easiest cichlid species to care for. But they still require plenty of time and attention - just like any pet.
The convict cichlid, as traditionally defined, displays significant color variations across its range.[9][10] Some of these regional variants are now considered different species.[7] One of these is A. siquia, the Honduran red point cichlid or Honduran red point convict, which ranges from the Atlantic slope of Honduras south to Costa Rica.[7] Two other species formerly included in A. nigrofasciata are A. kanna from Panama's Atlantic slope, and A. coatepeque from Lake Coatepeque in El Salvador; however, the latter is indistinguishable from A.
Convict Cichlid Characteristics
The convict cichlid (Amatitlania nigrofasciata) is a fish species from the family Cichlidae, native to Central America, also known as the zebra cichlid.
- Common Name: Convict Cichlid
- Scientific Name: Amatitlania nigrofasciata
- Origin: Central America
- Markings: 8-9 black vertical bars on a blue-grey body
- Size: Up to 4.7 inches (12 cm)
- Weight: 34-36 grams (1.2-1.3 oz)
- Color Variants: Wild-type, white convicts, pink convicts, gold convicts
- Habitat: Lakes and streams of Central America
- Water Conditions: pH 6.6-7.8, carbonate hardness (KH) 63-77 ppm CaCO3, temperature 26-29 °C (79-84 °F)
Convict cichlids prefer moving water, and are most frequently found in habitats with cover in the form of rocks or sunken branches. At four natural habitats of the convict cichlid in Costa Rica, the pH was found to range from 6.6-7.8, while carbonate hardness (KH) ranged from 63 to 77 ppm CaCO3. The daily water temperature ranged from 26-29 °C (79-84 °F).
Aggression and Diet
Convict cichlids are known to be highly aggressive and territorial when breeding, possessing a variety of complex behaviors and adaptations, which have been suggested to be a result of environmental conditions, individual development, and trait variation. Due to their aggressive nature, cichlids are popularly studied to investigate the factors that may potentially cause their behavior. It has been shown that environmental parameters like changes in temperature and prior residence may affect the cichlid's territorial aggression.
In natural habitats, the species has an omnivorous diet composed of plants, algae and various prey including small fish, crustaceans, insects and worms. The fish can protrude its jaw 4.2% of its standard length, allowing it to have a varied diet.
Breeding Habits
The convict cichlid can reach sexual maturity as young as 16 weeks, though sexual maturity more commonly occurs at 6 months. Sexually mature convicts form monogamous pairs and spawn in small caves or crevices. In the wild, the fish excavate caves by moving earth from underneath large stones. Like most cichlids, such as Oreochromis mossambicus, convicts brood (exhibit parental care of) both eggs and free-swimming fry. The eggs hatch approximately 72 hours after fertilization. Until that time the parents expel intruders and potential egg predators from around the nest. They also fan the eggs, moving water with their fins over the clutch to provide oxygenation.
They fan the eggs both day and night; at night they use their sense of smell to recognize the presence of the eggs in the dark, and they keep their pelvic fins in contact with the eggs to remain at the right distance for fanning. In darkness the pair recognizes each other and detect predators using their sense of smell. After hatching, the larvae spend another 72 hours absorb their yolk sacs and developing their fins before they become free-swimming fry. The fry forage during daylight in a dense school and return to the cave or crevice for the night. Like other cichlids, the parents retrieve their young just before dark, sucking up three or four at a time and delivering them into the nest.
The parents anticipate night, using a sense of time; in laboratory experiments convict cichlids continued to retrieve young as night approached even in the absence of any signal, such as dimming light. During the night, the fry bunch up at the bottom of the cave or nest, where the parents fan them.
Both parents remain involved in guarding the fry from brood predators and engage in behaviors to assist feeding such as moving leaves or fin digging (digging up the substrate with their fins). Brood care of eggs, larvae and free-swimming juveniles in the wild can last 4 to 6 weeks, and occurs only once per season for the majority of females. In contrast, females in aquaria are known to breed many times per year with short intervals of 12 or 13 days between broods, as long as suitable rocks or similar surfaces are available for them to lay their eggs on.
Territoriality and Breeding in Aquariums
Convict cichlids are serially monogamous, so pair bonds may form first before they establish a territory together, or the male and female may each obtain a territory before pairing with each other. Because the convict cichlids are also substrate-brooding, this territory will include a breeding site for the deposition of eggs.
Breeding convicts is as simple as having a male and a female in the same tank with adequate water quality and feeding. There is no special conditioning required. The species also occurs outside its natural range, even being found in Australia, where it can be found in the warm effluent of power stations in Victoria, and in tropical Queensland. It has also been captured in Perth, Western Australia, although this initial capture also resulted in its eradication. The aquarium should be decorated to mimic the natural environment and include rocks and artificial caves for breeding. Most experts agree that a pair of convicts should be kept in a 20-gallon aquarium or larger. The species is an unfussy omnivore and most types of prepared fish foods are readily accepted. The species also consumes aquatic plants so plastic plants or robust plants such as java fern or water sprite are recommended. Convict cichlids are aggressively territorial during breeding and pairs are best kept alone. Brood care is reduced in aquarium strains. Due to the species' tendency to dig, external filtration is superior to undergravel filter systems.
