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Today on Animal Fact Files we’re discussing some of the cichlid species from Lake Tanganyika. Lake Tanganyika is one of the largest natural freshwater lakes in the world. It's old, deep, located in Africa, and is home to many cichlid fish species. In fact, this great lake houses more than 250 cichlids, most of whom are only found there. This particular video is focused on the current largest Lake Tanganyika cichlid genus. Supposedly, this scientific name means something like "new flaming rabbit," though we couldn't find any reasoning as to why this particular name was chosen for these fancy fish. While they can come in some fiery colors, and often sport a bright stripe along the edges of their fins, these cichlids don't seem to have much relation to rabbits; unless you turn their lyre-shaped tails sideways and they look something like bunny ears. What do you think? This genus will probably be reclassified at some point, but generally speaking these cichlids are separated from other cichlids in the lake because they form breeding groups and they don't brood their eggs in their mouths. 

We've previously talked about animals that form breeding groups in which younger individuals remain as helpers to care for the next generation of offspring. Beavers are one of the first animals we ever discussed, and they have helpers. This breeding strategy isn't uncommon in mammals, like beavers, but it's not typically seen in fish. This particular genus of cichlids, however, do sometimes have breeding colonies in which members of the colony aren't the main breeders.

Now, a lot of this really depends on where the fish live. Even within a single species, they display different breeding strategies. For example, one shallow-living species may stick to a monogamous mating style in one part of the lake where there are more predators and both parents need to protect the eggs; but in other parts of the lake, where predators are less abundant, this same species forms harems in which the males have access to upwards of fourteen different females and don't participate in egg guarding at all! So where they live and what lives around them matters.

These fish can be found in the lake's shallow shores down to more than 100 feet (30m) below the waves. Told you it was a deep lake! This genus is most frequently found along rocky substrate where they brood their eggs in caves, or on soft, sandy bottoms where they collect snail shells and brood their eggs there instead. In fact, some cichlids in this genus show off some serious sexual dimorphism for this very reason.

Sexual dimorphism is when the males and females of a species display different observable traits. In this case, some males of certain cichlid species are far larger than the females, and here's why. The males have to be strong enough to gather up plenty of empty snail shells in order to entice as many females as possible. On the other hand, the females need to be small enough to fit inside the snail shells in order to lay their eggs. So, in some species the males can be upwards of 30 times as large as the ladies! On average, however, these fish reach about four inches (10cm) in length give or take two inches. 

These cichlids are considered predatory fish, coming out at night to hunt small prey in the form of small crustaceans, mosquito larvae, and more. Still, they have to watch out for their own predators like larger fish including larger cichlids! That's one reason these animals tend to form shoals in which to live. There's safety in numbers. While these groups are often made up of a few dominant breeding individuals and their helpers, the helpers benefit from getting protection from predators and the opportunity to breed if it arises. In fact, studies suggest that these fish actually punish group members who don't participate in group activities like egg brooding and guarding. Some individuals can even be expelled from the group if they don't do their tasks!

When they do get the chance to lay eggs, females of this genus can have anywhere from a few dozen to a few hundred eggs at a time. In the snail shell brooding species, they can even produce too many eggs at which point they spill outside of the snail shell. It takes about a week for the babies to hatch, though this is largely dependent on temperature. The young fish, called fry, stick around for more protection until they leave within another week's time. In the wild, some cichlids are known to reach at least a decade old! 

For more facts on these fish, check out the links below. Give a thumbs up if you learned something new today. Thank you to our Patrons SpikeSpiegel93, Dad, and everyone else for their support of this channel! And thank you for watching Animal Fact Files!