I’d like to dedicate this post to my mom, on this fine mother’s day. She was my very first reader on this blog, and in fact proofread my first post. She reads every single post I’ve put up, and always has good things to say. There are many Wednesdays and Sundays when I just don’t feel like posting, but knowing she’s waiting for my post to go up helps me continue this blog. So thanks, mom! In honour of your support, I’ve picked an animal today that I think is a wonderful example of a good mother.
Burton’s haplo is an African cichlid, that is found in south central Africa (Burundi, Rwanda, Tanzania and Zambia). It is a freshwater fish, found pretty much anywhere where there is water, from swamps and marshes to lakes and inland deltas. Burton’s haplo is often used as a model organism to study behaviour and physiology in cichlid species, and also for genomic research into cichlid phylogeny. That’s one useful little fish!
Burton’s haplo doesn’t get very big, only reaching a maximum of 15 centimetres in length. This species of cichlid has three types of sexes: territorial males, submissive males, and females. Male Burton’s haplos can switch between the two types of males, depending on their environment. Territorial males are brightly coloured, will defend their chosen territory vigorously, and try really hard to mate with females. Submissive males, on the other hand, are plain coloured like females, and do not have any interest in the other sex. They also do not possess a functional reproductive system.
Switching between the two male ‘sexes’ happens in stages – behavioural and colouration changes in both directions happen almost immediately, while reproductive changes take a little bit longer. When a territorial male is placed with a bigger, more aggressive male, it takes about three weeks for its gonads to regress. If a submissive male turns into a dominant one, the change lasts about a week. The exact mechanisms that elicit these changes are still unknown, although it is thought to be related to the hormone cortisol and the presence of nearby females. Females also have two reproductive stages, a gravid or egg-laying stage, and a non-gravid stage. When a female is in a gravid state, she chooses to hang around territorial males instead of submissive ones, while non-gravid females do not care who they spend time with.
Male Burton’s haplos must display in their territories to get a female’s attention. These displays involve visual signals, like the male’s bright colours and a quivering body posture, and auditory communication, which in cichlids is unique to this species. If the male’s display is successful, the female lays her eggs in his territory, and once they are fertilized she begins the brooding process. This is where Burton’s haplo really shines as a parent. They female takes her eggs into her mouth and keeps them there for two weeks. That’s two weeks of not eating and just swimming around with a whole mess of eggs inside her mouth. Now that’s dedication!
Anyway, happy mother’s day, and to all the mothers out there, just be thankful you don’t have to carry your babies in your mouth. Or hatch them out of your back like the Surinam Toad.
Cover image source: http://www.kmaruska.biology.lsu.edu/img4.jpg