OOOooh that smell! Can’t you smell that smell!?

Hello everyone! Today I want to tell you about how I smell my world! You see fish live in water (duh!), which means we constantly smell all of the dissolved odorants that are in the water around us while we swim around. In fact, we use smell for almost everything! I use it for finding food, avoiding becoming food (predator avoidance), navigating, and even finding mates or avoiding other males that may want to fight. Fishes have a sensitive “nose” comprised of an olfactory epithelium full of olfactory receptor neurons (ORNs) that detect all kinds of different smells. Each type of neuron detects a certain “type” of smell. For example, ones called ‘crypt neurons’ detect pheromones (which help me find my special friend Toni! ;)). Each of these different types of ORNs sends signals to a specific region in my olfactory bulb at the very front of my brain. You see, my olfactory bulb is a sorting center for all of these different kinds of smells. From there, the signals go on to other parts of my brain that help me decide how to behave. Should I try to eat this smell, should I do a pretty dance for this smell, or should I swim away from this smell??

Not only can I detect a whole lot of specific smells, but I also send a lot of smells! Especially to Toni, hehe. And Toni sends smells to me, too. You see one way that I communicate with Toni (and other male fish) is through my pee. That’s right! We all pee at each other! Our pee contains lots of molecules that have information on our species, sex, social status, and even reproductive state. So when I see that Toni is ready to spawn, I’ll pee at her more to let her know I am a big strong male with good qualities to pass on to our kids. And Toni pees at me to let me know that she’s ready to spawn. But my pee isn’t just for Toni. If another male wants to try to take over my territory (good luck, buddy!), we will pee at each other to show just how big and strong we are. This helps us assess one another and determine if it’s worth fighting. And Toni pees to other females, too! If she and another female start fighting, she will release pee towards her to show her strength.

So, as you might have gathered, smell is SUPER important for me. In fact, if I can only see Toni, and not smell her, I’m much less likely to dance for her, making her less likely to spawn with me. I need to smell her to be sure she’s ready for my dancing. This whole smelling each other thing is super handy in Lake Tanganyika too. Sometimes hippos or other giant wildlife can walk right through our homes, making things very murky and harder for me to see Toni or other males or even food. So having an excellent sense of smell really helps me out.


I hope you enjoyed learning about my awesome sense of smell and how I pee to communicate! If you want to know more, check out these papers on the lab website:

Field, K.E. and K.P. Maruska. (2017). Context-dependent chemosensory signaling, aggression, and neural activation patterns in reproductively-receptive female African cichlids. J Exp Biol. 220: 4689-4702. link

Nikonov, A.N., Butler, J.M., Field, K.E., Caprio, J., and K.P. Maruska. (2017). Reproductive and metabolic state differences in olfactory responses to amino acids in a mouth brooding African cichlid fish. J Exp Biol. 220: 2980-2992. link

Maruska, K.P. and R.D. Fernald. (2012). Contextual chemosensory urine signaling in an African cichlid fish. J Exp Biol 215: 68-74. link

Comments

Post a Comment

Popular posts from this blog

Fish Have Feelings Too!

Image
Hey guys, Tyrone here! I’m feeling down lately because I’ve been dealing with bullying a lot, especially from Burt. So, I’ve been trying to figure out how I should act when he inevitably decides to be mean to me again. Fortunately, the scientists in the lab care about my behavior and want to figure out what makes a fish susceptible or resilient to bullies like Burt! To cheer myself up, today I want to tell you all about the fun way the scientists study my behavior after repeatedly being bullied in a resident-intruder experiment (if you don’t remember the details check out my previous blog posts about this!). The scientists start with videos of these experiments to quantify our behavior. They specifically want to see how the intruder (like me, Tyrone) reacts to aggression from the resident (like Burt). By using a cool program called BORIS (which stands for B ehavioral O bservation R esearch I nteractive S oftware) they are able to see just how often and for how long we display certa...
Read more

Immune System to the Rescue!

Image
Hey guys! It's Burt back again with another exciting post. Sorry it’s been a while! I’ve been busy taking care of Toni as she has been sick for the past few weeks. I hope you all have been able to stay healthy during the COVID-19 pandemic. Surprisingly, we get sick just like humans, although our response to a pathogen is a bit different. You see, our immune systems are split into two types of responses; innate and adaptive. Innate immune responses are the body’s general immediate response to a pathogen, while the adaptive response works more slowly and is more specific. This means that adaptive immunity mounts responses that are specific to the type of pathogen attacking the body while the innate immune response generally fights pathogens the same way regardless of the type or class of pathogen threatening it. If we compare innate and adaptive immunity to COVID-19, the innate response would be similar to the first responders, like doctors and nurses that work extremely hard to trea...
Read more

Time Fries When You’re Growing Up!

Image
Hi everyone, Pia here! I’m a fry, which is just a fancy name for a baby fish. You might remember that my mom Toni is a mouthbrooder. That means she protects us fry in her mouth while we grow up! Before we get released from her mouth, we have yolk sacs that we use to feed ourselves and we don’t get to see or do too much – we just stay nice and protected inside mom’s mouth until we’re big enough to swim and eat on our own! Once we’re released, there’s SO much to do and see! We have to find our own food, communicate with other fish, and escape from predators back to the safety of mom’s mouth. Plus, there’s lots to see around our tank like our fancy clay pot shelters and the scientists when they come to visit! Because the environment is so different inside and outside our mom’s mouth, the scientists wanted to see which brain regions we use before and after we leave. They looked for a molecule in our brains called pS6 which tells them which neurons were “turned on” or “activated” while we w...
Read more