Episodes

  • Aba aba: Conservation

    Aba aba: Conservation
    Sep 3 2025
    Summary: What does conservation look like for the Aba aba? Join Kiersten to find out! For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. We have made it to our tenth and final episode of Aba aba. I hope you have enjoyed our journey with Gymnarchus niloticus, come on you have to admit, it is fun to say that, because I have had a blast talking about this amazing fish. The tenth thing I like about this unbelievably cool fish is conservation. As any of my longtime listeners know, I typically use the last episode to talk about the conservation status of the current animal or plant that we are discussing. This is the whole reason I started this podcast in the first place, to bring awareness to the animals and plants with whom we share this planet. We have to learn to live together if we are going to be good stewards of this amazing planet. Before we can learn to live together, we have to know what’s out there that is worth fighting for, and all the animals and plants I talk about are worth fighting for. Let’s talk about what conservation looks like for the Aba aba. When we look at the IUCN Red List, the International Union for Conservation of Nature, Gymnarchus niloticus is listed as Least Concern. This means that no conservation efforts need be taken at this time. The last time that the overall population of the Aba aba was assessed was in 2019, so this information needs some updating. The North African population was last assessed in 2007 and is also listed as Least Concern, but once again we need updated information for this population. The Western African population was last assessed in 2006 and is currently listed as Least Concern. The Eastern African population was last assessed in 2003 and is listed as Vulnerable. Vulnerable means that adult population numbers are decreasing. Overall and in the Western and Northern populations the population trends are unknown, so the Least Concern classification may be incorrect. What’s interesting is that the Eastern population that is labeled Vulnerable also has no population trend data. What does this mean? It means we really don’t know how many aba aba are out there and if they are holding their own as our plants changes. The IUCN does list the threats to the Aba aba and those include dams, water pollution related to the military and agricultural industry, logging and wood harvesting destruction of habitat, and overfishing. Natural climate impacts are droughts. The Aba aba relies on the seasonal flooding of rivers for breeding season. The overfishing impacts the Eastern population because the local humans use Aba aba as a food source in this region. Currently there are no conservation plans being implemented in any regions of residence, with the exception of small grassroots campaign in the Eastern population region informing local fishers about the risks of overfishing the Aba aba. Another threat to the wild population of the Aba aba in collection for the aquarium industry. Gymnarchs niloticus is a fascinating fish that many people fall in love with when they see them in a zoo or aquarium or learn about them from educational resources like this podcast. It’s great to develop an appreciation for nature after learning about a specific specie, but letting that appreciation grow into a need to possess that species can be disastrous. As I talked about in the last episode, Aba abas are not suitable for the home aquarium, but the market still exists. Some people think they can make it work even if they don’t have the correct size tank, or offer the type of food they need, or realize how dangerous Aba abas can be. They purchase a fish. And when it dies, they purchase another and so on and so on. Most of the time the Aba abas collected are so small and fragile that they are bound to die in transport or in the home aquarium. Collectors will come back for more and they aren’t just taking a few out of each nest they come across, they are taking all the babies and may even kill the adults to sell for food. There is some discussion about how to create an aquaculture program with Aba aba in response to the use of Aba abas as food. Whether this would work or not is yet to be seen since no one has tried to raise Aba abas in a captive situation. One ...
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    9 mins
  • Aba aba: Home Aquarium

    Aba aba: Home Aquarium
    Aug 27 2025
    Summary: Do Aba abas make good pets? The short answer is no, but join Kiersten as she discusses why this animal should not be on your next pet list. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: Seriously Fish: https://www.seriouslyfish.com Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. We’ve reached the second to last episode of Aba aba and I find myself in a quandary. This isn’t something I like about the Aba aba but it is a topic I think we need to address, so the ninth thing I would like to talk about the Aba aba is the possibility of having it as a pet. Whenever I start a new series for this podcast, I typically know at least a little about the animal. Even if I know a lot, like about bats, I always do extra research to make sure I offer you the best and most up to date information, I can. When I picked the Aba aba, it was one of the animals I thought of first when I decided to make this podcast, I did my extra research. I have personal experience with this animal, as I have mentioned, so I knew quite a bit about its behavior, diet, and life cycle, but you can always learn more, right? As I started researching for Aba aba I did find scientific research papers but the majority of information I found about this fish came from home aquarium sites. This surprised me because this fish gets big, really big and isn’t fit for the home aquarium. At the zoo we had a 250 gallon tank with multiple canister filters attached and our Aba aba wasn’t anywhere near full grown. Our aquarium was only a temporary home for him while the aquatic area of the zoo was under renovation. The 250 gallons tank would not be able to host him as he got bigger. Many of you may have had, or currently have, fish aquariums in your home. I have had some as well, both freshwater fish and saltwater fish. The largest we had was a fifty gallon saltwater tank, and I thought that was enormous for a home aquarium. So when I saw aquarium hobbyist websites talking about the Aba aba I was a little wary. The Aba aba is a terrible choice for a pet. Beyond the large tank, and when I saw large tank I mean a 2000 gallon tank to house a full grown Aba aba, and extensive filtration set up you need to provide a clean environment for a fish of this size, you have to provide large food items, not just fish flakes for the Aba aba. Food such as silverside fish and freshwater shrimp. Aba abas are also a dangerous pet to have in your home. Their feeding behavior is intentionally brutal, as a predator you don’t want your prey to get away. Once a fish is sucked into the Aba aba’s mouth, they most likely won’t get out again. If that happens to be a human finger, you’ll be one short for the rest of your life. I truly enjoyed taking care of our Aba aba at the zoo, and I can see what might attract a person to this amazing animal. They are mesmerizing to watch. The constant rippling of the fin is captivating. Watching them rearrange the aquarium furniture is a delight. Offering them various enrichment items and seeing them interact with each one figuring out the puzzle of the new item is rewarding. I personally think they have cute faces, but you have to remember this is a wild animal and they are not like your typical fish you buy at the pet store. This is a predator, a problem solving predator. And you just brought it into your home. You cannot house it with other fish, as the Aba aba will most likely eat anything you put in with it, so you will have a tank with only one fish. That isn’t typical what most home aquarists want. The Aba aba in unsuitable for a community tank. That includes keeping it with other Aba abas as they are solitary species in the wild with the exception of breeding season when they briefly tolerate each other's company to fertilize eggs and deposit them in a nest. I finally looked at what one of the hobby sites had to say about the Aba aba as a home aquarium fish, I was pleasantly surprised. This is what the Seriously Fish site had to say about Gymnarchus niloticus, quote “…the species is simply not suited to the home aquarium in any respect. If you see these for sale, and they are undoubtedly amazing looking fish, ask yourself if you have the money, facilities, and knowledge to house a species that can grow to 5 1/2 feet in length and ...
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    8 mins
  • Aba aba: Human Cultural Connection

    Aba aba: Human Cultural Connection
    Aug 20 2025
    Summary: Have Aba aba impacted human culture in the areas they are found? Join Kiersten to find out! For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Some Ecological Factors of the Tropical Floodplain Influencing the Breeding and Conservation of Gymnarchus niloticus (Cuvier 1829): A Review,” by Oladosu O. O., Oladosu G. A., and Hart A. L. https://core.ac.uk/downloads/pdf/158459099.pdf “Gross Anatomy and Histological Features of Gymnarchus niloticus (Cover, 1829) from the River Niger at Agenebode in Edo State, Nigeria,” by M. O. Agbugui, F. E. Abhulimen, and H. O. Egbo. International Journal of Zoology, Volume 2012, Issue 1, June 19, 2021. https://doi.org/10.1155/2021/3151609 “Morphology of Aba Knife Fish (Gymnarchus niloticus) (Cuvier, 1829)”, by S.O. Ayoola and C. E. Abotti. World Journal of Fish and Marine Sciences 2 (5): 354-356, 2010. Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. Through the last few episodes I think I have painted a pretty good picture of the Aba aba’s anatomy and natural history. I have fascinated you with the amazing way they hunt and today, I thought we’d investigate how this fish impacts human culture. The eighth thing I like about the Aba aba is how much humans value this fish. Animals of all kinds impact other animals that reside in their habitats. Aba abas are no exception to this and they have become important in many indigenous human cultures that live where these fish are found. The first thing you may think of when speaking about how fish impact people is as food. And no doubt, we, as do many other animals, eat fish. Aba abas are highly prized as a food fish. They can grow quite large, creating a lot of meat. A five foot long fish means a bunch a meat. They are an oily fish, but several sources say they are tasty. Smoking them seems to be delightful way to eat them. In West Africa they are also eaten raw. Some cultures also gift them, alive or dead is not entirely clear, my guess is probably both. Suitors will gift them to a bride’s family symbolizing respect and goodwill. Nothing like a long, electrical fish to start off a relationship right! Certain cultures, such as the Yoruba of West Africa, will also present them to community leaders as a sign of respect during community celebrations. The introductory paragraph of the scientific paper “Gross Anatomy and Histological Features of Gymnarchus niloticus from the River Niger at Agenebode in Edo State, Nigeria,” states: Gymnarchus niloticus commonly known as the Nile knife fish, trunk fish, or aba is one of the most valued fishes along the River Niger by the inhabitants of Agenebode and Idah. The trunk fish is highly valued for its good taste, rich nutrients, though oily flesh, ability to grow as large as 25kg, highly valued in customary rites for marriage and community celebrations. End quote. In Yoruba it is known as Eja Osan while in Hausa it is known as Dansarki which means son of a king. These names are a sign of respect for this amazing fish. (Do please forgive me if I mispronounced any words.) Since Gymnarchus niloticus is such a large fish and edible, a lot of research is going into whether it would be a good candidate for an aquaculture fish. Is raising them in a farming situation beneficial for protein production and economically sound? The answer is not yet decided but it would be extremely difficult to do in an aquarium situation since the fish get so big and they are aggressive to other animals. Someone did discover that polyculturing Aba aba with Tilapia might be possible. They can be kept together in the same space, feeding the tilapia food and then letting the Aba aba eat the tilapia fry. Tilapia grow quickly and create a lot of fry. The Aba aba can eat the tilapia fry but not all of them. Then both species can be harvested. Whether this is possible long term allowing Aba aba to reproduce is unknown, as they are a solitary species, it may not be functional. It is worthwhile investigating though. Current fishing practices of Aba aba often includes killing the adult and harvesting the young from the nest. This is an unsustainable fishing practices and to help this fish and humans weather the future of changing climate, we will need to work together. Some researchers believe that the Aba aba is a good candidate for an...
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    8 mins
  • Aba aba: Hunting

    Aba aba: Hunting
    Aug 13 2025
    Summary: How does the Aba aba find its food? Join Kiersten to find out! For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “The Mechanism of Object Location in Gymnarchus niloticus and Similar Fish,” by H. W. Lissman and K. E. Machin. Journal of Experimental Biology (1958) 35 (2): 451-486. Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. I know I left you with a cliffhanger last week and we will remedy that now! This is week seven of Aba abas and the seventh thing I like about this super cool fish is the way they hunt. We know that Aba abas are carnivores and that they eat aquatic insects, small fish, and fresh water crustaceans. We also know that they have tiny eyes and relatively poor eyesight. There is not much discussion of olfactory functions in animals that live underwater, and I found no mention of the sense of smell when deep diving the Aba aba. Sooo…we can rule out Aba abas using sight or smell to help them find their prey. What does that leave them with for hunting? Let’s find out! Something I haven’t mentioned about Gymnarchus niloticus, yet, is that they are an electric fish. This little quirk was discovered by Hans Lissman in 1950 when he received a living specimen as a wedding gift. As he watched the Aba aba swimming in the aquarium he noticed that they could swim backwards and forwards equally well. It never ran into the sides of the tank or into anything placed inside. He wondered how it was navigating so well, thus began some of the first European studies into electroreception in fish. Electroreception is the biological ability to detect electrical stimuli. Electrogenesis is the ability to create electrical fields. Both of these abilities are important to the Aba aba. There are two types of electrolocation. I know, there’s a lot of electric words here, bare with me. One type of electrolocation is passive. When using passive electrolocation the predator senes the electric field that the prey item creates. On the other hand, or fin shall we say, is active electrolocation. Here, the predator creates its own electric field and uses the distortions other objects create in its field to target prey or notice obstacles. Active electrolocation is practiced by three types of fish that we currently know of including Order Gymnotiformes, the knifefishes, Family Mormyridae, the elephantfishes, and our friend Gymnarchus niloticus. All of these fish are considered weakly electrical fish because they do not use their electric fields to stun their prey. Electroreception and electrogenesis are more common in aquatic animals as water conducts electricity more easily than air. An electric fish creates an electric field with an electric organ modified from muscles in the tail. The tissue of these modified muscles are called electrocytes and they have evolved at least six times among various fish species. These organs are used for everything from prey detection to communication, mating, and even stunning prey items. The electric field created by this tissue can emanate in short bursts, as in the elephantfishes, or as a continuous wave, as with the knifefishes. To detect electric fields generated by other creatures, our Aba aba, elephantfishes and knifefishes use sense organs called Ampullae of Lorenzini. They are electroreceptors that form a network of mucus-filled pores in the skin of various fishes. They evolved from the mechanosensory lateral line organs for early vertebrates. Most modern fish and mammals have lost this adaptation. How does this work in the Aba aba? This is truly amazing! The Aba aba makes its tail negatively charged while its head will stay positively charged creating a symmetrical electric field around its body. To keep this field present its back must remain straight. That’s why it has the long dorsal fin that they use to swim. This fin structure allows it to keep its body completely straight when in motion. This electrical field it has created allows the Aba aba to navigate around obstacles and underwater features it cannot see. It also allows it to find nearby prey items. It can sense the distortions that these objects or prey items create in its own electric field. It can actually sense this distortion on its skin with the Ampullae of Lorenzini organs. The Aba aba’s brain is larger than other species...
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    10 mins
  • Aba aba: Diet

    Aba aba: Diet
    Aug 7 2025
    Summary: What does the Aba aba eat? Join Kiersten and a guest co-host to find out! For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Morphology of Aba Knife Fish (Gymnarchus niloticus) (Cuvier, 1829)”, by S.O. Ayoola and C. E. Abotti. World Journal of Fish and Marine Sciences 2 (5): 354-356, 2010. “Aspects of the biology of juvenile Aba, Gymnarchus niloticus (Cuvier 1829) from Eye Lagoon, Lagos, Nigeria,” by FV Oluwale, Ugwumba AAA, and OA Ugwumba. International Journal of Fisheries and Aquatic Studies 2019; 7(30): 267-274. www.fisheriesjournal.com “Some Ecological Factors of the Tropical Floodplain Influencing the Breeding and Conservation of Gymnarchus niloticus (Cuvier 1829): A Review,” by Oladosu O. O., Oladosu G. A., and Hart A. L. https://core.ac.uk/downloads/pdf/158459099.pdf Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. This is episode six of Aba aba and the sixth thing I like about Gymnarchus niloticus is their diet. We have talked a bit about this is the past, but we will add a bit more detail of what Aba abas like to eat in this episode. I have a guest co-host with me this week as I have had some dental work done and need help with all this talking! My husband, Georgiy, is helping me today. Welcome Georgiy, and thanks for helping me out! Georgiy: Absolutely! Hi! Kiersten: I know you’ve been listening to this series…right? Georgiy: Riiight… Kiersten: Of course you love it. What’s your favorite thing about the Aba aba so far? Georgiy: The scientific name. Let me try to pronounce it. Gymnastic nalarcus? Kiersten: (laughs) Not even close! Gymnar-kus niloti-kus. Georgiy: (laughs) Gymnar-kus niloti-kus Kiersten: I like that too, but I like everything about the Aba aba. Can you tell our listeners what you’ve learned about what the Aba aba eats? Georgiy: I know they are carnivores, so they like to eat meat. Kiersten: Definitely! Georgiy: When they are small, 2 to 3 inches in length, they eat insects found in the water and very small fish. A study done in Nigeria found that 36% of juvenile diets were made up of aquatic insects. Kiersten: Really? Georgiy: Yes! 32% of the diet was made up of fish. Kiersten: Interesting. Did it say what kind of insects and fish? Georgiy: No. They looked at stomach contents of dead juveniles, so they only found small parts of the digested prey. Kiersten: Hmmm. It sounds like the juvenile Aba aba is a specialist feeder on insects? Georgiy: Yes! Exactly. Another study showed that Aba aba young that have used up their egg yolks will eat the midge larvae that are in the nests with them! The adult midges lay eggs on the grasses that the male Aba abas use to make their nests! Kiersten: Wow! That’s so smart. I love it! Bring the food to you. Does their diet change as they get older? Georgiy: Yes. As they get older, and larger, they can eat bigger prey items. They will eat more fish, such as silversides, tetras, or African catfish, and add crustaceans to their diet. They will still eat insects but this makes up very little of the diet when they are adults. Kiersten: That sounds like a smart survival plan. Georgiy: Yes. The Aba aba are not competing with each other for food sources and they don’t risk injury by hunting something larger than themselves. What did you feed them at the zoo? Kiersten: Ooo. Good question! We fed them silver side fish and shrimp. The nutritionist made sure we varied his diet so he got the right type of nutrients to keep him healthy. The nutrition staff made the diet for us and weighed out just the right amount of food, so he didn’t get overweight, but also didn’t get too hungry. He never turned his noise up at anything we offered him. It was one more thing I like about working with him. We never had to worry about him not eating. Georgiy: How did you feed him? Kiersten: This was also fun! Since his eyesight was not great, we fed him with tongs so we never had to remove decaying fish form the tank. That can get pretty gross and can be detrimental to his health. We offered him one piece at a time with tongs that were about 12 inches long. We just dipped the fish or shrimp into the water and it was only a matter of moments before he found it. Georgiy: That sounds fun. Kiersten: It was fun, but we had to be careful because if he accidental got one of our ...
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    9 mins
  • Aba aba: Anatomy

    Aba aba: Anatomy
    Jul 30 2025
    Summary: To get a thorough understanding of the Aba aba join Kiersten for a look at this amazing fish’s anatomy. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Gross Anatomy and Histological Features of Gymnarchus niloticus (Cover, 1829) from the River Niger at Agenebode in Edo State, Nigeria,” by M. O. Agbugui, F. E. Abhulimen, and H. O. Egbo. International Journal of Zoology, Volume 2012, Issue 1, June 19, 2021. https://doi.org/10.1155/2021/3151609 “Studies on the Biology of Gymnarchus niloticus in Lake Chad: Age Determination and growth; Meristic and Morphometric Characters,” by V. O. Sagua. https://aquadocs.org Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. I can’t believe we are half way through Aba aba already, but here we are at episode five. The fifth thing I like about Gymnarchus niloticus is their anatomy. Up until now, we’ve talked about some of the very interesting parts of the Aba aba’s body, but in this episode we’re going to talk about the Aba aba’s anatomy as a whole. If we start from the inside out, we already know that the Aba aba has a bony skeleton as it is classified as a ray-finned fish which has an internal bony skeleton. That is going to include a skull, elongated with small sharp teeth in the lower jaw and a bony tongue. Last week we discovered that bony-tongues fish have teeth in their tongues, but Gymnarchus niloticus is an exception to this. Instead of having teeth in the tongue they have teeth in both the lower and upper jaws. Their bony tongue is used to hold prey still for easier swallowing. The teeth, though sharp, are not triangular, but peg-shaped. They look like a flat-head screwdriver bit that fits into a power drill. The lower mandible is rounded and is deeper than the upper. The upper jaw does have teeth, as well. The upper jaws teeth are also peg-shaped. The bottom jaw teeth number around 24 teeth while the upper jaw has only 10 to 12. There is only one row of teeth on both jaws. The structure of the jaw gives the Aba aba a perpetual smirk. Let me inject a funny story here as it pertains to the teeth of this amazing fish. As you know, listeners, I worked with an Aba aba at the zoo and one day, I was cleaning the algae off the glass of his tank. This was a precarious job and typically entailed two people, one to clean the glass and one to watch where he was in the tank. Well, this day we were all busy but the algae on the glass had become a bit more unsightly than we liked so I said I would clean it alone. That was the day I got bit by an Aba aba. It was a bit more startling than terrifying, I must say, as he caught me off guard hiding in the plastic plant nest he’d built in the center of the tank. I thought I knew where he was but he got my upper arm as is it slipped below the water line just next to the nest. A scary sucking sound ending with a pop and a sting told me I’d just been bitten. He tagged me on the underside of my upper arm just below my armpit. It didn’t hurt much, or bleed that much either, it felt more like a scrapped knee, but the bite was wicked cool. It looked like a dotted circle and I hoped it would scare, because that would have been one heck of a scar to talk about later, but it healed up perfectly fine with nothing left to show for the exciting moment. I had a hard time finding research that described the internal skeleton of the Aba aba fish, with the exception of one study detailing the number of vertebrae. With ten specimens examined the number of vertebrae averages about 117 from the base of the skull to the tip of the tail. Internal organs include the typical fish guts with research paying particular attention to the gastrointestinal tract. The GI tract consists of long and longitudinally organized organs. I mean they have a long tubular body so this makes a lot of sense to me. It begins with a tubular oesophagus, followed by a long tubular stomach, two pyloric ceaca, and straight intestine, and the cloaca. The intestine is neatly folded and compacted to sit nicely within the fish. A single lung arises from a slit in the right side of the pharynx which is on the right side of the fish. The lung and pharynx are held together with sheaths of connective tissue and blood vessels. Let’s move to the external anatomy of this fish. ...
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    10 mins
  • Aba Aba: Osteoglossiformes

    Aba Aba: Osteoglossiformes
    Jul 23 2025
    Summary: Join Kiersten as she discusses the classification of the Aba aba a bit more closely to find out what it can tell us about this amazing fish. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Introduction to the Actinopterygii” https://ucmp.berkeley.edu Bony Tongue, EBSCO Research Starters: https://www.ebsco.com Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. In episode four, we're going to jump back a bit to episode one and delve into more detail about about the class, order, and family of the Aba aba. The fourth thing I like about Aba abas is their classification. In episode one I briefly described the classification of this fish, but I think we should investigate the class, order, and family of Aba abas a bit more closely. First for my first time listeners, or for those who are not students of biology, what is classification? It a system that scientists and researchers use to connect all living things but to also individualize all living things. Whether flora (plants) or fauna (animals) we are all related through physical characteristics. Way back in the day, like way back in the 1700s, Carl Linnaeus was a Swedish biologist and physician who developed a binomial nomenclature (a two part name) to organize every living thing into groups. It helped man understand the natural world around him. We still use this classification system today, even though the attributes we use to organize individual plants and animals into their groups has evolved over the years. In the beginning, naturalist used things like appearance and behavior to place animals and plants into the same groups, but now we look at genetic similarities to classify living things. The two part name consists of the genus and the species. This helps make sure that when you are talking about an individual animal or plant with another researcher you are talking about the same plant or animal. Animals often have different common names around the world and even have different names within the same country. For example, fireflies are known as fireflies, lightening bugs, and glow-worms. These common names vary depending on what region of the United States you may be visiting, but we’re all talking about the same insect. The Aba aba is known as Aba aba, African knife fish, Frankish, freshwater rat-tail, or aba fish, so researchers refer to it as Gymnarchus niloticus. If we take a few steps back in the classification we can learn even more about an animal. So let’s do that now with Gymnarchus niloticus. When we look at the Class level of this animal, Actinopterygii, we know that it is a ray-finned fish. What exactly does that tell us? Well, Actinopterygii are fish that possess fins that are made of webs of skin supported by bony or horny spines. We also know that fish in this Class usually have complex skeletons of true bone. Ray-finned fish are the dominant aquatic vertebrates in the water today. They make up about half of all vertebrate species known and are found in every aquatic habitat from the deepest depths of the ocean to freshwater streams and ponds. So this level of classification lets us know that Aba abas have a bony skeleton and some sort of webbed fin on their body. It’s a great start. The next step is the Order. This will narrow down things ever more. Aba abas are classified in Order Osteoglossiformes. In Ancient Greek this literally means ‘bony tongue’. Members of this Order have toothed to bony-tongues. They are also known for the forward part of their gastrointestinal tract passing to the left of the esophagus and stomach (in all other fish it passes to the right). They can vary in size ranging from 2 centimeters up to 8 feet or 2.5 meters. Up to the early 2000s we thought that Osteoglossiformes were fresh water fish only. All of the 245 known living species of bony-tongued fish are found in freshwater. In 2008 several marine bony tongued fish fossils were discovered in the Danish Eocene Fur Formation. Maybe there are some extant marine osteoglossiformes in the ocean we haven’t found yet. I guess we’ll have to wait and see! Okay, back to the Aba aba. What does bony-tongued mean in relation to our fish? Bony tongued fish have teeth on their tongues. When they catch prey they use their toothy tongues to crush the prey items ...
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    8 mins
  • Aba aba: Reproduction

    Aba aba: Reproduction
    Jul 16 2025
    Summary: How do Aba aba make more Aba aba? Join Kiersten to find out about the reproductive behavior of Gymnarchus niloticus. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Abundance, Distribution, Morphometric, Feeding Evaluation and the Reproductive Strategies of Gymnarchus niloticus in the Lower River Niger at Agenebode, Edo State Nigeria,” by Mo Agbugui, Fe Abhulimen, and Ao Adeniyi. J. Apple. Sci. Environ. Manage Vol. 25 (8). 1371-1377, August 2021. “Gymnarchus niloticus Cuvier, 1829 “Some Ecological Factors of the Tropical Floodplain Influencing the Breeding and Conservation of Gymnarchus niloticus (Cuvier 1829): A Review,” by Oladosu O. O., Oladosu G. A. And Hart A. I. Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… This is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. Episode three of Aba aba is here and we are talking about reproduction. The end of episode two hinted at reproduction kicking off with the rainy season so that’s where we’ll begin. Join me for the third thing I like about Aba abas, reproduction. It all begins when two Aba aba love each other, no really, it all begins with the rainy season. In the continent of Africa many animals rely on the abundance of the rainy season. This season brings rain that is a necessary resource for survival of all living things, as well as flooding the rivers. Flooded rivers overflow into flood plains where food becomes abundant. Terrestrial invertebrates are often caught off guard and drown leaving them to be consumed by aquatic carnivores, like the Aba aba. The Aba aba already lives in the water but when those waters rise nutrients increase and aquatic vegetation gets thicker. Then it’s time to start looking for a mate. In studies performed in the Lower River Niger, two breeding peaks were observed. One from May to July, the other from October to January. The breeding behavior of Gymnarchus niloticus is heavily dependent on the flooding of the rivers. Beyond the food resources that increase at this time the aquatic plants that increase are important for the nest making of the Aba aba. Now, the males of the species are the ones that make the nests. This is not uncommon in fish na the Aba aba is no exception. Their nests can be pretty big, but that is not a surprise for a fish that can get 5 feet in length. The male Aba aba makes a nest with uprooted aquatic plants. He pulls up the plants himself and weaves them into a floating nest that can be 1 meter, or 39 inches, in width. The perimeter of the nest is molded with the mud from the roots of the plants. It is expertly woven. It will be anchored to other plants and have an opening through which the male can enter and depart when needed. A little bit of the top of the nest will stick out of the surface of the water. If the nest becomes dislodged the male will remain with it as it floats down the river. Inside the plants the male will create a bubble nest. This portion of the nest is made of air bubbles and this is where the eggs will be nestled. The nest is important for several reasons: The first is to attract a mate. The ladies are attracted by large, well made nests, so the gentlemen will take their time picking the right plants for just the right nest. A few studies have indicated that they prefer plants in Family Poaceae, which are the grasses. The oblong leaves of the grass are perfect for weaving. We have to remember that this animal is weaving a nest. An animal that has no hands is weaving a nest. How extraordinary it that! The second reason the nest is important is that this is where the eggs will be hidden and held until they hatch. Eggs are between 7mm-8mm, some papers have even said 10mm. That is a very large fish egg. Once the eggs are in the nest and fertilized, the male aggressively protects the nest from all predators. It will not hesitate to attack any living thing that comes near, including humans. These guys have no fear, especially when protecting their young. As I mentioned before, the nest have an opening for the Aba aba to enter and leave. When they are inside the nest, the male has been seen agitating the water around the eggs. We are not sure why they do this, but it could be to make sure the eggs are well oxygenated and/or keeping the eggs clean of debris. Either way the male is doing a great job keeping the eggs healthy. I did not find any reference to how long it takes the ...
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    9 mins