Baby Whale Freshwater Fish Care

For many Europeans and Northward Americans, December brings out the festive traditions of the Christmas tree or tannenbaum, where evergreen trees often become decorated with electric lights, glowing and twinkling away into the night.

And at one researcher'due south lab, fish are lending a hand in the tree lighting.

Professor Jason Gallant of Michigan Land University studies a strange-looking group of fishes from African rivers called elephantfishes. Gallant keeps a few species of elephantfish at his laboratory, and recently turned over the light controls of his lab'south Christmas tree to these fish—which have the power to produce electrical signals:

The species controlling these lights is Brienomyrus brachyistius, a species of elephantfish found in Due west and Fundamental Africa, from the Autonomous Republic of Congo due north to The gambia.

Elephantfish got their funny name because many species accept oddly shaped mouths, either stretched out in a long snout or equipped with a long appendage on their chin—both resembling an elephant's trunk.

However, some species like Brienomyrus brachyistius take a stubby oral fissure and a squared-off caput, somewhat resembling a sperm whale. So these species have been given a rather ridiculous sounding proper name—"baby whale"—by the tropical fish pet trade.

Brienomyrus brachyistius, a species of elephantfish in the family Mormyridae. (Image Source: efishgenomics.zoology.msu.edu)

Their strange heads aside, elephantfish are likewise famous for having electric organs—highly specialized muscles which the fish utilise to discharge electricity in specific frequencies and bespeak patterns.

Jason Gallant's research focuses on the genetics and evolution of these electric organs in elephantfish and in other unrelated fish like the electric eel (Electrophorus electricus). I asked Gallant to tell united states of america more near his fish-activated Christmas tree lights, and what researchers are learning near the electric abilities of elephantfish.

Your fish-triggered tree lights are a bang-up way to visualize the unusual way these elephantfish are equipped to sense and communicate with their world. Explain to u.s. what we're actually seeing when the lights flash on and off.

Weakly electric fish like elephantfish produce electric discharges for communication and navigation in their environments with a specialized organ called an electrical organ. The electrical organ is equanimous of many tiny cells called electrocytes. Each electrocyte produces a pulse is very much the same speed and voltage equally the activity potentials produced in the fretfulness and muscles of your body.

The electrical organ is an organ with incredible precision and synchronization. When the fish'southward nervous system instructs the electric organ to discharge, all of the cells practise that simultaneously. The combined voltage of all these cells forms a weak electric field, which nosotros can find as pulses using our instruments.

The Christmas tree device we built monitors the water for each electrical pulse produced by the fish, and then turns on an electronic switch hooked upwards to a normal household outlet where nosotros plugged in the lights.So the fish are actually controlling the lights: each time the fish generates an electric pulse, the lights get switched on!

Professor Jason Gallant of Michigan State University studies electric fishes and the development and origin of their electric organs. (Paradigm Copyright: Jason Gallant/Michigan Land University)

So do elephantfish send out electric signals to talk to each other? What might they be saying to each other? Or are they also using electricity to feel their manner through their habitat, like a sonar browse?

Absolutely—the fish utilise the electricity in a manner analogous to "Morse lawmaking" to communicate with each other. The shape and timing of the waveform conveys data virtually the species and sexual activity of the individual, whereas the sequence conveys data virtually social contexts—information similar aggression, trying to courtroom a mate, and the like.

• Click to listen to the amplified electric signals of the elephantfishBrienomyrus brachyistius(MP3 recorded past Jason Gallant; file hosted by National Public Radio)

This communication is facilitated by specialized receptor organs, called knollenorgans, which are specially wired to only receive electrical information coming from other fish—these receptors are effectively deafened to the fish's own discharge, through a mutual nervous system play a trick on called a corollary discharge.

The fish besides utilise their electrical discharges to navigate through their environments—the arrangement works somewhat like sonar, but at the speed of light instead of sound! Electricity, unlike the acoustic information used by sonar is not reflected or refracted by objects, but rather is resisted or conducted by objects. In this sense, objects in the environment act like unlike types of "lenses". The fish has a 2nd assortment of electroreceptor cells, called mormyromasts, that detect distortions of the electric field every bit "vivid and dark" spots over the surface of their torso, giving an electrical readout of the environment. Admittedly, it is a strange sense for us very visual primates to imagine, merely the fish are enormously astute and tin discriminate tiny differences in objects with this sense.

Elephantfish are reported to accept a large cerebellum compared to other fish. What's the implication of these big brains?

Yes, the rumors are true—elephantfish have one of the largest vertebrate brains when scaled to trunk size because of their enormous cerebellums, which house the neural circuitry necessary to decode the electrical information they constantly send and receive.

The mormyrid fish Brienomyrus brachyistius can discharge electricity to communicate with ane another. (Image Copyright: Jason Gallant/Michigan Country University)

Amidst the questions you are researching is how electric organs evolved in fish, particularly since they are known in at to the lowest degree 6 widely unrelated groups of fish—torpedo rays, skates, elephantfish, catfish, electric eels, stargazers. How are these "musculus batteries" similar or different amid these fishes, and why exercise recollect natural selection has encouraged these electric organs to evolve time and time again?

Great question!  This is something that left Charles Darwin scratching his head.

Some fishes, like the torpedo ray and stargazer are just produce strong discharges, and the part is apparently to defend or kill potential prey. At his time, Darwin knew of these strongly electric fish, as well as the electrical eel. Just he was very bright and realized that there were all sorts of fishes that also had organs that resembled the organs of the strongly electrical fish, but did not apparently produce electricity.

Nearly 100 years later, at the beginnings of modern neurophysiology, amplifier technology were mutual in the laboratory, and a brilliant boyfriend past the proper noun of Hans Lissmann provided the starting time recording of Gymnarchus niloticus, a weakly electric fish. He provided the commencement clues into the solutions for this problem—fishes likely evolved (in the majority of cases) weakly electrical discharges start.

• Click to listen to the amplified electrical signals of the aba fishGymnarchus niloticus(MP3 recorded by Jason Gallant; file hosted by National Public Radio)

Lissmann and others went on to demonstrate with clever experiments that the fishes used this ability for communication and navigation in their environments. Scientists now think (though there is petty show to propose information technology) that electrical discharging abilities probably evolved from sound producing organs, and electroreception may take evolved second.  In the electric eel, the 600 Volt killer pulse probably evolved post-obit this.

Our lab's research has been asking the question of "how" these fishes build their electrical organs. In all cases, electric organs start out as humble skeletal muscle precursors, and then through additional (and unknown) developmental steps, become electric organs. And so, we asked the question, "are all types of electric organs different from muscle in the aforementioned ways?"

As information technology turns out, at that place seems to exist a set of 30 or so ordinarily musculus related genes that are ever expressed in the same fashion in every electric organ we've looked at to date. This suggests that at that place may be only one way to build a performance electrical organ from muscle, and that six groups have come up up with this solution by natural choice independently. This may seem hard to believe, simply many researches take shown that convergent molecular evolution occurs readily in nature, though we are amongst the first groups to provide this evidence for such a complex organ.

You lot are also studying how electrical signals in elephantfish tin change as they evolve into different species. How exercise these species come to "speak" different signals?

This is also a great question—the brusque reply is we don't know, simply we're working on it. Many groups of species, like the Paramormryops electric fish from Africa, the birds of paradise, Hawaiian crickets and Drosophillaflies, take evolved species at astonishing rates.

With its edgeless, squared olfactory organ, Paramormyrops kingsleyae does not resemble the other elephantfishes that exercise sport long jaws or trunk-like chin organs. (Image Copyright: Jason Gallant/Michigan State University)

In almost all cases, they are accompanied by corresponding diversity in communication signals.   Because nosotros define a species in biology as populations that can interbreed and produce fertile, viable offspring, the speciation process is very much related to mating behavior.

Since communication signals are nearly e'er utilized in facilitating mating, scientists have often wondered whether rapid evolution of communication signals might be sufficient to drive the speciation process itself.Elephantfishes in the genus Paramormyrops seem to be excellent candidates for such a procedure, though we are in the early stages of figuring this out. We take identified the major transitions of indicate variation beyond populations of fishes, and the morphological  and physiological changes that happen in the electric organ underlying these variations. We're now trying to figure out what the genetic footing of these changes are.

Paramormyrops kingsleyae is another species of elephantfish existence studied for its electrical communication abilities. (Image Copyright: Jason Gallant/Michigan State University)

At some point we experience an encounter with nature that hits us to the core. Was there a memorable experience in your life that helped steer your interests toward fish biology, and electrical fishes in item?

Sometime between beginning and fourth grade my fate was sealed. I've always kept fish and take been fascinated past them—but when I was in fourth form,Jurassic Park came out, and I was astonished by this chemic called DNA which seemed like ane of the most powerful chemicals on the planet.

After several amazing science teachers, I made information technology to higher, and all it took was a very enthusiastic faculty fellow member, who taught my offset course in animal communication, to introduce me to electric fish, and the questions have basically ruled my life ever sense!

Cheers for your time, Jason!

The Electric Fish Lab at Michigan State University headed by Dr. Jason Gallant, seated far right. (Image Copyright: Jason Gallant/Michigan State University)

Brienomyrus brachyistius (Gill, 1862)
Infant Whale
Click for name etymology (ETYFish Project)
Click for names in other languages (FishBase)

Class Actinopterygii (Ray-finned Fishes)
Order Osteoglossiformes (Bonytongues)
Family Mormyridae (Elephantfishes)

FishBase Page: http://www.fishbase.org/summary/5208

Citations

Gallant, JR, LL Traeger, JD Volkening, H Moffett, PH Chen, CD Novina, GN Phillips, R Anand, GB Wells, K Pinch, R Güth, GA Unguez, JS Albert, HH Zakon, MP Samanta, MR Sussman. 2014. Genomic basis for the convergent evolution of electric organs.  Science 344(6191): 1522-1525. doi: 10.1126/science.1254432

Gallant, J, M Arnegard, J Sullivan, CD Hopkins. 2011. Patterns of geographic indicate variation and its morphological correlates in a mormyrid electrical fish provide insights into evolution of electrogenic signal diversity. Journal of Comparative Physiology A 197(8):799-817. doi: 10.1007/s00359-011-0643-viii

A Annotation: This post is the 42nd installment of a more than 32,000-part series, "Better Know a Fish", and it is also being published on the final day of the U.S. idiot box program "The Colbert Written report", which inspired this website'south name with its "Better Know a District" segments. Fans of the show will know that Stephen Colbert has washed much to feature science and scientists on his programme, so to that and to his great milestone, I tip my hat to Stephen—and his very hungry fish.

— Ben Young Landis

Baby Whale Freshwater Fish Care,

Source: https://betterknowafish.com/2014/12/18/baby-whale-brienomyrus-brachyistius/

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