OF GOLDFISHES THAT DRIVE WHEELED WATER TANKS, AND UNIVERSAL NAVIGATIONAL SKILLS!

Goldfish drives fast a super car (by @sciencemug)
Goldfish pic by zhengtao tang, and car pic by Damian Ochrymowicz, are free images (source: Unsplash); all pics adapted by @sciencemug

So folks, four researchers from Israel (aka the Fab4), put six goldfishes (Carassius auratus) at work (Givonet al, 2022 (P)) to see whether space representation and navigation skills (which allow animals to do plenty of things, like finding food, shelter, sex buddies and so on) are shared properties across the animal kingdom, or, instead, they specifically depend on the different species, brain structure, and ecological system.

The researchers, in their study, use the "domain transfer methodology, where one species is embedded in another species’ environment and must cope with an otherwise familiar (in [their] case, navigation) task" (P): in layman's terms, the Fab4 want to see if a fish can navigate through a terrestrial environment.
To check that, the brains train each fish to "drive" something called <Fish Operated Vehicle> (aka FOV). The FOV is a water tank (35×35×28 cm) put on a four wheeled self-propelled platform (40×40×19 cm), equipped with a pole, on top of which there are a computer, a camera and a lidar. By this control apparatus, whenever (and only when) "the fish [gets] near one of the water tank walls and facing outwards, the FOV is automatically propelled in [such] direction" (P).

The machine, with its aquatic driver, is then placed in the center of a three by four meters room, illuminated with artificial light, and with white walls and one or more colored boards stuck on them. The colored spots are the targets the fishes are trained to reach in exchange for a food reward (consisting of a 0.002 g food pellet of the same kind the fishes are usually fed with).

Well, dear reader, in the end, the goldfishes training's success, they can reach the targets, adapt to changes in such targets positioning and overall overcome the "distortion in vision due to refraction through the air-to-water interface [and the] differences in the natural structure of the terrestrial and aquatic environments" (P).

The Fab4's work (that they define "an observational report, rather than a scientific study" (P), and that needs follow-ups ) shows, thus, that "a fish [is indeed] able to transfer its space representation and navigation skills to a wholly different terrestrial environment, thus supporting the hypothesis that the former possess a universal quality that is species-independent" (P).

But this dumb blog, in the following cartoon, shows you, dear reader, what's the next step of this experimental journey humanity has embarked on.

A green fish drives a car full of water to a sushi bar (by @sciencemug))
The car pic by Dan Gold , the green fish pic by Gábor Szűts, the bubbles pic by Alberto Bianchini and the spilling water pic by Pixa Karma, are free images (source: Unsplash); the fish drawing by Mrmw, is under the Creative Commons CC0 1.0 Universal Public Domain Dedication (source: Wikimedia Commons); all images adapted by @sciencemug

THE TRUE REASON WHY COELACANTHS CAN LIVE 100 YEARS!

Soo, dear reader, a fish, the "living fossil" (given it is already around 240 million years ago, in the Triassic Period) African coelacanth (Latimeria chalumnae) discovered to be still alive & swimming in East London, South Africa, in 1938 and thought to have gone extinct instead by the end of the Mesozoic era (1) (meaning around 65 million years ago), weeeeell, this already surprising fish manages to surprise once more, as it apparently has a lifespan of about 100 years.

This is, indeed, what three European researchers (aka the EuRs) find out after analyzing, by microscopy, the signs of growth of the scales of 27 specimens of African coelacanth (Ac) (13 females, 11 males, 1 juvenile, and 2 embryos) caught off the coast of the Comoros Islands (Indian Ocean, at large of Central/South Eastern Africa) between 1953 and 1991.

The new discovery, published (P) in the science journal Current Biology, contradicts two previous studies (P) (both of which investigate the same 12 specimens) that gave our - at this point - beloved fish a life expectancy of only 20 years, top.

The EuRs say that a long life suits the characteristics of the Ac. The beast's "biological features including low oxygen-extraction capacity, slow metabolism, ovoviviparity, and low fecundity, [are indeed] typical of fish with slow life histories and slow growth" (P).

We're talking, dear reader, of a swimmer that "has among the lowest growth rates of marine fish for its size" (P) that, by the way, at birth is pretty large already (around 35 cm), and "can reach up to 2 m in length and [...] up to 105 kg [in weight]" (P).

Moreover, with a gestation about 5 years long (so no surprise if the coelacanths "produce a relatively small number of offspring" (P)), and a maturation that takes about 55 years, these fishes have "one of the slowest life histories of all fish" (P).

So, buddy, to sum up, the African coelacanth takes it really slow, and kicks the bucket after a century. And, for this, it can be more in danger than previously thought, because "long-lived species with slow life histories are extremely vulnerable to natural and anthropogenic [meaning human driven] perturbations" (P).

Now, pal, all the above said, this dumb blog shows, in the following cartoon, what's the real secret of African coelacant's longevity...

African coelacant explains the secret of its longevity (by @sciencemug)

[Fish pic, by Zoo Firma, is under a Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) license (source: Wikimedia Commons); adapted by @sciencemug]

 

 

 

The paper this minipost is about (P) 

- Mahé, K., Ernande, B., and Herbin, M. (2021). New scale analyses reveal centenarian African coelacanths. Current Biology 0.

References

1- Smith, J.L.B. (1939). A Living Fish of Mesozoic Type. Nature 143, 455–456.

LE DIMENSIONI (DEL CERVELLO) CONTANO, SE SEI UNA PESCIOLINA TROPICALE

Sig. Guppy (Pub Dom img)

Avere un cervello grande aumenta la capacità di sopravvivere ai predatori nelle femmine, ma non nei maschi, di Poecilia reticulata, una specie di piccoli pesci tropicali detti guppy. La scoperta, fatta da un gruppo di scienziati delle università di Stoccolma e Vienna, è riportata sulla rivista scientifica Ecology letters

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SIZE DOES MATTER (WHEN IT COMES TO BRAIN AND YOU ARE A FEMALE LITTLE FISH)

Mr. Guppy (Pub Dom img)

Size does matter. At least when it comes to brain and the ability of surviving predators' attacks and when you are a female of Poecilia reticulata, a species of small tropical fishes called guppies. The discovery, made by a group of scientists from the universities of Stockholm and Vienna, is reported in the journal Ecology letters.

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The following text is that of the podcast
in Eng?ish

O-oooooh hallo dear English-hearing-speaking-thinking listener, welcome to the third of my podcasts in Engmark, that is English-question mark, a language that is to real English what “spaghetti bolognese” is to an actual Italian dish and the combination of a piece of evil chalk scraping a blackboard with Marge Simpson’s voice is to velvet.
Speaking of voices, the one you’re hearing is that of my avatar, a dumb human controlled via a wireless-voodoo trick by me, “sciencemug”, the blog which tells you about science, sings the song of love but scrambles all the words while skipping the rope of summer in company of ice creams in a blue mood aaand while shutting down the alien conspiracy which aims to take over the world production of donuts in order to change the recipe and make them taste like deep space tofu, that is as saaaad as the Earth’s one, but colder and with a bit of a Haggis aftertaste.
Soooo, what am I telling you this time? Weeell, I’m telling you a science story about dimensions, brains, little tropical fishes, predators and evolution! 

by sciencemug

[The guppies pic is a Public Domain image adapted by sciencemug (source: wikia.com)]

Size does matter, as usual. At least when it comes to brains and the ability of surviving predators' attacks and when you are a female, hence not a male, of Poecilia reticulata, a species of small tropical fishes called guppies. The discovery, made by a group of scientists from the universities of Stockholm and Vienna, is reported in the journal Ecology letters.

Ooooh, well well, doctor Alexander Kotrschal (which I’m gonna call Alex, from now on, to avoid to plead guilty of consonant slaughter in a trial for mass murder of the poor people of the alphabet and then face the wrath of the ghosts of those innocents letters for the rest of my blog-life, and, by the way, according to the usual reliable sources of the internet, 1 blog’s year is equal to 5 leap years of a sloth), so, doctor Alex, I was saying, and other 5 scientists form Sweden and Austria (and I‘m gonna call this science bunch “the Alexanders”, ‘cause, well, I think it’s really really cool) they decide to try to understand whether and how evolution kisses the kiss of blessing to the bigger brains. To do that the Alexanders decide to study little tropical fishes, the guppies, and to analyze the relationship