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