“On the Mutation of the ‘Escalo’”

On the mutation of the ‘escalo’: Open letter by Mário Domingues, published in the Real Gazeta Invicta on 23 March 1922

Esteemed readers of the Real Gazeta Invicta,

Forgive me the arrogance of these words, which I write with the best intentions. I’m not a specialist, nor am I an academic; my profession is, and will be, that of a humble accountant. The naturalist knowledge I possess, limited as it is, I obtained by my own studies. It’s a fascination that’s been with me since I was a boy, but which unfortunately I haven’t had the opportunity to pursue. However, I was compelled by Professor Manuel Almeida’s warning, published in an open letter in this very newspaper. The Professor draws attention to the extinction of our Acipenser sturio in the waters of the Douro River. The excess, and the residues of such excess, takes its toll on the fauna and flora that characterise our beloved Nation, and as if this case wasn’t alarming enough, I’m afraid it’s my duty to share another that I’ve been noticing and analysing in my spare time; not extinction, but mutation: of the ‘escalos’! It’s important to mention that I haven’t seen it in every specimen, but the cases I have been following are worrying. With the Latin name Leuciscus idus, this small silver fish, common to the waters of our Douro, has undergone a, frankly frightening, transformation. In several areas I’ve found shoals of this fish evidencing various stages of mutation: a mutation that not only lengthens and enlarges their bodies, but also gives them a row of needle-like teeth and uncharacteristic fins. Isn’t this phenomenon worthy of attention? I don’t think of myself, as I previously stated, as the best source. I therefore wonder if it wouldn’t be vital for one of the eminent naturalists from the Royal University of Porto to visit the vineyards fed by the Douro, to assess the phenomenon and confirm its validity. Perhaps, then, the measures such a situation requires will be taken; measures that I believe have not yet been adopted due to mere unawareness.

From a concerned citizen.

Yours faithfully,

Mário Domingues