Another puzzle

[Harvestman]

Hopefully easier than my previous one...

Credit for this one goes to Al, aka The Big Lebowski, hereafter to be known as The Pink Lebowski, or at least until his sunburn heals...

Up in the Elan Valley in mid-Wales, we came across this sign about the fishing rights.

Find the mistake. Al saw it immediately, but it defeated me.

 

[Robbi]

3 not 2

 

[mountainm]

mackerel.....

 

[Robbi]

well spotted sir, but your wrong....that would be the lesser stripped welsh fresh water mackerel, very common in reservoirs, in wales.

 

[Harvestman]

3 not 2

Hey! Neither of us noticed that. Well done sir.

'Tis the mackerel, of course.

Robbi, the lesser stripped welsh fresh water mackerel is actually confined to the top left hand corner of Wales, in Ivor the Engine country, and does not occur in Radnorshire. The greater stripped welsh fresh water mackerel is now extinct, due to over-fishing.

Obviously.