Most Wanted : Bitterling.

I recently purchased a copy of Mark Everard's rather excellent "The Little Book of Little Fishes" to further my research into the various mini species that can be found in UK freshwater. As well as the usual more familiar fish species like minnow, stickleback and gudgeon it covers some species that are less well known, some that are distributed in localised areas and also some non native species too that have been introduced to the UK from elsewhere. Of course, my favourite little spiky brown fish, the ruffe, is an example of all three. Another is the bitterling. Released from aquarium stock in the North West of England they seem to have found a niche for themselves and can still be found around the region. They are pretty little fish with the males taking on rather impressive colours during their mating season.

A male bitterling displaying some rather nice breeding colours. 

Bitterling have a very interesting relationship with freshwater mussels and the breeding cycle of the bitterling is in fact reliant on them. The female injects her eggs inside the shellfish and the males sperm then enters the mussel as it filters water in to breath. A very odd process indeed and one of those strange things that occur in nature that make you wonder how such things come about.

A female bitterling. Note the long egg tube (ovipositor) in front of the fishes anal fin that is used to deposit eggs inside the mussel.

Growing to an average size of only 5-7cm and with a small upturned mouth some very sensitive wagglers will no doubt be required as well as small hooks and probably a pint of pinkies or squats if I'm to successfully target and catch them. I have a couple of small stillwater venues in England in mind that rumour has it contains bitterling and I will hopefully get a chance to have a go for them later in the year.

Tight lines, Scott.