Hi Jim,
That's fair comment, the
oncorhyncus family of Pacific species includes the rainbow trout. Whilst it is true to say that they have more biologically in common with char species
salvelinus than
salmo it would be misleading of me to say they were char alone. However, they are closer to the american char species than the largely 'european'
salmo species and are biologically far more efficient/capable of rapid growth/food conversion as the char species can which makes them of great interest (obviously) to the fish farming interests.
Part of that ability for rapid growth might lie in genetic coding as the
oncorhyncus species generally have a shorter lifespan than
salmo species although the same growth characteristics can be discovered in brown trout and atlantic salmon via selective breeding - sadly, it doesn't come as 'naturally'.
The closest thing biologically that we have naturally in the UK to rainbows is the native char
salvelinus alpinus rather than the brook trout
salvelinus fontinalis which
some people have confused them with. The native char is an interesting wee fish which is just as capable of packing on the weight as a rainbow but, unless artificially encouraged, seems to be something of a mystery as generally they do not grow to large sizes in the UK. A chap I knew tried crossing them but I don't know how much luck he had.
Without going too much further off track the one species I would love to this day to get my hands on to 'play with' (as they interest me hugely) are the
hucho, specifically Taimen although Huchen would be just fine. Although slow growing they could, in theory at least, make a very interesting study in fish growth. I would have been very interested to see if they could have been crossed with brown trout...it should be possible... one day maybe
I'll leave you with that thought whilst I go warm up the frankenstein fish bath
Hamish exits stage right with a maniacs laugh and a stange twitch.......
H