Who from us does not know them? All of us fish with them (with the exception of purists), but even thus – as the saying goes – when two are doing the same, it must not necessarily be the same. At present, imitations of freshwater shrimps (Scuds – Gammarus) are part of the offer in all flyfishing shops as well as in our flyboxes. It is necessary, however, to start thinking, if all these are really freshwater shrimps.
In connection with the boom of technique of short nymphs, there started to expand flies, which acquitted themselves for this technique best – weighted flies on Gammarus hooks. I divide these flies into three groups: freshwater shrimps (scuds), sedges and flies called bobeš in Czech
A scud, as it is well known, is a freshwater crustacean. It grows up to length of 13 mm, but most of them are smaller. Colours are varied – from light beige to dark brown, sometimes with orange elements. It has a typically curved profile and body flattened on both sides. These are the main characteristics, therefore imitations of scuds should have these features. I am feeling, that among the flyfishermen there has spread an opinion, that anything curved must be a scud. On the contrary, I think, that there are only very few freshwater shrimps in flyboxes of our flyfishermen.
As scuds I would designate only real imitations of crustaceans. They should have, however, curved and flat body and a colour, corresponding with the natural specimen. They should also be of the same size. These flies should have by no means a dark head and back. The darkest part of a light coloured scud is its eye. Therefore I assume, that flies currently termed as scuds are most likely imitations of sedges - these are noted especially for the mentioned dark head part. Patterns imitating scuds are shown in pictures 1 and 2.
Among scud flies we can of course see the so-called trigger-elements, like coloured parts of the body, spectraflash backs or other sheeny elements. A question arises - does such a fly belong to imitative patterns, or is it a fancy pattern, that only makes use of the curved shape of the fly? A clear-cut, exactly and precisely defined border does not exist. It can happen, that one fly may be placed into two categories at the same time. Everyone can find an exception, everyone can have a supporting argument for this or that side. All the same I think that for all of us it would be very useful to put all these flies in order.
Sedge larvae are other flies, we like to use. They form a very important food part of salmonids, therefore their imitations are very successful. As I have already mentioned before, in contradistinction to freshwater shrimps they have a dark head. Together with a dark back it forms characteristic features of most sedge larvae. There is one more difference in comparison with scuds – the body is cylindrical. Thus, when you wind lead wire around the shank of a Gammarus hook, cover it by some dubbing material, add a dark vinyl foil, rib it and finish in a brown head, you have just bound a sedge larva, no freshwater shrimp, as it is often presented in fishing journals. Again, like with the scuds, we can add various trigger materials and similarly speculate over categorising the fly. Pictures 3 and 4 show typical sedge larvae.
Now I am coming to the category of flies with a nice Czech name „bobeš“ (read bobbesh). I think, that exactly these flies are the ones, all of us are using and knowing intimately. They cannot be specified exactly, because no exactly defined regulations exist – like the kind „the body must be like that, thorax like that, back like that“. The only things linking them together are a Gammarus hook and a layer of lead under dubbing of the body. There are no limits for phantasy here. Personally I would call it „free creation of Czech flyfishermen“ with the theme „flies for fishing with a short nymph“. These are the flies, named Czech Nymphs in foreign catalogues, which made the Czech flyfishing school famous. Personally, I would incorporate all scuds and sedges with various triggers into this category. We cannot well say, that a fly, that is yellow-red-orange-pink is a realistic pattern imitating a specific creature. There is no doubt, that they are very effective and have caught lots of trophy fish. But no one of us is a fish and cannot say, if these flies remind the fish more of scuds or sedges, or if they take them reflexively. There is a long row of fancy flies, not reminding us of anything definite, very effective and having their own names. Therefore I would put in a word for calling the flies by their proper names. Namely – a freshwater shrimp is a real, realistic imitation of a crustacean, a sedge larva is a proper imitation of a sedge larva and everything else beyond – a bobeš. Three from the inexhaustible palette of bobeš flies are in the pictures 5 and 7.