Trout will always pig out on those unassuming scavengers, hog-lice and freshwater shrimps. It’s time we got our noses in the trough too, says PAUL PROCTER
It’s easy to get excited about emerging insects. Nothing beats a hatch of buzzers, sedges or upwinged flies for sheer spectacle, and when trout are first on Mayfly they seem quite suicidal. But while these creatures make up a large part of the trout’s diet, their activities are seasonal. You wouldn’t fish a Mayfly pattern in October, would you?
Thankfully, other small denizens are available as a more consistent food source. Lets consider crustaceans, which in this context means the freshwater shrimp and freshwater hog-louse. Totally aquatic, and therefore available to trout 365 days a year, their artificials are fished in similar ways, but the bugs themselves demand an individual look.
There are several species of freshwater shrimp (Gammarus) in the UK. To be honest, I’ve never tried to identify the different types, and I’m sure the trout don’t care one jot when they’re busy munching on them. Summer or winter, rain or shine, shrimps will be going about their daily routine. So why do we tend to ignore this unassuming crustacean? Possibly because we rarely see them, so they seldom spring to mind during a day’s fishing. Emerging insects are much more in our faces (sometimes literally), and few things excite us more than arriving at the water to see olives or sedges hatching off.
Even if trout are not rising we attach an appropriate imitation and, pushing all reason aside, proceed to fish. Our faith in upwinged flies is reflected in the number of available patterns, whereas shrimp imitations are far less common. That said, a few standard patterns seem to find their way into most fly boxes.
Equally at home on river and lake, shrimps can be found inching about the bottom. They tolerate a wide range of water chemistry but thrive best in calcareous rivers, so it goes without saying that chalk and limestone-based waters support huge populations. The calcium content and consequent high pH factor allows shrimps to produce a strong, protective shell. That’s not to say that small, seemingly barren streams have little shrimp. Running off apparently infertile ground, many Lakeland hill streams hold surprisingly healthy stocks.
Favoured haunts for shrimp include weed beds, areas of loose stony substrate and some silty regions. Here the crustaceans find both food and shelter. Scuttling about on their sides, negotiating all kinds of obstacles, they graze on vegetation and micro-organisms. Not averse to scavenging, they rarely pass up the opportunity of an easy meal, and dead fish or any other decaying animal matter will attract hordes of shrimp.
They are not the most nimble looking of beasties, so you could be forgiven for thinking shrimps are slow, cumbersome and lethargic. Disturbing them tells a different story. Over short distances they have an incredible turn of speed, darting into nearby crevices or weed beds at a lightning fast pace which is achieved with extended body and frantic leg movements. This brings us to that much debated issue of whether shrimp imitations should be tied on straight or curved hooks. I have watched trout, grayling – and chub for that matter – swim into shallow water, actively flushing out Gammarus. What the pursuing trout must see is a fleeing shrimp, swimming with an elongated body. Reason enough to tie your fly on a straight shank hook.
But, shrimps which are washed out on a windward bank during stormy conditions are quite vulnerable. Finding it difficult to negotiate the rough and tumble of relentless waves, they assume the protective foetal position until quiet water is reached. This curled-up posture is best copied using a curved hook, and my feet tend to fall into the curved hook camp. Nearly all my shrimp patterns possess that characteristic hump of the natural. Also, flies tied on curved hooks tend to fish point uppermost, so are less likely to catch on snags. Ultimately, it’s down to what works for you – straight or curved hook. Confidence is key.
When still, it's easy to see why shrimp patterns are tied on curved hooks.
The shrimps’ colour can vary from water to water, and even pool to pool on a river system. On the whole, they tend to be a grey olive or pale watery brown. During mating time, some take on a slight pinky-orange tinge. Then there are those that have a conspicuous orange spot about their midsection, caused by the parasite Schistocephalus solidus. The tiny parasitic worm preys on shrimps, making them behave in an unusual manner. In this way they become easy pickings for trout, which is the intended destination of this nasty little creature. Over the years several flies sporting some form of hotspot have been devised, and one of the most killing shrimp patterns, by John Roberts, incorporates an orange Firefly bead.
Related to our common woodlouse, the hog-louse Asellus is in effect an aquatic version of this creepy-crawly. Also referred to as the Water Slater, like shrimps they frequent weedy areas. Most, though, move that bit slower when ambling about. A squat, flattened appearance with a segmented body helps distinguish them from shrimps. As scavengers they feed on animal and vegetable matter.
To achieve that squat look in imitations, it’s worth incorporating lead either side of the hook shank. That said, I’ve fooled many stillwater trout grazing on hog-lice with deep-fished Hare’s Ear patterns intended for shrimp feeders.
Situated in South Cumbria, Wych Elm is a relatively shallow fishery with modest weed growth. The annual autumn side-back sees all kinds of bugs gathering around the decaying matter. Such areas are a natural draw to fishermen, and a couple of years back we experienced some first-rate nymphing when the trout acquired a taste for hog-lice. As ever, it was more by accident than design. Fishing Whisper Nymphs slowly around the weed beds, many of the trout we caught had been feeding on hog-lice, mainly immature specimens no more than 5mm long. Obviously, the Hare’s Ear Whisper Nymph matched the naturals perfectly. I’m happy to present a buggy looking Hare’s Ear to imitate both shrimp and hog-lice.
Because both these crustaceans tend to loiter close to the lake bed it makes sense to present our flies there. In water up to 10ft deep, where weed growth is prolific, a floating line is fine. Using a sinking density tapered leader helps get the flies down quickly, especially in a breeze. I usually start with a leader of about 16ft and two flies positioned some 2ft apart (see diagram below). Being this close together, there’s more impetus that hopefully improves their sink rate. It’s then a case of casting out, taking up any slack and keeping in touch with the flies. Literally inch them back, watching the line for any untoward movement, which should be met with a confident lift.
To combat really gusty weather a switch to an intermediate line can be a shrewd move, but speed up the retrieve a fraction because you’ll now be relying on touch to detect takes. Still keep one eye on where the line enters the water off the rod tip. Sometimes this will lift before any heaviness is felt, giving you enough warning to tighten.
Often, I’ll fish shrimp/hog-lice patterns in conjunction with other nymphs. In early spring, when the days are cold and hostile, a heavy cased Caddis pattern can be used to present smaller shrimp-like flies on the droppers. Equally, at depths beyond 4-6ft, a weighted shrimp is a safe bet on the anchor, with Buzzers attached to droppers.
Summer heatwave conditions can suppress insect hatches. With little happening at the surface, a couple of crustacean patterns trickled across the bottom can often secure a trout or two before the late evening rise. If restricted to daytime fishing, try shrimp/hog-lice patterns over deep water. There’s scope here to use fast sinking lines with buoyant flies, Booby style (see diagram below), although I prefer a floater.
If there’s one time when fishing crustaceans comes into its own, it’s late autumn. The first frosts will see receding weed beds open up new hunting grounds, and with the best of any hatches long gone, tiny crustaceans become easy pickings for foraging trout. A team of three nymphs fished through these areas will form the cornerstone of my winter trouting. The point fly and first dropper will be positioned close together with a third nymph some way up the leader acting as a sweeper (see diagram below). While the two bottom flies might imitate shrimp/hog-lice, the top dropper will certainly be a Buzzer pattern.
As ever, wind direction will dictate potential fishing areas. Ideally, a breeze will impart natural drift to the flies. Obviously, we’re talking head or crosswinds here. Having cast out, allow to sink before taking up any slack. Now under slight tension, swing the nymphs round on a breeze, watching the line for takes.
Trout might turn to crustaceans at any time of day during winter. The productive spell is 11am to 3pm, but fish often have several short feeding bursts outside of this. Obviously, with them feeding sub-surface, you can’t know when a feeding spree begins or ends. I fish short spells with breaks. These stop you from going stale, because each mini session offers a new challenge.