SCUD FLY PATTERNS (also a great freshwater shrimp or louse imitation)
Scudding is the common term used to describe the darting and swift swimming habits of this freshwater shrimp-like creature. From the term scudding they get their name, Scud. Their other name is the Mussel shrimp or Ostracoda. Scuds are members of the class Crustacea, order Amphipoda. Scuds' are distant cousins to the crayfish, sowbugs and shrimp. The beauty of fly fishing with scud imitation flies is that you can use them at any time of the year. They are always available as food for fish even when other insect availability is limited. They are an ideal pattern to use during those non-hatch periods of early spring, late Fall/Autumn and low light conditions of very early morning and late evening. Scientists have identified over 90 different species in the fresh waters of the USA. There is a greater diversity of scud species in the Midwestern and Eastern states compared with the Western states. They are good general shrimp patterns for catching fish all over the world. Newly hatched young look like smaller versions of the adults. As the young grow they molt their skin (exoskeleton) five to nine times before reaching adulthood. Adults continue to molt another 15 to 20 times during their life as they grow. The time periods between molts can be anything from three days to around 40 days. It depends on the species, availability of food and water temperature. Most species mate and lay eggs anytime between spring and late summer one to fifteen times in the same season. The frequency depends again on the species, availability of food and water temperature. The normal life span of a scud is normally one year but they can live for two years.

A number of anglers use the term 'shrimp' when they mean scuds. If you look closer scuds differ from their distant cousins. Scuds have the appearance an armadillo: hard, segmented exoskeleton with seven pairs of legs carried underneath the body. The front two pairs of legs are used for grasping while the remainder are used for swimming. These legs enable the scud to swim quickly at times, although they commonly move in an erratic and random manner. Some species prefer moving around in an upside down fashion. Scuds also have 2 pairs of antenna. Located between the various pairs of legs are their gills. Scuds spend their entire life beneath the water's surface. There is no pupal stage or emergence of any kind.

One mating pair of scuds can produce upwards of 7 broods, totaling 20,000 offspring per year under ideal conditions. Scuds mate in a piggyback like fashion with the female usually on top. They are omnivorous feeders, eating just about anything. Scuds even attack larger aquatic insects such as damsel fly nymphs and water boatmen in Piranha like fashion, but they seem to prefer a vegetarian diet. Scuds are capable in living in depths as great as 50 ft, but prefer shallower depths of 15 ft or less. Scuds are light sensitive and are most active in low light overcast conditions. These are good days to fish a scud pattern. Scuds take refuge from the light in large numbers under boats and other shady areas like piers.

Scuds come in a wide range of colors. A good rule of thumb is, darker the water the darker the coloration of the scuds. Ttranslucent scuds has a chameleon like quality. During times of low weed growth the scuds will be pale in color. As the weeds grow, scuds are able to change color to match their surroundings. Scuds lose the ability to camouflage themselves effectively as they near the end of their lives. The coloration tends to become various tones of yellow. Scuds with an orange colored spot in the middle of their body, are pregnant females. The orange spot is the brood pouch, or Marsupium. In some Trout stomach samples you will see orange colored scuds. This is not their natural color. When a scud dies the natural coloration disappears, the orange color is due to the presence of Carotene. Carotene transfers to the fish during the digestive process and leads to the beautiful pink flesh.

Scuds inhabit lakes, rivers of all sizes, springs and streams. One study found a population density of 10,000 per square yard (meter). You can see why they are an important food source for trout. Scuds are more commonly found where you find decaying vegetation. Large concentrations of these crustaceans can be found in moderate to slow moving currents near thick aquatic vegetation like reed, weed or plant beds. Scuds eat a variety of plant material such as leaves and stems. They also eat dead mammals, fish and insects that they find on the bottom. They are rarely found deeper than one meter. They prefer clean, well oxygenated water over polluted water contrary to some common beliefs. In the nutrient rich waters of British Columbia and the western United States scuds are second only in importance to chironomids (buzzers). Research has shown that scuds' compromise over 20% of the trout's food intake. Lakes that contain lots of scuds have big trout. Phenomenal growth rates of over 1.5 lb. per season or greater can be attributed to a consistent scud diet.

Scuds swim in a stretched out position in contrast to the curved position they take when held in the hand or resting. They are more active in the evening, on cloudy, overcast days and at night. They dislike bright light and hide during bright sunny days. Use an eight to ten foot leader for stream fishing. I use a slightly longer leader in clear streams. In lakes I use a floating line with a sinking tip and a 4-6 foot leader as scuds are normally found in shallow water one yard (meter) deep as I already mentioned. If the fish in the shallows are spooking I use a longer leader between 12 to 15 foot long (4-5 meters).

When fishing in lakes I cast the fly around the edges of water plant beds, wooden piers, or other obstructions, natural or man made. It is around these areas that you will find the greatest concentration of scuds. I let the fly sink to the bottom and retrieve it in 4 to 6 inch smooth slow strips. Do not retrieve too fast. I do vary the speed to find out what produces the best action that catches the trout’s interest. You have to remember that you are trying to imitate the scud trying to flee from a predator or swimming to the next piece of edible plant.

I cast upstream and slightly across the current when fly-fishing in a stream. I dead drift the scud fly along the stream and plant bed edges. In clear streams where there are few plants I search out small pools and eddies with quiet water near the stream bank. Strikes can occur at any time especially during the pause between the strips. I do not use them but you may wish to add a strike indicator to your line as they can be very subtle and hard to detect. It is also a great pattern to use as a shrimp imitation in other parts of the world. You will normally see them when you disturb the river bottom as you wade through the water. When they dart away their bodies are straight. We have tied our flies on a straight (slightly curved) scud hook. Trout and other fresh water fish are more likely to chase and attack scud in this position as they look like fleeing scud when they are stripped.

FRESHWATER SHRIMP
These delicacies are available as a food source to trout throughout the year. They are part of the Amphipoda order of the family genus Gammarus. Here in Britain we have three species the most common being Gammarus pulex. Gammarus lacustris is found in Scotland's Lochs and Gammarus duebeni can be found in Irish waters. Gammarus pulex reaches about 20mm nearly the same size as a freshwater louse. They can be identified by the fact that shrimps, when held in the hand, has a slightly curved and flattened body and will always lay on its side where as the louse will try to remain upright and freely walk upon the palm of your hand. The color of the shrimp will vary light and dark shades of pink, gray and brown.

Freshwater shrimps are found in many ponds, reservoirs, lakes and most streams and rivers. They are normally found in shallower areas rather than in the deep open water stretches. The like well oxygenated alkaline water but can tolerate some acidity. They are an excellent indicator on how clean the water is as they cannot survive in polluted water. the hide under stones, sunken logs and other river and lake bed debris. They also lurk near the base of aquatic plants. They feed on dead plant material, smaller living marine organisms and other decaying organic material. 

A shrimps body consists of three sections: the pleon, peraeon and the head. The head carries the eyes, mouth and distinctive forward facing antennae. The second section contains the main legs and gills. The first two legs are used for grasping food and transporting it towards the mouth. the others are used for walking. The last section contains more legs. The front section help in swimming and to pass water over the gills. The very distinctive rear section legs are used to jump and give the shrimp its characteristic springing movement when threatened or disturbed. The front antennae and rear jumping legs are important features that should be included in any fly imitation. Mating occurs during the spring and summer. The lay about 20 eggs in a batch and kept in a brood pouch on the female. they hatch 16 to 17 days later but remain in the pouch for a few more days. The young develop and grow by a series of moults. The first takes place normally one week after hatching. If the amount of food available locally is high then development occurs at a faster rate. After about the 10th moult they are sexually mature and the sequence starts again.

You may find some shrimp with orange blobs in the egg sack. this is often confused a shrimp egg. In fact it is a nasty fish parasite called Pomphorhynchus laevis. Fish are attracted to this colour and it can be beneficial to incorporate a blob of orange on an imitation fly. The parasite releases its eggs whilst still inside the host fish. These pass out as fish shit, whoops sorry fish faeces, and sink to the river or lake bed. The shrimp eat them and the eggs hatch within the intestine of the shrimp, yuk! They then bore through the gut and stay within the body cavity of the shrimp until they develop into an orange colored cystacanth; the orange blob. They are in turn eaten by a fish. the parasite attaches itself the the stomach wall. of the host fish and the process starts again.

SHRIMP TACTICS
There are many different ways to fish a shrimp fly but you should always remember the life style of the lowly shrimp and try to match it. The fly should be fished close to weed beds close to the water margins. Do not waste your time casting out into deep water. In the winter with a current or after a summer rainstorm shrimps will often get dislodged from under rocks and logs. They are at the mercy of the strong water flow, ending up on the bottom. When suspended in the water they move at the same speed of the water. It is vital that you fish your fly dead drift so that it moves at the same speed as well. The shrimps do not try to swim against the tide and therefore you should not try to imitate it swimming otherwise you will definitely come up a blank days fishing. When they land back on the bottom they are very open to attack from hungry trout until they can find new safe cover. In these conditions it is best to have a heavy shrimp point fly and two droppers floating at different levels in the water column. 

Fishing with a single fly gives you more freedom. It is ideal in shallow water. The fly can be allowed to drift longer and therefore fool more wary fish that your fly is the real thing. Cast upstream and allow the fly line to move with the current of the water. Retrieve the line at the same speed that the water is moving at. You are therefore in contact with the fly so you can strike as soon as a fish takes your fly.  In stillwater or very slow moving water conditions the situation is reversed. You have to suggest movement to attract the attention of patrolling trout. Try to imitate how a shrimp moves. Being tiny it moves in very small irregular erratic jumping spurts. Use small sharp jerks or an erratic figure of eight retrieve. Try varying the sped and length of the strokes to maintain interest. No shrimp moves with consistent regular systematic movements. 

Try to find out the color and size of the local shrimp population by spooning a caught fish or turn over rocks near the shore. Males, during the breeding cycle, change color so make sure you try to match it otherwise you will lose out. Shrimps do like water with high oxygen content so look out for a water inlet or other fast flowing water source coming into an area of stillwater. Cover this with a shrimp pattern as they will probably be there along with the hungry fish.

TAILING TROUT
There is a trout feeding pattern that you should always be on the look out for. The tell tale sign is when you see a fish tail popping out of the water. The fish is head down in the weed, sometimes ripping out the weed with its mouth, trying to disturb all the shrimp, nymphs, pupa and scuds that have sort refuge in the weed. This is where they live and feed. This is the only way trout and grayling can get at weed imbedded insects and crustaceans. The fish dive aggressively head long into the weed mass with the object of panicking the residents to make a dash to an alternative place of safety. This is what the fish are after. They start to feed on all the fleeing food forms. Do not cast when you see tailing trout. Wait until the tails have disappeared and the fish are hunting. The harvesting of panicked insect phase is when the fly fisher can make the most impact. Place your fly in the feeding zone and let it let it drift at the mercy of the current and to tumble about just like the naturals. Give a short sharp strip to imitate them fleeing to escape.

A BRIEF HISTORY OF NYMPH FISHING
Many of the very early flies fished below the surface were being used in the North of England and Scotland. Many of these wet fly techniques were being developed into a fine art. Down in the South of England , during the Victorian era, on the clear chalk streams of Hampshire and Wiltshire it was the floating or Dry Fly technique that became popular in fly fishing  circles. It was considered the most sporting method of tempting trout. By the end of the nineteenth century the rule of 'dry fly only' had become entrenched on most rivers. this was despite knowing fact that large river fish rarely feed on the surface. These values were transported around the British Empire.

However this dogma was challenged by one G.E.M. Skues, who fished on the famous River Itchen. Skues made himself very unpopular with the Victorian dry fly traditionalists, by singing the praises of a nymph pattern fished just beneath the surface to represent a hatching fly. Eventually Skues' arguments won the day and on most chalk streams the rules were changed so Gentlemen could fish either a floating fly or a nymph.  With the 'rot' having set in, Frank Sawyer, a South England, Hampshire Avon river keeper, publicized his new 'induced take' method of fishing a heavily weighted nymph from near the river bottom. A method still widely used on both chalk and rough water streams.

With the building of  reservoirs for public water supplies the opportunity for trout fishing increased in areas that previously had poor fishing resources. Many of the reservoirs are extremely deep and new nymph fishing techniques and lures have been developed to tempt the huge trout that live at the bottom. The growing popularity of stillwater trout fishing has led to many farmers and landowners digging trout pools as an extra source of revenue. These small stillwater lakes and ponds make fly fishing accessible to more people.

CUSTOMER'S COMMENTS
I was stillwater fishing, sitting quietly in my boat. Trout were cruising right up to and under my boat. I could see their white mouths opening as they fed but could not see what they were taking. About 10 feet away I observed one trout tip up and root his nose around the lake bottom. He created a small cloud of silt and debris. This commotion attracted other trout. I guessed they were feeding on scuds as there was no observable hatch taking place. They were feeding on some small food items. I allowed the pattern to sink. After 10 seconds I began a slow hand twist retrieve with a couple of quick 3 to 4 inch strips. My line tightened. I lifted my rod. The water erupted. I slipped my landing net beneath a beautiful 4 lb rainbow. I caught 7 good sized trout using your Scuds. Thanks.
George Ryan, Seattle

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