CRUSTACEANS

YABBIES

Large populations of dark olive Yabbies of the Cherax Genus have developed in both Lake Jindabyne and lake Eucumbene and many anglers suggest that the Yabby has been responsible for changing the feeding habits of trout in the lakes as the populations of Yabbies have increased. Yabbies live around the margins of the lake with the preferred habitat being muddy banks and shallows. They live in holes that they borrow into the banks and shallows and move from hole to hole as the water levels change. Whilst they are sometimes active during daylight hours it is the dusk to dawn that they prefer. They move out of their holes to relocate, to forage for food and to find mates. All of these activities make them vulnerable to trout. Juvenile Yabbies are available from February and trout targets yabbies of all sizes.

SHRIMP

You only have to run a fine mesh net through a weed bank in either lake Jindabyne or Lake Eucumbene to determine that both hold large populations of Shrimp.

SNAILS

Water snails are often found in still water and Lake Jindabyne and Lake Eucumbene are no exceptions. They are found shallow water generally in the proximity of weed and drowned vegetation. Trout readily eats them and a snail representation is a particularly good choice when polaroiding fish working in those sorts of habitats. Mature snails range in sizes up to 10mm but 5mm is the size most often encountered. Colours are typically olive to brown and the single foot of the snail is generally darker then the shell.

SCUD

Scud are Crustaceans of the order Amphipod. They are available in large numbers in both Lake Jindabyne and Lake Eucumbene. Scuds have a curved body and are shrimp like in nature with colours ranging from light olive through to dark olive. They are found in large numbers in and around weed beds and along flooded margins of the lake.

DAPHNIA

 Whilst not of significance individually to fly fishers Daphnia are certainly a common and substantial food source for trout particularly rainbows.

They are Crustaceans of the sub-order Cladocera (Water Fleas). Individually Daphnia are less than 0.5mm in size and colours range from pale green to dark olive. They are communal  in nature and are often described as clouds of Daphnia. It is this communal nature that puts Daphnia on the trout's shopping list. They are high in nourishment and when the clouds are dense the trout can literally swim through the cloud gulping down hundreds at a time and getting a feed. These clouds are mostly found at depths of from 20 to 70 feet in thermo-clines or layers of water trapped between the warmer surface layer and the much colder deep water. When the weather cools down however and the Epilimnion or surface layer thins out, particularly in the evenings, the Daphnia can rise right to the surface. Tell tails signs of the presence of Daphnia are the presence of a green granular slime in the stomach contents of fish, clouds showing up on sounders, or as the water cools down, active surface feeding when there is clearly no hatch.