Scuds & Freshwater Shrimp

A year-round, high-value food — and a productivity tell. Shrimp need calcium-rich water for their shells, so they aren't in every lake; the lakes that do hold good populations grow big, well-conditioned trout.

Hatch timing / abundance

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Available all year gofishbc articles 2026 06.

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Require high calcium levels (chitinous exoskeleton) — absent from low-calcium lakes; present-and-abundant = a big-fish lake gofishbc articles 2026 06.

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A staple of the summer trout diet alongside leeches and dragonfly nymphs gofishbc articles 2026 06.

Imitated by

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Scud/shrimp patterns (olive, tan, pink, UV) fished slow near weed/structure; hares ear nymph also passes.

Found in (waterbodies)

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Productive Kootenay stillwaters (e.g. rosebud lake in fall); confirm per lake. #open

Data & occurrence sources

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Amphipods (scuds) are picked up in CABIN benthic samples, and the water-chemistry that comes with CABIN/BC EMS/ECCC monitoring can flag the calcium-rich lakes they favour; add occurrence records via GBIF and iNaturalist. Access, licences and the FWA-segment join method are in aquatic invertebrate and river health data sources 2026 07.

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hot weather stillwater — part of the summer diet.

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water boatman — another sub-surface invertebrate.

Sources

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Go Fish BC articles — availability, calcium link, productivity.