Stream Animals

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Stream Animals the Heterotrophic Food Chain
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Processing of Organic Matter

• In fall, leaf debris from overhanging deciduous
  trees accumulates in the stream
• Flowing water leaches the leaves soluble organic
  matter as dissolved organic matter (DOM) or fine
  particulate organic matter (FPOM)
• The leaves remain as coarse particulate organic
  matter (CPOM)

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Microbial Processing

• The remaining leaf surface is colonized by
  bacteria (on FPOM) and fungi (on CPOM)
• These microorganisms convert the cellulose and
  lignin into forms useable by invertebrates

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Invertebrate Processing1) Shredders

• The shredders feed on the leaves and their
  resident microbes, and convert the CPOM into FPOM

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Common Shredders

• Craneflies(Diptera)
• Caddisflies (Trichoptera)
• Stone-Fly Nymphs (Plecoptera)
• Crayfish

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2) Filtering and Gathering Collectors

• FPOM carried down stream is acquired by the
  Filtering and Gathering Collectors, processed,
  and turned into DOM

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Common Collectors

• Blackflies(Diptera)
• Fan and net spinning Caddisflies (Trichoptera)
• Midges

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3) Scrapers, Piercers, Gougers

• Algae and mosses coating the surface or rocks is
  processed too
• Scapers and Piercers feed on algae, while Gougers
  feed by burrowing into the trunks of fallen trees

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Common Scrapers, Piercers, Gougers

• Scrapers
• Beetle Larvae (Coleoptera)
• Mobile Caddisflies
• Snails
• Piercers
• Microcaddisflies
• Gougers
• Fly Larvae (Diptera)

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Invertebrate Predators

• All the invertebrate organisms that process the
  leaves, algae, and wood are potential food for
  invertebrate predators
• One common predator is the Hellgramite or
  Dobsonfly Larvae (Megaloptera)