Marine Consumers OCN 201 Biology Lecture 6

Transcription

1 Marine Consumers OCN 201 Biology Lecture 6 Goetze/Peijnenburg Consumer Types Grazers (Herbivore) Predators Parasites Scavengers Detritivores Decomposers Feeding on algae or phytoplankton, consuming the whole plant/cell or cropping the surface Kill their prey. Often refers to an animal that preys on other animals Intimate, prolonged interaction between two organisms where one feeds on the other without killing it Consume things already dead, carcasses Consume things already dead, detritus Final degraders of organic compounds

2 manatee grazing on sea grass Large Grazers Examples urchin eating kelp Trophic interactions Most primary production in the sea is by microscopic single-cell organisms Therefore, most primary consumers in the ocean are also microscopic!

3 Trophic interactions Omnivory is common Prey size, encounter rate, capture efficiency controls diet for many organisms Some organisms feed very selectively, others are non-selective filter feeders Most of the primary production is consumed by microzooplankton Flagellates (5-20 µm) Ciliates ( µm) Amoeboid Radiolaria (0.5 mm) silica skeleton Foraminifera (1 mm) calcium carbonate test Protists (protozooplankton)

4 Heterotrophic Flagellates suspension feeding active interception 1 µm 1 µm raptorial Pseudobobo tremulans Monosiga sp. Heterotrophic Flagellates suspension feeding active interception 1 µm 1 µm raptorial Pseudobobo tremulans Monosiga sp.

5 Ciliates create feeding current, locomotion and grazing are linked Ciliates create feeding current, locomotion and grazing are linked

6 Ciliates (Montagnes 2013) Amoeboid Protists Radiolarians Bernd Walz Silica or Strontium Sulfate skeleton Robert Brons

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8 Ernst Haeckel Amoeboid Protists Foraminifera Globigerinella Calcium carbonate shell/test

9 Protists No Mouth - Ingest particles mostly by phagocytosis. What do they eat? -bacteria -phytoplankton Digest particles in food vacuole inside the cell (in some cases, outside the cell) Heterotrophic Protist Phagocytosis Prey Digestive vacuoles

10 Dinoflagellate Feeding Modes Phagocytosis Peduncle Pallium Peduncle Feeding

11 Pallium Feeding Planktonic Animal Herbivores & Omnivores Crustaceans Copepods Euphausiids (Krill) Complex feeding behavior: selective particle capture, some filter feeding, omnivorous Tunicates salps larvaceans pyrosomes True filter feeders Steven Haddock Laurence Madin

12 Koehl & Strickler (1981) video Subeucalanus pileatus Selective particle feeders Gelatinous Pelagic solitary or aggregate phase Major consumers of phytoplankton Salps Pegea confoederata mucous nets. Zooids ~ 5 cm (Hamner 1974) Mucous filter net of salp Pegea confoederata Bone et al 1991

13 Pyrosomes Colonial pelagic tunicates Filter feeders known for their brilliant bioluminescence John P. Hoover John P. Hoover Pyrosomes Colonial pelagic tunicates Filter feeders known for their brilliant bioluminescence John P. Hoover John P. Hoover

14 Jellies Carnivorous Predators Copepods Arrow worms (Chaetognaths) Fish and Sharks Squid & Octopuses Parasites Leeches (Segmented sea Worms) lice = parasitic copepods, isopods Nematodes (Roundworms)

15 Scavengers Some fish, sharks, molluscs, crustaceans Decomposers Bacteria Fungi

16 Bacterial colonization & degradation of blooms How do Bacteria Eat? No Mouths - digest food outside of the cell Digest larger molecules and particles with cell-surface enzymes Take up small molecules through special channels (porins, transporters) Many are motile (they move) - flagellum They decompose all the leftover organic matter from the messy feast of the food web

17 Questions?