Which one of the following is a filter feeder?
Contents14
- ACatfish
- BOctopus
- COyster
- DPelican
Show answer
Answer: (C) Oyster
A filter feeder is an animal that obtains food by filtering tiny organisms or organic particles from water flowing through its body.
Oysters are classic filter feeders — they pump water through their gills, trapping food particles, nutrients, and suspended sediments.
A single oyster can filter up to 50 gallons of water per day.
Catfish are bottom feeders that actively scavenge.
Octopus is a predator that hunts prey.
Pelicans scoop fish with their beaks.
Answer: (c).
Filter feeders like oysters can process enormous volumes of water daily - a single oyster filters up to 50 gallons per day, making them crucial for water purification in marine ecosystems.
The question tests whether students can distinguish between different feeding strategies - filter feeding (passive water filtration), bottom feeding (active scavenging), predation (hunting), and surface feeding (scooping).
Filter Feeders
Environment filter feeder Oyster
Filter Feeders: Mechanism & Examples
Filter feeders extract food by filtering water through specialized body parts
Oysters can filter up to 50 gallons of water per day
Filter feeding removes plankton, organic particles, and suspended matter from water
Definition
Filter feeders are organisms that obtain food by straining tiny particles, organisms, or nutrients from water flowing through specialized body structures. This feeding strategy is common in aquatic environments where microscopic food sources are abundant.
Filter Feeders vs Other Feeding Types
Feeding Type | Method | Example | Food Source |
|---|---|---|---|
Filter Feeder | Strain particles from water | Oyster, Clam, Whale | Plankton, organic particles |
Bottom Feeder | Scavenge from substrate | Catfish, Crab | Detritus, dead organisms |
Predator | Hunt and capture prey | Octopus, Shark | Fish, other animals |
Surface Feeder | Capture prey from surface | Pelican, Duck | Fish, insects |
How Filter Feeding Works
Water is pumped through gills or specialized filtering structures
Cilia (tiny hair-like structures) create water currents and trap particles
Food particles stick to mucus lining the filtering organs
Clean water is expelled while nutrients are absorbed
Process also removes bacteria and sediments from water
Question Analysis
This question tested knowledge of feeding strategies in aquatic organisms. Oyster was the correct answer because it actively filters water through its gills to extract plankton and organic matter.
Catfish seems aquatic but is a bottom feeder, not a filter feeder
Pelican catches fish by scooping, not by filtering water
Octopus is an active predator that hunts prey, not a passive filter feeder
Don't confuse filter feeding with simply living in water
Aquatic Feeding Strategies
Environment Catfish Octopus Pelican
Major Feeding Strategies in Aquatic Ecosystems
Different aquatic organisms use specialized feeding strategies based on their anatomy
Bottom feeders like catfish scavenge from sediments
Active predators like octopus hunt live prey using intelligence and tools
Surface feeders like pelicans capture prey from water surface
Feeding Strategy Classification
Aquatic organisms have evolved diverse feeding mechanisms based on their habitat, anatomy, and available food sources. Each strategy represents an ecological niche that reduces competition.
Aquatic Feeding Strategies Detailed
Strategy | Organism Example | Body Adaptations | Food Type | Habitat |
|---|---|---|---|---|
Filter Feeding | Oyster, Mussel | Gills with cilia | Plankton, particles | Attached to substrate |
Bottom Feeding | Catfish, Carp | Whiskers, downward mouth | Detritus, worms | River/lake bottom |
Active Predation | Octopus, Squid | Tentacles, beak, intelligence | Fish, crustaceans | Open water, reefs |
Surface Feeding | Pelican, Kingfisher | Large beak/pouch | Fish, aquatic animals | Water surface |
Grazing | Manatee, some fish | Flat teeth, lips | Aquatic plants | Shallow waters |
Ecological Significance
Filter feeders improve water quality by removing suspended particles
Bottom feeders recycle nutrients from sediments back into water column
Predators control population of prey species, maintaining balance
Each strategy occupies different trophic levels in food webs
Catfish has 'fish' in name but feeds differently from surface-hunting fish
Pelican is aquatic but is a bird, not a marine organism
Don't assume all aquatic animals are filter feeders - most are predators or scavengers
Oyster Ecology & Water Filtration
Environment Oyster
Oysters: Ecological Role & Commercial Importance
Single oyster filters up to 50 gallons of water daily
Oysters are bivalve mollusks with two hinged shells
They form reef ecosystems that support other marine life
Oyster farming helps restore degraded coastal waters
Anatomy & Function
Oysters belong to bivalve mollusks - organisms with two hinged shells. They remain attached to hard surfaces and pump water through their gills using coordinated cilia movement.
Oyster Filter Feeding Process
%%{init: {"flowchart": {"wrappingWidth": 460}}}%%
flowchart TD
s1["`**Water Entry**
Water enters through **incurrent siphon**`"]
s2["`**Gill Filtration**
**Cilia** on gills create currents and trap particles`"]
s3["`**Mucus Coating**
Food particles stick to **mucus** on gill surface`"]
s4["`**Nutrient Transport**
Cilia move food-laden mucus to **mouth**`"]
s5["`**Water Expulsion**
Clean water exits through **excurrent siphon**`"]
s1 --> s2
s2 --> s3
s3 --> s4
s4 --> s5Environmental Benefits
Remove excess nitrogen and phosphorus that cause algal blooms
Increase water clarity by filtering suspended sediments
Oyster reefs provide habitat for fish and crabs
Coastal protection - reefs reduce wave energy and erosion
Commercial & Ecological Value
Oyster farming (aquaculture) serves dual purposes - food production and water quality improvement. Many coastal restoration projects use oyster reefs to combat eutrophication and habitat loss.
Don't confuse oysters (bivalves) with sea anemones (cnidarians)
50 gallons per day is for one adult oyster - remember this specific number
Oysters are sessile (attached) - they don't swim like fish