4.2 Key Groups of Marine Organisms Flashcards
Plankton
Microscopic free floating marine organisms
Zooplankton
Planktonic consumers that are either floating or weakly swimming animals
Echinoderms
A marine invertebrate group with pentaradial symmetry and tube feet
Crustaceans
A marine invertebrate group with a hard exoskeleton, ten jointed legs and a nauplius larval stage
Bony Fish
Fish that have a bony skeleton and belong to the class Osteichthyes
Cartilaginous Fish
Fish that have jaws and skeletons made only of cartilage and belong to class Chondrichthyes
Macroalgae
Marine producers such as kelp and seaweeds
Marine Grasses
Aquatic flowering plants that are often found in estuarine and coastal environments
Keystone Species
An organism that plays a unique and crucial role in the way an ecosystem functions; without keystone species, the ecosystem would be dramatically different or cease to exist altogether
Larvae
A planktonic stage of development which occur between the egg and juveniles; found in nearly all species of fish and invertebrates
Pentaradial Symmetry
Five arms (or fans) radiating from a central body cavity
Tube Feet
Tubular projections that assist in locomotion, feeding, and respiration
Nauplius
Distinctive larval stage of crustaceans
Carapace
The part of the exoskeleton that protects the dorsal side of the cephalothorax
Gills
The gaseous exchange surfaces of fish
Operculum
A thin body flap of skin covering and protecting the gills
Lateral line
A canal on the head and the side of the fish that contains sense organs; it is externally visible in bony fish but in cartilaginous fish it is under the skin
Scales
Overlapping segments of bone covered by skin and mucus found on the outside of the fish
Fins
Protrude from the body surface and assist in movement, stabilizing position, reproduction and protection
Swim Bladder
A buoyancy organ found in bony fish
Denticles
A type of overlapping scales that provides protection and improved hydrodynamic efficiency in sharks
Gill Slits
External openings from the gills through which water taken in at the mouth can pass back to the ocean
Holdfast
Strong, root-like structure that anchors the macroalgae to the seabed
Stipe
Long, tough, vertical stalk similar to the stem of plants
Blades
Leaf-like structures that ‘hang’ in the water and absorb light and minerals
Gas Bladder
A gas-containing structure that provides buoyancy for some species of seaweed
Root
Structure at the base of plant that anchors it to the substrate and absorbs nutrients from the sediment
Rhizomes
A horizontal underground structure that enables seagrasses to reproduce asexually
Leaf
Photosynthetic organ of plants
Flower
Sexual reproductive organ of plants
