4.1 4.2

Taxonomic hierarchy: the classification of the species within living organisms by describing the domain kingdom, phylum, class, order, family, genus and species.

binomial nomenclature: the two part Latin name given to each species comprising the genus followed by the species.

Dichotomous key: an identification tool utilizing a series of choices between alternative characteristics, with direction to another stage in the key, until the species is identified.

Biological drawing: a scientific drawing that records an image and important features of the specimen.

Plankton: microscopic free floating marine organisms.

Zooplankton: planktonic consumers that are either floating or weakly swimming animals.

Echinoderms: a marine invertebrate group/phylum with pentaradial symmetry and tube feet.

Crustaceans: a marine invertebrate group/phylum with a hard exoskeleton, ten jointed legs and a nauplius larval stage.

Bony fish: fish that a bony skeleton and belong to the class Osteichthyes.

Cartilaginous fish: fish that have jaws and skeletons made of cartilage and belong to the class Chondrichthyes.

Macroalgae: marine producers such as kelp and seaweed.

Marine grasses: aquatic flowering plants that are often found in estuarine and coastal communities.

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

Pentaradial symmetry: five arms (or fans) radiating from a central body cavity.

Tube feet: tubular projections that assist in locomotion, feed 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 bony 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, stabilising 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 seagrass to reproduce asexually.

Leaf: photosynthetic organ of plants.

Flower: sexual reproductive organ of plants.

Cephalothorax: the fused head and thorax (chest) of crustaceans.

Emergent plant: plants that are rooted in the substrate and project above the water surface

Submergent plants: plants that are rooted in the substrate but remain beneath the waterline.

Aerenchyma: specialised tissue of "air cells" within stems which delivers air containing oxygen for aerobic respiration to all the submerged areas of the plant.

Turtle grass: Thalassia testudiunum a seagrass found in the Gulf of Mexico, Caribbean Sea and Bermuda, and is a vital food source for turtles, manatee and herbivorous fish.

Diatoms: unicellular phytoplankton having cell walls made of silica (silicon dioxide) which is a major constituent of sand.

Dinoflagellates: unicellular protoctista do not have a silica cell wall but have a flagella (whip-like structure) that allows them to swim.

Copepods: crustaceans that comprise the most abundant and diverse group of zooplankton.

Molluscs: the second largest marine invertebrate group/phylum usually wholly or partially enclosed in a calcium carbonate secreted by a soft mantle covering the body.