Chapter 4: Classification and Biodiversity Vocabulary

Ocean

a continuous mass of seawater on the Earth's surface, its boundaries formed by continental land masses ridges on the ocean floor

Seas

smaller bodies of saltwater which are frequently enclosed by land; they are found where the ocean and land meets

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

a key for the identification of organisms based on a series of choices between alternative characters, with a direction to another stage in the key, until the species is identified

blades

leaf-like structures that 'hang' in the water and absorb light and minerals

bony fish

fish that have a bony skeleton and belong to the class Osteichthyes

carapace

the part of the exoskeleton that covers the cephalothorax

cartilaginous fish

fish that have jaws and skeletons made of only cartilage and belong to the class Chondrichthyes

crustaceans

a marine invertebrate group with a hard exoskeleton, ten jointed legs and a nauplius larval stage

denticles

a type of overlapping scale that provides protection and improved hydrodynamic efficiency in sharks

echinoderms

a marine invertebrate group with pentaradial symmetry and tube feet

fins

protrude from the body surface and assist in movement, stabilizing position, reproduction and protection

flower

sexual reproductive organ of plants

gas bladder

a gas-containing structure that provides buoyancy for some species of seaweed

gill slits

external openings from the gills through which water taken in at the mouth can pass back to the ocean

gills

the gaseous exchange surfaces of fish

holdfast

strong, root-like structure that anchors the macroalgae to the seabed

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 occurs between the egg and juveniles; found in nearly all species of fish and invertebrates

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

leaf

photosynthetic organ of plants

macroalgae

marine producers such as kelp and seaweeds

marine grasses

aquatic flowering plants that are often found in estuarine and coastal environments

nauplius

A distinct planktonic larval stage seen in many crustaceans.

operculum

a thin bony flap of skin covering and protecting the gills

pentaradial symmetry

five arms (or fans) radiating from a central body cavity

plankton

microscopic free floating marine organism

rhizomes

a horizontal underground structure that enable seagrasses to reproduce asexually

root

structure at base of plant that anchors it to the substrate and absorbs nutrients from the nutrients

scales

overlapping segments of bone covered by skin and mucus found on the outside of the fish

stipe

long, tough, vertical stalk similar to the stem of plants

swim bladder

a buoyancy organ found in bony fish

tube feet

tubular projections that assist in locomotion, feeding, and respiration

zooplankton

planktonic consumers that are either floating or weakly swimming animals

biodiversity

a measure of the species, genetic and ecosystem diversity of different species

ecological diversity

the variation of ecosystems or habitats on a regional or global level

genetic diversity

the variety of forms of genes (alleles) within species

species diversity

the abundance and richness of a species in a given place

ecosystems

the living organisms and the environment with which they interact

habitat

the natural environment where an organism lives

niche

the role of a species within ecosystem

species

a group of similar organisms that can interbreed naturally to produce fertile offsprings

population

all of the individuals of a species that live in the same place and time

biotic factors

the living parts of an ecosystem, which includes the organisms and their effects on each other

disease

an illness characterized by a recognizable set of signs and symptoms

intra-specifc competition

competition between individuals of the same species (for example, for food or a mate)

inter-specific competition

competition between members of different species (for example, predator-prey)

mark-release-recapture

a method to estimate the population size of mobile species

lincoln index

a mathematical equation that can use the mark-release-recapture data to estimate the population size

frame quadrat

a plastic or metal square that sets a standard unit of area for study of the distribution of marine organisms

transect

a rope or tape marked at regular intervals that sets standard distances for study of the distribution of marine organisms

line transect

a sampling method involving counting of species that touch the transect

continuous sampling

samples are taken along the whole length of the transect

systematic sampling

samples are taken at fixed intervals along the transect

belt transect

a sampling method involving counting of species ==in== frame quadrats placed adjacent to the transect

random sampling

samples are taken at random places within the sample site

ethical method

evaluates and chooses ways to protect the natural habitat under investigation

safe method

Identifies potential hazards and then reducing their risk of occurring

kite graph

A graph of the distribution and abundance of organisms in the littoral zone that allows zonation patterns to be easily seen.

richness

the number of species in a community

evenness

a measure of the relative abundance of the different species making up the richness of an area

Simpson's Diversity Index

a biodiversity measure that accounts for both species of richness and evenness

Null Hypothesis (H0)

there is no correlation between the two sets of variables

hypothesis

an explanation of an observation that can be tested through experimentation

scatter graph

when two sets of variables are plotted to indicate if there is a relationship between them

Spearman's rank correlation

a mathematical tool used to find out if there is a correlation between two sets of variables, when they are not normally distributed

critical values of rs

indicate when the calculated spearman's rank is sufficient to suggest a correlation between the two sets of variables

alternative hypothesis

there is a significant correlation between two sets of variables