Download glossary - The Shark Trust

GLOSSARY
Adaptations
Modifications which have evolved to make an animal or plant more successful in their environment.
Algae
Algae is chiefly aquatic but can occur terrestrially, it can vary in size from being of single-celled form to giant kelp
forests. Algae were once considered to be plants but are now classified separately because they lack true roots,
stems, leaves, and embryos.
Amphibian
The word amphibians translates as "double life". Amphibian are vertebrate animals that live in the water during
their early life (by breathing through gills), but usually live on land as adults (and breathe with lungs). This taxon
includes frogs, toads, newts and salamanders.
Anal fin
Anal fins are paired fins near the tail end of fish (including sharks). This fin is used to stabilise the fish whilst
swimming.
Apex Predator
Apex predators are at the top of the food chain and as adults are not normally preyed upon by other species.
Great White Sharks are apex predators.
Barbels
Long fleshy lobes on the snouts of sharks which are used to locate prey.
Bird
Birds are warm-blooded vertebrate animals that have wings, feathers, a beak, no teeth and a skeleton in which
many bones are fused together. Most (but not all) birds can fly.
Bottom dwellers
Bottom dwellers are organisms that live in or on the bottom of a body of water.
Bones
Bones are dense, calcified connective tissues that form the major portion of the skeleton of most vertebrates.
Breaching
Some sharks leap clear of the water and this is called breaching. There are many theories surrounding why they
do this (for display, to remove parasites, method of feeding) but it still remains unclear.
Bycatch
Species that are not targeted as catch, but are caught along with a target species during fishing are known as
bycatch. They are accidentally caught in the process of fishing.
Calcium
A mineral essential for strengthening bones and teeth.
Camouflage
An animal's disguise, usually through colour, that enables it to blend in with its surroundings.
Carnivore
A carnivore is an animal with a diet consisting mainly of meat.
Cartilage
Sharks' skeletons are made out of cartilage. This is a light-weight rubbery material which actually helps keep the
shark afloat. Human ears and bones are also made of cartilage and it surrounds the joints of animals with bony
skeletons.
Cartilaginous Fish
Cartilaginous fish, are fish whose skeletons are made up of cartilage, not bone. They include sharks, skates and
rays.
Caudal fin
The caudal fin is the tail of a fish.
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Consumer
A consumer is a living organism that eats other living organisms in order to survive. Primary consumers eat
producers, secondary consumers eat primary consumers, and so on.
Conservation
The protection, management, or restoration of wildlife and of natural resources, such as forests and oceans.
Conservation aims to preserve the Earth’s biological diversity.
Contamination
The presence of environmental chemicals, radioactive elements or organisms can contaminate food or water
sources and make it impure and unfit for consumption or inhabiting.
Crustaceans
Crustaceans are mostly marine animals (invertebrates) that have an exoskeleton and jointed legs. They are
arthropods. Copepods, barnacles, amphipods, isopods, lobsters, crabs, shrimp, and crayfish are crustaceans.
Destruction
Destruction is the process of ruining the structure, organic existence or condition of a thing. Habitat destruction in
particular involves a change in land-use, where one habitat is removed and replaced with another type. Due to
this process, plants and animals are often displaced or destroyed.
Diatom
A microscopic algae, usually unicellular – there are more than 10 000 species!
Distribution
Distribution refers to how something (e.g. a species) is spread out across an area.
Diversity
The variety of different shark and ray species.
Dorsal fin
Dorsal fins are located on the back of a fish. They can have up to three of them and they function to protect the
fish against rolling and assist them in sudden turns and stops.
Endangered
An endangered species is a species which is dwindling in numbers and may become extinct.
Endoskeleton
An internal supporting skeleton, characteristic of vertebrates.
Exoskeleton
A hard outer structure that provides protection or support for an organisms such as insects, arachnids and
crustaceans.
Extinct
If an animal species has become extinct, then it has died out completely
Filter feeders
Filter feeders are animals that eat by sieving through lots of sea water and straining out tiny bits of nourishment,
such as plankton. The Whale shark, Basking shark, and Megamouth shark are all filter feeders.
Fish
Fish are scaly, cold-blooded animals with fins that get their oxygen from the water using gills.
Food Web
A food chain is the sequence of who etas whom in a biological community (an ecosystem) to obtain nutrition. A
food web is all of the interactions between predators and prey in which plants and animals obtain food in an
ecosystem. The chain starts with plants or other autotrophs (organisms that make their own food from light
and/or chemical energy) that are eaten by herbivores (plant eaters). The herbivores are eaten by carnivores
(meat eaters). These are eaten by other carnivores. When any organism dies, it is eaten by tiny microbes
(detritivores) and the exchange of energy continues.
Gestation
The carrying of an embryo or foetus inside a female animal. The gestation period for a human is 9 months.
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Gillrakers
Sieve-like structures branching from the gills which trap microscopic plankton from the water.
Gills
As a shark breathes, oxygen-rich water enters its mouth. The water passes over the gills and respiration takes
place: oxygen in the water is exchanged for carbon dioxide in the blood. The now oxygen-depleted water exits
through the gill slits.
Gill slits
These are the slit-like openings behind a shark's head. Most sharks have five pairs of gill slits, but some have six
or seven pairs.
Habitat
A habitat is the natural environment where an organism lives. A number of different habitats exist on land and in
the sea.
Herbivore
An animal that primarily eats plant matter
Hydrodynamic
A shape designed to move efficiently through the water.
Hydrostatic skeleton
A hydrostatic skeleton is a structure found in many soft-bodied animals. They have a fluid filled cavity surrounded
by muscles, this helps to change an organism’s shape and also produce movement. Starfish, jellyfish and
earthworms all possesss hydrostatic skeletons.
Ingest
Food is taken into the mouth as food for digestion or absorption.
Interdependence
Organisms are mutually dependent; therefore they depend upon each other.
Invertebrate
Invertebrates are animals without a backbone. The term includes insects, worms, jellyfish, sponges, octopus,
snails, clams, oysters, scallops, and many others.
Joint
In an endoskeleton, a joint is a connecting point between two or more bones allowing motion. Joints are also
present in an exoskeleton of an invertebrate, these joints also connect inflexible parts of the body, allowing them
to move.
Juvenile
A juvenile animal is one that has been weaned from its mother so no longer requires milk from them, but is not
yet mature enough to reproduce their own young.
Lungs
Lungs are organs that many animals use to breathe air. Cetaceans (whales, porpoises, and dolphins) have lungs.
Sharks do not have lungs.
Mammal
Mammals are warm-blooded animals with hair that nourish their young with milk.
Mermaid’s Purses
The name given to the eggcases of sharks and skates once the baby has hatched and the eggcase washes up on
the beach
Microscopic
Too small to be seen by the unaided eye but large enough to be studied under a microscope.
Migrate
Periodic movement to and from a given area, usually along a well defined route.
Omnivore
Omnivores are animals that eat both animals and plants.
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Organism
An organism is an individual form of life, such as a plant or animal. The body is made up of organs and organelles
which all function together to carry out the processes of life.
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any
body of water from a pond to the oceans.
Oviparity
Laying eggs instead of giving birth to live young.
Ovoviviparity
Giving birth to live young which have developed from eggs that hatched within the mother's body.
Oxygen
An element essential for plant and animal respiration.
Pectoral fin
The paired pectoral fins aid fish in swimming and are wide, flat limbs situated either side of marine mammals and
fish.
Pelvic fin
Pelvic fins are located below the pectoral fins.
Plankton
Aquatic organisms that drift with water movements. Phytoplankton (plants) consist mainly of diatoms which carry
out photosynthesis and for the basis of aquatic food chains. Zooplankton (animals) feed on the diatoms. They
consist of single celled organisms, small crustaceans and the larval stages of many larger animals.
Pollution
Pollution refers to the introduction of substances into the environment, resulting in damaging nature and living
ecosystems.
Predator
An animal that hunts, kills, and eats other animals. A shark is a well-adapted predator.
Producer
A producer is an organism that makes its own food from light energy (using photosynthesis), or chemical energy
(using chemosynthesis). Most green plants are producers and make up the the base of the food chain.
Prey
Prey are animals attacked and eaten by other animals
Recycle
Re-using an old item to make a new one.
Reproduction
Reproduction is the biological process by which new organisms are produced. It is an important process for all
living organisms as each individual exists as the result of reproduction.
Reptile
Reptiles are a group of animals that have scales, breathe air, are cold-blooded, and usually lay egg. Lizards,
snakes and turtles are all reptiles.
Rib cage
The enclosing structure formed by the ribs and the bones to which they are attached. The rib cage protects vital
organs such as the heart.
Seaweed
Seaweed is a type of algae that is present in the sea.
Senses
The means through which animals feel and perceive.
Skull
The skull is the bony structure that serves as the general framework for the head of animals and protects the
brain.
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Species
A species is a group of closely related organisms that can reproduce. A group of similar species forms a genus. In
the scientific name of an organism, the second name is its species (for example, people are Homo sapiens - our
species is sapiens)
Spiracles
The spiracle is a special gill slit found in some sharks. It is located just behind the eyes and supplies oxygen
directly to the eyes and brain.
Streamlined
Streamlined means having a contoured shape that minimizes resistance to currents of water (or air). Many sharks
have a streamlined shape. This type of shape lets these sharks swim quickly through the water.
Toxic
Toxic substances are capable of causing injury or death.
Vertebrae
The backbone consists of ring-like bones (vertebrae) that protect the soft spinal cord.
Vertebrate
A vertebrate is an animal with a backbone. Vertebrates include amphibians, reptiles, birds and mammals, sharks
are also vertebrates.
Viviparous
Giving birth to live young which have developed inside the mother by means of a plancenta and umbilical cord.
Vulnerable
An organism or environment is vulnerable if it is exposed to danger. If a species is classed as being vulnerable
then it is threatened with extinction unless action is taken to prevent this process.
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