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Glossary of Crustacean Terms

Muscular, segmented body part, posterior to the thorax; the edible "tail" portion of a lobster or shrimp

Number of individuals in a particular area

Segmented worm in Phylum Annelida; includes earthworms, marine worms, and leeches

Toward the head end; opposite of posterior

Elongated, movable sensory structure found on the head

Sensory structure, smaller than the antennae and located more toward the midline of the body than the antennae

Posterior opening of the digestive tract

Limb; leg, for example

Folded-under abdomen of a crab

Member of Phylum Arthropoda having a hard exoskeleton and jointed legs; includes insects, crustaceans, and arachnids

Paddle-shaped posterior leg on a swimming crab

On or associated with the bottom of a body of water

Female crab carrying eggs

Gills composed of thin plates, constructed like the pages of a book

Bycatch Reduction Device; a device installed in a net to allow the escape of non-targeted species

Blue crab that has split at the back of the carapace in preparation for molting

Non-targeted species that are caught with the targeted species

Dorsal covering of the body in many arthropods

Animal that eats only animals

"Forearm" portion of a crab claw

Body segment consisting of the head and thorax fused together

Small feeding appendage found in Chelicerates

Arthropod of Subphylum Chelicerata; includes horseshoe crabs, spiders, and scorpions

Claw of a crustacean; it is actually a modified walking leg

Polysaccharide that makes up the exoskeleton
of an arthropod

Level of scientific classification; below Phylum and above Order

Average weather of an area, usually averaged over at least 10 years

Batch of eggs extruded during a single spawning

To clot

All individuals of a species hatched or born during a certain time period

All the species within a particular area

Eye formed of multiple lens components

Large, heavy claw used for crushing hard-shelled prey

Primarily aquatic arthropod of Subphylum Crustacea; includes crabs, isopods, krill, and barnacles

Crustacean of Order Decapoda having ten legs; includes crabs, lobsters, and shrimp

Movement of individuals away from the place of birth

A measure of the number of different things; e.g., species diversity is the number of different species in an area

Deoxyribonucleic Acid; the molecule that carries the genetic code

Broadest level of scientific classification; above Kingdom

Toward the back of the body; opposite of ventral

Mating pair of crabs

To capture and pull along

Open area in the wire of a crab trap that allows escape of crabs smaller than the legal size

Semi-enclosed body of water where freshwater and saltwater meet

Change over time

External skeleton; the shell of a crustacean

Species not native to an area

To use or take advantage of

Level of scientific classification; below Order and above Genus

Organism that strains water to capture small food particles

Population of aquatic organisms that supports a commercial or recreational industry

Amount of time and equipment devoted to catching a target species

Time of the year when a species can legally be caught

Stone crab that has recently molted; if the claws are put in a pot of water they will float

Accumulation of organisms attached to an underwater object; e.g., barnacles and algae

Measure of the proportion of genetic differences between individuals, populations, or other taxonomic classes

Science dealing with heredity and variation of traits

Level of scientific classification; below Family and above Species

Organ for grinding food; usually found in animals lacking teeth or mandibles

Specific environment in which an organism lives; will include the physical space and environmental conditions

Total quantity (usually number or pounds) of an organism removed from an area over a specific amount of time

Molecule in blood that is based on copper, giving it a bluish color; found in most crustaceans, horseshoe crabs, and mollusks

Animal that eats only plants

Offspring resulting from the mating of two different species

Idea or working explanation that can be tested

When members of two populations mate and produce offspring; interbreeding of two different species will produce hybrid offspring

Associated with the area of the shore between low and high tide lines

Any animal that is not a member of Subphylum Vertebrata; an animal without a backbone

Male blue crab

Young, immature life stage

Level of scientific classification; below Domain and above Phylum

Limulus Amoebocyte Lysate; found in horseshoe crab blood, this substance clots in the presence of bacterial toxins; it is used to test for contamination

Quantity (usually pounds or numbers) of individuals brought to shore

Early life stage of some animals; this stage often looks very different than the adult

Toward the sides; opposite of medial

Only a certain number of licenses are awarded for a particular fishery

Government plan developed to ensure the sustainable harvest of a species

Mouthpart used for crushing hard prey

"Hand" portion of a crab claw

When an organism is capable of reproduction

Toward the center; opposite of lateral

Transitional stage between a crab larva and a juvenile

"Upper arm" portion of a crab claw

Movement from one area to another

Member of Phylum Mollusca having a soft body and usually a shell; includes clams, snails, and octopuses

To shed an exoskeleton; this process is necessary to allow for growth

Rate at which organisms are removed from the population; death rate

Sudden change in the genetic material that can be inherited by offspring

Active at night

Individuals produced from a mating

Single lens component of a compound eye

Animal that eats both plants and animals

Hard cover protecting gills

Level of scientific classification; below Class and above Family

When harvesting of a population exceeds the population's ability to replenish itself

Bearing eggs; i.e., a crab carrying eggs is considered ovigerous

Organism that lives on and harms another organism

Blue crab in the process of molting

Shrimp of Family Penaeidae; includes pink, brown, and white shrimp

Sensory structure that detects changes in light levels

A measure of the level of acidity of a solution

Level of scientific classification; below Kingdom and above Class

Thin, tapered claw used for tearing

Blue crab that is 3-6 days from molting

Organisms that cannot swim or are very weak swimmers and are at the mercy of the currents

All individuals of a species found in a specific area

Crab of Family Portunidae; includes blue crabs and pass crabs

Toward the tail end; opposite of anterior

Animal that captures its prey live

Immovable component of the pinching part of a claw

Posterior leg in horseshoe crabs; it is fringed and used for crawling on land

Blue crab that is 1-3 days from molting

Entry of individuals into a particular population, life stage, age, or size category; e.g., recruitment into the stone crab fishery occurs when crabs reach legal size

To regrow a body part that has been lost; crabs can regenerate lost claws

When two populations are incapable of interbreeding due to physical, temporal, or biological barriers

Saltiness of the water; usually measured in parts per thousand (o/oo)

Immature female blue crab

Animal that feeds on dead organisms or organic matter

Number of males versus females in a population

Crab that has recently molted and has not yet hardened its new exoskeleton

Mature female blue crab

To release sperm and eggs

Most specific level of scientific classification; below Genus

Egg mass (in crustacean biology)

A population of individuals that are managed as a single unit within a fishery

Year-to-year, the number or weight of animals that can be harvested without reducing the stock

Appendage on the abdomen; in crustaceans, females attach eggs to their swimmerets

Classification and naming of organisms

Turtle Excluder Device; device designed to allow turtles to escape from nets

Tail portion of a crustacean

Final molt, usually at maturity, after which the animal no longer molts

Hypothesis that has substantial evidence to support it

Central body part to which the walking legs are attached

Poisonous substance produced by a living organism

Any factor that can change

Toward the front of the body; opposite of dorsal

Blue crab that is 1-2 weeks from molting

All individuals of a population spawned and hatched during a year; a generation or cohort

Crab larva