Glossary

GLOSSARY of terms

This glossary is a quick guide to some terms you may see when browsing the site and shop. 

ampullae of Lorenzini
Tiny, jelly-filled sensors in the head of sharks and rays that are used to detect electrical signals from other animals or objects in the water. The ampullae of Lorenzini can also pick up changes in the temperature or salinity of the water. 

anal fin
A single fin underneath the body between the pelvic fins and caudal fin of some sharks. 

barbel
A long, thin strip of flesh near the mouth of some fish (including some sharks and catfish), which are used to feel around in substrate for food. 

biofluorescence
When an organism absorbs low wavelength light (blue) and emits high wavelength light (usually red, orange, or green) that makes it glow.

bioluminescence
The production and emission of light by a living organism due to specific biochemical reactions. 

cartilage
A firm, lightweight, flexible, but very strong connective tissue. Sharks and ray skeletons are made of this material, rather than bone like other vertebrates. 

caudal fin
The fin on the end of the tail in fish. In sharks, the caudal fin as two lobes. 

claspers
A pair of extensions to a male shark's pelvic fins, which are used to transfer sperm to a female.

countershading
A protective coloring strategy in marine animals. A lighter belly color helps hide the animal against a lighter sky when seen from below, and a darker dorsal side helps hide against the dark ocean when seen from above. 

dentin
Calcified tissue

dermal denticles
Tiny "scales" that cover the skin of elasmobranchs. Although similar to scales, they are actually modified teeth. 

dorsal fin
A large, triangular fin on the back of ocean animals (fish, whales, etc) which helps keep them balanced while swimming.

dorsal spine
Some sharks have a spine on the front side of their dorsal fins. It is used as protection from when a larger animal tries to eat the shark and, in some species, it is capable of secreting venom. 

elasmobranch
A subclass of cartilaginous fish that includes sharks, rays, skates, and sawfish. 

endotherm
An animal that is capable of the internal generation of heat; warm-blooded

extant 
An organism with species that are alive in the modern era. 

extinct 
A organism species, or family, that has no living members. 

gills
Breathing organs used by fish to extract oxygen from the water. 

gill slit
Long, narrow openings where water exits the body after flowing through the mouth and over the gills.

keel
A narrow ridge near the tail that potentially helps an animal twist and turn quicker while swimming.

lateral line
A pair of sensory tubes that run along the sides of a fish's body, under the skin. The lateral line detects ripples, currents, and other water movements, including those made by prey. 

nictitating membrane
Thin, lid-like layers of skin that can be drawn across the eye for protection. 

oviparous
A form of producing young by means of laying eggs that are hatched outside of the parent. 

ovoviparous
A form of reproduction where each embryo develops within an independent egg and feeds off of an independent yolk inside of the mother's body. 

pectoral fins
A pair of fins at the front of the body just behind a fish/shark's head, helping to control the direction of movement during locomotion.

pelvic fins
A pair of fins located on the underside/ventral side of a shark's body, behind the pectoral fins and just in front of the anal fin. 

pelagic zone
The upper layer of the open ocean - being neither close to the bottom nor near the shore line. 

rostrum
A long, stiff snout of an organism

spiracle
An external respiratory opening that allow sharks and rays to take in water containing oxygen without opening their mouth. 

viviparous
A form of producing offspring where live young have developed inside the body of the parent, leading to a live birth.