Department of Commerce National Oceanic and Atmospheric Administration Department of Commerce
National Oceanic and Atmospheric Administration

Glossary of Terminology: J

The glossary is organized alphabetically by page -- A through Z. Literature sources are listed on the References Page.

The entire glossary is also provided as a PDF document (13 MB). The document includes all terms, photographs, images, and literature sources.

Click here to search the Glossary of Terminology by keyword(s).

Glossary Pages

A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Number of records found : 16

J curve - a J-shaped growth curve that depicts exponential growth

JabRef - an open source bibliography reference manager; a reference management software that uses BibTeX as its native format. JabRef provides an easy-to-use interface for editing BibTeX files, for importing data from online scientific databases, and for managing and searching BibTeX files

Jack - any species of bony fishes in the family Carangidae (which also includes the pompanos). Jacks are cosmopolitan in warm and temperate marine waters, some even venturing into brackish and fresh water. As a group, they are swift and strong predators. Typical

Java - a programming language created by Sun Microsystems which allows the user to create programs which run well in a networked environment (such as the World Wide Web). Java programs are commonly called "applets" and can be used to add anything from calculators to animated images to web sites

jetsam - objects that have been thrown overboard in order to lighten a ship when it is in trouble

Image of a jetty

A jetty protecting the shore line. (Photo: NOAA)

jetty - a structure extending into the ocean to influence the current or tide in order to protect harbors, shores, and banks

joint probability - the probability of two or more things occurring together

Jordan's Rule - In general, closely related species do not have identical ranges, but often their ranges are not very far apart. They are usually adjacent but separated by some kind of a geographic barrier, such as a mountain, desert, or river. A second Jordan's Rule is: fishes develop more vertebrae in cold environments than in warm ones

JPEG (Joint Photographic Experts Group) - the original name of the committee that wrote the standard. It is a lossy compression technique for color images. Although it can reduce files sizes to about 5% of their normal size, some detail is lost in the compression

jugostegalia - a basket-like structure formed midventrally by overlapping branchiostegals in some families of eels

Image of blenny

Blennies have their pelvic fins in the jugular position, anterior to the pectoral fins. (Photo: South Florida Water Management District)

jugular - pertaining to the throat area

junior homonym - in taxonomy, the younger, or most recently established taxonomic name

junior synonym - in taxonomy, the younger name of two synonyms

junk DNA - a term used to describe the excess DNA which is present in the genome beyond that required to encode proteins. The term is misleading since these regions are likely to be involved in gene regulation, and other not yet known functions; a non-coding sequence of DNA; an intron

juvenile - a young animal that has not reached sexual maturity

juxtaposed - placed near together