A group of elongate elasmobranchs. Sharks are mostly marine fish, with certain species large and voracious.

A species of shark in the family SQUALIDAE, used for its oil (SQUALENE) and as fish meal. It also figures heavily in biological research, especially with reference to its RECTAL GLAND in studies of WATER-ELECTROLYTE BALANCE.

Sharks of the family Squalidae, also called dogfish sharks. They comprise at least eight genera and 44 species. Their LIVER is valued for its oil and its flesh is often made into fertilizer.

A compound tubular gland, located around the eyes and nasal passages in marine animals and birds, the physiology of which figures in water-electrolyte balance. The Pekin duck serves as a common research animal in salt gland studies. A rectal gland or rectal salt gland in the dogfish shark is attached at the junction of the intestine and cloaca and aids the kidneys in removing excess salts from the blood. (Storer, Usinger, Stebbins & Nybakken: General Zoology, 6th ed, p658)

A subclass of cartilaginous fish comprising the SHARKS; rays; skates (SKATES (FISH);), and sawfish. Elasmobranchs are typically predaceous, relying more on smell (the olfactory capsules are relatively large) than sight (the eyes are relatively small) for obtaining their food.

Communications using an active or passive satellite to extend the range of radio, television, or other electronic transmission by returning signals to earth from an orbiting satellite.

The common name for all members of the Rajidae family. Skates and rays are members of the same order (Rajiformes). Skates have weak electric organs.

Images used to comment on such things as contemporary events, social habits, or political trends; usually executed in a broad or abbreviated manner.

Marked developmental anomalies of a fetus or infant.

A plant genus of the family ERICACEAE known for species with edible fruits.

Poisonous animal secretions forming fluid mixtures of many different enzymes, toxins, and other substances. These substances are produced in specialized glands and secreted through specialized delivery systems (nematocysts, spines, fangs, etc.) for disabling prey or predator.

NATIONAL LIBRARY OF MEDICINE service for health professionals and consumers. It links extensive information from the National Institutes of Health and other reviewed sources of information on specific diseases and conditions.

A non-vascular form of connective tissue composed of CHONDROCYTES embedded in a matrix that includes CHONDROITIN SULFATE and various types of FIBRILLAR COLLAGEN. There are three major types: HYALINE CARTILAGE; FIBROCARTILAGE; and ELASTIC CARTILAGE.

A protective layer of firm, flexible cartilage over the articulating ends of bones. It provides a smooth surface for joint movement, protecting the ends of long bones from wear at points of contact.

Derivatives of chondroitin which have a sulfate moiety esterified to the galactosamine moiety of chondroitin. Chondroitin sulfate A, or chondroitin 4-sulfate, and chondroitin sulfate C, or chondroitin 6-sulfate, have the sulfate esterified in the 4- and 6-positions, respectively. Chondroitin sulfate B (beta heparin; DERMATAN SULFATE) is a misnomer and this compound is not a true chondroitin sulfate.

Preparations made from animal tissues or organs (ANIMAL STRUCTURES). They usually contain many components, any one of which may be pharmacologically or physiologically active. Tissue extracts may contain specific, but uncharacterized factors or proteins with specific actions.