Range : The natural distribution of a species, including
migratory pathways and seasonal haunts.
Recurved : Curved or bent backward.
Resident : Stays in one area all year round.
Rooster Tail : Forward-angled spray of water formed when certain small cetaceans surface at high speed.
Rorqual : A baleen whale of the genus Balaenoptera (some experts include the Humpback Whale in this category)
Rostrum : In cetaceans, a forward extension of the upper jaw. Adj. rostral.
Saddle or Saddle Patch : A blotch or patch of pigment that
extends across the midline of the back and onto the sides.
Sargassum : A free-floating brown seaweed that occurs in warm marine environments.
School : A co-ordinated group of cetaceans (term is most often used when referring to dolphins).
Serrated : Saw-toothed or jagged.
Snout : The part of the head extending from the front margin of the eye to the anterior tip of the head.
Sonar : The system used by many cetaceans to echolocate (echolocation).
Sounding dive : A deep (and usually longer) dive after a series of shallow dives.
Species : A group of similiar animals, reproductively isolated from all other such groups and able to breed and produce viable offspring.
Spiracle : An uncommonly used name for the blowhole.
Spout : A visible cloud expelled by a cetacean during exhalation at the water surface; also called the blow.
Spyhopping : Raising the head vertically out of the water, then sinking below the water without a splash. Used to check an area for hazards.
Stranding : The act of a cetacean coming onto land, either alive or dead.
Striations : Narrow, parallel grooves or lines.
Stripe : A thin horizontal line or area of pigment.
Subspecies : A recognisable sub-population of a species.
Tail-breaching : The act of throwing the rear portion of
the body out of the water amd slapping it sideways onto the surface.
Tail Stock : In cetaceans, the tapered rear part of the body, just in front of the flukes.
Temperate : Mid-latitute regions between the tropics and polar circles, with a mild, seasonally-changing climate; cold temperate regions are nearer the poles, warm temperate, near the equator.
Terete : Slightly tapering at both ends.
Terminal : Located at the tip of the snout; describing the position of the mouth.
Throat grooves : Grooves on the throat present in some whales.
Toothed whale : A suborder of whales, dolphins and porpoises with teeth, members of the Odontoceti suborder.
Transient : Always on the move rather than mostly in one area (term applies mostly to Orcas)
Transverse : Situated or lying across; crosswise.
Tropical : Pertaining to the low latitudes of the world between the tropics of Cancer and Capricorn.
Truncate : Having the edge vertical and straight.
Tubercles : Circular bumps along the flippers, dorsal fins or heads of some cetaceans.