Search results
Results from the WOW.Com Content Network
An operculum is an anatomical feature, a stiff structure resembling a lid or a small door that opens and closes, and thus controls contact between the outside world and an internal part of an animal. Examples include:
Shell of marine snail Lunella torquata with the calcareous operculum in place Gastropod shell of the freshwater snail Viviparus contectus with corneous operculum in place. The operculum (Latin for 'cover, covering'; pl. opercula or operculums) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also ...
For example, fresh water threespine sticklebacks form a less dense and smaller opercular series in relation to marine threespine sticklebacks. The marine threespine stickleback exhibits a larger and thicker opercular series. This provides evidence that there was an evolutionary change in the operculum bone.
Operculum (fish), a flap covering the gills of bony fish; Operculum (gastropod), a sort of trapdoor used to close the aperture of some snails; Operculum papillare, the iris found in the eyes of elasmobranchs (skates, sharks, and rays) The anterior end of the puparium in some insects, through which the adult emerges; for example the wasp ...
A bony flap that covers the gills; another name for the operculum. gill filaments A series of projections along the posterior edge of the gill arch, the site of gas exchange. gill membranes Membranes covering the gill openings, attached to the branchiostegals. gill opening The opening behind each operculum, leading to the gills. gill rakers
The rock dove's operculum is a mass at the base of the bill. The nares of some birds are covered by an operculum (plural opercula), a membraneous, horny or cartilaginous flap. [5] (p117) [47] In diving birds, the operculum keeps water out of the nasal cavity; [5] (p117) when the birds dive, the impact force of the water closes the operculum. [48]
In contrast, bony fishes have a single outer bony gill covering called an operculum. Most sharks and rays have five pairs of gill slits, but a few species have 6 or 7 pairs. Shark gill slits lie in a row behind the head. The anterior edge of a gill slit is motile, moving outward to allow water to exit, but closing to prevent reverse flow.
The operculum consists of a long, thick stalk with a cartilaginous, cone-shaped plug at the distal end. [25] This plug can be used to seal the opening of the tube after the animal has retreated inside. The operculum, which is usually red in color, secretes a mucus which seems to possess antibiotic properties. It is not unusual for the animal to ...