What do the gill lamellae do sharks?
…of each filament constituting the gill lamellae draws a water current through the gill, which provides oxygen, but more importantly now sieves food from this current and transfers such material along tracts in the gill axes or their ventral margins (bound in mucus) toward the labial palps.
What is the function of the gill slits on a dogfish shark?
Five vertices slits that allows water to exit the mouth after passing over the gills. Small openings behind the eyes that allows water to pass through the gills even when the sharks mouth is closed.
What is the function of gill arch?
Branchial arch, also called Visceral Arch, or Gill Arch, one of the bony or cartilaginous curved bars on either side of the pharynx (throat) that support the gills of fishes and amphibians; also, a corresponding rudimentary ridge in the embryo of higher vertebrates, which in some species may form real but transitory …
What are gill filaments and lamellae?
Gill filaments are the red, fleshy part of the gills; they take oxygen into the blood. Each filament has thousands of fine branches (lamellae) that are exposed to the water. Some fish species absorb a large part of their necessary oxygen through the skin, particularly when they’re juveniles.
Where are the gill lamellae located in a dogfish shark?
The gill lamellae are radially folded, highly vascularized tissue attached to the surface of a tough connective tissue, the interbranchial septum. Each septum is attached medially to a portion of the cartilaginous gill arch. The superficial constrictor muscles act as flap-like valves to open and close the external gill slits.
How are the gill slits in a dogfish shark supported?
The gill slits are supported by cartilaginous gill arches and guarded by small cartilaginous papillae-like gill rakers which act as strainers to prevent food particles from leaving the pharynx through the gill slits. The partitions between gill pouches are referred as branchial bars.
Where are the demibranchs located on a dogfish shark?
The demibranchs on the anterior and posterior surface of a single branchial bar are termed a holobranch, or complete gill. Thus, one holobranch belongs to two different gill pouches; the anterior half (demibranch) to the anterior gill pouch, the posterior gill demibranch to the posterior gill pouch.
Where does the blood come from in a dogfish shark?
The gills are provided with a rich blood supply. Arteries run directly from the nearby heart to the gills, bringing deoxygenated blood into the gill lamellae. Oxygen diffuses from the ventilating water current flowing over the gills into the blood.
