pharyngeal slit

(noun)

filter-feeding organs found in non-vertebrate chordates (lancelets and tunicates) and hemichordates living in aquatic environments

Related Terms

Examples of pharyngeal slit in the following topics:

  • Characteristics of Chordata

    • Animals in the phylum Chordata share four key features: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
    • Some invertebrate chordates use the pharyngeal slits to filter food out of the water that enters the mouth.
    • In vertebrate fishes, the pharyngeal slits develop into gill arches, the bony or cartilaginous gill supports.
    • In most terrestrial animals, including mammals and birds, pharyngeal slits are present only during embryonic development.
    • In these animals, the pharyngeal slits develop into the jaw and inner ear bones.

  • Chordates and the Evolution of Vertebrates

    • Adults only maintain pharyngeal slits and lack a notochord, a dorsal hollow nerve cord, and a post-anal tail.
    • Suspended material is filtered out of this water by a mucous net (pharyngeal slits) and is passed into the intestine via the action of cilia.
    • Members of Cephalochordata possess a notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail in the adult stage.
    • Adult lancelets retain the four key features of chordates: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
    • Water from the mouth enters the pharyngeal slits, which filter out food particles.

  • Phylum Chordata

    • Pharyngeal slits, which allow water that enters through the mouth to exit without continuing through the entire digestive tract.

  • Characteristics of Vertebrates

    • As chordates, all vertebrates have a similar anatomy and morphology with the same qualifying characteristics: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.

  • Class Anthozoa

    • They have slit-like mouth openings and a pharynx, which is the muscular part of the digestive system that serves to ingest as well as egest food.
    • Mesenteries do not divide the gastrovascular cavity completely; the smaller cavities coalesce at the pharyngeal opening.

  • Evidence of Evolution

    • For example, all vertebrate embryos, including humans, exhibit gill slits and tails at some point in their early development.

  • Chromalveolata: Stramenopiles

    • Some diatoms exhibit a slit in their silica shell called a raphe.

  • Gnathostomes: Jawed Fishes

    • They can be distinguished from sharks by their flattened bodies, pectoral fins that are enlarged and fused to the head, and gill slits on their ventral surface.