Chordata and Taxonomy Characteristics

These flashcards encompass key vocabulary and concepts related to the traits and characteristics defining the phylum Chordata and its classifications.

Notochord

A protein rod that runs the length of an animal's body, providing support for the developing embryo, larva, and some adults.

Dorsal hollow nerve cord

The nerve cord of a chordata embryo located on their dorsal side, which develops into the central nervous system (brain and spinal cord).

Pharyngeal clefts

Slits that develop into openings leading to the outside of the body, functioning differently in invertebrates, aquatic, and terrestrial chordates.

Muscular post-anal tail

A tail with muscle that aids in movement and balance in terrestrial chordates and helps with swimming in aquatic chordates.

Urochordata

A subphylum of chordates that consists of marine animals with sac-like body structures, filter feeding as larvae but losing chordate characteristics upon development.

Cephalochordata

A subphylum of chordates that includes small, translucent fish that retain all four derived chordate structures throughout their life.

Chondrichthyes

A class of fish that includes sharks and rays, characterized by a body structure mainly made of cartilage and distinct paired fins.

Placoid scales

Tiny teeth-like scales covering the outer shell of sharks and rays, providing protection.

Squalene

An oil produced by shark lungs that helps them float in water.

Cloaca

A common exit for the digestive, reproductive, and urinary systems in certain animals, functioning like an anus but additionally serving other systems.

Operculum

A bony structure covering the gills of fish, providing protection and structural support.

Amphibia

A class of animals that includes frogs, characterized by tetrapod body structure and a life cycle that typically starts in water with gills.

Double loop circulatory system

A circulatory arrangement where blood travels in two loops—one to the lungs for oxygenation and one to the body for distribution.

Positive pressure breathing

A method used by amphibians where air is pushed into the lungs by contracting the throat.

Negatively pressured breathing

A method of breathing, such as in humans, where a vacuum effect draws air into the lungs.

Lateral line

A sensory system in fish that detects pressure changes and vibrations in the water.

Ampullae of Lorenzini

Sensory pores on the heads of some fish that help detect electric currents, aiding in prey detection.