Review of Phylogeny and Anatomy of Chordates and Echinoderms

These flashcards cover key vocabulary and concepts related to the phylogeny, anatomy, and unique characteristics of chordates and echinoderms as discussed in the lecture.

Phylogeny

The evolutionary history and relationships among groups of organisms.

Clade

A group of organisms that includes an ancestor and all its descendants.

Predatory Adaptations of Sharks

Features that aid in the hunting and capturing of prey, including powerful jaws, fusiform body shape, countershading, lateral line system, and ampullae of Lorenzini.

Heterodont Teeth

Teeth of different shapes and sizes that are continuously replaced, aiding sharks in predation.

Fusiform Body

A streamlined body shape that allows for efficient, hydrodynamic swimming.

Countershading

A coloration pattern that helps organisms blend in with their environment for better hunting success.

Lateral Line System

A system that detects vibrations in the water, enabling fish to sense movement and position.

Ampullae of Lorenzini

Sensory structures that detect electrical fields, assisting sharks in locating prey.

Anadromous

Referring to species, like lampreys, that migrate from the sea to freshwater to spawn.

Catadromous

Referring to species that migrate from freshwater to the sea to spawn.

Petromyzontida

The class of jawless fish that includes lampreys, known for their parasitic behavior.

Key Chordate Characteristics

1. Notochord, 2. Dorsal hollow nerve cord, 3. Endostyle, 4. Post-anal tail, 5. Pharyngeal gill slits.

Triploblasty

The condition of having three germ layers in the embryo: ectoderm, mesoderm, and endoderm.

Deuterostome

An animal whose mouth does not develop from the blastopore but from a secondary opening; includes chordates and echinoderms.

Coelomate

An organism with a true coelom, a fluid-filled body cavity lined with mesoderm.

Acoelomate

An organism that lacks a coelom; body cavity is filled with tissue.

Pseudocoelomate

An organism with a body cavity that is not completely lined with mesoderm.

Ganoid Scales

Hard, bony scales found in nonteleost bony fishes.

Placoid Scales

Small, tooth-like scales found in sharks and rays.

Cycloid and Ctenoid Scales

Types of scales found in teleost bony fishes that are flexible and allow for smoother movement in water.

Water Vascular System

A unique system in echinoderms used for locomotion, feeding, and respiration.

Madreporite

The entry point for water into the water vascular system of echinoderms.

Chondrichthyes

A class of cartilaginous fishes, including sharks and rays.

Osteichthyes

A class of bony fish with a skeleton composed of bone.

Heterocercal Tail

A tail type with an asymmetrical shape; larger dorsal lobe, typically seen in sharks.

Homocercal Tail

A tail type that appears symmetrical; spinal column ends before the rays, found in most bony fish.

Echinoderms Unique Traits

Features that distinguish them, such as a water vascular system, secondary radial symmetry, and a calcareous endoskeleton.