5.1 Deuterostomia

Deuterostomia

Deuterostomia

Develops anus first from blastopore. Undergoes radial cleavage and produces coelom through enterocoely.

Cephalochordata

Head + Chord, segmented marine animals with notochord from head to tail

Urochordata

Tail + chord, gill slits, dorsal nerve cord, notochord

Hemichordata

Half + chord, gill slits, post anal tail, dorsal hollow nerve cord, stomochord

Echinodermata

Phylum of deuterostomes with spiny skin; exclusively marine organisms like feather stars, sea cucumbers, sea urchins, sea stars, and basket stars.

Pentaradial Symmetry

Body plan that contains five ambulacral zones.

Tests

Dried skeletonized bodies of Sea Urchins that show zones.

Ambulacral Zone

Houses important structures such as nerves, blood vessels and water vascular systems.

Ossicles

Tiny, hard bones/plates used to protect the body of an echinoderm. Bound by catch collagen and covered with tubercules.

Tubercles

Attachment points of spines or spicules in the dermis which aids structural ability, protection and movement.

Water Vascular System

Set of canals and tube-feet that form a hydraulic system for locomotion, food and waste transportation and respiration.

Madreporite

A part of the water vascular system by which entry of seawater is controlled.

Papulae

Skin gills/dermal branchiae (soft bumps on the body). Absorbs oxygen from water. Covered with epidermis.

Pedicellarae

Tiny pincer-like projections. Functions to keep the body surface free of debris, protects the papulae and aids in food capture. (Claw-like)

Aristotle's Lantern

Mouth of sea urchins that's located on the underside of their bodies.

Ectoneural

With circumoral ring and radial nerves.

Hyponeural

Away from the mouth.

Aboral

Farthest from mouth, nerve ring around anus.

Nerve Net

Collection of nerves that branch anywhere.

Tactile and chemoreceptors

Senses surroundings, pressure, and substrate including movement and chemicals.

Podia

Senses surfaces.

Terminal tentacles

Senses food particles, surfaces, and water quality.

Photoreceptors

Senses light.

Statocysts

Senses balance, sinking and rising.

Hemal System

Circulates body fluids. Involved in transport of nutrients but doesn't include gaseous exchange. Arranged in a series of hemal rings.

Peritoneal Cilia

They circulate body fluids by lining the body wall and using a beating motion to move the fluid around.

Axial Complex

Filters blood vascular fluids that flows in the hemal system.

Notochord

Major distinguishing feature of phylum Chordata. Flexible rod, first of endoskeleton to appear.

Dorsal Nerve Chord

It is a unique feature in chordates found in the anterior end of the body. It comprises of the brain and spinal chord.

Endostyle

Group of cells that can secrete mucus for food trapping.

Post-Anal Tail

Associated with muscle for motility.

Pharyngeal Gill Slits/Pouches

Filter-feeding apparatus.

Superclass Agnatha

Animals with no jaw and no paired appendages but has pore-like gill openings and a slender and elongated body form

Ostracodermi

Armored fish that are extinct.

Class Myxini

"Slime". Hagfishes or slime eels. They produce incredible amounts of mucus when in danger.

Barbels

Whisker-like structure in mouths of Myxini. Used for sensing the environment like water pressure, water quality and chemical presence in water.

Class Petromyzontida

"Stone" + "Sucking". Lampreys. They are known for their specific oral structures and long larval growth. They have a distinct mouth with suckers.

Buccal Funnel

Mouth of a lamprey which as rows of keratinized teeth used for sticking while its tongue creates the hole it feeds on.

Superclass Gnathostomata

Account for 99% of the diversity of vertebrates. Have jaws, and paired appendages.

Class Chondrichthyes

"Cartilage" + "Fish". Rays, skates and sharks. Has cartilaginous skeleton and are living fossils. Form is torpedo-like.

Placoid Scales

Old scales that serve as a thermal armor for Chondrichthyes.

Lateral-line sensors

Sensitive to disturbances in water, enabling sharks to detect nearby objects by reflected waves in the water.

Ampullae of Lorenzini

Respond to weak electric and magnetic fields, can be used to locate prey and geophysical location.

Class Actinopterygii

"Rays" + "Wing". Comprises 50% of living vertebrate species. Form always has ray-fins and is bilaterally flattened.

Ctenoid and Cycloid Scales

Replaced heavy dermal armor (ganoid) and increased mobility and speed, improving predator avoidance and feeding efficiency.

Swim Bladder

Internal gas filled organ. Allowed control over buoyancy, conserving energy. Acts as a stabilizing agent and functions as a resonation chamber that can produce and receive sound.

Operculum

Provides protection to the gills and increases respiratory efficiency.

Class Sarcopterygii

"Flesh" + "Wing". Includes 3 subclasses: lungfish, coelacanths and tetrapods.

Subclass Dypnoi

Includes lungfish. They possess Diphycercal caudal tails, one or two lungs are modified swim bladders and they have strong, fleshy, paired lobed fins.

Subclass Actinista

Oldest Known living lineage of Sarcopterygii. Morphologically similar to lungfishes.