Exam 2: Chapter 32 The Deuterostomes

Adaptive Radiation

formation of many new species from an ancestral species, often occurs rapidly in geological time when a new niche opens up

Cloaca

common exit point shared by reproductive, excretory and digestive systems (literal translation is sewer)

Arboreal

Living in the trees

Desiccate

Dry out from lack of water (dehydration)

Ectothermic

animals whose body heat goes up and down with changes in the external environmental temperature (cold-blooded)

Endothermic

animal whose body heat is maintained independent of the external temperature

Eutheria

animals that nourish the embryo via a placenta

metamorphosis

undergo a change in body form from one developmental stage to another

Metatheria

animals that raise their young in a pouch (e.g. kangaroos)

Oviparous

animals that lay eggs and embryo is nourished by the yolk

Ovoviviparous

Animal that incubate an egg internally, embryo gets nourishment from the yolk, and have live births

Protheria

egg laying mammals (e.g. duckbilled platypus)

Viviparous

animals where the young develop inside the uterus and nutrients are transferred from mother to embryo

Phylums of Deuterostomes

Echinodermata and Chordata

Ancestral features of deuterostomes

multicellularity

tissues (3 layers)

triploblastic

bilateral symmetry

true coelom

deuterostomic development

notice segmentation revolved in chordates

Habitat of Echinoderms

Marine

Echinoderms have what type of vascular system?

water vascular system

Madreporite

sievelike structure through which the water vascular system of an echinoderm opens to the outside

Stone canal

tube that connects the madreporite to the ring canal

Ring canal

in echinoderms, a circular canal that is near the mouth and that is part of the water-vascular system

Ampullae

the bulb that squeezes water into the tube foot

Tube feet

Extensions of an echinoderm's water vascular system that stick out from the body and function in movement and obtaining food.

Echinoderm characteristics

Bilateral in young

Pentaradial in adults

Has an oral and aboral surface

Major classes of Echinoderm

Asteroidea

Crinodea

Echinodea

Asteroidea

Sea Star

Chrinodea

Sea lilies and feather stars

Echinoidea

sea urchins and sand dollars

Echinoidea body features

Bodies are round, flat, with no arms

Skeleton is plated flattened and fused which form a solid shell

Endostyle

ciliated groove in urochordates and cephalochordates and lamprey larva.

It is involved in transporting food to the esophagus.

This region is the thyroid gland in vertebrates.

Subphylum Urochordata Characteristics

1. squirt out water is streams when touched

2. name comes from the tunic that surrounds them

3. small

4. filter feeders

5. sessile in shallow areas of water

Subphylum Cephalochordata characteristics

Adults: all 4 chordate features: no paired fins, jaws, sense organs, heart, head, or brain.

Filter feeders

4 chordate features

notochord, dorsal hollow nerve cord, pharyngeal gill slits, post-anal tail

Genus Brachiostoma

Latin for gill plus mouth.

Originally amphioxus: Latin for sharp on both sides

Distinguishing features of vertebrates

Vertebral column

Pronounced cephalization

Brain (in cranium)

Neural Crest Cells

Hox gene clusters

Systems

Neural Crest Cells

Influence development of many structures including melanocytes, smooth muscle, nerves, and craniofacial cartilage

Hox gene clusters

involved in the regulation of development; code for transcription factors

Systems in vertebrates

Circulatory, digestive, endocrine, endoskeleton, excretory

Ten Extant (living) classes of vertebrates

6 are fish and 4 are tetrapods

Class Myxini

hagfish

What is special about hagfish

They are craniate but not a vertebrate

Habitat of hagfish

marine only

Cranium of hagfish

brain inclosure: clade craniata

Teeth of hagfish

Keratin and on the tongue as well. (they don't have jaws)

Notochord of hagfish

flexible cartilage rod only craniate with no true vertebrae

Fins of hagfish

no true fins, long dorsal fold: used to burrow into a carcass

Also absorb nutrients

Feeding type of haglish

Scavenger or predator

Hagfish Defense system

secretes slime: covers gills of attacking fish or prey

Sneezes to clear own passage ways from its own slime.

Class Pteromyzontida

lampreys (oldest living vertebrate lineage

Habitat of lampreys

marine and freshwater and estuaries

Lifestyle of lampreys

parasites

Vertebral column of lampreys

jawless vertebrate (primitive)

Class Chondrichthyes

cartilaginous fish; sharks, skates, rays

Habitat of cartilaginous fish

mostly marine (some freshwater skates)

Skeleton and cranium of cartilaginous fish

cartilage infused with calcium salts

Teeth of cartilaginous fish

replaceable, modified scales

Scales of cartilaginous fish

placoid (tooth-like), nonoverlapping and replaceable

Fins of cartilaginous fish

paired and used for mobility

Mouth of cartilaginous fish

on the ventral surface

Gill opening in sharks

Lateral

Gill opening in skates and rays

ventral

Brain of cartilaginous fish

well-developed

Nostrils of cartilaginous fish

blind-ended: olfaction

electroreceptors of cartilaginous fish

detect prey

Lateral line organ of cartilaginous fish

detect vibrations in water

Body density of cartilaginous fish

causes them to sink when no swimming

but pectoral fins provide lift

Cloaca of cartilaginous fish

common opening to outside for 3 systems:

reproductive, excretory, and digestive

Sexual Dimorphism of cartilaginous fish

Cartilaginous extensions of male pelvic fin.

Males transfer sperm along clasper groove into female cloacas

Class Osteichthyes

Bony fish

Bony fish habitat

marine and freshwater

Skeleton and Cranium of Bony Fish

calcified

Teeth of Bony Fish

replicable

Scales of Bony Fish

overlapping and flexible (origin dermal bone)

Fins of Bony Fish

paired, supported by cartilage or bone

Mouth of Bony Fish

anteriorly directed

gills of Bony Fish

internal, covered by operculum

Swim bladder of Bony Fish

Buoyancy (gas exchange in some)

Reproduction of Bony Fish

most oviparous w external fertilization

male parental care in many

ray-finned bony fishes

Group of bony fishes with fins supported by parallel bony rays connected by webs of thin tissue.

Lobe-finned bony fish

some use lungs instead of gills, gave rise to land-dwelling tetrapods

Fleshy w/bones at base (evolved in phalanges)

Mitochondrial DNA indicated connections to tetrapod land dwellers

Class Amphibia

Having 2 lives (one in H2O and one on land)

metamorphosis of amphibia

mant complete, some adults (salamanders) retain many larval characteristics (pedomorphosis)

Respiratory organs of amphibians

Lungs, gills, and skin

How many chambers does an amphibians heat have

3 chambers (2 atria, 1 ventricle)

Amphibian orders

Anura, Urodela, Apoda

Urodela or Caudata

"Visible tail" Salamanders, mud pups, and newts

Anura

"no tail" frogs and toads

Apoda

"No feet" wormlike caecilians (internal fertilization)

Amnoites

terrestrial vertebrates

Transition to land required evolution of an amniote egg

Body surface of Reptilia

Hard scales (water tight)

Respiration of Reptilia

Lungs and many chambers

Circulation of Reptilia

3 chambered heart (separate O2 rich from O2 poor blood)

Sense organs of Reptilia

well developed to locate prey

Reptilia are ectotherms meaning

They are cold blodded

4 Orders of Reptiles

Testudines

Squamata

Crocodilia

Sphenodonta

Testudines

Turtles, terrapins, tortoise

Squamata

lizards and snakes and worm lizards

Crocodilia

crocodiles, alligators, caimans, gavials

Sphenodonta

tuataras only

Superorder archosauria

extant order of crocodilia, and aves (birds)

Shell of Testudine

bony plates and horny scales