General Zoology   Unit Five
Download
1 / 58

General Zoology Unit Five - PowerPoint PPT Presentation


  • 78 Views
  • Uploaded on

General Zoology Unit Five. Hemichordata. Eukaryotic, eumetazoans, deuterostomes. Triploblastic, eucoelomates. Bilaterally symmetrical (cephalization). Worm like body divided into three segments. Complete digestive system. Closed circulatory system with dorsal heart.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' General Zoology Unit Five' - kamal-huff


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Hemichordata

Eukaryotic, eumetazoans, deuterostomes

Triploblastic, eucoelomates

Bilaterally symmetrical (cephalization)

Worm like body divided into three segments

Complete digestive system

Closed circulatory system with dorsal heart

Respiration through gill slits

Sexual reproduction – dioecious, external fertilizers with metamorphosis




Chordate Taxonomy

Kingdom - Animalia

Phylum - Chordata

Subphylum - Urochordata (tunicates)

Subphylum - Cephalochordata (lancelets)

Ex. Branchiostoma

Subphylum - Vertebrata

Superclass - Agnatha

Class - Myxini (hagfish)

Class - Cephalaspidomorphi (lampreys)


Chordate Taxonomy

Kingdom - Animalia

Phylum - Chordata

Subphylum - Vertebrata

Superclass - Gnathostomata

Class - Chondrichthyes (sharks, skates, rays)

Class - Actinopterygii (ray finned bony fish)

Class - Sarcopterygii (lobe finned bony fish)

Class - Amphibia

Class - Reptilia

Class - Aves

Class - Mammalia






Developmental Definitions

Paedomorphosis - the retention of larval traits in the adult body

Neotony - a process in which the growth rate is slowed to the extent that sexual maturity is reached before the ancestral adult form is obtained


Developmental Definitions

Progenesis - the precocious maturation of the gonads in a juvenile body that stops growing and never attains the adult body form

Post-displacement - a delay of the onset of a developmental process relative to sexual maturity, so that the ancestral adult form is not attained before reproductive maturity




Fish Taxonomy

Kingdom - Animalia

Phylum - Chordata

Subphylum - Vertebrata

Superclass - Agnatha

Class - Myxini (hagfish)

Ex. Myxine

Class - Cephalaspidomorphi (lampreys)

Ex. Petromyzon


Fish Taxonomy

Kingdom - Animalia

Phylum - Chordata

Subphylum - Vertebrata

Superclass - Gnathostomata

Class - Chondrichthyes (sharks, skates, rays)

Subclass - Elasmobranchii (sharks, skates, rays)

Ex. Squalus, Raja

Subclass - Holocephali (chimeras or ratfish)

Ex. Chimera


Fish Taxonomy

Kingdom - Animalia

Phylum - Chordata

Subphylum - Vertebrata

Superclass - Gnathostomata

Class - Actinopterygii (ray finned bony fish)

Ex. Perca, Amia, Polyodon

Class - Sarcopterygii (lobe finned bony fish

Ex. Latimeria


Subphylum Vertebrata

All five chordate hallmark characteristics

Endoskeleton of cartilage or bone

Complete digestive tract

Closed circulatory system with a ventral heart

Complex nervous system with a brain, dorsal nerve cord and advanced sense organs

Excretion carried out by paired kidneys

Most have two pairs of appendages


Superclass Agnatha

All members have the vertebrate characteristics

All are jawless

All are elongated and eel shaped

None have paired appendages

Scales are absent

Complete digestive system without a stomach

The notochord is persistent into adulthood




Superclass Gnathostomata

All members have the vertebrate characteristics

All members have a jaw

All have or have had paired appendages

All have an endoskeleton of cartilage or bone















Vertebrate Thermoregulation

Ectothermic – obtaining body heat from the environment

Poikilothermic – non-regulatory, the body temperature is the same as the ambient environment

Regulatory ectotherms – maintain a consistent body temperature through physiological and behavioral means


Vertebrate Thermoregulation

Endothermic – body heat is produced internally (homeothermic)

Fish are poikilothermic because water is a heat sink


Buoyancy in Fish

Squalene (liver oil)


Buoyancy in Fish

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Physostomous bladder


Buoyancy in Fish

aaaaaa

aaaaaaa

Physoclistous bladder


Fish Feeding Strategies

Most fish are carnivores

Most ocean species are suspension feeders

Some are scavengers

A few species are parasites

A few species are herbivores

A few species are omnivores


Fish Reproductive Adaptations

Oviparous - egg laying

Ovoviviparous - retention of eggs

Viviparous – live birth

All three methods are found in cartilaginous and bony fishes

Cartilaginous fish are internal fertilizers while most bony fish are external fertilizers


Fish Reproductive Adaptations

Diadromous - fish that make “two runs” in their life to live and reproduce

Anadromous - fish that “run up” - salmon

Catadromous - fish that “run down” - eels

Parthenogenesis - no males required, females produce diploid eggs - Amazon molly


Amphibian Taxonomy

Kingdom - Animalia

Phylum - Chordata

Subphylum - Vertebrata

Superclass - Gnathostomata

Class - Amphibia

Order - Gymnophiona (caecilians)

Order - Caudata (salamanders)

Ex. Ambystoma, Necturus

Order - Anura (frogs)

Ex. Rana, Bufo


Class Amphibia

All five chordate hallmark characteristics

Endoskeleton of bone

Thin, gland rich skin with no scales or claws

Large mouth - all members carnivores

Closed double looped circulatory system with a ventral three chambered heart

Respiration - lungs, gills or cutaneous

Regulatory ectotherms


Class Amphibia

Excretion through opisthonephric kidneys and urea as the primary nitrogenous waste

Nervous system with a brain and dorsal nerve cord - well developed sight and hearing

Reproduction – dioecious, some internal, others external fertilizers, some metamorphosis

Most are tetrapods


Order Gymnophiona

Caecilians

Legless, elongated worm-like bodies

Fossorial, tropical & subtropical organisms

Most are blind, with smell and touch being the best senses

Eggs are laid in moist soil

Some species are viviparous


Order Caudata

Salamanders, newts, amphiumas, sirens

Most have four legs & all have a tail

Some aquatic, some terrestrial

Respiration by gills, skin and lungs

Internal fertilization

Metamorphosis and direct development

Paedomorphosis common


Order Anura

Frogs

All have four legs and no tail (one exception)

Some aquatic, some terrestrial

Respiration by skin and lungs

Good vision and nictitating membranes

External fertilization

Metamorphosis and direct development


Amphibian Evolutionary Pressures

Respiration

Thermoregulation

Support

Ecological diversity


Amphibian Respiratory Strategies

Cutaneous

Pulmonary

Buccopharyngeal





Amphibian Thermoregulation

Many amphibians are regulatory ectotherms, using physiological and behavioral means

Aquatic species and salamanders are poikilothermic, but other terrestrial species will drop to this level of thermoregulation during hibernation and estivation



Caudatan Development

Remember!

Neotony - a process in which the growth rate is slowed to the extent that sexual maturity is reached before the ancestral adult form is obtained

In caudatans there are two forms of neotony - obligate and facultative


Obligate neotony

Facultative neotony


ad