species names: ciona intestinalis oikopleura branchiostoma (amphioxus)
TRANSCRIPT
Invertebrate Chordates and Fish
Presented to you by: Sanchita Agrawal, Priyanka Mangtani, Inga
Gurevich, Melody Chua
Part 1: Invertebrate Chordates
OBJECTIVES:
Examples
Evolution
Body Structure
Nutrition/Digestion
Transportation
Circulation
Reproduction
Water Balance and Excretion
Nervous System
Examples:Species Names:
Ciona intestinalis
Oikopleura
Branchiostoma (Amphioxus).
Main Subphylums
Urochordata – marine subphylum of chordates
Sea squirts (eg. Ciona), pelagic forms (eg. Oikopleura)
Cephalochordata – marine subphylum of chordates
- lancelets
Urochordata & Cephalochordata
Evolution
“Explosion” of invertebrate evolution in the lower Cambrian period (Beginning 570 million years ago)
- lasted 10 million years. - Melting glaciers => more water/places to live
Retinoic acid (a vitamin A-deirved morphogen) a possible component for their evolution.
=> too much or too little of it during embryo development could lead to mutations => evolutionary change
Evolved from lanceletsNotochord ( a cartilaginous rod along the back)No jaws
Image
At some point…
At some point in the invertebrate chordate life they have…
• A flexible, fibrous notochord that gives support.
•A hollow dorsal nerve cord in the back.
•Gill slits in the pharynx (throat area).
•Muscular tail which prolongs past the anus. (for locomotion and balance).
Structural Support
Urochordata Endoskeleton
Cephalochordata Endoskeleton
Endoskeleton- an internal skeleton made of bone or cartilage.
Nutrition and Digestion
Urochordata are filter feeders.
•1.) Water enters into the incurrent siphon
•2.) It goes to the slits in the pharynx
•3.) Food filtered by the pharynx moves to the stomach
•4.) Undigested moves to anus•5.) And exits through excurrent siphon.
Nutrition and Digestion
Cephalochordata are also filter feeders.
• 1.) Water is drawn by cilia into the mouth.
•2.) It moves to the pharynx.
•3.) The pharynx traps food particles from the water.
•4.) Food enters the intestine for digestion
•5.) The water leaves through atriopore. (An opening in the body).
Respiration
-Uses Pharyngeal pouches-portion of the digestive tract which is between the mouth and the esophagus
-Pouches have slits and evolved first into filter feeding structures and later into gill chambers
-Gill chambers help in respiration
Excretory System-Food particles in the water are trapped as the water passes through slits in the pharynx
-Water leaves the body through an opening called an atriopore
-Excretion occurs through paired kidneys
-Ex: Lancelets
Reproduction-Sexual
-Most Invertebrate Chordates reproduce sexually
-Majority lays eggs instead of bearing live young
-Few give birth to live young
Reproduction-Asexual
-Chordates in the phylum Urochordata reproduce asexually
-Invertebrate chordates are hermaphrodites
-Sperm and eggs are released through the excurrent to the surrounding water.
-External fertilization in the water
-Ex:Tunicates
Circulatory System
Urochordates
Open circulatory system
Cephalochordata
Nerve net
It can sometimes depend on the animal
• Hydra
• Flatworm
Higher invertebrates have more complex systems.
Annelids, arthropods, mollusk
• Ex: insects have compound eyes
Nervous System
Urochordata
Adults have neither notochord or dorsal tubular nervous system
Cephalochordata
Dorsal nerve chord
Notochord
• adulthood
Nervous System Subphylum
Invertebrates Nervous SystemHollow dorsal nerve chords Just above the notocord.
• brain
- Nerves connect internal organs, muscles, and sensory organs.
Part 2: FishOBJECTIVES:
Examples
Evolution
Body Structure
Nutrition/Digestion
Transportation
Circulation
Reproduction
Water Balance and Excretion
Nervous System
Unique Characteristics (for both
invertebrates and fish)
Examples
Pike - World’s first known chordate- large carnivorous, bony fish
- genus Esox in the family Esocidae.
More ExamplesLampreys
(Cephalaspidomorphi)
- Jawless fish
- No paired fins
- No scales
- Sharks, Rays, Skates, and Ratfishes (Chondrichthyes)
- Jaws & paired fins
- Cartilaginous skeletons
- Unique Scale Covering
- Ray-finned Fish (Actinopterygii)
- Jaws & paired fins
- Fins supported by rays
More Examples Continued…
- Lobe-finned Fish (Sarcopterygii)
- Fins supported by main aixis of bone.
- Lung fishes and coelacanth
Hagfishes (Class Myxini) – • Elongated, eel-like
bodies• No vertebrae• Jawless Fish• No true fins
CoelecanthCoelacanth
“living fossil”
A combination of 2 different types of fish: cartilaginous and bony fishes
• Evolutionary link
IMPORTANT: Has 4 muscular, limb-like fins underneath body; uses like legs to perch/support itself on ocean bottom.
- Lungfish
Coelecanth
Evolution - Fish: the first vertebrates.
- Example: Myllokunmingia, found from fossil deposits in China.
-Earliest fish- lampreys and hagfishes- Ordovician period
- jaws- => major advancement
- Earliest jawed fishes were covered in bony armor b/c of strengthening predatory race. => - ---
- Placoderms => extinct
- Jawed fishes that survived became: Chondrichthyes (cartilaginous fishes) Osteichthyes (bony fishes).
Symmetry & Body Cavity• Bilateral Symmetry
CoelomateÞ Muscle movementÞ body complexityÞ blood vascular system
Hagfish and Lamprey
Hagfish have endoskeleton.
(An internal support structure that consists of cartilage.)
Instead of having a jaw they have tooth-like projections that are used to pull food.
Lamprey have an Endoskeleton
Also are jawless.
Structural support continuedSharks, Rays, Skates, Ratfish
Endoskeleton
Ray-finned fish
Endoskeleton
Lobe-finned fish
Endoskeleton
Digestion and Nutrition for HagfishScavenger hunters that feed on dead or dying fish or
invertebrates
• Attach to prey
• Gets inside the prey
• With rasping tongue eats the inside of the prey
• They don’t have a true stomach
• Food travels form the esophagus to the straight intestine.
Nutrition and Digestion for Lampreys Parasitic
Feed on body fluids of hosts.
Attach to the body
Cut flesh with their tongues
Digestion for sharks, Rays, Skates, Ratfish
Most are carnivores
Some are scavengers
Enters through mouth
Travels to the stomach
Mush enters the intestine
DigestionFor Ray-finned Fish
Carnivores
Enters the mouth
Enzymes in stomach break it down.
For Lobe-finned Fish
Carnivores
Enters the mouth
Enzymes in stomach break it down.
circulatory systemAll fish have closed circulatory system
Has four hearts
• Brachial heart
• Partal heart
• Cardinal heart
• Caudal heart
Circulatory system
But hagfish have an intermediate one. Both a closed and an open one.
Fish have a two chambered heart
Closed systemProcess
Blood is pumped by the heart
Moves through arteries to the capillaries in the gills
There it exchanges carbon dioxide for oxygen.
Blood moves through body tissues.
Then back to the heart in veins.
Respiration
Extract oxygen from water & transfer it to blood stream
Need specialized gills which allow for rapid gas exchange
Gills are supported by four sets with filaments
RespirationCountercurrent flow-water flows across the gill
filaments in a direction opposite to the blood flow
Causes more oxygen to diffuse into the blood
Excretory System
Kidney filters dissolve chemical wastes from blood.
Kidney’s help regulate water and salt balance
Water is lost through osmosis
Reproduction-Bony FishEggs produced by ovaries and sperm are produced by
testes in the male
External Fertilization
High mortality rates among the eggs cause fish to lay a large amount of eggs to ensure some survive.
Some bear live young
Reproduction-Cartilagenous Fish
Internal fertilization using claspers-pelvic fins
Lay eggs after fertilization
Eggs hatch and are mini versions of adults
Some babies are born live
No parental care after birth/hatching
Reproduction-Jawless FishExternal Fertilization
Larvae resemble an invertebrate chordate
Larvae become adults
Nervous SystemThe nervous system is organized around the brain of the fish
The brain has different regions and eachofteh different regions do a different job.
• Ex: vision, smell, body movements, etc.
They have great sense of smell and taste
Nervous System Cont.
Eyes on both side of body
• Large, no eyelid.
• Retinas
• Large pupils
Inner ear, no outer ear opening.
Lateral line system
Nasal sac
Electrical Current
Example: HagfishPrimitive nervous system
Schreiner Organs
• Epidermis
• Pharynx
• Resemble taste buds
Did You Know….?- About 99% of the animals in the world are invertebrates?
-They are usually darker color on the top and lighter on the bottom to protect them from predators/enemies.
- Their body shape is streamlined to allow it to move through water more rapidly.
-They can change their color in an instant with color and reflective cells in their pigmentation!
-Scales protect the fish and reduce the friction while they swim.
-Fish are very diverse species…- Size range from 1 inch to 16 feet long!!!- They can be almost any color in nature
Works Cited
“Atlantic Hagfish” Sea and sky. 2009. Sea and Sky. 04 Apr. 2009. <http://www.seasky.org/deep-sea/atlantic-hagfish.html.> "Coelacanth." UXL Encyclopedia of Science. Ed. Rob Nagel. Vol. 3. 2nd ed. Detroit: UXL, 2002. 508-511. Gale Virtual Reference Library. Gale. VERNON HILLS HIGH SCHOOL. 7 Apr. 2009 <http://go.galegroup.com/ps/start.do?p=GVRL&u=vern39182>. “Hagfish.” Aquatic Community. 2006. Aquatic Community.com. 04 Apr. 2009. <http://www.aquaticcommunity.com/mix/hagfish.php.> "Hagfish." Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 02 Apr. 2009 <http://www.britannica.com/EBchecked/topic/251522/hagfish>. Hine, Robert. "Chordata." The Facts On File Dictionary of Biology, Fourth Edition. New York: Facts On File, Inc., 2005. Science Online. Facts On File, Inc. http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin= FDBF0554&SingleRecord=True (accessed April 7, 2009).
"Invertebrate Nervous System." Neuroscience for Kids. 12 Apr 2009 <http://faculty.washington.edu/chudler/invert.html>. “Lobe-Finned Fishes.” Natural History Notebooks. Canadian Museum of Nature. 23 Mar. 2009. 05 Apr. 2009. <http://www.nature.ca/NOTEBOOKS/ENGLISH/lobefish.htm.> Marlétaz F, Holland LZ, Laudet V, Schubert M. Retinoic acid signaling and the evolution of chordates. Int J Biol Sci 2006; 2:38-47. Available fromhttp://www.biolsci.org/v02p0038.htm "Nervous System - Evolution Of Invertebrate Nervous Systems." 12 Apr 2009 <http://science.jrank.org/pages/4595/Nervous-System-Evolution-invertebrate-nervous systems.html>. "Paleontology." The Gale Encyclopedia of Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. Vol. 4. 4th ed. Detroit: Gale, 2008. 3178-3185. Gale Virtual Reference Library. Gale. VERNON HILLS HIGH SCHOOL. 7 Apr. 2009 <http://go.galegroup.com/ps/start.do?p=GVRL&u=vern39182>. "Pike." The Gale Encyclopedia of Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. Vol. 4. 4th ed.Detroit: Gale, 2008. 3339-3340. Gale Virtual Reference Library. Gale. VERNON HILLS HIGH SCHOOL. 7 Apr. 2009 <http://go.galegroup.com/ps/start.do?p=GVRL&u=vern39182>. Postlethwait, John, and Janet Hopson. Modern Biology. Austin: Holt, Rinehart and Winston, 2006. Print. Schlager, Neil. Grzimek's AnimalLife Encyclopedia Fishes 1. 2nd ed . 2003. Shark Diet and Drinking.” Enchanting Learning. 1999. Enchanting Learning Software. 05 Apr. 2009. <http://www.enchantedlearning.com/subjects/sharks/anatomy/Diet.shtml.> “Shark Digestion.” Enchanting Learning. 1999. Enchanting Learning Software. 05 Apr. 2009. <http://www.enchantedlearning.com/subjects/sharks/anatomy/Digestion.shtml.> "The Invertebrate Animals." 15 Jan 2009. 12 Apr 2009 <http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/I/Invertebrates.html>.