Invertebrate Chordates and Fish

1. Invertebrate Chordates and Fish Presented to you by: Sanchita Agrawal, Priyanka Mangtani, Inga Gurevich, Melody Chua

2. Part 1: Invertebrate Chordates OBJECTIVES: • Examples • Evolution • Body Structure • Nutrition/Digestion • Transportation • Circulation • Reproduction • Water Balance and Excretion • Nervous System

3. Examples: Species Names: Cionaintestinalis Oikopleura Branchiostoma (Amphioxus).

4. Main Subphylums • Urochordata – marine subphylum of chordates • Sea squirts (eg. Ciona), pelagic forms (eg. Oikopleura) • Cephalochordata – marine subphylum of chordates • - lancelets

5. Urochordata & Cephalochordata

6. 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-deirvedmorphogen) a possible component for their evolution. • => too much or too little of it during embryo development could lead to mutations => evolutionary change • Evolved from lancelets • Notochord ( a cartilaginous rod along the back) • No jaws

7. Image

8. 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).

9. Structural Support Urochordata Endoskeleton Cephalochordata Endoskeleton Endoskeleton- an internal skeleton made of bone or cartilage.

10. 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.

11. 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).

12. 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

13. 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

14. Reproduction-Sexual -Most Invertebrate Chordates reproduce sexually -Majority lays eggs instead of bearing live young -Few give birth to live young

15. 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

16. Circulatory System Urochordates Open circulatory system Cephalochordata

17. Nervous System • Higher invertebrates have more complex systems. • Annelids, arthropods, mollusk • Ex: insects have compound eyes • Nerve net • It can sometimes depend on the animal • Hydra • Flatworm

18. Nervous System Subphylum Cephalochordata • Dorsal nerve chord • Notochord • adulthood Urochordata • Adults have neither notochord or dorsal tubular nervous system

19. Invertebrates Nervous System • Hollow dorsal nerve chords  Just above the notocord. •  brain - Nerves connect internal organs, muscles, and sensory organs.

21. Part 2: Fish OBJECTIVES: • Examples • Evolution • Body Structure • Nutrition/Digestion • Transportation • Circulation • Reproduction • Water Balance and Excretion • Nervous System • Unique Characteristics (for both invertebrates and fish)

22. Examples • Pike • - World’s first known chordate • - large carnivorous, bony fish • - genus Esox in the family Esocidae.

23. Lampreys (Cephalaspidomorphi) • Jawless fish • No paired fins • No scales More Examples • 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

24. 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

25. Coelecanth • Coelacanth • “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

26. Coelecanth

27. 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).

28. Symmetry & Body Cavity • •Bilateral Symmetry • Coelomate • Muscle movement • body complexity • blood vascular system

29. 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.

30. Structural support continued • Sharks, Rays, Skates, Ratfish Endoskeleton • Ray-finned fish Endoskeleton Lobe-finned fish Endoskeleton

31. Digestion and Nutrition for Hagfish Scavenger 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.

32. Nutrition and Digestion for Lampreys • Parasitic • Feed on body fluids of hosts. • Attach to the body • Cut flesh with their tongues

33. Digestion for sharks, Rays, Skates, Ratfish • Most are carnivores • Some are scavengers • Enters through mouth • Travels to the stomach • Mush enters the intestine

34. Digestion For 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.

35. circulatory system • All fish have closed circulatory system • Has four hearts • Brachial heart • Partal heart • Cardinal heart • Caudal heart

36. Circulatory system • But hagfish have an intermediate one. Both a closed and an open one. • Fish have a two chambered heart

37. Closed system Process • 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.

38. 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

39. Respiration • Countercurrent flow-water flows across the gill filaments in a direction opposite to the blood flow • Causes more oxygen to diffuse into the blood

40. Excretory System • Kidney filters dissolve chemical wastes from blood. • Kidney’s help regulate water and salt balance • Water is lost through osmosis

41. Reproduction-Bony Fish • Eggs 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

42. 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

43. Reproduction-Jawless Fish • External Fertilization • Larvae resemble an invertebrate chordate • Larvae become adults

44. Nervous System • The 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

45. 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

46. Example: Hagfish • Primitive nervous system • Schreiner Organs • Epidermis • Pharynx • Resemble taste buds

48. 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

50. “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 BiolSci 2006; 2:38-47. Available from http://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'sAnimalLife 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>. Works Cited