Animalia

1. Animalia A Brief Survey of Animals

2. The study of animals is referred to as zoology. Animals are the largest of the 6 kingdoms, and exhibit a great diversity in form and function.

3. Major Animal Characteristics • 1. Multicellular, eukaryotic organisms, with a division of labour amongst cells that are specialized. • 2. A variety of systems have evolved and are specialized for specific functions. These systems include: - Circulatory - Integumentary (skin) - Lymphatic - Digestive - Skeletal - Respiratory - Excretory - Muscular - Endocrine - Reproductive - Nervous

4. 3. Heterotrophic: Animals have more complex systems than plants. These systems are based upon the animal’s nutrient requirements. 4. Locomotion: Most are mobile at some point in their lifetime. 5. Reproduction: This may be through sexual or asexual means. Asexual occurs in some lower forms, sexual occurs in all higher forms.

5. Five Major Areas Used to Describe Animals • 1. Systems: When moving from simpler to more complex animal forms, the number and complexity of systems increases. • In the case of digestion, all animals except Poriferans digest food extracellularly, meaning outside of their cells. Poriferans digest food intracellularly, within their cells. Animal digestive systems can be either : Incomplete: two way system. Having only one opening to the gut. Both food and waste enter and exit the same opening. Complete: one way system, having two openings to the gut. Food enters one way, exits the other.

6. Intracellular digestion Extracellular digestion

7. 2. Symmetry: This is a term used to describe the body plan of an animal. To find the symmetry of an animal, an imaginary line is drawn to divide the animal in half. • There are three forms of symmetry:

8. (A) Asymmetric - An organism cannot be cut into two matching halves. (e.g. sponges) (B) Radial - Any line passing through the central axis of an organism divides it in half. These organisms are rounded. (e.g jellyfish) (C) Bilateral: An elongated body plan. There is only one line that divides the animal in half. This line runs down the middle of the longitudinal section. This is the most common form of symmetry. (e.g. humans, frogs, etc.)

9. Body Symmetry

10. When an animal has bilateral symmetry, the body can be divided into 5 regions: • Anterior: head region • Posterior: rear region • Dorsal: back region • Ventral: bottom region • Lateral: side region • The body symmetry of all animals is related to the necessity of them to move in order to obtain food. This is why most sensory organs are located at the anterior end of the animal.

11. 3. Coelom • A coelom is a body cavity. The presence or absence of a fluid-filled cavity is one of the most significant features of animal body plans used in classification. • The coelom is located between the digestive tract and the body wall. • The peritoneum is associated with organisms which have a true coelom. The peritonem lines body cavities and covers internal organs. It may provide support and hold internal organs in place.

12. Body cavities are important for the following reasons: • (i) They provide space in which internal organs can be suspended so they are not negatively affected by muscle pressure and body movement. • (ii) They provide space for internal organs to develop and expand. • (iii) They contain fluids which may assist in internal transportation and nutrient and gas exchange. • Lower animal forms have no or partial coeloms. They are at a disadvantage in light of the efficient functioning of a true coelom.

13. Development of coelum

14. 4. Cell Layers: Animals contain either two or three embryonic cell layers. Simpler animals contain only two; all others have three. Each layer is responsible for producing various tissues and structures in the adult animal. These layers include: • Ectoderm - forms the outer body (skin, nerves) • Mesoderm - forms the middle organs (kidney, heart, urinary, skeletal and muscular) • Endoderm - form lining of gut or digestive tract, lungs,liver,pancreas • simple animals have no mesoderm.

15. Germ layers

16. 5. Reproduction: Moving from simpler to more complex animal forms, the reproductive system becomes more complex. Animals have the ability to reproduce sexually and asexually. Several invertebrates classes have the ability to reproduce asexually, whereas all vertebrates reproduce sexually.

17. Reproduction

18. Classification • There are two major groups of animals. They are classified according to the presence or absence of a backbone. • Invertebrates lacking a backbone Roughly 97% of the animal kingdom • Vertebrates Having backbone Roughly 3% of the animal kingdom

19. Invertebrates • 1. These organisms lack a backbone, and include the following phyla: • (a) Porifera (sponge) • (b) Coelenterata (jellyfish) • (c) Platyhelminthes (tapeworm) • (d) Nematoda (ringworm) • (e) Annelida (earthworm) • (f) Mollusca (shellfish) • (g) Arthropoda (insects) • (h) Echinodermata (starfish)

20. 2. Make up 97% of the animal kingdom. 3. Higher forms are characterized by cephalization. This is an evolutionary tendency towards specialization of the body with concentration of sensory and neural organs in the anterior end( such as the brain). 4. They possess body plans which have been enormously successful both ecologically and evolutionarily.

21. Key Terms / Definitions Used in Animal Classification • Pseudocoelom - partial, not a true body cavity • 2-way Digestive System - only one opening through which food enters and undigested food exits • 1-way Digestive System - two openings. Food enters through the mouth and undigested food exits the anus. • One way system is better because it allows the animal to eat continuously. • Diffusion - a substance goes from an area of high to low concentration without any expenditure of energy • Open Circulatory System - blood is not always inside blood vessels, and is not under pressure. It is slow and inefficient, and does not transport oxygen.

22. Key Terms / Definitions (continued) • Closed Circulatory System - blood is always inside blood vessels, and is under pressure. It is fast, efficient and transports oxygen. • Ganglia - a mass of nerve cells that give rise to a nerve center. • Eye Spot - sensory organ capable of detecting light from dark, does not see images • Flame Cell - cells that contain cilia that push waste from an organism. • Nephridia - a unit that filters body fluids to remove waste so that the fluid may be recycled.

23. Key Terms / Definitions (continued) • Malpighian Tubules - tubules that collect liquid wastes within an organism and dump them into the hind gut of the organism • Green Glands - structures in which wastes are collected and become concentrated within an organism • Tracheals - tubes leading into the body of the organism for the purpose of gas exchange • Hermaphroditic - possessing both ovaries and testes

24. Phylum Porifera • Means pore bearing • Includes sponges • Are asymmetrical aquatic organisms made of two layers • They have one body opening that allows for food to enter and waste to pass, however they do not have a digestive system. All of their food is digested intracellularly. • Poriferans can reproduce asexually or sexually Asexual via budding Sexual via hermaphrodites( fertilization occurs external) • They do not possess any sensory organs nor do they possess a nervous system

25. Phylum Cnidaria • Means thistle, referring to stinging tentacles • Includes Hydras, Sea Anemones, Jellyfish, and Coral • They are radially symmetrical, aquatic organisms made of two layers • They have one body opening through which food enters and waste leaves and unlike Poriferans, they have no digestive system, thus making it incomplete. food is digested extracellularly • They reproduce asexually (budding) and sexually where organisms will either have opposite sexes or will be hermaphrodites fertlization is external • Their circulatory, excretory, and respiratory system occur via diffusion • they have simple nervous system known as a nerve net

26. Phylum Platyhelminthes • Means flat wide worm therefore refers to flatworms • Includes Planarians, Flukes and Tapeworms • They are bilaterally symmetrical organism made of 3 germ layers that can be eitehr aquatic terrestrial or parasitic(living inside and feeding off other organisms) • They have only one body opening through which food enters and waste leaves. They do not have a digestive system thus because there is only one opening, the digestive system is known as incomplete food is digested extracellularly • They reproduce asexually through regeneration or sexually with species having opposite sexes or in some cases species can be hermaphroditic fertilization is internal

27. Their nervous system is simple , comprising of a primitive brain and nerve cords. Sensory organs are also very limited, with some species having eye spots- a sensory organ capable of detecting light from dark. • Their circulatory and respiratory systems occur via diffusion while their excretory systems are accomplished via flame cells • Flame cells are ciliated excretory cells found in lower invertebrates that function like a kidney to remove waste

28. Phylum Nematoda • Means thread like commonly called roundworms • Includes pinworms and hookworms • They are bilaterally symmetrical organisms, made of 3 germ layers, that can be either aquatic, terrestrial or parasitic • They have 2 body openings, therefore have complete one way digestive system food is digested extracellularly • They reproduce sexually with species having either opposite sex or in some cases species can be hermaphroditic fertilization is internal • Like plathyelminthes, their nervous system are simple, made of a primitive brain and nerve cords. Their sensory capabilities are limited to touch. • Their circulatory and respiratory systems occur via diffusion and their excretory system is controlled by flame cells

29. Phylum Annelida • Means ring referring to body being segmented into repeating units • Includes earthworms, leeches and tubeworms • Bilateral symmetry, made of 3 germ layers, and are aquatic or terrestrial • Have 2 body openings, one way digestive n system and tube-tube body plan food is digested extracellularly • Reproduce sexually with species of either opposite sex or hermaphrodites fertilization is internal • Fairly simple nervous system made of primitive brain , some nerves and ganglia- a mass of nerve cell that give rise to a nerve center

30. The added neural attachments heightens their sensory capabilities, species are able to touch taset and sense light and moisture • Annelids have a closed circulatory system, ,meaning that at all times their blood is contained within vessels • Respiratory system occurs via diffusion through the skin • Their excretory system are controlled by organs called Nephridia similar to flame cells nephrida function like kidneys, to remove wastes out of body. They filter body fluids , the pass wastes through to the organisms exterior.

31. Phylum Mollusca • Means “soft bodied” • Includes Clam, Oysters, octopus, and snails • They are bilaterally symmetrical organism, made of 3 germ layers, that are mainly aquatic, but few do live on land- ie. Snails • They have two body openings, a one way complete digestive system and a tube within a tube body plan • Food is digested extracellularly • They reproduce sexually with species being of either opposite sexes or hermaphrodites • fertilization is primarily internal however some species do display external fertilization • Like annelids their nervous system is slightly more developed than previous phyla. They have primitive brain, a few nerves with ganglia. And like Annelids because of this their sensory abilities are heightened. They can sense touch taste smell and in some species vision is possible (octopus).

32. Have an open circulatory system, their blood is contained within vessels and therefore has the ability to slosh around • Many of they are aquatic and therefore they’ve adapted gills for respiration while those few species that live on land do have a very simple lung • Excretory system mainly controlled by nephridia

33. Phylum Arthropoda • Means jointed foot, arthropods have jointed appendages and hard exoskeleton • Includes insects, crustaceans, and centipedes • They are bilaterally symmetrical organisms , made of 3 germ layers that re aquatic, terrestrial and air borne • They have two body openings and one way complete digestive system • Food is digested extracellualrly • They reproduce sexually with species being either of opposite sexes or some being hermaphrodites • Fertilization is internal

34. Their nervous system are advanced compared to other invertebrates with that in mind their sensory abilities are also advanced. Many have the ability to hear taste smell touch and see • They have open circulatory systems • Have respiratory systems made of gills and tracheals. Tracheals are tubule networks involved in gas exchange • Excretory system made of malpighian tubules and green glands • Malpighian tubules: are a tubule network that collects liquid wastes and sends them to the hind gut in the form of nitrogenous wastes • Green glands: collect and excrete urine

35. Phylum Echinodermata • Means spiny skinned • Includes starfish, sea urchin and sea cucumber • They are radially symmetrical organism, made of 3 germ layers that are solely aquatic. • They have two body openings, a one way digestive system and have a tube –within- a tube body plan • Food is digested exrtacellularly • They reproduce sexually and asexually via regeneration, sexual reproduction is only possible through opposite sexes, there are no hermaphrodites • Fertilization is external • Their nervous system is relatively simple comprising an oral ring and radial nerve cords • Sensory abilities limited to touch and eye spots in some species • They have an open circulatory system and their respiratory system utilizes gills and diffusion through skin • Excretory system made possible by diffusion

36. Why are Arthropod so successful? • 1. Most biologically successful and abundant animal group on earth. • 2. There are more arthropod species than all other species combined. • 3. There are 1 million known species. • 4. Symmetry is bilateral. • 5. Small coelom. • 6. Jointed appendages for efficient locomotion.

37. 7. Exoskeleton that provides: (a) protection of internal organs (b) waterproof covering allowing many to live on dry land • 8. Segmented body with parts modified and fused to form specific body regions: (a) head – anterior (b) thorax - middle (c) abdomen - posterior

38. 9.Possess a variety of well developed systems: • a) Digestive • b) Respiratory • c) Excretory • d) Reproductive • e) Skeletal • f) Circulatory - open system • g) Nervous - well developed with the following features: (i) distinct brain ii) ventral nerve cord (iii) sense organs such as eyes, auditory organs, sensory bristles, and antennae that touch and sense chemicals

39. Arthropod Exoskeleton • Arthropods have developed a rigid and jointed external skeleton made of a waterproof material known as chitin. • The skeleton provides many advantages including a site for muscle attachment and protection of bodily tissues. • Because Arthropods do grow and because their exoskeletons cannot expand they are forced to periodically shed their exoskeletons. This is called molting

40. Arthropods: Specialized Body Segments • Arthropods have developed three body segments which are often fused • Head • Thorax • Abdomen • Their appendages are attached to these regions providing them with the ability to develop and specialized for specific functions including sensory reception (antennae),feeding, (mouth parts) and locomotion (Legs, swimmerets, wings). • They have evolved in such a way that they`ve adapted to obtain nourishment in a variety of ways, eating both plant and animal tissues. Some may feed on either other insects of different phyla or their own. Some may feed on blood. Mouth parts have also evolved to cope with feeding difficulties such as larger and stronger mandibles fangs and teeth.

41. Modified Mouth parts • Sucking Mouthparts • Form a tube that can pierce tissues of plants and animals • ex. Mosquitos butterflies • Madibles, maxillae, and other parts of the pharynx are fused into a needle like structure • Sponging and lapping mouthparts • Labium has a modification at its apex • Ex. fruit and house flies • Have a pair of soft lobes that serve as food channels • lap up food or liquefy with salivary secretions • Chewing mouthparts • Mouthparts adapted for seizing, grasping, and crushing food • Adaptations for herbivores and carnivores¸ strong mandibies, toothed plates • Enzymes are secreted from salivary glands that by way of chemical actions can liquefy food to aid in the chewing process

42. Reproduction • Despite short life spans they reproduce in extremely large numbers. They` ve also adapted various techniques to attract mates including the use Pheromones (enticing odours) • Some also have the ability to produce unfertilized eggs that are capable of growing into adults, a process known as Parthenogenesis

43. Appearance • Many have adapted appearance strategies with an advantage for protection or in some cases attraction • Camouflage: organisms blend in with the environment so it cannot be easily seen • Coloration: organisms seeking to attract or repel prey, warning coloration signalling toxicity • Mimicry: insects adapt to look like another dangerous or poisonous insect

44. Developed Nervous System • Have a larger brain than nearest invertebrate relative (Annelid). May have the ability to see, hear, taste, smell and touch • Have a greater range of responsibility • Social interactions and behaviours • Ants and bees demonstrate a hierarchical social lifestyle, one is required for their survival

45. Social Behaviour of bees • Societies display as caste differentiation there is a clear division of labour • All stages of life are present(larvae, pupa, adults) • Activities are collective, each individual works to benefit the community. • social castes of bees • Queen: single sexually mature female • Drone: sexually mature males that mate with the queen • Workers: sexually inactive females that cars for the colony, feed young gather food and care for the hive • Casts are determined by fertilization and by what larvae are feed • Drones develop parthenogenetically from unfertilized eggs and are haploid • queens and workers develop from fertilised eggs they are diploid • Queens are fed royal jelly produced by workers which contains enzymes that allow queen to sexually mature

46. The most successful class is class Insectawith 900,000 known species • Nearly all are terrestrial with a few fresh • Size range is broad; from 0.25 mm for some species of beetles and up to 30 cm for some tropical moths water and saltwater forms

47. The success of insects is credited to the following reasons: • (1) They are the only invertebrates capable of flying. This allows them to move over great distances to find food, escape predators, and spread to new environments. • (2) There is tremendous variation in how they are adapted for feeding and reproduction, so they can exist in all kinds of environments and obtain nourishment from many sources. • (3) High rate of reproduction and short life cycle. This increases the ability of insects to adapt. • (4) Small in size. This means they don’t need large areas to live. • (5) Social insects • (6) Variations in body form

48. Phylum Chordata

49. There are three basic characteristics that distinguish phylum Chordata from all other animal phyla • (1) The presence of a flexible, rod-like, internal supporting structure called a notochord. It runs the length of the organisms near the dorsal surface. In vertebrates it is replaced during embryonic development by cartilage or bone • (2) The presence of a hollow dorsal nerve cord. This lies just above the notochord. This tube will eventually form the brain and spinal cord of the adult. • (3) Gill slits are present at some time in development. These are paired openings in the wall of the pharynx. In some vertebrates, gill slits are only seen in the embryo. In others such as fish they are present and function during respiration for life

50. Vertebrates • 1. They are a subphylum under the Phylum Chordata. This means they possess a dorsal nerve cord, notochord, and gill slits at the embryo stage. • 2. Vertebrates are the most numerous (95%) and most complex of all chordates. • 3. Possess a backbone. The vertebrae surround and protect the nerve chord. Vertebrae develop from and replaces the notochord.