SCIENCE AND TECHNOLOGY IN OUR LIVES (UGRC 142)
Animals as Friends of Humans
Vertebrate Biology and Venomous Animals (Weeks 2)
Mr. Musah YAHAYA
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LECTURE SYNOPSIS
VERTEBRATE BIOLOGY (WEEK 2)
• What is a Vertebrate?
• Why study vertebrates?
• Vertebrate Classification and Nomenclature
• Basic Requirements of Animals
• Native, Exotic (Alien) and Invasive Species
• Vertebrate Morphology and Physiology
• Important Vertebrates of Ghana
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WHAT IS A VERTEBRATE?
• A vertebrate is an animal possessing a backbone or vertebral column,
as contrasted with another type of animal called an invertebrate, which
lacks a vertebral column
• Other features of vertebrates are the possession of:
– a distinct and well-differentiated head with a skull and brain
– an internal skeleton (endoskeleton)
– a post-anal tail
– a closed circulatory system (heart and blood vessels)
• Examples of Vertebrates: Fishes (tilapia, shark), Amphibians (frogs,
toads), Reptiles (lizards, snakes, tortoises, crocodiles), Birds (pigeon,
vulture, ostrich), Mammals (elephant, human, lion, monkey, antelope)
• Examples of Invertebrates: Worms (tapeworm, earthworm), Arthropods
(insects, spiders, crabs), Molluscs (snails, clams, octopus),
Echinoderms (starfish, sea urchin)
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WHY STUDY VERTEBRATES?
BENEFICIAL INTERACTIONS
Sources Examples
Food supply Livestock, game, fish, animal products (eggs, milk, blood, blubber)
Other economic products Leather, wool, fur, ivory, down
Labour/transport Horse, cattle, donkey, camel, hunting dog, elephant, shepherd dog.
Biomedical products Venom, insulin, replacement organs for transplants, antibodies
Scientific research/teaching Animal models (frogs, foetal pigs, rats, primates, dogs, cats, mice).
Psychological value Aesthetics, art, recreation (wildlife parks, zoos), companionship (pets, ornamental)
Ecological value Components of food chains/webs, pollination, seed dispersal, pest control.
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WHY STUDY VERTEBRATES?
DETRIMENTAL INTERACTIONS
Sources Examples
Predators Large carnivores (tigers, crocodilians, sharks)
Defensive “attackers” Bites of venomous snakes.
Vectors of disease Rodents, bats, dogs, birds.
Agricultural pests Rodents, rabbits, birds, large herbivores.
Vampire batTiger: Panthera tigris
Green tree snake
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VERTEBRATE CLASSIFICATION AND NOMENCLATURE
• CLASSIFICATION = SYSTEMATICS
• Defining and describing different animals• Group them according to similarities and differences• Levels of groups – how to organise and recognise them• Show and explain their relatedness = evolutionary sequence
• NOMENCLATURE = TAXONOMY • Name different groups (clades) and individual units = species• The names should give a good description a species/group• Common and scientific names • Rules and naming systems in Animal Nomenclature
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VERTEBRATE CLASSIFICATION
• DEFINITION
The ordering of animal species into groups or sets on the
basis of their evolutionary relationships (e.g. association by
similarity, and shared derived characters
• WHY CLASSIFY?
• Difficulty in identifying millions of animal species
individually – need a better overview and understanding
• Helps to generalize or specialize as appropriate
• Powerful information retrieval and organizing system
• Comparison and communication of research results
worldwide (i.e. making sure we refer to the same animals)
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VERTEBRATE CLASSIFICATION - RULES
Classification rules have seven (7) major classification levels in a hierarchy
= Taxa: Kingdom → Phylum → Class → Order → Family → Genus → Species.
Example: classifying a lion and a human being (mammal) and lizard (reptile)
Category Lion Human Being Agama Lizard
KINGDOM ANIMALIA (Animal)
PHYLUM CHORDATA (Vertebrate)
CLASS MAMMALIA (Mammal) REPTILIA (Reptile)
ORDER CARNIVORA (Carnivore)
PRIMATES (prosimians, monkeys, apes, humans)
SQUAMATA (lizards, snakes)
FAMILY FELIDAE (cats) PONGIDAE (apes, humans) AGAMIDAE (typical lizards)
GENUS Panthera (large cat) Homo (Hominids: e.g. erectus) Agama
SPECIES Panthera leo (Lion) Homo sapiens (Human being) Agama agama(Agama lizard)
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VERTEBRATE CLASSIFICATION - OUTLINE
Kingdom: ANIMALIA (separated from plants, bacteria, fungi, viruses)
Phylum: CHORDATA (separated from animals without a backbone)
Class: PISCES (Fishes: Lampreys, Sharks, rays, Tilapia, salmon)
Class: AMPHIBIA (Amphibians: Frogs and toads)
Class: REPTILIA (Reptiles: Lizards, snakes, tortoises, crocodiles)
Class: AVES (Birds: Pigeons, vultures, ostrich, sparrows, crows)
Class: MAMMALIA (Mammals: shrews, elephants, rats, humans)
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VERTEBRATE NOMENCLATURE
• A system of naming organisms (animals), OR a system of animal names
• It is important for any living organism to have a name, to avoid the use of
cumbersome descriptive phrases.
• Every living organism has two types of names: a common/vernacular and a
scientific: Common name = Leopard; Scientific name = Panthera pardus
• Common names can vary depending on locality and language used, but there
is only one scientific name in Latin, which is accepted worldwide
• Scientific names have two parts, a generic name (Panthera) and a specific
name (tigris). This is referred to as the binomial system of nomenclature,
and the two-part name is called a binomen. The system was developed by the
Swedish biologist Carolus Linnaeus (Carl Linné 1707-1778) in 1735.
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VERTEBRATE NOMENCLATURE - THE NEED FOR A SCIENTIFIC NAME
• Common names of animals differ from country to country and even from region to
region within a particular country. Species therefore have hundreds such names.
• Since Zoological Science is universal, and it is important to compare or
communicate scientific results across national or regional boundaries, there is the
need for a universally-accepted scientific name in a language which is universally
acceptable = Latin: E.g. Human being = Homo sapiens everywhere on earth)
• Some common names do not provide a clue as to the type of animal involved, and
this makes identification difficult if the animal does not have a universally-
acceptable scientific name – some examples:
• John Dory (Zeus faber) .............................…Bony fish
• Prairie Dog (Cynomys parvidens) .............…Ground squirrel
• Sergeant-Major (Abudefduf saxatilis) ......…Bony fish
• Horny Toad (Phrynosoma platyrhinos) ........Lizard
• River Jack (Bitis nasicornis) .....................….Snake
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VERTEBRATE NOMENCLATURE - RULES FOR SCIENTIFIC NAMES
• Scientific names should always be italicised or underlined (e.g. Panthera leo, Bufo regularis)
• The generic name is always initially capitalised, while the specific name is not (E.g. Homo sapiens)
• Each binomen must describe only one species. Common names of animals differ from country to country and even from region to region within a particular country. Species therefore have hundreds of common names.
• The specific name by itself is meaningless, unless accompanied by the generic name (Homo sapiens, not sapiens for a human being)
• Once the full binomen has been listed or cited in the text, its generic name can be abbreviated to only its initial letter in subsequent citations (E.g, Homo sapiens = H. Sapiens)
• New scientific names must be approved by the ICZN (International Code of Zoological Nomenclature). It is the discoverer that serves the right to name a new species; the person may use another persons name: Nectarinia johannae
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VERTEBRATE DIVERSITY AND DISTRIBUTION:BASIC REQUIREMENTS OF ANIMALS
• Animals have basic needs for survival and breeding:
1) Habitats of sufficient size for a viable population: This area
will depend on the animal size and the specific needs for
reproduction and feeding (e.g. nesting holes in trees, open
water or nectar).
2) Food resources of sufficient size, thereby reducing
competiton within and between the species: If compe-tition is
too much within a species, individuals’ mortality increase and
population size will decrease; if compe-tition is too much
between species, the inferior one will have to retreat (be
excluded), either by moving away or becoming locally extinct.
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VERTEBRATE DIVERSITY AND DISTRIBUTION:BASIC REQUIREMENTS OF ANIMALS (cont.)
3) Conducive Climatic Conditions:
All animals have limitations and an optimum range
within gradients in their environments:
a) Temperature: some adapted to cold (e.g. arctic
tundra) others to hot weather (e.g. tropical deserts).
b) Humidity/Water: some adapted to dry conditions
(e.g. tundra, desert, peatland) others to humid (e.g.
rainforest, swamps, marshlands).
4) Species interactions: Survival of some animals
depends to a large extent on other organisms
activities - e.g. breeding in cuckoos (brood parasitic
bird) depends on the breeding activity of hosts.
Bactrian Camel: Camelus bactrianus
Polar Bear: Ursus maritimus
Common Cuckoo fed by Warbler
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VERTEBRATE DIVERSITY AND DISTRIBUTION: NATIVE, EXOTIC AND INVASIVE SPECIES
Native/Indigenous Species:
Species living in areas in which they originally evolved or naturally dispersed to.
Exotic/Alien Species:
Species which have been intro-duced either intentionally or by accident either through importation or domestication, to areas that did not originally harbour them (e.g. deer in Africa).
Invasive Species:
An exotic or local animal which adversely affects the habitat or bioregion (disruption, dominance) it invades economically, environmentally, and/or ecologically.
Helmeted Guineafowl:Numida meleagris
Red Junglefowl: Gallus gallus
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VERTEBRATE DIVERSITY AND DISTRIBUTION: MORPHOLOGY AND PHYSIOLOGY
• Morphology = The structure of an animal or organ (e.g. skin, hair, feathers or skeleton).
•Physiology = The function of an animal or organ (e.g. respiratory, circulatory and excretory systems).
• Morphology and physiology both relate to adaptations
of an animal to its
(i)habitat, (ii) food, and (iii) reproduction,
ensuring that animals are well fitted to their environment to survive, reproduce and disperse.
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VERTEBRATE DIVERSITY AND DISTRIBUTION: MORPHOLOGY AND PHYSIOLOGY
•Important morphological features in some vertebrates:
•Mammals: hair, mammary glands, teeth and tusks, wings
(bats), claws, nails, hooves, horns.
• Birds: feathers, beaks, wings, claws, colouration, gizzard
• Reptiles: scales, olfactory (Jacobson’s) organ, claws, teeth
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IMPORTANT VERTEBRATES IN GHANA
• Many vertebrates in Ghana are important assets for
various industries, hence providing jobs and income:
• Ecotourist Industry: Elephants (e.g. Mole, Kakum
National Parks), rare Picathartes (bird), > 700 bird
species (birding tours), crocodiles (Paga), sea turtles
and whales (safari), monkeys (Boabeng-Fiema sanctuary).
• Bushmeat Industry: Grasscutter (cane rat), duikers, giant
rat, porcupines, bushbuck, francolins.
• Medicinal Industry: Venomous snakes, frogs and toads.
• Animal Pet Export Industry: Parrots, canaries, glossy
starlings, weavers, chameleons, pythons, lizards, geckos,
frogs, toads, fishes, etc.
Savanna elephant: Loxodonta africana
in tourist camp (Mole National Park)
Rearing of Cane rat:
Thryonomys swinderianus
Chameleons – objects for the pet trade
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