WEEK 3
PART 2
Competency:
Describe the
different ways of
how representative
animals reproduce.
(S11/12LT-IIej- 15)
W H AT A M I ?
Identify the animals being shown and
share what you know about these
animals.
SPONGES
SEA ANEMONE
FLATWORM
ASCARIS LUMBRICOIDES
The members of the animal
kingdom are subdivided into
different groups called phyla.
The organisms
within a phylum
are more closely
related to each
other than they
are to organisms
of other phyla.
Depending on the
classification
scheme, there are
roughly 34 animal
phyla and nine are
considered the
major phyla.
Major Phyla of Kingdom Animalia
Phylum Animal It Includes
Porifera sponges
Cnidaria jellyfish, corals, sea anemone, hydra
Platyhelminthes flatworms, tapeworms, flukes
Nematoda roundworms
Mollusca snails, clams, squids
Annelida earthworms, leeches, marine worms
Arthropoda insects, spiders, crustaceans, centipedes
Echinodermata sea stars, sea urchins, sand dollars, sea cucumbers
Chordata tunicates, lancelets, fish, amphibians, reptiles, birds,
mammals
The first eight phyla
listed in the table
include only
invertebrate
animals.
Invertebrates are
animals that lack a
vertebral column,
or backbone.
The last phylum in
the table, the
Chordata, also
includes many
invertebrate
species and
vertebrate
species.
Vertebrates are
animals that
have a
backbone. They
include fish,
amphibians,
reptiles, birds,
and mammals.
Invertebrate
Reproduction
The vast majority of
animals on earth
today are
invertebrates. They
make up 97% of all
animal species.
The invertebrate
phyla include a
wide array of body
plans and
adaptive
strategies.
Although invertebrates are
ALL capable of sexual
reproduction, most phyla
include species that are
also capable of asexual
reproduction.
Reproduction in Selected Invertebrates
Phylum & Example Asexual Reproduction Sexual Reproduction
Porifera budding • most are
Example: sponges hermaphrodites
• can’t self-fertilize
Reproduction in Selected Invertebrates
Phylum & Example Asexual Reproduction Sexual Reproduction
Cnidaria usually binary fission • some are
Example: Sea hermaphrodites
Anemone • most
hermaphroditic
species can’t self-
fertilize
Reproduction in Selected Invertebrates
Phylum & Example Asexual Reproduction Sexual Reproduction
Platyhelminthes fragmentation • most are
Example: flatworm hermaphrodites
• fertilization may
involve two
individuals or self-
fertilization may
occur.
• oviparous
Reproduction in Selected Invertebrates
Phylum & Example Asexual Reproduction Sexual Reproduction
Nematoda does not reproduce • need a mate to
Example: Ascaris asexually reproduce
lumbricoides • oviparous (females
(human intestinal lay huge numbers
roundworm) of eggs)
Reproduction in Selected Invertebrates
Phylum & Example Asexual Reproduction Sexual Reproduction
Mollusca does not reproduce • most have
Example: squid asexually separate sexes
• external
fertilization
Reproduction in Selected Invertebrates
Phylum & Example Asexual Reproduction Sexual Reproduction
Annelida • some species can • hermaphrodites
Example: earthworm reproduce through • most need a mate
parthenogenesis to reproduce
• can regenerate • external
small portions of fertilization
their bodies, but
do not reproduce
through
fragmentation
Reproduction in Selected Invertebrates
Phylum & Example Asexual Reproduction Sexual Reproduction
Arthropoda male bees are the • queen bee
Example: bees result of chooses which egg
parthenogenesis to internally
fertilize before
laying
• fertilized eggs
become female
bee workers
Reproduction in Selected Invertebrates
Phylum & Example Asexual Reproduction Sexual Reproduction
Echinodermata fragmentation external fertilization
Example: starfish
Vertebrate
Reproduction
The vertebrates are a
highly diverse group
of animals that
consist of
approximately 50,000
different species.
They reproduce sexually, and almost
all of them have separate male and
female sexes. Generally, aquatic
species have external fertilization,
whereas terrestrial species have
internal fertilization.
Parthenogenesis, which is a type of
asexual reproduction, has also been
observed in more than 80 vertebrate
species, about half of which are fish or
lizards.
It is rare in
complex
vertebrates
such as
sharks,
snakes, and
large lizards.
Reproduction in Vertebrates
Group Reproduction
fish • Nearly all fish reproduce by sexual
(examples: reproduction.
bangus, shark, • Most species have separate female and
stingray) male sexes, but there are also many
species that are hermaphrodites.
• Fertilization is external in most fish
species.
• In the case of shark and ray species, most
are ovoviviparous.
Reproduction in Vertebrates
Group Reproduction
amphibians • Amphibians usually reproduce via sexual
(examples: reproduction.
frogs, toads, • Fertilization is most often external for
salamanders) frogs but internal for salamanders and
caecilian.
• Amphibians must lay their eggs in water
to protect the eggs from dehydration.
Reproduction in Vertebrates
Group Reproduction
reptiles • Most reptiles reproduce sexually and
(examples: have internal fertilization.
turtles, snakes, • Oviparous - Reptile eggs are amniotic
lizards, (has a shell and a series of membranes
crocodiles) that surround the developing embryo), so
they can be laid on land instead of in
water.
• Asexual reproduction has been identified
in six families of lizards and one snake
family.
Reproduction in Vertebrates
Group Reproduction
birds • Birds reproduce sexually and have
(examples: internal fertilization.
eagle, maya, • Oviparous - Birds' amniotic eggs have
chicken, duck, hard shells and are laid in a nest. The
penguin) eggs are usually incubated until they
hatch.
• Most species have a relatively long period
of parental care. In the case of penguins,
the males incubate the eggs.
Reproduction in Vertebrates
Group Reproduction
mammals • Mammals reproduce by sexual reproduction
(humans, and internal fertilization.
monkeys, bats, • The platypus and echidnas lay eggs, but
dogs, cats, rats, most mammals give birth to live young
kangaroos, (viviparous).
whales) • Substances are passed from the mother to
the fetus through the placenta like humans.
• Mammals can be marsupial, like kangaroos,
where the embryo is born at an immature
stage and develops in the pouch.
