Internal & External Fertilization-JanaDeGuzman.pdf

SEA LION & SEA URCHIN
Internal & External Fertilization
California sea lions
lack the "mane" that
gives sea lions their
name.
have a more slender
neck
one of the noisiest
pinniped species
have numerous
vocalizations used not
only on land but
underwater as well.
There are over 800
species of sea urchins
found in waters
around the world.
They move rather
slowly and feed on
algae.
These invertebrates
are hard shelled,
globular and spiny in
structure.

Adult males are about 8 feet
(2.4 meters) long from nose to
tail and weigh an average of
600 pounds (272 kilograms).
In preparation for the
breeding season, their weight
often increases up to 1,000
pounds (454 kilograms).
Adult females are
significantly smaller and
slimmer than males. They are
about 6 feet (1.8 meters) long
and weigh an average of 220
pounds (100 kilograms).
The red sea
urchin is the
biggest of them
all and is about 7
inches in
diameter.
Size

California sea
lions live 15 to 20
years in the wild
and average 25 to
30 years in
human care.
Based on growth
rates, it has been
estimated that
these animals can
live over 50 years
Lifespan

Land and aquatic
habitat
(seashores)
Live on the rocky
sea floor
Shallow sea water
Deepest ends of
the oceans
Habitat

female
reproductive tract
consists of the
ovaries, uterus,
cervix, and vagina
male reproductive
system consists of
the testicles, vas
deferens,
epididymis,
prostate, and penis
Dioecious animals: male
and female sexes are
separate
no distinguishing
features are visible
externally
Genital gland of a sea
urchin, the so-called
gonad
five gonads, some
irregular forms of urchins
have just four gonads
Sexual
Organs

Small Number
Females give
birth to a single
pup.
Large Number
Only 10% to 40%
of the total gonads
released are
actually fertilized.
Number of
gametes
produced

Lower Higher
Wastage
of gamete

bulls establish breeding
territories on the beach
from May to August.
A male breeds with an
average of 16 females in
one season.
Females initiate
courtship and copulation
Not present
Copulation

The dominant male will
mate with an average of
16 females in one season.
Once the egg is fertilized
inside the female, she
can delay implantation of
the egg to stop the
embryo from growing.
The delayed implantation
may last up to three
months with an average
gestation period lasting 9
months.
males who release their
sperms in water that gives a
cue to the female to release
millions of tiny, jelly-coated
eggs.
The eggs and sperms collide
with each other and
fertilization may take place.
10 minutes
Four important events of
fertilization in the sea
urchin
Fertilization

Total gestation
lasts 11 to 11.5
months.
begins to divide
and multiply
rapidly
By this time, six
divisions are
complete within 3
hours
Gestation Time
After Fertilization

Pups are born on
land.
Pupping may last
from a few minutes to
an hour.
Approximately 63%
of pups are delivered
head-first.
Not present
LABOR

Pups are about 75 cm
(29.6 in.) And 6 kg (13.2
lbs.).
Pups are well developed
at birth.
They are born with their
eyes open and can
vocalize.
Within 30 minutes they
are able to shake,
groom, scratch, and
walk.
In a month’s time, the
pluteus begins to sink to
the ocean floor. It
buries itself in the sand
and undergoes a full-
fledged metamorphosis.
It begins to appear like
an adult sea urchin and
will continue to grow for
a few years.
DEVELOPMENT

Embryo and
Offspring got
parental care
(father left after
giving birth)
Little or No
parental care
Parental
Care

At around age
four or five, they
are able to
breed
After about 5
years, it achieves
sexual maturity
and will start
undergoing
reproduction.
Sexual
Maturity

Internal & External Fertilization-JanaDeGuzman.pdf

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