Download Eisenia veneta - St. Olaf Pages

Hermaphrodites
Both Female & Male
Life Span
1-8 years
Copulation & Reproduction
2 separate processes
Feeding Rate is related to
body size
Converts food to offspring
Temp and body size growth/
reproduction correlates
L. Fayolle, H. Michaud, D. Cluzeau, J. Stawiecki, Influence of
temperature and food source on the life cycle of the earthworm
Dendrobaena veneta (Oligochaeta), Soil Biology and Biochemistry,
Volume 29, Issues 3–4, March–April 1997, Pages 747-750
Earthworm
Eisenia veneta
Earthworm
Eisenia veneta
 Life
History
T. Jager, S.A. Reinecke, A.J. Reinecke, Using process-based modelling to analyse earthworm life cycles, Soil Biology and
Biochemistry, Volume 38, Issue 1, January 2006, Pages 1-6, ISSN 0038-0717, http://dx.doi.org/10.1016/j.soilbio.2005.04.009.
The Orb Snail ( Planorbidae
Orb snails are hermaphroditic
corneus)
They mate sexually or self fertilize






many times in their life cycle.
During copulation, each snail
passes sperm to the other snail.
The spermazoa travel down the
oviduct and are stored in the
bursa copulatrix.
That sperm does not necessarily
fertilize the eggs because both
snail’s sperm are passed down the
ovaduct towards the eggs.
Self fertilization is limited in that
the offspring are less viable
without genetic recombination
Planorbidae corneus





After fertilization, the snails lay
their eggs in a gelatinous mass in
a damp area.
FUN FACT: Snails do not follow
Mendel’s principles of
inheritance.
Instead they exhibit the
phenomena of maternal
inheritance in the trait of shell
coiling.
Female cytoplasm contains the
mitochondria, which is always
inherited by the offspring. The
cytoplasm in snails contains the
gene for the direction of shell
coiling.
The phenotype of the mother will
ALWAYS be expressed in the
offspring, even if the males have
the dominant trait.
Jack-in-the-pulpit : Arisaema triphyllum
• Herbaceous perennial plant
• Three reproductively isolated subspecies of
Arisaema; triphyllum is most common
• Tetraploid with 56 chromosomes
• Sexual reproduction
• True dioecious plant, flowers are unisexual;
When plant is young and small, flowers are male.
As the plant ages and grows, the male flowers die
and female flowers mature.
• This prevents self pollination.
Jack-in-the-pulpit : Arisaema triphyllum
• Flowers from April to June
• Pollinated by flies, which are attracted by smell
• Fertilized flowers develop into a cluster of berries,
which start out green and then turn red; fruit
ripens late summer and fall
• Each berry produces 1-5 seeds
• Seedlings need 3+ years of growth before they are
big enough to flower
•
http://www.jstor.org/stable/1936800?seq=2
•
http://www.theprimrosepath.com/Featured_Plants/Arisaema_triphyllum/tr
iphyllumcomplex.htm
Cicadas
Kristin Heslep
•
Sexual reproduction (m/f)
• Mate for 3-5 days (male clasper)
• Fertilized eggs laid in slits of twigs
that the female makes with her
ovipositor (400 eggs in 40 sites)
 Sexual Dimorphism
• Males “sing” from trees -vibrating
abdominal membranes to attract
mates, females are mute
• air sacs in male’s abdomen amplify
the song, digestive and reproductive
organs are reduced
• Males detect the closeness of
competing males (opercula)
• Females can detect direction of
sound (track the singing males)
Dog Day Cicada
(Tibicen canicularis)
• Lifecycle
• Egg (haploid gametes->diploid)
• 2 months
• Laid in twigs so they can hatch
then burrow
• Nymph
• Dog Day is annual (but also 13-17
year periodical cicadas)
• Sap from xylem
• Development completed
underground
• Adult
• Emerge from exoskeleton
• Reproduce then die
http://entomology.osu.edu/~bugdoc/PerioCicada/PeriCicadaBehav.htm
http://lanwebs.lander.edu/faculty/rsfox/invertebrates/tibicen.html
http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/05/29/sex-and-the-cicada-and-an-updated-coverage-map/
Melanoplus - Grasshopper
•
•
•
•
Sex: male and female
Females produce eggs – internally fertilized
Males produce spermatophore
Female grasshoppers lay eggs in soil – production areas
 Lay eggs throughout autumn into September and October
 Female can lay up to 25 eggs
 Eggs remain in soil over winter and begin to hatch in spring
• Nymphs molt five times and reach adulthood in 60 days
• Identify species through inspecting male genetalia
 Different species lay eggs on different plants and hatch at different
times
The Nitty Gritty
• Spermatophore forms in ejaculatory duct once pair is coupled
 Takes five minutes to fully formed
 Up to 14 in one copulation
 Nutrients from spermatophore incorporated into eggs
• Polygynandric mating system
 Females with more mates →more nutrients from ejaculate transfer →
higher fecundity
 Second males → egg pods produced and deposited more frequently
 Ejaculate is a mating effort, not insurance of paternity
 Males insure paternity through frequent and extended copulation
 Risk of predators
•
•
•
•
•
•
•
http://bugguide.net/node/view/710076
http://www.nwroc.umn.edu/ResearchAreas/Entomology/EntomologyPublications/RedRiverI
PM/MNGrasshopperMgmt/index.htm
http://naturallycuriouswithmaryholland.wordpress.com/2013/09/23/grasshoppers-matingand-laying-eggs/
Cardero, Carlos. “Ejaculate substances that affect female insect reproductive physiology and
behavior: Honest or arbitrary traits?” Journal of Theoretical Biology, 1995, 4:453-461.
Carothers, Eleanor E. “Notes on the taxonomy, development and life history of certain
Acrididae (Orthoptera).” Transactions of the American Entomological Society, 1923, 49:7-24.
Mardo, M.C. et. al. “Female fitness is increased by frequent mating in grasshoppers.” The
Genetical Society of Great Britain, 1995, 74:654-660.
Pickford, R. and Gillott, C. “Insemination in the migratory grasshopper, Melanoplus
sanguinipes.” Canadian Journal of Zoology, 1971, 49:1583-1588
.
Camponotus pennsylvanicus
●
●
●
●
●
●
Commonly known as the black carpenter ant
Nupital flight: winged males and females mate while
flying
o males die, females lose wings and become new
queens
Queens lay eggs who will become her workers as
adults
Queens wait in chamber during this time, using fat
reserves and wing muscle as energy source
Total lifespan: 6-12 weeks.
o Can be increased for up to 10 months if cold
After about 2 years of colony growth, the queen
begins to produce winged males and females to mate
and start colonies of their own.
Camponotus pennsylvanicus
●
Haplodiploidy
o Males are haploid and develop
from unfertilized eggs
o Females are diploid and develop
from fertilized eggs
o Females are more closesly related
to their sisters (r>0.75) than to
their offspring (r=0.5)
o Workers are sterile, and exhibit
altruism because of the high
degree of relatedness to the rest of
the colony