Non mammalian repro

Asexual reproduction

New organism produced from one parent

Identical to parent

Advantages: will get all of parent's good characteristics

Disadvantages: will get all of parent's bad characteristics, less able to adapt to environment

Binary fission

Type of asexual reproduction undergone by bacteria and other single celled organisms

Copy & divide into two identical organisms

Vegetative propagation

Type of asexual reproduction

Results in a new plant identical to the parent plant - runners

Budding

Type of asexual reproduction

Organism produces a bud that breaks away to live on its own (hydra)

Common in invertebrates

Regeneration

Type of asexual reproduction

Organism uses cell division to regrow body parts

Sea stars, salamanders

In sea stars, if you cut off an arm with part of the main disk both parts will regenerate into identical sea stars

Sexual reproduction

Two parents; offspring are a combination of both parents and are therefore unique

Advantages: variety/diversity of offspring makes them more able to adapt to environmental changes

Disadvantages: sometimes traits needed for survival aren't passed on

Invertebrate types

Sponges

Cnidarians

Platyhelminthes

Molluscs

Annelids

Nematodes

Arthropods

Echinoderms

Sessile

Non moving

Porifera - sponges traits

Form colonies

Sessile (offspring move around though)

No nerves/muscles (no tissue differentiation/cell layers)

Mostly marine (few freshwater)

Filter feeders

Most are hermaphrodites

Sponge sexual reproduction

- Sperm released into water from porocytes, can travel to other sponges

- internal fertilization, fertilized eggs develop into zygotes in jelly like substance between cell layers

- Zygotes become free swimming larvae (swim from body of sponge on currents created by collar cells)

- Larvae eventually settles on a surface and develops into a sessile adult that can reproduce

Sponge asexual reproduction

Gemmules - clusters of choanocytes and amoebocytes from the sponge break off and develop into an identical sponge

Sponge digestion

Food gets stuck in mucousy collar

Cnidaria classes/examples

Hydrozoas: hydras, some corals

Scyphozoa: Jellies, sea wasp, sea netles

Anthozoa: sea anemones, most corals, sea fans

Defining characteristics of cnidaria

Wide range of reproductive strategies

Nerve net

Planula larval stage in life cycle

Diploblastic (body derived from two layers, ectoderm and endoderm)

Polyp

Sea anemones

Tube shape

Solitary or colonial

Usually sessile

Mouth/tentacles point upwards

Thin mesoglea

Fluid skeleton or calcium carbonate exoskeleton

Medusa

Jellyfish

Solitary

Free swimming

Mouth/anus/tentacles point downward

Thick mesoglea

Cnidaria life cycle

Polyp grows and produces buds (asexual)

Produces a medusa bud that pops off

Medusa has gonad, undergoes sexual reproduction/meiosis (externa fertilization)

Zygote --> planula larva that settles and develops into a mature polyp

Mature polyp buds, buds become medusas

Scyphozoa vs hydrozoa vs anthozoa reproduction

Scyphozoa & hydrozoa - sexual stage is medusa

Alternates between polyp (asexual reproduction) and medusa (sexual reproduction)

Anthozoa - no medusa, polyp is sexual stage; always polyps

Polyp release egg/sperm to produce planula larvae

Polymorphisms

Different forms on the same structure do different things

Ex. A mature polyp will have reproductive buds, digestive buds, etc.

Dioecious

Has gonads that produce just sperm and gonads that produce just eggs

Zooids

Individuals of different forms, structures, and functions within one stage of the life cycle or within one colony

i.e. gastrozooids = zooid that does digestion

Hydrozoa traits

Small, plant like appearance (similar to algae), sometimes present in freshwater

Polyp & medusa

Thin/absent mesoglea

Solitary or colonial

Polymorphisms: Gastrozooids (feeding), dactylozooids (defense), gonozooids (reproduction)

Hydrozoan reproduction

Gonozooids release medusa to reproduce sexually

Hydroid stage can reproduce by asexual budding (bud detaches, becomes independent medusa, or regeneration)

Scyphozoa defining characteristics

Asexual replication by strobilation from scyphistoma (polyp is kind of like a stack of mini medusas)

Dioecious

Fertilzed eggs become planula larvae

Anthozoa defining characteristics

Anatomy: Pedal disc, gut with gonads, and tentacles

No medusa stage

Anemones, corals, sea whips, sea pansies

Some solitary, some colonial

Anthozoa asexual reproduction

Pedal laceration (if there is predation and enough of the disk is left it will grow into a new identical anemone)

Longitudinal fission (if it gets too wide it will just split in half)

Phylum platyhelminthes classes/examples

AKA flatworms

Turbellaria, monogenea, trematoda (aka flukes), cestoidea (tapeworms)

Class trematoda

Phylum platyhelminthes/flatworms

Live as parasites in vertebrates

Blood fluke life cycle

Class trematoda, phylum platyhelminthes

Mature blood fluke lives in blood vessels of intestines of human host, reproduces sexually

Fertilized eggs exit host in feces

Eggs develop in water into ciliated larvae, infect snails

Undergo asexual reproduction within snail to become another type of motile larvae

Larvae penetrate skin/blood vessels of humans

Class cestoidea

AKA tapeworms, phylum platyhelminthes

Live as parasites

Heads contain suckers/hooks that lock onto host's intestinal lining

Rest of body is proglottids (sex organs) - can cross fertilize or self fertilize

Literally a head and 20 meters of sex organs

Eggs transferred to new hosts by consuming fecal contaminated water

Class turbellaria

Flatworms

the penis fencers :(

Phylum mollusca - mollusks traits

Can be hermaphroditic or dioecious

Snails, nudibranches, clams, oysters, octopi, squids, cephalopods

Lots of species

Similar body plan:

- Muscular foot

- Visceral mass with organs

- Mantle that secretes shell

Mate or spawn depending on species

Leopard slug sex

The really dramatic one where they dangle from the tree and twist around each other

Class cephalopoda

Phylum: mollusks

Intelligent

Octopus, squid, cuttlefish, nautilus

Octopi have GnRH-like neurons

Octopus mating

Hectocotylus

- Arm that has a grove in it for sperm packet (spermatophore) to slide down

- Used to deliver sperm packet to female

- Inserted into female's mantle cavity

In some species, female brood then die young

Cuttlefish mating

Use of chromatophores in skin to change color - communicates sexual receptivity

Also, males guard females to prevent another from mating with her

Phylum annelida classes/examples

Segmented worms

1mm-3mm

Hermaphrodites, cross fertilize

Oligochaeta (terrestrial/freshwater segmented worms like earthworms)

Polychaeta (marine segmented worms)

Hirudinea (leeches)

Earthworm mating

Phylum annelida, class oligochaeta

Hermaphrodites that cross fertilize

Have gonads that produce gametes on one side and clitellum (receptacle - band thing) that produces egg casing on the other end

They line up next to each other and deposit eggs into their mucous sacs (slime tubes) that then slide down the body, getting fertilized

The slime tube slips off the end and forms a cocoon filled with eggs that the worms hatch from

Phylum nematoda traits

AKA Roundworms

Non segmented

Common parasites of animals

Includes pinworms/hookworms (aka trichinella)

Trichinosis

Disease - infestation of trichenella (worm)

Obtain from eating encrusted larvae in undercooked pork --> larvae released in stomach

Larvae mature in 1-2 weeks, cause diarrhea, irritation, mild cramping

Then the larvae enter lymph or blood vessels and penetrate muscle cells, causing lesions in striated muscle (symptoms: periorbital edema, fever, eosinophilia, occasional CNS & cardiac drainage)

Nurse cell L1 complex matures in about 20 days

Caenorhabditis elegans life cycle

C elegans

Model for a lot of reproduction

If environment not good, larvae undergo dauer larval stage - arrested development for up to 4 months

If environment returns to okay, they resume developing

Largest penis to body size ratio

Arthropods - barnacles

Sessile - can't move around

Dioecious - males and females

Means penis has to extend and move around to deposit sperm in females

Phylum arthropoda: traits/examples

Crustaceans, spiders, insects

Most successful of all animal phyla - nearly a million species

Traits:

Hard exoskeleton

Segmented bodies

Jointed appendages

Arthopoda evolutionary lineages

Trilobites

- Extinct

Chelicerates

- Horseshoe crabs

- Spiders

Uniramians

- Centipedes

- millipedes

- insects

Crustaceans

- crabs

- lobsters

- barnacles

Arthropoda classes/examples

Arachnida (spiders, scorpions, ticks, mites)

Diplopoda (millipedes)

Chilopoda (centipedes)

Insecta (insects)

Crustacea (crabs, lobsters, crayfish, shrimp, pill bugs)

Crustacea reproduction

Dioecious

Males release sperm packets using modified appendages similar to octopus hectocotylus

Females molt during mating, and hold sperm packet until fertilization

Most are brooders (generally the female)

Blastospore

First body opening

Hole in bottom of embryo

Coelom

Future body cavity

Archenteron

Body cavity of embryo - forms digestive tube

Protostome vs deuterostome eight cell stage

Deuterostomes:

- Radial (cells lined up)

- Indeterminate (any cell can be anything)

Protostomes:

- Spiral (cells not lined up)

- Determinate (need all 8 cells)

Protostome vs deuterostome coelum formation

Formation of body cavity

Deuterostomes

- Enterocoelous = folds of archenteron (body cavity) form coelom

- kind of looks like little cat ears

Protostomes:

- Schizocoelus = solid mases of mesoderm split to form coelom (archenteron is round, not part of coelom formation)

Protostome vs deuterostome fate of blastopore

Deuterostomes:

- Anus develops from blastospore

Protostomes

- Mouth forms from blastospore

Deuterostome development

Eight celled:

- Radial

- Indeterminate

Coelum

- Formed by folds of archenteron

- Entercoelous

Blastospore

- Becomes anus

Echinoderms, chordates

DRIFA - deuterostome = radial, indeterminate, folds, anus

DRIFEACE - deuterostome = radial, indeterminate, folds, enterocoelous, anus, chordates, echinoderms

Protostome

Eight celled:

- Spiral

- Determinate

Coelom

- Forms from mesoderm splitting

- Schizocoelous

Blastospore

- Becomes mouth

Mollusks, annelids, arthropods

MAAPS DSMM - mollusks, annelids, arthropods are protostomes, spiral, determinate, schizocoelous from mesoderm split, mouth

Phylum echinodermata

Sea stars, sea urchins, sand dollars, brittle stars, sea cucumbers, crinoids

Deuterostomes

Radial as adults, bilateral as larva

Gonads divided into radial lobes - dioecious

Sea stars can regenerate asexually

All are spawners

What is our closest invertebrate relative?

Echinodermata

(e KIN odermata)

Sea urchins as a model

Fertilization

- Fast block to polyspermy

- Fertilization of cortical granules (mediated by calcium wave in egg)

Early development

- Early cell division is easily visible

- All early cell divisions identified (which are very similar in all species up to 64 cell blastula)

- Early embryonic development model for 100 years

- Indeterminate development

- Development speed controlled by temperature

Sea stars as a model

Model for cell signaling behind oocyte maturation

Germinal vesicle clearly visible

Hormone 1-methyladenine induces germinal vesicle breakdown (GVBD) in sea stars, which is immediately followed by spawning

GVBD is first step of meiosis, studied in sea stars

Bony fish reproductive morphology

Male:

Testes --> vas deferens --> urogenital pore

Female:

Ovary --> oviduct --> urogenital pore

Most are not internal fertilizers/brooders

Cartilaginous fish (like sharks) reproductive morphology

Male:

testes --> leydig's gland --> seminal vesicle --> cloaca --> claspers

Female:

Ovary --> ostium tubae --> oviduct --> shell gland --> "uterus" --> cloaca

Most are internal fertilizers/brooders or lay eggs

MTLSCC

FOOTOSUC

Fish reproductive traits

Fecundity

Size of offspring

Mating system

Frequency

Parental care

Method of fertilization

Gender system

Reproductive behaviors

Fecundity

Number of eggs

Increases geometrically with body size

Early growth + deferred reproduction = higher fecundity but higher probability of dying before reproducing

Size of offspring

Probability of offspring survival increases with size (larger supply of reserves, fewer predators, greater feeding efficiency), but cost to parent increases (also decreases fecundity)

Mating systems

Promiscuous

- Both sexes mate with multiple partners

- Most common

Polygynous

- Males with multiple female mates

- Cichlids

Polyandry

- Females with multiple male mates

- Anglerfish (males super tiny, parasitize females and basically just become a pair of testes on her)

Monogamy

- Pair remains together over time

- Longest gestation of young

- Some cichlids, seahorses, pipefish

Semelparous

Single spawning effort in life

Metabolically efficient

Max fecundity

Match offspring to ideal growing conditions

Overwhelm predators

Risky - likelihood of dying before spawning

Iteroparous

Repeated spawning efforts

Spawn before death

Spread offspring over multiple entry times

Reduces fecundity but ensures SOME reproduction occurs

Parental care

Increases probability of offspring survival (reduces predation risk, increased food access)

Costs energy = reduces energy

Behavioral

Internal gestation

Caregivers

Behavioral parental care

Brood hiding (in mouth sometimes)

Nest guarding

Caregivers parental care

Males:

- Behavior (except seahorses - PRL induces male seahorse brooding)

- Cichlids (males make a nest and brood, females just drop off eggs)

Females

- Mostly physiological

- Oviparous

- Oviviparous

- Viviparous

Also biparental care

Oviparous

Egg laying with parental care

Yolk fed (lecithotrophy)

External development

Oviviparous

Embryo within female

Yolk fed (lecithotrophy)

Internal development

Viviparous

Live birth

Yolk supplemented (matrotrophy)

Internal development

Lecithotrophy

Yolk fed

Matrotrophy

Yolk supplemented

Caregiving behavior

Non guarders

- open substrate spawners

- brood hiders

Guarders

- substratum spawners

- brood hiders

Bearers

- external

- internal

Method of fertilization

Most fish use external fertilization - less energy/time in courtship & pair bonding

Increased number of potential mates, greater fecundity

Some do internal fertilization (chondrichthyes - sharks, rays, skates, ratfishes, poeciliidae, goodeidae - guppies, mollies, embiotocidae - surfperches)

Male bites female to hold her in place

Internal fertilization - fish

Requires lengthy courtship/prep for mating, intromittent organ, male structure for storing sperm (seminal vesicle)

Intromittent organ:

Chondrichthyes:

- Claspers (pelvic fins)

- Appendage that delivers sperm inserted into cloaca

Poeciliids, goodeids

- Modified anal fin

Embiotocids

- Modified genital papilla

Buccal fertilization

Sperm swallowing in callichthyid (corydoras) catfish

Females approach males urogenital pore and swallow sperm

Gender system fish

Most are gonochoristic - single sex fixed at maturity

Some are hermaphroditic - simultaneous or sequential

Some are parthenogenetic

Secondary sex charateristics

Simultaneous hermaphrodites

Function as male and female at the same time

23 families (anguilliformes, eels, atheriniformes, killifish)

Sequential hermaphrodites

Start life as one sex and change sex after maturity

Protandrous - sperm first, then eggs

Protogynous - eggs first, then sperm (more common, wrasses)

Parthenogenetic types

Gynogenetic

Hybridogenetic

Gynogenetic

All female species - like lesbian lizards

Still need to mate, but it doesn't do anything - just induces egg laying

Daughters are genetic clones of mothers (diploid females from diploid eggs)

Any males would be triploid from triploid eggs (rare)

Hybridogenetic

Egg development with fertilization by males of other species

Male genes discarded at next generation

Diploid - haploid eggs

Secondary sex characteristic types

Monomorphic

Permanently dimorphic

Seasonally dimorphic

Polymorphic

Secondary sex characteristics - monomorphic

Males and females alike

Secondary sex characteristics - permanently dimorphic

Mature sexes distinguishable

Secondary sex characteristics - seasonally dimorphic

Mature sexes distinguishable only at spawning time

Salmon

Reproductive behaviors - courtship

Color

Size

Movements

Reproductive behavior - spawning site selection

Substrate - broadcast

Water spawners - broadcast

Site preparers

Internal fertilization (may also be habitat specific)

What did Dr Roepke get their masters working with?

C elegans

What did Dr Roepke get their pHD working with?

Echinoderms

Doctoral studies at UCD - studied effects of environmental contaminants on early embryonic development in sea urchins (tattoo is sea urchin development