Salamander Courtship, Mating, & Egg Depositionfwf.ag.utk.edu/mgray/wfs493/Lectures/Hamed18.pdf ·...

2/27/2018

1

Kevin Hamed

Salamander Courtship,

Mating, & Egg Deposition

Lecture Goals

To familiarize students with salamander

courtship, mating, and egg deposition strategies

Reading Assignments:

1) Organ 1958

2) Wells 2007

Chpt. 9: 404 – 418

434 – 447

Chpt. 10: 459 – 461

487 – 493

Chpt. 11: 540 – 546

Photo by Tim Herman

Lecture Structure1. Migration

2. Fertilization

3. Courtship

A. Plethodontidae

- Plethodon

- Desmognathus

B. Ambystomatidae

C. Salamandridae

4. Sperm Competition

5. Egg Deposition

A. Fecundity

B. Location

C. Parental Care

2/27/2018

2

• Male & Female must meet

• Environmental Conditions

• Transfer of Gametes

Why Do Salamanders Reproduce?

What is necessary for reproduction

• Doomed for extinction

Migration to Breeding Areas

• Often Ambystomatids

• Rainy nights

• Typically males migrate first

(A. opacum & A. maculatum)

• 164 meters – 95% adults (Semlitsch 1998)

• Plethodontids – D. organi, H. scutatum

Conservation Implications

• Cloacal Swelling in males

Hellbender Photos by Jeff Humphries

• Cryptobranchidae

• Sirenidae

• Hynobiidae

•August - November

• Large flat rocks

• Male trap females in nest

• Male guards nest and often consumes eggs

• Mean fecundity = 450 eggs

• Polyspermy

Similar?

External Fertilization

2/27/2018

3

External Fertilization

Captive Breeding:

Nashville Zoo

St. Louis Zoo

Chattanooga Zoo

Nesting Boxes

Copulatory organ? Spermatophore

Internal Fertilization

(Arnold et al. 1993) Ambystoma opacum

Plethodon glutinosus

Spermatotheca

50–70+% Failure

1.5

2

2.5

3

3.5

4

4.5

4 6 8 10 12 14 16 18 20 22

Spe

rmat

op

ho

reH

eig

ht

(cm

)

Maximum TL (cm)

(Organ and Lowenthal 1963)

Photo by Tim Herman

2/27/2018

4

“Courtship” glands named for anatomical location

Courtship

Functions of Exocrine Secretions:

• Identification ?

• Orientation

• Persuasion

Glycoproteins

Mental

Cephalic or “genial”

Courtship - Plethodontidae

Abrading female’s skin

(Arnold 1980)

Ron Bonnett’s Lab University of Tulsa

2/27/2018

5


Male places

his snout

along the

female’s back

and side

“foot dance”

(Organ 1958)


• Male moves

head toward

female’s head

• Male presses his mental gland

over female’s nasolabial grooves


(Organ 1958)

2/27/2018

6


Male passes under females chin and begin to undulate

his tail

(Organ 1958)


Video


“Tail straddle walk”

(Organ 1958)

https://www.youtube.com/watch?v=LwG8CN5aICw

2/27/2018

7


Plethodon yonahlossee


Maintain contact even over objects


Female – lateral head movements

Male – sacral movements

(Organ 1958)

2/27/2018

8


Video


• Spermatophore deposition

• Both stop when female is over spermatophore

(Organ 1958)

Typically only 1 spermatophore per courtship

Photo by Todd Pierson


https://www.youtube.com/watch?v=GNDDXKmXlM8

2/27/2018

9


Video


Video


Photo by Steve Tilley

Desmognathus ochrophaeus

complex

• Male “follows” female

• Male snout makes

contact “nudge”

• Front limbs move in circular motion “butterfly”

• Male rubs female head :

cheek to cheek

top of males head to females throat

https://www.youtube.com/watch?v=_UIpOcmejvI

https://www.youtube.com/watch?v=_UIpOcmejvI

2/27/2018

10




• Males presses his

chin against the

female’s dorsum and

“pulls” back

• Modified pull with

quick back movement

“snap”

• Tail undulation &

Slide(Mead & Verrell 2002)



2/27/2018

11



Courtship

Can courtship be used

for evolutionary

relationships?

(Tilley)

2/27/2018

12

Courtship – Incompatibility

(Verrell & Mabry 2000)

Courtship

(Mead & Verrell 2002)

Courtship - Ambystomatidae

Variation in clasping:

-Absent

-A. annulatum

-A. maculatum

-A. opacum

-A. talpoideum

-Present

-A. jeffersonianum

-A. laterale

-A. macrodactylum

2/27/2018

13


• Male contacts

female’s dorsum

• Male circles &

female nudges

male

• Circles repeatedly

“waltz”


• Male moves away with vent

contacting the substrate

•Arches body upward

and undulates tail


• Nudging and

circling is

repeated

• Females might

collect 15-20

spermatophores

before ending

courtship

2/27/2018

14

Spotted Salamander Breeding

Marbled Salamander Breeding

Fall not Spring in TN(Life in Cold Blood)


Number of spermatophores per night:

A. maculatum 40.4 (10-81)

A. tigrinum 20.6 (8-37)

A. laterale 23.6 (13-34)

A. jeffersonianum 12.4 (6-21)

(Arnold 1977)

Time per spermatophore:

A. maculatum 1.4 min

A. opacum 4.5 min

P. jordani 56 min

2/27/2018

15



(Arnold 1977)

Competition

Spermatophore covering


Competition

Benefit of Clasping?

Rapid Courtship?

(Arnold 1977)

2/27/2018

16

Courtship - Salamandridae

Notophthalmus viridescens

• Cephalic glands applied to female's

nares

• Clasping and continued gland

application (> 45 min.)

Not always!

(Arnold 1977)


• Male fans female with tail

• Violent contortions

• Dismounts and deposits

spermatophore

• Turns and blocks female

• 3.8 spermatophores per

courtship


2/27/2018

17

Red spotted Newt - Notophthalmus viridescens


Video

Alpine Newt – Ichthyosaura alpestris


(Life in Cold Blood)

Courtship - SalamandridaeGenus - Triturus

Sexually dimorphic

https://www.youtube.com/watch?v=Yq47VuL7sDk

2/27/2018

18


T. vittatus

T. marmoratus

T. carnifex

Courtship - Similarities

• Males face away from females

• Females orients toward male’s gland

• Male responds to contact with his cloacae

• Female movement to pick-up spermatophore

Sperm Competition

D. ochrophaeus

D. wrighti

D. fuscus

Inseminated up to 15 times during

one season

Paternity?

(Houck et al. 1985)

7% of all clutches

products of more

than one male

(Tilley & Hausman 1976)

Photo by Steve Tilley

2/27/2018

19

Fecundity

r/K-selected ?

K

30,000 / lbs.

D. organi 6

D. orestes 15

D. quadramaculatus 32

P. welleri 6

P. cinereus 7

?

A. opacum 120

A. maculatum 400

A. tigrinum 700

Paedomorphs >5,000

r

Egg Development

Larger eggs Slower development

More advanced (often larger)

Warmer temperatures Faster development

Larger prey Larger eggs

Surface area to volume

Terrestrial Larger eggs

Aquatic Smaller eggs

Egg Deposition Locations

Aquatic vs. Terrestrial

2/27/2018

20

Parental Care

• Typically Plethodontids

• Why guard nests?

DesiccationAntimicrobial

Predation

Next

Photos by Tim Herman

Next

Photo by Tim Herman

Salamander Courtship, Mating, & Egg Depositionfwf.ag.utk.edu/mgray/wfs493/Lectures/Hamed18.pdf ·...

Documents

Transcript of Salamander Courtship, Mating, & Egg Depositionfwf.ag.utk.edu/mgray/wfs493/Lectures/Hamed18.pdf ·...