Comparative Male Reproductive Investment Across Three Species of Pipefishes With Differing Mating Systems

Sana Rashid, Janaee Wallace, and Dr. Raelynn Deaton HaynesSt. Edward’s University https://c2.staticflickr.com/6/5216/5384524083_61f5ece12a_z.jpg

http://31.media.tumblr.com/tumblr_lpzpn2r7F01qm9k25o1_500.jpg

http://www.sibuya.co.za/files/uploads/images/Longsnout%20pipefish%202.JPG

My Experiment

In this experiment I will be collecting sperm from three species of pipefish

Gulf pipefish (Syngnathus scovelli)

Dusky pipefish (Syngnathus floridae)

Chain pipefish (Syngnathus louisianae)

http://www.nicholls.edu/biol-ds/biol348/fishsets/pics/dusky%20pipefish.jpg

http://www.sms.si.edu/irlspec/images/Syngna_louisi_close.jpg

Mating Systems

Dusky pipefish practice polygynandry

Gulf pipefish practice polyandry

It is expected that Chain pipefish practice polygynandry as well.

http://o.quizlet.com/c2BMw3plKPrH4EolzLG-.w_m.jpghttp://www.bio.tamu.edu/USERS/ajones/Pipefish/images/S_scovelli.jpg

https://c1.staticflickr.com/9/8294/7866475994_e5a210ef03_z.jpg

Sexual Selection Theory

The sexual selection theory assumes that organisms can attract more mates if they are appealing to the opposite sex.

In this case we are observing if sperm competition due to mating systems is a factor in the sexual selection.

http://web.evolbio.mpg.de/~mobley/Dusky_Pipefishcrop.jpghttp://www.fishchannel.com/images/exclusives/aquarium-fish-international/pipefish.jpg

Predictions

There should be a relation between gonads/sperm count and mating systems.

Duskies and Chains are expected to have higher sperm count

http://www.bio.tamu.edu/USERS/ajones/Pipefish/images/Syngnathus_floridae.jpg

http://www.bio.tamu.edu/USERS/ajones/Pipefish/images/Dusky_pipefish.jpg

Overall Aim

To test assumptions of sexual selection theory by comparing reproductive output of males in related species that differ in mating systems.

http://upload.wikimedia.org/wikipedia/commons/0/03/Seagrass_Grahams_Harbour.jpg

Objective

Figure out methods for sperm extraction

Test if certain morphological features can determine reproductive output

http://www.dep.state.fl.us/coastal/habitats/seagrass/images/Seagrass_Turtlegrass1.jpg

Methodology

We collected Gulf pipefish and immature Chain pipefish by seining in the Gulf

Methodology

Immerse in clove oil

Measure the pipefish

Dissect to gather testes and stage eggs

Isolate testes and gather sperm with saline solution

Count sperm

Measurements

Data: Length vs. Mean Sperm Number

Total Length (mm)

60 70 80 90 100 110

Me

an

Sp

erm

Nu

mb

er

0

2e+4

4e+4

6e+4

8e+4

1e+5

Data: Sperm Count Across Males

Individual Males

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

Sp

erm

Co

un

t

0

2e+4

4e+4

6e+4

8e+4

1e+5

Sperm Success

Collecting sperm samples was very difficult due to variables such as maturity and how clear testes were

First time collecting sperm with sygnathids

Finding sperm was a huge success

http://upload.wikimedia.org/wikipedia/commons/1/18/Hemocytometer_with_gloved_hand.JPG

http://www.microbehunter.com/wp/wp-content/uploads/2010/06/counting_chamber2.jpg

http://bioquest.org/icbl/projectfiles/spermh.jpg

Obstacles

We have only been able to gather Gulf pipefish because Dusky and Chain pipefish appear in

July.

http://theseasproject.weebly.com/uploads/5/3/8/4/5384258/6567916.jpg?277

Future Goals

To take seasonal samples in order to test that sperm varies

Weigh gonads at University of Texas

Increase sample size

Include S. floridae and S. louisianae into sample size to test if sexual selection assumptions hold in sex role reversal species

Acknowledgments

St. Edward's University

Dr. Raelynn Deaton Haynes

Janaee Wallace

Dr. Richard Kopec

TG Public Benefit Grant Program

TG Cohort

Thank You!Questions?