Kellar, N. M., Trego, M. L., Chivers, S. J., and Archer, F. I. (2008).

205 Pages·2008·6.6 MB·English

UNIVERSITY OF CALIFORNIA, SAN DIEGO

Hormones and blubber: An endocrinological approach for assessing life-history states
in free-ranging cetacean populations

A dissertation submitted in partial satisfaction of the
requirements for the degree Doctor of Philosophy

in

Marine Biology

by

Nicholas M. Kellar

Committee in charge:

Professor William F. Perrin, Co-Chair
Professor Ronald S. Burton, Co-Chair
Professor Gerald L. Kooyman
Professor Pamela L. Mellon
Professor Greg W. Rouse

2008
3319846

Copyright 2008 by
Kellar, Nicholas M.

All rights reserved
3319846
2008
Copyright
Nicholas M. Kellar
All rights reserved
The dissertation of Nicholas M. Kellar is approved, and it is
acceptable in quality and form for publication on microfilm:

Co-Chair

Co-Chair

University of California, San Diego

2008
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DEDICATION

My dissertation is dedicated to Dr. Susan Stewart Suchocki. Leading by example, she
taught me the utility of the scientific method, the strength of perseverance, and the
power of compassion for all. She cultivated my love for nature, the pursuit of
knowledge, and pitcher dominated baseball. She has been my motivation from the
start of it all.

Mom, you will be missed…always.
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TABLE OF CONTENTS
Signature page ……………………………………………………... iii
Dedication…………………………………………………………. iv
Table of contents………………………………………………….. v
List of figures………………………………………………………. vi
List of tables……………………………………………………… x
Acknowledgements………………………………………………... xi
Vita………………………………………………………………… xvi
Abstract……………………………………………………………. xvii
I. General summary………………………………………………….. 1
II. Chapter one: Growth and development of the Stenella attenuata
corpus luteum: identifying potential characters to
differentiate CLs of ovulation from those of pregnancy…… 28
III. Chapter two: Determining Pregnancy from blubber in three
species of Delphinids………………………………………. 59
IV. Chapter three: Blubber testosterone: A marker of male
reproductive status in short-beaked common dolphins…….. 93
V. Chapter four: Pregnancy patterns of pantropical spotted dolphins
(Stenella attenuata) in the eastern tropical Pacific
determined from hormonal analysis of biopsies and
correlations of the patterns with the purse-seine
tuna fishery………………………………………………… 136
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LIST OF FIGURES

Figure 1. Computer image analysis of luteinized CL tissue……………….… 35
Figure 2. Computer image analysis of vascularized CL tissue………………. 36
Figure 3. Frequency distribution of spotted dolphin CL volume
with and without observed fetuses……………………………………. 39
Figure 4. CL volume as a function of fetal length during early gestation …… 40
Figure 5. Luteinized tissue as a function of fetal length……………………… 42
Figure 6. Fraction of vascularized tissue as a function of fetal length……… 43
Figure 7. Relationship between fraction of lutienized and vascularized
tissue of CL observed with and without a fetus………………………. 46
Figure 8. Blubber progesterone concentrations as a function of body
length in pregnant and non-pregnant female common dolphins…… 75
Figure 9. Maternal blubber progesterone concentrations as a
function of fetal length of 15 common dolphins..……………….. 76
Figure 10. Progesteorne concentrations in the outer, middle, and
inner blubber layers of pregnant common dolphins……………… 78
Figure 11. Blubber progesterone concentrations at seven anatomical
locations in a recently pregnant northern right-whale dolphin….. … 79
Figure 12. Geogrpahic distribution of blubber samples from fishery-
killed and biopsied males common dolphins……………………….. 100
Figure 13. Compund light miscopy images showing histological
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characteristics of testes development in male shorted-beaked
common dolphins…………………………………………………… 102
Figure 14. Completion curves showing parallel displacement
between known standard concentrations and serial dilutions of
pooled extracts of unknown concentration…………………………. 110
Figure 15. Blubber testosterone concentrations as a function of ordinal
date for immature, pubertal, and sexually mature short-beaked
common dolphins…………………………………………………… 113
Figure 16. Blubber testosterone concentrations as a function of right
testis mass…………………………………………………………… 114
Figure 17. Testosterone concentrations of the outer, middle, and
inner blubber layers in ten mature male common dolphins ………. 116
Figure 18. Blubber testosterone concentrations at nine anatomical
locations in three mature male common dolphins…………..….. … 117
Figure 19. Logistic model for the p(mature) relative to blubber
testosterone concentration…………………………………………. 119
Figure 20. Logistic model for the p(mature) relative to blubber
testosterone concentration and ordinal date……………………….. 120
Figure 21. Blubber testosterone concentration as a function of ordinal
date in biopsied male short-beaked common dolphins in the
Northeastern Pacific………………………………………………… 123
Figure 22. Mean right testis mass in reference specimen as a function
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of date……………………………………………………………….. 126
Figure 23. Geographic distribution of female pantropical spotted
dolphin biopsy samples that were analyzed to determine
progesterone concentration………………………………………… 143
Figure 24. Frequency distribution of blubber progesterone
concentrations in biopsies females pantropical spotted
dolphins…………………………………………………………… 149
Figure 25. Results of randomized nearest neighbor distance analysis……. 155
Figure 26 Ripley’s K analysis of 24 biopsied pregnant pantropical
spotted dolphins relative to all females sampled………………... 156
Figure 27. Prediction map from ordinary Kriging interpolation of
the proportion pregnant for biopsies of female pantropical
spotted dolphins…………………………………………………… 157
Figure 28. Geographic distribution of the female spotted dolphin
biopsies designated as pregnant and non-pregnant as determined
from blubber progesterone concentrations……………………....... 159
Figure 29. Spatial distribution of pregnant and non-pregnant females
pantropical spotted dolphins in the observed historic fishery kill….. 160
Figure 30. Frequency distribution of simulated (permuted) difference of means
statistic for Archer’s fishery exposure index (140-nmi ambit) of biopsied
pregnant and non-pregnant female S. attenuata. ………………… 163
Figure 31. Prediction map from an ordinary Kringing interpolation of
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Archer’s fishery exposure index (140-nmi ambit) for biopsied
female pantropical spotted dolphins………………………………… 164
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