Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1979 Morphological and Behavioral Polymorphism in Poecilia Latipinna Males (Pisces: Poeciliidae). Carol Louise Luckner Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Luckner, Carol Louise, "Morphological and Behavioral Polymorphism in Poecilia Latipinna Males (Pisces: Poeciliidae)." (1979). LSU Historical Dissertations and Theses. 3449. https://digitalcommons.lsu.edu/gradschool_disstheses/3449 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This was produced from a copy of a document sent to us for microfilming. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help you understand markings or notations which may appear on this reproduction. 1. The sign or “target” for pages apparently lacking from the document photographed is “Missing Page(s)”. If it was possible to obtain the missing page(s) or section, they are spliced into the Film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure you of complete continuity. 2. When an image on the film is obliterated with a round black mark it is an indication that the film inspector noticed either blurred copy because of movement during exposure, or duplicate copy. Unless we meant to delete copyrighted materials that should not have been filmed, you will find a good image of the page in the adjacent frame. 3. When a map, drawing or chart, etc., is part of the material being photo- . graphed the photographer has followed a definite method in “sectioning" the material. It is customary to begin filming at the upper left hand comer of a large sheet and to continue from left to right in equal sections with small overlaps. If necessary, sectioning is continued again—beginning below the first row and continuing on until complete. 4. For any illustrations that cannot be reproduced satisfactorily by xerography, photographic prints can be purchased at additional cost and tipped into your xerographic copy. Requests can be made to our Dissertations Customer Services Department. 5. Some pages in any document may have indistinct print. In all cases we have filmed the best available copy. University Micrdrilms International 300 N. ZEEB ROAD. ANN ARBOR. Ml 48106 18 BEDFORD ROW. LONDON WC1R 4EJ, ENGLAND 8013130 LUCKNER, CAROL LOUISE MORPHOLOGICAL AND BEHAVIORAL POLYMORPHISM IN POECILIA LATIPINNA MALES (PISCES: POECILIIDAE) The Louisiana State University and Agricultural and Mechanical Col. PH.D. 1979 University Microfilms International300 N, Zeeb Road, Ann Arbor, MI 48106 18 Bedford Row, London WC1R 4EJ, England MORPHOLOGICAL AND BEHAVIORAL POLYMORPHISM IN POECILIA LATIPINNA MALES (PISCES: POECILIIDAE) A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Zoology and Physiology by Carol L. Luckner B.S., Virginia Polytechnic Institute, 1971 M.S., Louisiana State University, 1974 M.S., Virginia Polytechnic Institute and State University, 197 5 December, 1979 ACKNOWLEDGEMENTS My major professor, Dr. J. Michael Fitzsimons, and the members of my committee, Dr. Kenneth C. Corkum, Dr. Albert Meier, Mr. John D. Newsom, and Dr. Arthur J. F.iopelle gave me their time, ideas, and support; they were most helpful. Dr. Franklin Snelson contributed much to the conceptual framework of this research.- I would like to acknowledge the help and suggestions of the following people: Dr. Clark Hubbs, Dr. Robert Miller, Kris Kucharski, Dr. Royal D. Suttkus, Dr. Joseph Balsano, Kirk Easley, Dr. George C. Kent, Dr. Kenneth Koonce, David Garton, Dr. John Van Conner, and Mr. Jack Evans. I would also like to thank Albert Doucette, Lorraine Madsen, Eugene Beckham, and my husband Dr. Robert C. Luckner They helped me collect and offered suggestions and encourage ment; this work would not have been possible without them. Figures 1, 2, and 7 were drawn by Eugene Beckham. TABLE OF CONTENTS Page ACKNOWLEDGEMENTS .................................... ii LIST OF TABLES ...................................... V LIST OF FIGURES .................................... vi ABSTRACT ............................................ vii INTRODUCTION ........................................ 1 METHODS AND MATERIALS .............................. 6 Morphometries .................................... 7 Population D a t a .................................. 8 Reproductive Behavior ............................ 8 RESULTS ............................................. 10 Description of Females, Immature Males and the Mature Male Classes .............................. 10 F e m a l e s ...................................... 10 Immature males ................................ 17 Sneaky males . .............................. 17 Intermediate males ............................ 18 High m a l e s .................................... 18 Differences in Fin Sizes and Positions........ 19 An Alternative Classification System .......... 23 Population Structure ............ .............. 24 Reproductive Behavior ............................ 31 iii TABLE OF CONTENTS (Continued) Page Description of Male Reproductive Behavior . 31 Orientation Phase ....................... 3 2 Display Phase ........................... 3 2 Contact Movements ....................... 35 Gonopodial Swinging ...................... 37 Female Reproductive Behavior.................... 38 Analysis of Male Reproductive Behavior .......... 39 Behavior Observed in the Laboratory ......... 39 Field O b s e r v a t i o n s ......................... 46 Behavior of Males Tested with a Dominant Male . 51 Behavior of Testosterone Treated Males .... 54 Summary of Male Reproductive Behavior........ 54 Function and Relationships of the Sigmoid Display and Anal Nibbling........................... 55 Sigmoid Display ............................. 55 Anal Nibbling............................... 56 Interspecific Comparisons of the Reproductive Behavior of Male Poeciliids................. 59 DISCUSSION ....................................... 61 LITERATURE C I T E D ................................. 74 VITA ............................................. 7 8 iv LIST OF TABLES Table Page 1 Body and Fin Proportions as Percent Standard Length and Dorsal-Fin Ray Count in Females, Immature Males, and Mature Males of Each Class of Poecilia latipinna.................. 12 2 Vertebral Counts and the Angle of the First Dorsal-Fin Pterygiophore for Females, Immature Males, and Mature Males of Each Class in Poecilia latipinna.................. 14 3 Reproductive Behaviors of Poecilia latipinna Males Expressed as Average Number per Male and Percent of Total Behaviors ............ 41 4 Reproductive Behaviors of High Males Observed in the Laboratory and in the Field Expressed as Percent of Total .......................... 50 5 Reproductive Behaviors of Poecilia latipinna Males Tested Singly and with Dominant Males . 53 V 4 LIST OF FIGURES Figure Page 1 Relative Size and Fin Position of the Male Classes in Poecilia latipinna ................ 3 2 Relative Size and Fin Position of A. High Male B. Intermediate Male C. Sneaky Male D. Immature Male E. Female * ............ 16 3 Schematic Diagram of the Angle of the First Six Dorsal-Fin Pterygiophores in Females, Immature Males, and Mature Males of Each Class in Poecilia latipinna................ 2 2 4 Monthly Percent of Females and Juveniles, Immature Males, and Mature Males of Each Class of Poecilia latipinna from Fresh­ water Populations.......................... 26 5 Monthly Percent of Females and Juveniles, Immature Males, and Mature Males of Each Class of Poecilia latipinna from Salt­ water Populations.......................... 28 6 Sizes of Immature Males of Poecilia latipinna Collected in each Mo nt h .................... 3 0 7 Dorsal and Lateral Views of a High Male Displaying................................. 34 8 Reproductive Ethogram for Sneaky Males ... 43 9 Reproductive Ethogram for Intermediate Males. 45 10 Reproductive Ethogram for High Males .... 48 11 Survival, Reproductive Success, and Fitness as a Function of Investment................ 71 vi ABSTRACT Sailfin molly males, Poecilia latipinna, form three distinct classes: Sneaky males, Intermediate males, and High males- Class members can be defined by body size, color, fin size and position, and reproductive behavior. In 1975, Constantz described Sneaky males in Foeciliopsis occidentalis and, in 1936, Hubbs characterized High males in Poecilia. Intermediate males have not been described previously. In Poecilia latipinna Sneaky males are similar to females in color, size, and general body proportions. The dorsal fin originates behind the pelvic-fin origin and is no longer than that of females. High males have breeding colors of gold, blue, and black on the body and caudal and dorsal fins. They are large with a disproportionately