University of New Hampshire University of New Hampshire Scholars' Repository Doctoral Dissertations Student Scholarship Spring 1976 THE BIOLOGY OF THE PREDATORY CALANOID COPEPOD TORTANUS DISCAUDATUS (THOMPSON AND SCOTT) IN A NEW HAMPSHIRE ESTUARY DAVID GEORGE PHILLIPS Follow this and additional works at: https://scholars.unh.edu/dissertation Recommended Citation PHILLIPS, DAVID GEORGE, "THE BIOLOGY OF THE PREDATORY CALANOID COPEPOD TORTANUS DISCAUDATUS (THOMPSON AND SCOTT) IN A NEW HAMPSHIRE ESTUARY" (1976). Doctoral Dissertations. 1124. https://scholars.unh.edu/dissertation/1124 This Dissertation is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. 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Xerox University Microfilms 300 North Zeeb Road Ann Arbor, Michigan 48106 76-23,131 PHILLIPS, David George, 1947- THE BIOLOGY OF THE PREDATORY CALANOID COPEPOD TORTANUS DXSCAUDATUS (THOMPSON AND SCOTT) IN A NEW HAMPSHIRE ESTUARY. University of New Hampshire, Ph.D., 1976 Zoology Xerox University Microfilms,Ann Arbor, Michigan 48106 THE BIOLOGY OF THE PREDATORY CALANOID COPEPOD TORTANUS DISCAUDATUS (THOMPSON AND SCOTT) IN A NEW HAMPSHIRE ESTUARY by DAVID G. PHILLIPS B.S., The Pennsylvania State University, 1969 M.S., University of New Hampshire, 1971 A THESIS Submitted to the University of New Hampshire In Partial Fulfillment of The Requirements for the Degree of Doctor of Philosophy Graduate School Department of Zoology May, 1976 This thesis has been examined and approved. fzjhlAJorfk fjOliJUiU Thesis director, Ellsworth H. Wheeler, Jr, Asst. Prof. of Zoology James F. Haney, Asso. Prof./of Zoology Larryrry G.^Iterris, Asso. Prof. of Zoology hn J. rof. of Zoology /c'Lc.jPiZ^J _____________ Richard G. Strout, Prof. of Animal Science Date ACKNOWLEDGEMENTS I wish to acknowledge the help and encouragement offered by the members of my Doctoral Committee and other faculty members of the Department of Zoology, U.N.H. I thank the personnel of the Jackson Estuarine Laboratory, U.N.H., particularly Dr. Arthur Mathieson, Director, for making work space and ship time available and Captain Edward McIntosh for much help and information offered during the bi-weekly sampling trips. I appreciate the assistance provided by many students, graduate and undergraduate, on those trips. Support was provided by Graduate Teaching Assistantships with the Department of Zoology, U.N.H. and a Dissertation Year Fellowship from the Graduate School, U.N.H., Semester II, 1976. I thank Mrs. Claudia Foret for the professional typing of the final copies of this dissertation. Last, but not least, I thank my wife Carol for her patience, encouragement and dependability while this study was conducted and assembled. iii TABLE OF CONTENTS LIST OF TABLES.................................................. vi LIST OF FIGURES...................................................vii LIST OF APPENDICES.............................................. x ABSTRACT......................................................... xi INTRODUCTION..................................................... 1 SECTION I: TORTANUS DISCAUDATUS AND ITS HABITAT................ 3 Introduction............................................ 3 Methods and Materials...................... 4 Results.................................................. 7 Discussion.............................................. 11 Summary.................................................. 18 Bibliography............................................ 20 SECTION II: FEEDING BEHAVIOR OF TORTANUS DISCAUDATUS........... 62 Introduction............................................ 62 Methods and Materials................................... 66 Results.................................................. 68 Discussion.............................................. 73 Summary.................................................. 84 Bibliography............................................ 86 SECTION III: REPRODUCTIVE BEHAVIOR OF TORTANUS DISCAUDATUS 99 Introduction............................................ 99 Methods and Materials................................... 103 Results.................................................. 106 Discussion......................................... 115 Summary.................................................. 120 Bibliography......................................... 122 APPENDIX...................................................... 147 v LIST OF TABLES PAGE Sex ratios, male/female, of adult Tortanus discaudatus collected over a 24-hr period, January 23 to 24, 1975, at three depths near the mouth of the Piscataqua River... 60 Length vs. weight of adult Tortanus discaudatus......... 61 Prey preferences of Tortanus discaudatus................. 97 Prey consumption and egg production of adult Tortanus discaudatus under four combinations of temperature, salinity, and prey ration................................. 98 Mortality during the first two months of keeping pairs of adult Tortanus discaudatus together in the labora­ tory....................................................... 142 Hatching success of Tortanus discaudatus eggs as a function of temperature and salinity..................... 143 Hatching time in days of Tortanus discaudatus eggs as a function of temperature and salinity................ 144 A comparison of predicted development time with observed development time of T_. discaudatus eggs using Belehradek's (1935) equation and McLaren's (1966) parameters for subjects from Halifax, N.S........ 145 Hatching period and success of ]T. discaudatus eggs transferred to 32 o/oo water after 60 days in distilled water............................................. 146 LIST OF FIGURES NO. PAGE 1. Map of the Piscataqua River Estuary........................... 26 2. Salinity and temperature profiles from the Piscataqua River Estuary showing typical summer and winter conditions, August 28, 1973 and February 27, 1974, and the conditions present during the periods of thermal uniformity, October 31, 1973 and April 10, 1974..... 28 3. Temperature (° C) at a depth of one meter at the four field stations taken from June, 1973 to June, 1974 at two-week intervals................................... 30 4. Salinity (o/oo) at a depth of one meter at the four field stations taken from June, 1973 to June, 1974 at two-week intervals......................................... 32 5. Temperature (° C) at three depths over a 24-hr period, January 23 to 24, 1975........................................ 34 6. Salinity (o/oo) at three depths over a 24-hr period, January 23 to 24, 1975........................................ 36 7. Density of the chaetognath Sagitta elegans and the calanoid copepod Temora longicornis over a 24-hour period, January 23 to 24, 1975................................ 38 8. Density of the calanoid copepod Tortanus discaudatus at three depths over a 24-hr period, January 23 to 24, 1975....................................................... 40 9. Total zooplankton density at the four field stations, August, 1973 to June, 1974.................................... 42 vii No. Page 10. Density of Tortanus discaudatus. copepodid stages III, IV, V, and VI (adults) at four field stations in the Piscataqua River Estuary, June, 1973 to June, 1974 at intervals of 2 weeks............................. 44 11. Tortanus discaudatus collections separated into stages III-VI by percent.............................. 46 12. Density of I?. discaudatus compared