Hydrozoa of Southern Chesapeake Bay
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W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 1968 Hydrozoa of Southern Chesapeake Bay Dale R. Calder College of William and Mary - Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Marine Biology Commons, and the Zoology Commons Recommended Citation Calder, Dale R., "Hydrozoa of Southern Chesapeake Bay" (1968). Dissertations, Theses, and Masters Projects. Paper 1550154024. https://doi.org/10.25773/r8f9-eg95 This Dissertation is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. HYDROZOA OF SOUTHERN CHESAPEAKE BAY A Thesis Presented to The Faculty of the School of Marine Science The College of William and Mary in Virginia In Partial Fulfillment Of the Requirements for the Degree of Doctor of Philosophy By Dale Ralph Calder 1968 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Dale Ralph Calder Approved, July 1968 M. L. Brehmer, Ph.D., Major Professor Aj J" D. Andrews , Ph. D rgis, Jr M. M. Nichols, Ph.D. M. L. Wass, Ph.D. Dean, hool Marine Science DEDICATION This thesis is dedicated with heartfelt thanks to my ^parents, Mr. and Mrs. Wilfred Calder, for their many sacrifices on my behalf. iii ACKNOWLEDGMENTS It is a pleasure to acknowledge with gratitude the help of Dr. M. L. Brehmer, Virginia Institute of Marine Science, under whose supervision this research was conducted. His patience, assistance, encouragement, and ready provision of the necessities required for the study are sincerely appreciated. Thanks are due the following hydrozoan specialists for their aid: Dr. Sears Crowell, Indiana University; Dr. P. L. Kramp and Dr. X. W. Petersen, Universitetets Zoologiske Museum, Copenhagen, Denmark; Dr. N. A. H. Millard, Zoology Department, University of Cape Town, South Africa; and the late Dr. W. J. Rees, British Museum (Natural History), London, England. I am indebted to the following staff members of VIMS for their"loan of apparatus used in the project: Mr. D. S. Haven, Dr. E. B. Joseph, Mr. R. Morales-Alamo, and Mr. W. I. Simmonds. Mr. M. Castagna and Mr. P. E. Chanley of the VIMS Wachapreague Laboratory aided in providing compressed air for SCUBA early in the study. Miss Evelyn Wells, VIMS librarian, is to be thanked for her assistance in procuring the necessary literature. Salinities were determined by Mr. Weston Eayrs of VIMS. I am grateful to the following persons who either provided specimens or aided in their collection: Victor Burrell, Elizabeth Calder, Harold Cones, James Feeley, James Greene, Sarah Haigler, William Johnson, Gail Mackiernan, Alex Marsh, James Melvin, Morris Roberts, W. A. Van Engel, Dr. M. L. Wass,J and particularly Reinaldo Morales-Alamo for his large iv collection made during 1959-1961. I am obligated to my wife, Elizabeth, for her patience throughout the study and for typing the original manuscript. Mrs. Beverly Ripley is to be thanked for typing the final copy. The constructive criticisms of the manuscript by Dr. J. D. Andrews, Dr. M. L. Brehmer, and Dr. M. L. Wass are greatly appreciated. This study was supported in part by contract NBy-46710 from the Bureau of Yards and Docks, United States Navy. TABLE OF CONTENTS Page ACKNOWLEDGMENTS......................... iv LIST OF TABLES. .................... vii LIST OF F I G U R E S........................ ix LIST OF PLATES................. X ABSTRACT.................... xi INTRODUCTION. ...... 2 MATERIALS AND METHODS . 7 RESULTS Taxonomic Account. 13 Life History Dipurena strangulata. 90 Bougainvillia rugosa. 95 Proboscidactyla ornata. 99 Lovenella gracilis........ 102 Phenology. ................ ,109 DISCUSSION. .......... 125 LITERATURE CITED. ........ 144 APPENDIX. ................ 156 VITA vi LIST OF TABLES Table Page 1. Data on Moerisia lyonsi medusae from the James River, Virginia .......... 28 2. Comparison between Clytia paulensis hydroids from the York River, Virginia, and the south coast of South Africa . - 61 3. Comparison between Obelia geniculata hydroids from Chesapeake Bay, Virginia, with colonies from Deer Island in Passamaquoddy Bay, Canada .......... 66 4. Hydroids reported from the Virginia Institute of Marine Science (Virginia Fisheries Laboratory) collection up to 1959 ............ 88 5. Data on laboratory-reared Bougainvillia rugosa medusae of different ages. 98 6. Summary of gross morphological differences between Proboscidactyla ornata populations from Virginia and the Gulf of Naples. 103 7. Occurrence of hydromedusae at Gloucester Point during 1966-1967.................... 116 8. Number of hydroid cultures showing growth after 192 hours under two regimes of temperature . .... 119 vii Table Page 9. Influence of temperature on growth after 192 hours in laboratory cultures of hydroids............................... 120 10. Influence of temperature on growth after 192 hours in laboratory cultures of hydroids....................................... 121 11. Water temperatures at the beginning and end of activity for several species of hydroids . 124 12. Zoogeographic comparisons of the hydroid fauna along the eastern United States . 134 13. List of hydroids from Chesapeake Bay, with their east coast distribution. 13 5 14. Comparison of the neritic hydromedusae in the three provinces of Xramp?s (1959) West Atlantic Boreal region . 139 15. Zoogeographic comparisons of the neritic hydromedusae along the eastern United States. ......... .............. 140 16. List of hydromedusae known from Chesapeake Bay, and their east coast distribution. 141 viii LIST OF FIGURES Figure Page 1. Southern Chesapeake Bay and adjacent waters .......... 2. Water temperature at Gloucester Point, 1966-1967 . 110 3. Salinity at Gloucester Point, 1966-1967 . Ill 4. Seasonality of athecate hydroids in southern Chesapeake Bay......... 113 5. Seasonality of thecate hydroids in southern Chesapeake Bay................. 114 6. Seasonality of fixed gonophores ...... 115 ix LIST OF PLATES Plate 1. Hydroids, Moerisia lyonsi to Cordylophora lacustris. 2. Hydroids, Turritopsis nutricula to Amphinema dinema. 3. Hydroids, Proboscidactyla ornata to Obelia bicuspidata. 4. Hydroids, Obelia commissuralis to Opercularella lacerata. 5. Hydroids, ?uCampanopsis1T sp. to Halopteris tenella. 6. Hydromedusae, Moerisia lyonsi to Turritopsis nutricula. 7. Hydromedusae, Hydractinia arge to Obelia sp. 8. Hydromedusae, Eucheilota ventricularis to Cunina octonaria. ABSTRACT Hydrozoans of southern Chesapeake Bay and its tributaries were studied from April 1965 until March 1968 to determine faunal diversity, seasonality and reproductive periodicities. Laboratory culture techniques were used in describing unknown or inadequately known stages in the life history of several species and as an aid in identification. A total of 55 species was identified, including 43 hydroids and 32 medusae. Of these, 22 hydroids and 15 medusae are reported in Chesapeake Bay for the first time. Two species earlier reported from the bay, Eudendrium carneum and Blackfordia virginica, were not found. Clytia paulensis and the hydroid of Proboscidactyla ornata are previously unreported in North America, and the hydroid of Amphinema dinema is recorded for the first time from the North American Atlantic coast. The southern range of Hybocodon prolifer, Obelia longissima and Opercularella pumila is extended, as is the northward range of Podocoryne minima, Clytia kincaidi and Phialucium carolinae. Both hydroids and hydromedusae show an affinity with the Carolinian Zoogeographic Province; 76% of the hydroids and 77% of the hydromedusae occur south of Cape Hatteras, while 59% of the hydroids and 35% of the hydromedusae occur north of Cape Cod. The hydroid of Dipurena strangulata and the older medusae of Bougainvillia rugosa and Lovenella gracilis are described for the first time. Partial life histories are described for four other species. The genus Calyptospadix Clarke, 1882 is placed in synonymy with Bimeria Wright, 185 9. Hydroids are shown to be characteristically seasonal in occurrence due to the annual water temperature range, which varies from approximately 2 C to 28 C. During seasons of inactivity, laboratory-tested species, Ectopleura dumortieri, Bougainvillia rugosa and Eudendrium ramosum, remained in a dormant state in the stems, stolons, or both, until favorable temperatures returned. Field observations on other hydroid species indicated a similar phenomenon. Dormant stages are resistant to unfavorable temperatures and may have important implications on hydrozoan zoogeography. In nature, the temperature at which renewed growth commenced in spring for winter-dormant species was higher than that at which regression occurred in autumn, and the converse was true for summer-dormant species. This may be an adaptive mechanism insuring favorable conditions for growth once development has begun. Of 23 hydroids whose seasonality was studied in detail, 16 were ’’summer” species and 7 were ’’winter” species. Among the hydro medusae, seasonality was typically less prolonged, with a maximum diversity in late summer and early autumn and a minimum diversity in winter. Although undescribed species or endemics to the bay were not found, two unidentified hydroids, ’’Campanulina” sp. and