THE STRUCTURE AND FUNCTION OF THE CAUDAL LAMELLAE OF THE DAMSELFLY Pvrrhosoma nymphula (SULZER) [ODONATA:ZYGOPTERA]. By David Wilson Brown. A thesis submitted for the degree of Doctor of Philosophy Department of Zoology University of Glasgow July 1995 ProQuest Number: 11007806 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 11007806 Published by ProQuest LLC(2018). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 ^Tr:; /03c?? Gq / GLASGOW UNIVERSITY LIBRARY Table of contents Page number List of tables I List of plates III List of figures V Acknowledgements vm Summary IX Chapter 1 - General introduction 1 Chapter 2 - The occurrence and effects of caudal lamellar loss in a population of R nymphula 2.1 Introduction 7 2.2 Materials and methods 16 2.3 Results 21 2.4 Discussion 37 Chapter 3 - Morphology of the caudal lamellae of P. nymphula. 3.1 Introduction 51 3.2 Materials and methods 69 3.3 Results 73 3.4 Discussion 88 Chapter 4 - Physiology of the Caudal lamellae of R nymphula. 4.1 Introduction 99 4.2 Materials and methods 114 4.3 Results 124 4.4 Discussion 131 Chapter 5 The role of lamellae during aggresive encounters between larvae. 5.1 Introduction 142 5.2 Materials and methods 150 5.3 Results 154 5.4 Discussion 160 Chapter 6 - General discussion 165 Appendices Appendix 1 172 Appendix 2 173 Appendix 3 174 Appendix 4 Following page 174 Appendix 5 Following page 174 Appendix 6 175 References 177 LIST OF TABLES Table 2.1 Summary of seasonal variation in size of larval R nymphula collected during 1984/1985. 2.2 Correlation between total larval length, head dimensions and metathoracic wing pad length of P. nymphula larvae collected during 1984/1985. 2.3 Summary of seasonal variation in measured dimensions of larval P. nymphula collected during 1987/1988. 2.4 Correlation between total larval length, head dimensions and metathoracic wing pad length of P. nymphula larvae collected during 1987/1988. 2.5 Summary of seasonal variation in density of larval R nymphula at each sampling station during 1987/1988. 2.6 Kruskal-Wallace analysis of variance on seasonal change in the mean density of R nymphula larvae and habitat type. 2.7 Cohort sex ratios and mean cohort sizes for R nymphula larvae collected during 1987/1988. 2.8 Sex and mean total length of larval P. nymphula greater than 6mm total length. 2.9 Analysis of variance; total length of larvae by larval sex and sampling date. 2.10 Frequency of lamellar damage, larval dimensions during 1987/1988 sampling. 2.11 Lamellar damage and sex of P. nymphula larvae over 6mm total length, larvae collected during 1987/1988. 2.12 Mean density of larvae with and without lamellar damage. 2.13 Analysis of variance, total length of larvae by Sex, sampling season, sampling station and presence of lamellae. 2.14 Analysis of variance; total length of larvae by collection season, sampling station and presence of lamellar damage. 2.15 Mean total length of P. nymphula larvae with and without 32 lamellar damage in each habitat type. 2.16 Mean values of pH and Conductivity for the Ross burn 35 during 1984/1985 and 1987/1988 sampling. 2.17 Oxygen concentration at different depths from core samples taken 35 during summer and winter at sampling station 3. 3.1 Comparative morphology of insect tracheal gills. 75 4.1 Mean respiration rate of L+ and L- P. nymphula larvae according 126 to weight category and mean experimental oxygen concentration. 4.2 Regression formulae and oxygen critical point estimates 126 4.3 Correlation and regression of Logio S.O.R. on Logio wet 128 weight. 4.4 Results of analysis of covariance on regressions of Logio S.O.R. 128 on Logio wet weight for larvae with and without lamellae. 5.1 Perch occupancy by larvae with and without lamellae 154 5.2 Frequency and type of change in ownership of perch occupants 154 during experiments. 5.3 Frequency and type of behaviour showed by larvae during experiments. 156 5.4 Frequency of aggressive displays shown by larvae 156 5.5 Frequency of occasions when perch occupant larva was challenged 156 by the intruder. II LIST OF PLATES Plate Following Page 2.1 The sampling site, Ross Bum, Stirlingshire. 16 3.1 Final instar larva of P. nymphula (X10). 73 3.2 Transverse section (T.S.) through the prenodal region of a median 73 lamella from an instar 4 larva of P. nymphula (XI00). 3.3 T. S. through the thickened midrib region of a lateral lamella 73 of a final instar R nymphula larva. 3.4 T.E.M. of a T.S. through the postnodal region of a lamella from 73 a final instar larva of P. nymphula (X4690). 3.5 T.E.M. of a T.S. through a lateral lamella of a final instar 73 larvae of R nymphula (X76496). 3.6 T.E.M. of a T.S. of the prenodal region of a lateral lamella of a 75 final instar larva of R nymphula (XI0868). 3.7 T.E.M. of a T.S. through the cuticle of the abdomen of a final 75 instar larva of P. nymphula (XI0032). 3.8 Transmission electron micrograph (T.E.M.) of a T.S. through the 75 postnodal region of a median lamella from a final instar larva of P. nymphula (X8778). 3.9 Scanning electron micrograph (S.E.M.) of a lateral lamella from an 76 instar 5 larva of P. nymphula (X49). 3.10 S.E.M. of the nodal region of a median lamella from a final instar 76 larva of R nymphula (X162). 3.11 T.S. of a functional lateral spiracle of a final instar P. nymphula 77 larva (X100). 3.12 T.E.M. through the hypodermis of the prenodal region of a lateral 77 lamella from a final instar larva of R nymphula (X62829). 3.13 T.E.M. of a T.S. through the prenodal region of a lateral lamella of 77 a final instar larva of P.nymphula (X33509). 3.14 S.E.M. of the abdomen and lamellae of a final instar larva 83 of P. nymphula (X93). 3.15 Longitudonal section (L.S.) through the breaking joint of a lateral 83 lamella from a final instar larva of P. nymphula (X200). IE 3.16 S.E.M. of the surface of a freshly autotomised breaking 83 joint of a lateral lamella from a final instar larva of P. nymphula (X462). 3.17 S.E.M. of the surface of a lateral lamellar breaking joint 83 following autotomv from a final instar larva of P. nymphula (X753). 3.18‘T.S. through the fracture point of the breaking joint of a median 83 lamella from a final instar larva of P. nymphula 1X200). 3.19 T.S. through the median lamellar tracheal trunks at the point 83 of fracture of the breaking ioint of a final instar larva of P. nymphula. 3.20 T.S. of the rectum of a final instar P. nymphula larva showing 85 thickened epithelial cells (X200). 3.21 S.E.M. of the dorsal edge of a lateral lamella from a final 86 instar larva of P. nymphula (X816). 3.22 S.E.M. of a sensory hair on a median lamella from a final 86 instar larva of P. nymphula (X1920). 3.23 S.E.M. of a sensory pit on the postnodal region of a median 86 lamella from a final instar larva of P. nymphula (X1920). IV LIST OF FIGURES Figure Following Page 2.1 Plan of Ross Bum sampling site showing sampling station 1 to 5. 16 2.2 Diagram of a final instar larva of P. nymphula showing dimensions 19 measured. 2.3 Diagram of a junior instar larvae of P. nymphula. 19 2.4 Total length plotted against head width at eyes forP. nymphula 21 larvae from 1984/1985 sampling period. 2.5 Total length plotted against mesothoracic wing pad length for 21 P. nymphula larvae collected during 1984/1985 sampling. 2.6 Size frequency histograms for total length of larvae 23 collected during 1987/1988 sampling. 2.7 Seasonal variation in mean cohort size 23 2.8 Seasonal variation in total density of larvae 24 2.9 Seasonal variation in the percentage of P.nymphula larvae 27 in each age class with lamellar damage during 1987/1988 sampling. 2.10 The frequncy of lamellar damage and larval density 27 2.11 Comparison of cohort density and frequency of lamellar damage 27 2.12 The frequency of lamellar damage and larval density 29 according habitat type, summmer 1988. 2.13 The frequency of lamellar damage and larval density according 29 to habitat type, winter samples. 2.14 Growth rate of larvae with and without lamellae during summer 1987. 34 2.15 The size difference between the mean sizes of larvae with and 34 without lamellae in each emergence group. 2.16 The size difference between the mean sizes of larvae with and 34 without lamellae and larval density accoording to emergence group.