University of Texas Rio Grande Valley ScholarWorks @ UTRGV UTB/UTPA Electronic Theses and Dissertations Legacy Institution Collections 4-2014 Temperature and relative humidity effects on water loss and hemolymph osmolality of Littoraria angulifera (Lamarck, 1822) Phillip J. Rose The University of Texas Rio Grande Valley Follow this and additional works at: https://scholarworks.utrgv.edu/leg_etd Part of the Animal Sciences Commons, Environmental Sciences Commons, and the Oceanography and Atmospheric Sciences and Meteorology Commons Recommended Citation Rose, Phillip J., "Temperature and relative humidity effects on water loss and hemolymph osmolality of Littoraria angulifera (Lamarck, 1822)" (2014). UTB/UTPA Electronic Theses and Dissertations. 39. https://scholarworks.utrgv.edu/leg_etd/39 This Thesis is brought to you for free and open access by the Legacy Institution Collections at ScholarWorks @ UTRGV. It has been accepted for inclusion in UTB/UTPA Electronic Theses and Dissertations by an authorized administrator of ScholarWorks @ UTRGV. For more information, please contact [email protected], [email protected]. Temperature and Relative Humidity Effects on Water Loss and Hemolymph Osmolality of Littoraria angulifera (Lamarck, 1822) A Thesis Presented to the Faculty of the College of Science, Mathematics and Technology University of Texas at Brownsville In Partial Fulfillment of the Requirements for the Degree Master of Science In the field of Biology by Phillip J. Rose April 2014 Copyright By Phillip J. Rose April 2014 Acknowledgements I would like to acknowledge and especially thank the many people who assisted and/or contributed to this project in some way, shape, or form…………..and there were many! First, I would like to say a big thank you to the thesis committee comprised of Dr. Andrea Schwarzbach, Dr. Kenneth Pruitt, and Dr. David W. Hicks. Thank you to Dr. Schwarzbach, for agreeing to be on my thesis committee and for her many helpful comments and insights on the subject matter. Thank you to Dr. Pruitt, for agreeing to join the thesis committee on short notice and for his helpful feedback on the project. Finally, a very big thanks goes to my thesis advisor Dr. Hicks, for all of his assistance, for sharing his extensive knowledge of the subject matter, and especially for his patience. Also, for always making it a point to be available to meet and answer my many questions, as well as lend his assistance wherever and whenever he could. Thank you! I would like to thank Dr. Emilio Garrido, Dr. Boris Ermolinsky, Dr. Daniele Provenzano, and Dr. Pacheco for sharing their knowledge on the subject matter of hemolymph and blood osmolality, showing me how to use the osmometer, and allowing me the use of some of their lab equipment. I would like to thank Dr. Richard Klein, who gave me lots of useful things to think about when conversing about the project. I would also like to thank Reuben Trevino, who gave me instruction on how to operate the environmental chambers. I would also like to thank the following graduate students. Rebekah Rodriguez, who was always very helpful in the lab when I had a question about lab equipment or needed help finding something. Claudia “CAT” Tamez, who helped me with some of the formatting of the figures as well as locate lab equipment manuals so that I could figure out how to operate some of the lab equipment. Liana Lerma and Andres Garcia, who while out in the field on one occasion, collected some snails and brought them back for me. Last but certainly not least, Maria T. Cooksey who was a great help in assisting me with some of the formatting of this thesis. I would also like to thank Jennifer E. Rose-White, who was a big help straightening out my tables. I also need to thank James E. Rose and Cristina G. Rose for scouting possible snail collecting sites whenever they happened to find themselves out in the Port Isabel/South Padre Island area. Again, a huge thanks goes to all of you for all of your help! I greatly appreciate it! - Phillip J. Rose iii Abstract Desiccation stress is considered to be one of the more significant determining factors that influence how organisms are distributed in the marine littoral. Gastropods living above the high tide mark, referred to as eulittoral fringe gastropods are not wetted as regularly and face unpredictable and prolonged periods of emersion. Consequently, adaptations displayed by eulittoral fringe gastropods are aimed at minimizing water loss and surviving prolonged periods of desiccation stress. Littoraria angulifera, is a tropically distributed marine eulittoral fringe gastropod. Because L. angulifera spends a majority of its time emersed there was interest in studying how the weight loss and hemolymph osmolality of this species changed over a period of time in response to varying environmental conditions. Hypotheses were that weight loss and hemolymph osmolality would be dependent upon temperature and relative humidity with weight loss and hemolymph osmolality being highest at high temperatures and low relative humidities. Additionally, it was predicted that this species should also exhibit some form of regulation of either weight loss or osmolality. Specimens ranging in size from 15.24 to 28.40 mm were collected from concrete marina bulkheads in Port Isabel, Texas. Weight loss rate and hemolymph osmolality were examined at test temperatures of 15°, 25°, and 35°C and relative humidities (RH) of <5%, 33%, 53%, 75%, and >95%. Weight loss rates were tracked for 5 individuals in each temperature/RH treatment. Hemolymph osmolality of was determined at 0, 5, 10, and 15 days in each of the temperature/RH treatments. The weight loss rates were significantly affected by test temperature and relative humidity and varied significantly across each test temperature/RH combination. Hemolymph osmolality was not significantly affected by test temperature but was affected by RH. Results indicated that weight loss increased as temperatures increased and RH decreased and hemolymph osmolalities generally increasing as relative humidity decreased. Specimens did not seem to display any signs of osmoregulation, but this may have been due to an experimental shortcoming. Behavioral responses to emersion that were observed were consistent with the responses displayed by other eulittoral fringe species displaying how this species’ is well adapted to life in its exacting habitat. iv Table of Contents Chapter Page Acknowledgements………………………………………………………………..iii Abstract……………………………………………………………………………iv Table of Contents………………………………………………………………….v List of Tables……………………………………………………………………...vi List of Figures……………………………………………………………………..vii I. Introduction Project Overview…………………………………………………………..1 Objectives………………………………………………………………….4 II. Methods Collection and maintenance of specimens…………………………………5 Weight loss..………………………………………………………………..6 Hemolymph osmolality…………………………………………………….7 Statistical analyses……………………………………………………….....8 III. Results Weight loss..……………………………………………………………….10 Hemolymph osmolality…………………………………………………....12 IV. Discussion Weight loss..……………………………………………………………….13 Hemolymph osmolality……………………………………………...…….17 V. Literature Cited………………………………………………………………...22 VI. Tables…………………………………………………………………………..27 VII. Figures………………………………………………………………………….30 v List of Tables Page 1. Mean weight loss during emersion in % water lost d-1 (±SE), shell morphometrics, and hemolymph osmolality under five relative humidity (RH) treatments for specimens of Littoraria angulifera at test temperatures of 15° , 25° , and 35°C…………………………………….. 26 2. The Scheffé method of pairwise differences of mean weight loss (% d-1) rates among specimens of Littoraria angulifera in response to the test temperatures of 15°C, 25°C, and 35°C and relative humidity (RH) treatments of <5%, 33%. 53%, 75%, and >95%. The values in the table are the probabilities that the two groups that are being compared are the same…………………………………………………….27 3. The Scheffé method of pairwise differences among hemolymph osmolalities (mOsmkg-1 d-1) of pooled samples for specimens of Littoraria angulifera, in response to five relative humidity (RH) treatments of <5%, 33%, 53%, 75%, and >95%. Values shown in table below are the probability that the two groups that are being compared are the same ……………………………………………28 vi List of Figures Page 1. Figure 1. Percent of mean weight loss (A), and hemolymph osmolality (B) versus days of emersion at 15°C for specimens of Littoraria angulifera under <5%, 33%, 53%, 75%, or >95% relative humidity (RH). Error bars represent standard errors of percent weight loss estimates and hemolymph osmolality estimates………………………………………………..30 2. Figure 2. Percent of mean weight loss (A), and hemolymph osmolality (B) versus days of emersion at 25°C for specimens of Littoraria angulifera under <5%, 33%, 53%, 75%, or >95% relative humidity (RH). Error bars represent standard errors of percent weight loss estimates and hemolymph osmolality estimates………………………………………………..31 3. Figure 3. Percent of mean weight loss (A), and hemolymph osmolality (B) versus days of emersion at 35°C for specimens of Littoraria angulifera under <5%, 33%, 53%, 75%, or >95% relative humidity (RH). Error bars represent standard errors of percent weight loss estimates and hemolymph osmolality estimates…………………………………………...32 4. Figure 4. Rate of mean weight loss in percent total weight lost d-1 for standard 22 mm shell length of Littoraria angulifera under <5%, 33%, 53%, 75%, or >95% relative humidity at 15°, 25°, or 35°C………………………………………..………………………………....….33