Sponges Dominant In The Alaska Intertidal: Biology, Ecology, And Genetic Diversity Item Type Thesis Authors Knowlton, Ann Lynette Download date 27/09/2021 10:34:55 Link to Item http://hdl.handle.net/11122/8617 INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand corner and continuing from left to right in equal sections with small overlaps. ProQuest Information and Learning 300 North Zeeb Road, Ann Arbor, Ml 48106-1346 USA 800-521-0600 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. SPONGES DOMINANT IN THE ALASKA INTERTIDAL: BIOLOGY, ECOLOGY, AND GENETIC DIVERSITY A THESIS Presented to the Faculty of the University of Alaska Fairbanks in Partial Fulfillment of the Requirements of the Degree of DOCTOR OF PHILOSOPHY By Ann Lynette Knowlton, B.S. Fairbanks, Alaska December 2002 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: 3071430 UMI UMI Microform 3071430 Copyright 2003 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. SPONGES DOMINANT IN THE ALASKA INTERTIDAL: BIOLOGY, ECOLOGY, AND GENETIC DIVERSITY By Ann Lynette Knowlton RECOMMENDED: Advisory Committee Chair ^ i i. r. /£-■>---- Head, Graduate Program in Marine Science and Limnology APPROVED: v Dean, School of Fisheries & Ocean Sciences ^ _________________ Dean of the Graduate School / p • Date Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Abstract The role of the sponge,Halichondria panicea, in a Kachemak Bay, Alaska, intertidal community was investigated through field and laboratory experiments. The relationship betweenH. panicea and co-occurring macroalgae was studied and results indicate that removing macroalgae had no effect on sponge abundance. A laboratory feeding trial investigating H. panicea and its primary predator Archidoris montereyensis showed that nudibranchs consuming symbiotic sponge had higher feeding and egg production rates than individuals eating aposymbiotic sponge. In a simulated predation event, initial sponge growth rates into experimental feeding scars were high, indicating a response mechanism to tissue damage. A naturally occurring high nudibranch recruitment into a sponge population resulted in the local decline and extinction of both sponge and predator. Genetic studies revealed that at least two sponge species likely comprise the intertidal populations investigated, Halichondria panicea and H. bowerbanki. The reproductive cycle ofH. panicea at exposed, hard-substrate habitats, and H. bowerbanki at sheltered, soft-sediment sites, exhibited seasonal peaks in oocyte production and maturation. H. panicea produced embryos 3-4 months earlier than H. bowerbanki. Six genomic DNA microsatellite loci were isolated and utilized in the characterization of two Halichondria panicea populations. The two populations Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. were differentiated from one another with no significant inbreeding or bottleneck effect detected. All individuals were genetically unique, indicating little or no cloning. Sexual reproduction appears to be the dominant mode of reproduction maintaining the populations. DNA sequence analyses suggest that at least two species are likely present in Kachemak Bay. Distributions of ITS and C01 haplotypes corresponded to habitat type. Analyses of the data grouped Alaska haplotypes separately from European samples of Halichondria panicea and H. bowerbanki, suggesting separate species may occur in Alaska. A re-examination of sponge systematics in southcentral Alaska is needed. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. V Table of Contents Abstract ........................................................................................................................iii Table of Contents.........................................................................................................v List of Figures............................................................................................................. ix List of Tables...............................................................................................................xi Acknowledgements................................................................................................... xiii Chapter 1: Introduction ................................................................................................1 Literature Cited.................................................................................................9 Chapter 2: Structuring Mechanisms in a Sponge-Dominated Intertidal Community..................................................................................................... 14 Introduction .....................................................................................................14 Materials and Methods .................................................................................. 16 Study Site ............................................................................................ 16 Space Occupation ..............................................................................18 Nudibranch Feeding Trials ................................................................ 20 Sponge Recovery Rates....................................................................22 Results............................................................................................................23 Space Occupation ............................................................................. 23 Nudibranch Feeding Trials ................................................................ 31 Sponge Recovery Rates....................................................................38 Discussion...................................................................................................... 38 Space Occupation ............................................................................. 38 Nudibranch Feeding Trials ................................................................ 42 Sponge Recovery Rates....................................................................46 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. vi Summary ........................................................................................................ 49 Literature Cited...............................................................................................50 Chapter 3: Convergence in the Space-Time Continuum: A Predator-Prey Interaction....................................................................................................... 56 Introduction.....................................................................................................56 Materials and Methods...................................................................................58 Study Site ............................................................................................58 Observations ....................................................................................... 59 Results............................................................................................................ 64 Discussion...................................................................................................... 70 Summary .........................................................................................................72 Literature Cited...............................................................................................73 Chapter 4: Seasonality of Egg Production of Intertidal Sponges in Southcentral Alaska ....................................................................................... 77 Introduction.....................................................................................................77 Materials and Methods ...................................................................................79 Study Sites .......................................................................................... 79 Sample Collection and Processing...................................................83 Oocyte Diameters and Developmental Stages...............................