Show simple item record

dc.contributor.advisor Steele, Mark A. en
dc.contributor.author Spies, Brenton Tyler en
dc.date.accessioned 2014-08-08T15:24:17Z en
dc.date.available 2014-08-08T15:24:17Z en
dc.date.copyright 2014 en
dc.date.issued 2014-08-08 en
dc.date.submitted 2014-05 en
dc.identifier.uri http://hdl.handle.net/10211.3/124014 en
dc.description Includes bibliographical references (pages 46-50) en
dc.description California State University, Northridge. Department of Biology. en
dc.description.abstract In benthic associated fish species, the time an individual spends in the larval phase until settlement to a benthic substratum is a vulnerable and critical period determining survival. In many species, the length of this period can strongly influence dispersal potential, further affecting a species geographic range, population connectivity, and community structure. The type of habitat in which a fish resides can significantly influence its larval development due to variations in the abiotic environment, such as temperature. In addition, the degree of habitat isolation can strongly influence dispersal potential, as seen in seasonally closed, or isolated, estuaries in California when compared to fully tidal marine estuarine systems. This study examines the variations in larval traits of two California endemic gobiid species found in differing estuarine habitat types. The arrow goby, Clevelandia ios, is commonly found in fully tidal bays, estuaries, and mudflats with consistent marine influence. The tidewater goby, Eucyclogobius newberryi, is the sister species to the arrow goby, and prefers estuaries and lagoons with some degree of seasonal isolation from the sea. This habitat preference exposes the tidewater goby to much greater temperatures and limits its dispersal potential. In the first part of this study, I used otoliths to examine the larval duration, size at settlement, and pre-settlement growth rates of newly settled gobies collected in eighteen estuaries along the California coast in the summer of 2011. I found that the arrow goby, on average, had a longer larval duration than the tidewater goby, but smaller size at settlement based on back-calculated size measurement. Additionally, larval growth rate of the arrow goby was slower than that of the tidewater goby. Although variations in larval traits between these two species were significantly different, they were much more similar than initially expected. In the second part of this study, I examined the effects of temperature and latitudinal distribution on the larval traits of the arrow and tidewater goby in eighteen study systems. Hourly temperature measurements were recorded in 18 study sites in order to determine the mean temperature experienced by each fish during its larval phase. Temperatures found in seasonally closed estuaries inhabited by the tidewater goby had greater variability among sites (10o C range) than the fully tidal marine sites inhabited by the arrow goby in (5o C range). Among site variation in larval traits was greater for the tidewater goby, likely linked to the greater temperature range of seasonally closed estuaries. On average, for both species, fish that experienced warmer temperatures had a shorter larval duration, faster growth rates, and were smaller in body size (SL) at settlement. Projected increases in global temperatures will likely accelerate larval development for many species. For the arrow goby, tidewater goby, and related estuarine species, this can either be beneficial or damaging depending on local habitat conditions and community structure. A decrease in larval duration could potentially reduce dispersal distance and gene flow between populations. However, decreases in larval duration could potential increase the rate of survival to settlement by reducing predator exposure. This would, in turn, decrease the size at settlement, which could prove to be detrimental in populations where a larger body size at settlement gives a greater competitive advantage in the juvenile stage. Therefore, further knowledge on the effects of temperature on endemic species can be useful for planning conservation and management strategies in the face of climate change en
dc.description.statementofresponsibility by Brenton Tyler Spies en
dc.format application/pdf en
dc.format.extent xi, 50 pages en
dc.language.iso en en
dc.publisher California State University, Northridge en
dc.rights.uri http://scholarworks.csun.edu/xmlui/handle/10211.2/286 en
dc.subject otolith en
dc.subject Eucyclogobius newberryi en
dc.subject Clevelandia ios en
dc.subject arrow goby en
dc.subject tidewater goby en
dc.subject estuary en
dc.subject California en
dc.subject growth rate en
dc.subject settlement en
dc.subject larval duration en
dc.subject.other Dissertations, Academic -- CSUN -- Biology. en
dc.title The effects of temperature and latitude on larval traits of the endangered tidewater goby (Eucyclogobius newberryi) and its sister species the arrow goby (Clevelandia ios) en
dc.type Thesis en
dc.date.updated 2014-08-08T15:24:17Z en
dc.contributor.department Biology en
dc.description.degree M.S. en
dc.contributor.committeemember Allen, Larry G. en
dc.contributor.committeemember Dudgeon, Steven R. en
dc.rights.license By signing and submitting this license, you the author grant permission to CSUN Graduate Studies to submit your thesis or dissertation, and any additional associated files you provide, to CSUN ScholarWorks, the institutional repository of the California State University, Northridge, on your behalf. You grant to CSUN ScholarWorks the non-exclusive right to reproduce and/or distribute your submission worldwide in electronic or any medium for non-commercial, academic purposes. You agree that CSUN ScholarWorks may, without changing the content, translate the submission to any medium or format, as well as keep more than one copy, for the purposes of security, backup and preservation. You represent that the submission is your original work, and that you have the right to grant the rights contained in this license. You also represent that your submission does not, to the best of your knowledge, infringe upon anyone's copyright. If the submission contains material for which you do not hold copyright, or for which the intended use is not permitted, or which does not reasonably fall under the guidelines of fair use, you represent that you have obtained the unrestricted permission of the copyright owner to grant CSUN ScholarWorks the rights required by this license, and that such third-party owned material is clearly identified and acknowledged within the text or content of the submission. If the submission is based upon work that has been sponsored or supported by an agency or organization other than the California State University, Northridge, you represent that you have fulfilled any right of review or other obligations required by such contract or agreement. CSUN ScholarWorks will clearly identify your name(s) as the author(s) or owner(s) of the submission, and will not make any alterations, other than those allowed by this license, to your submission. en


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record

Search DSpace


My Account

RSS Feeds