Comparison of Fish Ageing Techniques: Using Scales and Otoliths from Largemouth Bass in Old City Lake. Joey Dyer Undergraduate, Department of Biology Tennessee Technological University Cookeville, TN 38505

Project Summary The objective of this study is to compare the two most common aging techniques of bass. The techniques are using the scale and otolith method. The scale method is the easiest of the two but not as precise as the otolith method. The problem with using the otolith method is that the fish is sacrificed in the process.

Scale Method Otolith Method

Introduction The use of hard parts is based on the appearance of annuli rings (Kruse et la 1995). Historically, scales have been most often used (Weisberg 1993b). Otolith samples are more accurate ( Eveson et la 2004).

Hypothesis Statement Although the fish will be sacrificed, the otolith sample will give a better estimate of the fishes age, due to the regeneration of scales that have been lost prior to capture.

Methods and Materials 17 bass were collected from Old City Lake by electro-fishing Scale samples and otoliths were removed Annuli rings on both scales and otoliths were recorded Rings pressed and counted under a projector for scales Rings counted under a microscope for otoliths

Data Form

Expected Results Otolith samples will be more precise but the fish will have to be sacrificed in the process The scale method will give a good estimate of the fishes age

Project Timeline  Research Topic/Title(Research title was developed)Week(s) 1-2 Library Literature Search (Searched for relevant literature)Week(s) 2-4 Scientific Method Objective/Hypothesis (Developed matrix, objective and hypothesis) Week(s) 3-6 Research Proposal Key Words (determined good keywords) Week(s) 4-6 Web Page (began development of the webpage)Week(s) 5-9 Data Form / Format / Midterm Outline (developed a data form, learned the format for the research proposal outline and drafted the outline) Week(s) 5-6 Research (compiled and analyzed data, completed research) Week 5-6 Abstract (began writing the abstract, summary and conclusion Week 5-6 Midterm (gave research proposal presentation)Week 7 Spring BreakWeek 8 Platform presentation (started developing presentation)Week 9 Developed a resume and Ethics statementWeek 10 Designed poster and had the manuscript evaluated.Week11  Wrote a research progress reportWeek 12  Rewrote the research proposal as a research proposal application Week 13  Time for the platform presentation Week 14

Literature Cited Caldow, C., G. M. Wellington Patterns of annual increment formation in Otoliths of pomacentrids in the tropical western Atlantic: Implications for population age structure examination. Marine Ecology Progress Series 265: Campana, S. E., M. C. Annand, and J. I. McMillan Graphical and statistical methods for determining the consistency of age determinations. Transactions of the American Fisheries Society 124: Eckmayer, W. J., J. F. Margraf Ageing early age – 0 white bass (Morone chrysops) by daily otolith increment analysis. Journal of Freshwater Ecology 16: Eveson, J. P., G. M. Laslett, and T. Polacheck An integrated model for growth incorporating tag-recapture, length frequency, and direct aging data. Canadian Journal of Fisheries and Aquatic Science 61: Kruse, C. G., C. S. Guy, and D. W. Willis Comparison of otolith and scale age characteristics for black crappies collected from South Dakota waters. North American Journal of Fisheries Management 13: Weisberg, S. 1993b. Using hard-part increment data to estimate age and environmental effects. Canadian Journal of fisheries and Aquatic Sciences 50:

Budget Salaries & Wages10,000 First Year Professional Technician Secretarial Graduate Student Student Hourl Subtotal Benefits Travel Non-Expendables2,000 Expendables1,000 Computer Supplies & Expenses2,000 Copying & Telephon Tuition & Fees Subtotal15,000 Total Direct Costs Indirect Costs Total Costs15,000