Bream Lab: Relative Weight BIOL 3500L Dr. Christopher Kodani

Learning Objectives (for Lab Quiz) Calculate relative weight Calculate relative weight Explain: Explain: Relative weights, below 0.8, from 0.8 to 1.0, above 1.0 Relative weights, below 0.8, from 0.8 to 1.0, above 1.0 Why using fish board is important Why using fish board is important Discuss example from Florida Fish & Wildlife Discuss example from Florida Fish & Wildlife Identify largemouth bass, bluegill, warmouth, redbreast sunfish, channel catfish Identify largemouth bass, bluegill, warmouth, redbreast sunfish, channel catfish Discuss linear and non-linear regression Discuss linear and non-linear regression

Shelford’s Tolerance Curve Note Y-axis “Performance” Note Y-axis “Performance” Could be some measure of condition: Could be some measure of condition: Speed of animal Speed of animal Height of plants Height of plants # of offspring # of offspring

Relative Weight For fish, condition measured as “Relative Weight” For fish, condition measured as “Relative Weight” Ratio of actual weight to standard weight Ratio of actual weight to standard weight Similar to “Body Mass Index” for humans Similar to “Body Mass Index” for humans CDC website _adult_BMI.htm CDC website _adult_BMI.htm _adult_BMI.htm _adult_BMI.htm

Standard Weight What a fish “should” weigh What a fish “should” weigh Depends upon Depends upon Size of fish Size of fish Species Species Other factors (region, sex, reproductive condition) Other factors (region, sex, reproductive condition) Available in literature Available in literature Georgia Adopt-a-Lake Manual Georgia Adopt-a-Lake Manual Alabama Cooperative Extension Alabama Cooperative Extension

Fish Measurements Florida Fish and Wildlife l Florida Fish and Wildlife l l l Ignore girth, we only want length Ignore girth, we only want length Use fish board! Use fish board!

Calculating Relative Weight Actual weight / standard weight Actual weight / standard weight If you like, you can x100 for percentage If you like, you can x100 for percentage

Identifying Fish These could be present in Swan Lake: These could be present in Swan Lake: Channel Catfish Channel Catfish Look like a cat! Look like a cat! Largemouth Bass Largemouth Bass Two distinct dorsal fins Two distinct dorsal fins Sunfishes a.k.a. “bream” (two dorsal fins merged) Sunfishes a.k.a. “bream” (two dorsal fins merged) Bluegill Bluegill All black ear tab All black ear tab Redbreast sunfish Redbreast sunfish Has very long ear tab Has very long ear tab Warmouth Warmouth Stripes on face Stripes on face

Fish ID Study Resources Texas Parks land.phtml Texas Parks land.phtml land.phtml land.phtml Virginia Fish & Wildlife Virginia Fish & Wildlife NC State University fication.html NC State University fication.html fication.html fication.html Tennessee Wildlife Resources Agency fication.html Tennessee Wildlife Resources Agency fication.html fication.html fication.html Florida Fish and Wildlife fication.html Florida Fish and Wildlife fication.html fication.html fication.html

Actual Research Example Florida study shows flooding may improve some fish’s condition Florida study shows flooding may improve some fish’s condition Florida Fish and Wildlife ticle.asp?id=24545 Florida Fish and Wildlife ticle.asp?id= ticle.asp?id= ticle.asp?id=24545 Note box and whiskers plot Note box and whiskers plot

For Your Notebooks Frequency Distribution Tables (separate species) Frequency Distribution Tables (separate species) Body mass Body mass Total length Total length Relative weight Relative weight Make histograms (separate species) Make histograms (separate species) One for length One for length One for body mass One for body mass Scatter Plot (all fish on one) Scatter Plot (all fish on one) Mass vs. length Mass vs. length Plus standard lab write up in your notebook, by next lab (10 points) Plus standard lab write up in your notebook, by next lab (10 points)

Frequency Distribution An organized, summarized list of measurements An organized, summarized list of measurements Tells number within each interval Tells number within each interval Ex: Ages of people in a group Ex: Ages of people in a group Age Interval Number of Individuals 15 to to to to 34 80

Frequency Distribution Example Bluegills (cm): 8.83, 9.25, 8.77, 10.38, 9.31, 8.92, 10.22, 7.95, 9.74, 9.51, 9.66, 10.42, 10.35, 8.82, 9.45, , 11.06, 9.84, Bluegills (cm): 8.83, 9.25, 8.77, 10.38, 9.31, 8.92, 10.22, 7.95, 9.74, 9.51, 9.66, 10.42, 10.35, 8.82, 9.45, , 11.06, 9.84, Body Length (cm) Number of Individuals 7.00 to to to to to

Histogram

Scatter Plot

Mean Mean = average Mean = average Not the only measure of centrality! Not the only measure of centrality! Also median and mode! Also median and mode! Example Example Bluegills (cm): 8.83, 9.25, 8.77, 10.38, 9.31, 8.92, 10.22, 7.95, 9.74, 9.51, 9.66, 10.42, 10.35, 8.82, 9.45, , 11.06, 9.84, Bluegills (cm): 8.83, 9.25, 8.77, 10.38, 9.31, 8.92, 10.22, 7.95, 9.74, 9.51, 9.66, 10.42, 10.35, 8.82, 9.45, , 11.06, 9.84, 10.75

Mode Mode = most common category Mode = most common category Bluegills (cm) Bluegills (cm) 8.83, 9.25, 8.77, 10.38, 9.31, 8.92, 10.22, 7.95, 9.74, 9.51, 9.66, 10.42, 10.35, 8.82, 9.45, , 11.06, 9.84, , 9.25, 8.77, 10.38, 9.31, 8.92, 10.22, 7.95, 9.74, 9.51, 9.66, 10.42, 10.35, 8.82, 9.45, , 11.06, 9.84, 10.75

Median Median = the “middle one” (for odd sample size) Median = the “middle one” (for odd sample size) Or average of the two in the middle for even sample size Or average of the two in the middle for even sample size Body Length (cm) Number of Individuals 7.00 to to to to to

Regression Makes a “best fit” line for data Makes a “best fit” line for data We can use MS Excel’s Graph Wizard function We can use MS Excel’s Graph Wizard function Enter length into column A Enter length into column A Enter body mass into column B Enter body mass into column B Use Graph Wizard to graph of bluegill weight vs. length Use Graph Wizard to graph of bluegill weight vs. length

Linear vs. Non-Linear Regression Linear regression Linear regression Assumes straight-line relationship Assumes straight-line relationship y = mx + b y = mx + b Non-linear regression Non-linear regression Uses other equations for line Uses other equations for line Y = a + bx + cx 2 Y = a + bx + cx 2 In Excel, click on line In Excel, click on line Add trendline Add trendline Choose linear or power Choose linear or power Options: Options: Show equation Show equation Show r 2 Show r 2