This dataset is from a research project at Murdoch Univeristy, carried out by Peter Coulson and Jake Chandler, in conjuction with the Department of Fisheries of Western Australia.

The data is a very comprehensive biological assay of the Southern Calamari of Western Australia.

The samples were collected from various locations, every month for 2 years. Once the specimens were collected, bioligcal data was measured and recorded. Variables which were recorded include:

• Date and Site data
• Method of Capture
• Fish ID number
• Biological Data:
• Hood length (HL)
• Mantle width (Width)
• Whole Weight
• Mantle Weight
• Quill Length *see picture below
• Reproductive data:
• Sex
• Gonad Stage
• Gonad Weight
  • Ovary / Testes Weight
  • Sperm / Oocyte Weight

###Underlying question and task

• To investigate the reprodutive cycles of the Southern Calamari
• To find out where the spawning locations of the Southern Calamari
• Investigate the maturation of the Southern Calamari

###Analysis:

• 🐙 🐙 Data Exploration (MURUG meeting 2)

• Calculate the Gonadosomatic Index, defined as:

  • (Gonad Weight / Whole Weight) * 100

• Calculate the Sex Ratio, defined as:

  • (Number of Males / Number of Females) * 100

• Plot the Gonadosomatic Index (GSI) as a time series, contrasting between males and females for each sampling region

• Plot the Gonad Stage as a time series, contrasting between males and females for each sampling region

• Compare the mean weight (using fresh, mantle weight) between males and females (t test)

• Compare the mean weight (using fresh, mantle weight) of Southern Calamari over time, using simple linear regression

• Compare the mean length (using quill length) between males and females (t test)

• Compare the mean length (using quill length) of Southern Calamari over time, using simple linear regression

Useful references:

• Squid Reproductive Data Analysis (Chapter 7, page 72): Zuur, A. F., et al. "Mixed effects models and extensions in ecology with R. 2009.
• Data Exploration Protocol: Zuur, A. F., Ieno, E. N. and Elphick, C. S. (2010), A protocol for data exploration to avoid common statistical problems. Methods in Ecology and Evolution, 1: 3–14