Critique of:

Warner, R. and S. Swearer. 1991. Social Control of Sex Change in the Bluehead Wrasse, Thalassoma bifasciatum (Pisces: Labridae). Biol. Bull. 181: 199-204.

The research conducted by Robert Warner and Stephen Swearer, on sex change in the bluehead wrasse was published in the journal Biological Bulletin in 1991. It is addressed to an audience with scientific knowledge, but not necessarily with a complete knowledge of fish biology. Therefore, it is necessary to explain some key terms that might not be common knowledge to every biologist. Throughout the paper, R. Warner and S. Swearer do this by defining key terms that might not be common knowledge to all scientist. In his abstract he defines terms such as large terminal color phase (TP) and initial color phase (IP). Establishing this abbreviations early in his paper makes the rest of the study flow with greater ease.

In the introduction Warner and Swearer give a brief background on the bluehead wrasse and its importance on behavioral ecology. Nevertheless, there are terms that are not really familiar to the common scientific reader like "protogyneous hermaphrodites." A paper published in a scientific journal must be directed to the entire scientific community. Terms like this one exclude those scientist that do not have a fish biology background. Therefore, Warner and Swearer should keep in mind that not everybody is familiar with these terms and should clarify terms that are not common scientific jargon.

The background and methods section of Warners'and Swearers' paper was clear and organized well. Warner and Swearer did an excellent work in explaining step by step the major color phases of the bluehead wrasse. The explanation of the actual research and how it was conducted was so detailed, that it might be confusing for a non-scientist. Nevertheless, it is clear enough for people with science background. The details make the experiment easily reproducible.

The result section of the paper is not as clear as the rest of the paper. Although the reading is fairly easy, most of the data reported in the table was hard to follow. The tables weaken the discussion because they are unclear and confusing. Most of the results are clearly explained in his analysis without having to use graphs to explain the data. The data might be organized in a different type of graph that is not as confusing as the ones Warner Swearer use. The authors' organized this section of the paper well and divided the results into different categories like changes in coloration or sex change verified. These classifications make the results easier to follow and eliminate some of the confusion created by the various graphs.

The final discussion of the experiment was excellent. Warner and Swearer make multiple references to earlier research on the subject and compare old results to their own. The author also use references to strengthen the results. Warner and Swearer establish their hypothesis early and work towards answering their thesis question. The experiment that they performed on the bluehead wrasse population was a good way to test their hypothesis. Nevertheless, the study did not include controls on the outside envi ronment. The outcome of the experiment can vary if external factors on the coral reef are control. Further study should be performed on the reaction of the bluehead wrasse to other changes in their social environment. For example, the introduction of competitor species may cause abrupt sex change in large female bluehead wrasses?