Despite the increasing use of zebrafish in research, scientists still have much to learn about the biology and behavioral preferences of these fish. To better understand behavior of this species, Ruhl et al. investigated shoaling and spawning in small groups of zebrafish in the lab. When given a choice between a single fish or a group of three fish, male and female fish had different shoaling preferences. The authors also evaluated spawning behavior in groups with different ratios of male to female fish. See
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Urethral catheterization of the dog is useful for diagnostic, clinical and research purposes but is a challenging procedure to master. Voronin and colleagues describe a catheterization technique in which they use a rigid endoscope to visualize the urogenital vestibule. The scope is attached to a video camera and monitor, allowing others to observe the procedure. The technique is particularly valuable for training students to carry out catheterization successfully. See
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