Attractive visual spots play an important role in defensive, feeding, agonistic, courtship, parental and other visually guided behavioural responses in fish (for review, see Price et al., 2008) as well in many other animals. Now to study the influence of spots on these responses (starting with the first techniques: see Rowland, 1979), more perfect dummies, fishinig lures, computer images and live fish with manipulated coloration are chiefly used.

Interestingly, in many cases modern fishing lures are much more perfect than models used in scientfic research.

Coss (1979) has conducted laboratory experiments with early fry of jewel fish, Hemichromis bimaculatus, and artificial models of head of adults equipped with symmetric and asymmetric spots. It is shown that models with two horizontal spots (Fig.1) induce the most intensive fright responses of fry than any others. According to Blest (1957), pair horizontally arranged crosses, spots and eye-spots induce fright responses in birds. It is shown in experiments with naïve chicks, Gallus gallus domesticus, that any asymmetry in size, shape and color of pair stimuli affects their effectiveness (Forsman & Herrström, 2004).

Fig.1 (read text)

The effectiveness of spots as amimetic stimuli is detemined by common mechanisms of visual perception. So the foregoing preferences for specially arranged spots is valid in context of other behavioural responses.

As shown in experiments with fry of jewel fish, three and four spots are bilaterally symmetric but less effective than two horizontal spots (Coss, 1979). It may mean that fry must spend more time to recognize the more complicated stimuli and, finally, to make the corresponding decisions.

Fig.2 (read text)

In fishing, there are numerous deviations from the foregoing ethologically grounded design patterns. For example, Yakima Bait Company uses so called "frog” pattern, FR, with three, four or five yellow eye-spots (Fig.2) in coloration of Triple Teazers, Freak Spoons and other lures. In the light of the saying above, it is clear that this design pattern must be considered as incorrect.

Basic References

Blest A.D. 1957. The function of eyespot patterns in the Lepidoptera. Behaviour 11, 209-256

Coss G.R. 1979. Delayed plasticity of an instinct: Recognition and avoidance of 2 facing eyes by the jewel fish. Developmental Psychobiology 12, 335-345

Forsman A., Herrström J. 2004. Asymmetry in size, shape, and color impairs the protective value of conspicuous color patterns. Behavioral Ecology 15, 141-147

Price A.C., Weadick C.J., Shim J., Rodd F.H. 2008. Pigments, patterns, and fish behavior. Zebrafish 5, 297-307

Rowland W.J. 1979. Some methods of making realistic fish dummies for ethological research. Behavior Research Methods & Instrumemation 6, 564-566