摘要
Cuttlefish, Sepia officinalis, can produce a variety of patterns, thee visual background cues for eliciting mottled patterns have not been studied systematically. The objective of this study was to determine the visual features that elicit mottled body patterns, which are characterized by light and dark splotches on the body. First, animals were presented withatrificial substrates-black and white checkerboard squares of various sizes-to determine the area of tthe squares that would elicit mottled body patterns. Results indicate that checkerboard squares wuth an area of about4%-12% of the area of the animal's white square (a light bod patterning compoment in the dorsal mantle) elicited mottled body patterns in three test groups (10 animals of 1.65 cn mantle length (ML); 6 animals of 10 cm ML; 6animals of 17 cm ML). Second, different ratios of black and white squares (of the apporiate size) were tested to deterimine whether a predominance of black vs. white had a stronger sensory influence on the resulting body pattern; i.e., do the animals cue preferentially on the dark or light visual background objects? With 10 animals of 1.65 cm ML, three combinations worked similaly well: 1 white: 1 black; 1w:3b and 3w:1b. The forward and reverse combinations of 1:15, 1:63 and 1:1023 did not dlivit mottled body patterns cinsistently. Our conclusion is that a high frequency of light and dark small objects of similar proportions(1:1, 1:3, 3:1) in the visual background tends to elicit mottled body patterns. Future experiments are meant to determine the exact combinations of light and dark background objects and contrast randes that are used by cuttlefish to produce adaptive coloration by means of mottled body patterns.