BIOLOGY OF THE SEA-HOW THEY LIVE 45 



furiously for a minute or two, distracting the enemy, and allowing the 

 crustacean a chance to slip away unnoticed. The discarded limb may be 

 eaten, but this doesn't bother the crustacean which simply grows another 

 as good as the one lost. 



Disguise 



Disguise is like concealment, but in the case of disguise the resemblance to 

 objects is real and not abstract. That is, animals are adapted not just to become 

 inconspicuous by destroying parts of their own identity, but by resembling 

 objects about them. Cott (1940) calls these animals "posers." Concealingly 

 colored animals are "self-effacers." Disguise is put on either for protection or 

 ambush as is the case with concealment. 



The sargasso weed community shows several good examples of disguise. The 

 sargassum fish QColor Plate 10^ and some crustaceans that live in this weed 

 are not only colored like the weed, but they bear fleshy, weed-resembling 

 protruberances on their bodies. 



Se\'eral sea horses and pipefishes bear extensions of their bodies to make 

 them look weedy. The angler, Lophins, is colored a'nd roughened to look like 

 a flat rock. Scorpion fishes look like weedy pieces of coral rock. Filefishes 

 imitate floating seaweed. The decorator crab, Stenorhynchiis, clothes itself with 

 seaweed as an adventitious disguise. Several other crabs become clothed with 

 sponges or anemones in a symbiotic relationship. 



Disguise is particularly interesting because it demands not only that an animal 

 look like some foreign object, but also that it act like that object. The trumpet 

 fish is brown and slender like a eoreonian stalk, but this eff^ect would be lost if 

 this fish remained horizontal. Therefore, trumpet fishes assume a vertical 

 position (usually near gorgonians) when alarmed and let the water currents 

 sway them so that the illusion is complete. Similarlv, the angler fish stays 

 motionless like a rock and the sargassum fish moves very little in sargasso weed 

 in order to accentuate their disouises. 



Mimicry 



Mimicrv involves a resemblance even stronger than in disguise for it involves 

 strong imitation of one living organism by another in both habits and appearance. 

 The purpose of mimicry is restricted to warning and false warning. 



Two types of mimicry are known. First, if a relatively scarce, palatable, or 

 nondangerous species mimics a relatively abundant, distasteful, or dangerous 

 species, Batesian mimicry is said to exist. This mimicry involves learning by 

 predators of the pattern of color and form of the distasteful species which is 

 not eaten. Animals which imitate this distasteful species then are presumably 

 also not eaten. However, the mimic can never become abundant or the learning 

 of the warning pattern is weakened. For instance, the tasty viceroy butterfly 

 mimics the distasteful monarch, but viceroy butterflies are much less plentiful 

 than monarchs and are generally shunned by predators. Examples of Batesian 

 couples in the sea are rare. Cott states that the English sole, Solea inilgaris, has 

 a dark spot on its side which mimics the black, poisonous dorsal spines of the 

 European weaver fish, Trachinns. 



