Náměty na pokusy a pozorování vodních živočichů ve školním akváriu IV (mimetické jevy)

or to stay alive. In this contribution some types of mimicry are presented. The crypsis (concealing coloration) gives the
oportunity to an animal to become inconspicuous in its natural environment to avoid being detected by potential observer.
Anticrypsis – an organism´s coloration and/or body shape that facilities attack of the enemies (e.g. water scorpion,
phantom midge larva, reef stone fish). Procrypsis – a pattern or shade of coloring in animals that is adapted to concealing
animals from their natural enemies (transparent body see, e.g. Indian glassy fish). The effect of countershading (obliterative
shadding) is created with a darkly colored dorsal body surface and a lightly colored underside. Disruptive coloration
uses specially placed markings to conceal a animal by obscuring the contour of its body. Animals that are equipped with
chemical defenses tend to be very brightly colored. Bold colors and patterns that advertise an animal’s danger to potential
predators is called aposematic coloration (or warning coloration). Deflective marks redirect bites from an adversary
towards less vital areas of the body. Allocrypsis – an organism´s concealing itself under a covering of living, or nonliving,
material that it does not produce (see e.g. caddisfly larvae). Caddisfly cases are diverse in their appearance, and vary
in the materials used for construction and the shape, structure, and size of the case. These aquatic larvae manufacture
cases using different materials from the environment. Caddisflies build cases that function as protective armor against
predators out of a variety of materials in their environment. These materials consist of organic particles, including pieces of leaves, sticks, or bark, as well as inorganic material such as sand. Experiments also with unusual materials for case
building in caddisflies are presented.