Human uses of living things used; and as symbols or concepts through totemism and animism. More recently, anthropologists have also seen living things as participants in human social interactions. This article describes the roles played by living things in human culture, so defined. The human population exploits and depends on a large number of animal and plant species for food, mainly through agriculture, an essential component of human culture, but also by exploiting wild populations, notably of marine fish. Livestock animals are raised for meat across the world; they include (2011) around 1.4 billion cattle, 1.2 billion sheep and 1 billion domestic pigs. Plants provide
Leaping blenny a maximum water depth of 2 metres. They inhabit holes in limestone deposits in intertidal zones, and leap between holes when disturbed, earning them their common name. They are very social at mid-tide, using visual displays to warn off competitors and attract mates. Although they must remain moist to breathe, the blennies are able to breathe air, and avoid submersion by tide waters. Leaping blennies feed primarily off of algae. They are oviparous and form distinct pairs when mating. They can reach a maximum total length of 10 centimetres (4 inches). Leaping blenny The leaping blenny ("Alticus saliens"), also known