Given below is a list of autotrophs and heterotrophs. With your knowledge about food chain, establish various linkages between the organisms on the principle of ’eating and being eaten’. What is this inter-linkage established known as? 
Algae, hydrilla, grasshopper, rat, squirrel, crow, maize plant, deer, rabbit, lizard, wolf, snake, peacock, phytoplankton, crustaceans, whale, tiger, lion, sparrow, duck, crane, cockroach, spider, toad, fish, leopard, elephant, goat, Nymphaea, Spirogyra. 

Explanation

Food Chain and Food Web A straight line sequence of “who eats whom' or eating and being eaten in an ecosystem is called a food chain. A network of cross connecting food chains involving producers, consumers and decomposers are termed as a food web. 
Lion. Tiger -Top carnivore (T op tropic level)
Spider. cockroach. lizard, wolf, snake, toad, fish, crane Seoondry Consume: (IIIrd trophic level).
Crustaceans, grasshopper, deer, mouse, squirrel, rabbit, elephant, goat- primary Consumer (IInd trophic level).
Phytgplankton, algae, HydriIla, maize plant, Nymphaea, Spirogyra - Producers (lst trophic level).