Nourishing of the Carp and His Pond-Companions. Extracts from the Work on the Basis of Pond-Culture

The warmer the water and the more suitable the spot and the weather are the quicker life develops in the spawning ponds and the more intensive appears the result. [...] The one special part is intended for the development of the young in the egg the other remaining in the yolk bag which again adheres to the belly offers food to the hatched fry so long as the siezing and digestive organs have attained the necessary form and strength and enable the fry to possess itself of the free food. [...] The Hoppers are not as prolific as the water-flea but what they miss one way is partly gained in another namely the constitution of the body is superior The sociable life of the hopper is proved by the fact that they frequently entwine themselves in coils and push together in groups which to the great delight of the carp swim about in the water like a prepared compact meal. [...] Of course the fish can only use the younger softer layers of the shell and as in the case of the shell species the fish can only make use of the smaller snail species for then the food is more digestible.(8) THE PR380BRANCHIATA found in the carp's intestines are represented by the following species the swamp snail PALUDINA VIVIPARA the cover snail BITHYNIA TENTACULATA and the comb snail (VALVA [...] The rational pond economist must of coarse use discretion and consider the object of the pond the natural properties of the ground and the character of the district.