Bombyx mori 300 to about 900 m (1,000 to 3,000 ft) long. The fibers are very fine and lustrous, about 10 μm (0.0004 in) in diameter. About 2,000 to 3,000 cocoons are required to make a pound of silk (0.4 kg). At least 70 million pounds of raw silk are produced each year, requiring nearly 10 billion cocoons. Due to its small size and ease of culture, the silkworm has become a model organism in the study of lepidopteran and arthropod biology. Fundamental findings on pheromones, hormones, brain structures, and physiology have been made with the silkworm. One example of this was
Müller's larva Müller's larva Müller's larva or Mulleria is a larva of some Polycladida. It has 8-fold symmetry and is somewhat like a ctenophore. Müller’s larva is ciliated and has several paired and unpaired lobes. The cilia on the lobes are longer than cilia on the rest of the body. At the anterior and posterior ends of the larva are tufts of longer cilia (apical and caudal). The apical tuft originates from the apical organ, a sensory structure associated with the central nervous system. It is named after Johannes Peter Müller (1801-1858), a German physiologist who invented the plankton net, and first