leucon

zoology

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June 30, 2026

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The term "leucon" refers to a type of sponge or sponge larva with a complex internal structure. In a leuconoid sponge, the flagellated cells (choanocytes) are located in numerous small chambers scattered throughout the body. These chambers are part of a sophisticated water-current system that sponges use for feeding, respiration, and waste removal.12

This system involves water entering through small pores, passing through incurrent canals, then into the flagellated chambers, and finally exiting through excurrent canals and the osculum (a larger opening). This leucon type represents the most complex of the three main water-current systems found in sponges, with the other two being the simpler ascon and sycon types. The word "leucon" itself originates from the Greek word for "white".21

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sponge
Water-current system
of canals—ascon, sycon, and leucon. The simplest, or ascon, type, found only in certain primitive genera of the Calcarea (e.g., Leucosolenia), is characterized by an arrangement of choanocytes around a central cavity that directly communicates with the osculum. The walls of these sponges are thin, lack canals, and are…
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of canals—ascon, sycon, and leucon. The simplest, or ascon, type, found only in certain primitive genera of the Calcarea (e.g., Leucosolenia), is characterized by an arrangement of choanocytes around a central cavity that directly communicates with the osculum. The walls of these sponges are thin, lack canals, and are…
Read More