Pleurocera acuta

   Digestion and Feeding


The digestive tract of Pleurocera acuta includes a mouth, pharynx, esophagus, stomach, small and large intestine, and anus (Dazo, 1965).  Accessory organs include salivary glands, a radula, liver, and jaw (Dazo, 1965). Like many other Gastropods, Pleurocera acuta is a herbivore feeding on decaying organic material and algae (Hickman, 2009).  To acquire this material they use their radula.  A radula is a chitinous, rasping, tongue-like organ that contains as many as 250,000 teeth that are used to scrape surfaces and in some cases to spear prey (Dazo, 1965; Hickman, 2009)

 The radula also acts like a conveyor belt to transport food into the mouth by working rhythmically with the odontophore cartilage (Hickman, 2009).  The feeding cycle begins when the mouth opens, followed by the odontophore being pushed forward while the radula strongly scrapes food against the odontophore and into the pharynx (Hickman, 2009). This motion, and the motion of the supporting cartilage known as the odontophore is controlled by nearby muscle bundles (Dazo, 1965; Hickman 2009).  These complex structures are bright red due to the presence of Hemoglobin, which is also found in the blood of humans (Dazo, 1965).  

Pleurocera acuta has a small jaw with left and right parts that are made out of a chitin-like material (Dazo, 1965).  The chewing surface is often brown due to food coloration and contains serrated scales for increased efficiency (Dazo, 1965).  The stomach is found in the second whorl of the shell and has a specialized rod known as the style that is used for grinding food like a pedal and mortar (Dazo, 1965; Hickman 2011).  This action is aided by the effects of cellulase which digests cellulose, the main chemical component of plants (Dazo, 1965).  The osphradium organ of Pleurocera acuta is also an important digestive structure (Dazo, 1965). According to Dazo, it was historically known to be a sensory organ but caused confusion as to what it was sensing.  It was finally determined that it was a sensory organ responsible for sampling water currents.  The sampling input is used by the snail to determine food selection (Dazo, 1965). 


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