Mayflies are herbivores that eat numerous forms of plants including algae, rooted aquatic vegetation, and plant debris.  They have a crucial role in ecosystems based on their food choice and life cycle.  After the mayflies hatch there is always some form of plant debris around so transportation to food is not a major problem for this organism.


Mayflies have a straight through digestive system divided into three sections, the stomodaeum, the mesenteron, and the proctodaeum (Traver, 1972).  The stomodaeum is formed as an invagination of the ectoderm and consists of the buccal cavit, the pharynx, and the esophagus.  The mesenteron, or mid-intestine is the longest portion of the digestive tract and it extends from the anterior stodaeum to the posterior proctodaeum.  The proctodaum extends from the mesenteron to the posterior opening of the mayfly also known as the anus.  Histology of the mesenteron consists of an interior lining of columnar epithelium surrounded by a layer of circular muscle which itself is covered with longitudinal muscle fibers (Traver, 1972).  The epithelial lining serves as a means of nutrient uptake from digested materials traveling through the intestine, and the muscular layers help move food along the digestive tract via peristaltic movements.   

Transport of Nutrients

The circulatory system for mayflies is universal across all the species with some minor differences.  It of a single dorsal vessel that lies just below the the dorsal body wall.  The posterior portion of the dorsal vessel is the widest section of the vessel and serves as a primitive heart with ten chambers corresponding to the ten abdominal segments (Traver, 1972).  Each chamber has slit like openings called ostia as well as a pair of internal valves (Traver, 1972).  The body cavity is called the haemocoele and it forms a sinus along either side of the midline that carries the blood, a lymph like fluid, to the flies appendages including the legs.   
    The respiratory system of the mayfly differs depending o the stage in the life cycle.  The nymph breaths via seven pairs of plate like gills on the sides of the abdomen.  These gills are connected to many branches of tracheal tubes that disperse the oxygen to the rest of the body.  Once the imago stage of the life cycle is reached the entire respiratory system of tracheal tubes open up to the environment by using ten pairs of spiracles (Traver, 1972).  The spiracles are elongated openings with two on the thorax and eight on the abdomen (Traver, 1972).  This change in the respiratory system reflects the diversity of life styles the mayfly undergoes by needing to breath both under water and on land at different stages. 
    Still want to learn more about mayflies?  Visit the classification section to learn about mayfly phylogeny and classification.  For more general information about mayflies, visit


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