Found in estuarine and marine environments on organic debris, algae, diatoms, and marine vascular plants, these microscopic organisms can be identified by the association of their globose or colonial structures with a network of branched, anastomosing, wall-less filaments. The network, known as an ectoplasmic net, is produced by a specialized cell-surface organelle called a bothrosome (also referred to as a sagenogen). The two families that are currently recognized by Porter (1990) include the Labyrinthulaceae and the Thraustochytriaceae. Labyrinthulaceae contains one genus, Labyrinthula, with nine species while Thraustochytriaceae contains thirty species classified in seven genera. One species of Labyrinthula, L. zosterae, has been proven to cause a wasting disease of eelgrass, an ecologically important marine vascular plant. Schizochytrium aggregatum is being used as a source of commercially produced omega-3 fatty acids. Though it is known that the group as a whole is basal to the Oomycota, the relationships of the members within the order are still being worked out. At the University of Georgia, Dr. David Porter and his student, Celeste Leander, have found that the thraustochytrid-labyrinthulid clade is monophyletic based on 18S small subunit ribosomal DNA. However, the clade is composed of two supported branches; the first contains threes species of Thraustochytrium and Ulkenia profunda, the second includes three species of Labyrinthula, two species of Labyrinthuloides and Schizochytrium aggregatum.

Current research links:

• Charla Haarbauer
• Celeste Leander