There are two distinct types of sporangium within the strains of marine oomycotes now designated as Halophytophthora vesicula, the "delicate"type, and the "robust" type, as in the image below. In the image, the tip of the sporangium is shown, with its more easily visible inverted cone, clearly containing a more complex structure than that of the "delicate" type. The vesicle that is released upon eversion of the "robust" cone is also more easily seen and more complex than that of the "delicate" type. Within Atlantic mangroves, the "robust" strains are found almost exclusively in decaying leaves of black mangroves (Avicennia germinans), along with Halophytophthora masteri, a species that is wholly restricted to black mangrove. The strain pictured here is SAP 100 (also CBS 154.96), one of several halophytophthoras maintained in my laboratory. SAP 100 was collected from Crooked Island, far southeastern Bahama Islands. See Newell SY, Fell JW. 1997. Aquat Microb Ecol 12:21-28; Nakagiri A. 1993. Trans Mycol Soc Jpn 34:87-99.