464 MARINE FUNGI 



body membrane. Eventually an isolated branch or the entire 

 mycelium is transformed into sporangia that liberate motile zoo- 

 spores 5 to 8 /x in diameter. Apstein also observed structures 

 which he doubtfully referred to as oogonia. 



In England Atkins (1929) found that pea crabs (Pinnotheres) 

 are killed by one of the Saprolegniaceae. Infection is indicated 

 by whitish patches that show through the body wall in the region 

 of the gills and along the junctions of the abdominal segments. 

 Intricately branched hyphae occupy the tissues of the gills and 

 those between the gill chamber and the dorsal surface of the 

 carapace. Hyphae do not appear at the exterior. The sporangia, 

 which are confined to the gills and pleopods, form at hyphal tips 

 and are cut off by septa. They are of the same diameter as the 

 assimilatory hyphae. The zoospores are pyriform and bicilate. 

 After a brief period of motility they encyst and may undergo a 

 second motile phase. Atkins' evidence for diplanetism, however, 

 is not conclusive. Its identity among Saprolegniaceae is not estab- 

 lished beyond the fact that it differs from all other members of 

 this family, mainly in its occurrence wholly within the body of 

 the animal. 



Two other parasites of marine animals, described by Niezabitow- 

 ski (1913), are of interest, Thalassoviyces spizakovii and T. batei. 

 He placed them in the new family, Thalassomycetineae, among 

 the Oomycetes. ThalassoiJiyces spizakovii occurs on the deep-sea 

 decapod, Pasiphaea sivado, in the Mediterranean, and T. batei on 

 P. cristata on the coast of the Fiji Islands. Evidence of infection 

 is the presence of clusters of colorless hyphae on the underside 

 of the crustacean's body. Apparently the assimilatory mycelium 

 lives wholly within the interior of the body, and the reproductive 

 hyphae constitute the external hyphal tufts. The non-septate, 

 external hyphae consist of a stalk cell that divides dichotomously 

 one or more times, and each tip eventually becomes segmented to 

 form a row of three cells, which are liberated as conidia. Nieza- 

 bitowski (1913) places Thalassomyces near the Saprolegniaceae 

 and Monoblepharidaceae. 



In the vicinity of Beaufort, North Carolina, mud crabs, Pano- 

 pens herbstii, and mole crabs, Emerita talpoida, are commonly 

 parasitized by a species of Enterobryus, apparently unnamed. 

 The organism consists of thick-walled, cvlindrical filaments of uni- 

 form diameter that are about 2 to 3 mm long and 15 to 20 fx wide. 



