Althougli Fiicus and Laminaria are both brown algae, their Ufa cycles are 

 quite different. The Ufe cycle of Fucus (Figure 8-1) is very much like that of an 

 animal. Mature, diploid thaUi produce haploid eggs and sperm which fuse to 

 form zygotes that ultimately develop into new diploid thalli. The Ufe cycle of 

 Laminaria (Figure 8-2), in which an alternation of generations occurs, is much 

 more complicated than that of Fucus. The macroscopic, blade-like, diploid 

 sporophyte alternates with microscopic, filamentous, haploid gameto- 

 phytes. The variability and complexity of algal life cycles provide several 

 opportunities to study the effect of a specific pollutant on growth and 

 development. In the present study, the effects of different petroleum 

 products on the growth of Fucus zygotes and Laminaria gametophytes 

 were observed. 



MATERIALS AND METHODS 



Both Fucus and Laminaria plants were collected from various locations in 

 and around Narragansett Bay (i.e., Camp Varnum, a National Guard 

 installation, the dock of the Environmental Research Laboratory, Narragansett, 

 R.I., and Monohan's Cove, Narragansett, R.I.). In developing techniques, 

 several species were used, including Fucus vesiculosus, F. edentatus, F. 

 distichus, Laminaria saccharine, and L. digitalis. 



The Fucus species represent both monoecious and dioecious types. In 

 deciding which species of Fucus and Laminaria to use, Httle difference was 

 noted in preliminary response among various species. Data presented herein 

 represent the responses of Fuais edentatus and Laminaria saccharina, but are 

 representative of other species in both genera. 



For Fucus, methods of procurement of eggs and sperm were evaluated (4, 

 5), and a technique was devised that is applicable to all species tested. The 

 method is essentially a combination of other methods reported in the 

 literature, and consists of the following: receptacles (fertile plant tips) that 

 appeared most erumpent and mature, even to the point of being partially 

 eroded, were collected from mature plants. These receptacles were observed 

 to produce the highest numbers of viable eggs and sperm. Receptacles were 

 rinsed in sterile charcoal filtered* seawater at 30 ppt. salinity, and were 

 placed in a moist chamber overnight. The moist chamber consisted of large 

 150 X 25 mm plastic petri dishes (Falcon Plastics) containing filter paper of 

 the same diameter moistened with sterile seawater. 



* Cartridge filtration through Commercial Filter Corporation honeycomb 

 wound filters, \5 fi porosity, and .22 ^porosity pleated Gelman filters. 



102 



