Although Fucus and Laminaria are both brown algae, their life cycles are 
quite different. The life cycle of Fucus (Figure 8-1) is very much like that of an 
animal. Mature, diploid thalli produce haploid eggs and sperm which fuse to 
form zygotes that ultimately develop into new diploid thalli. The life cycle of 
Laminaria (Figure 8-2), in which an alternation of generations occurs, is much 
more complicated than that of Fucus. The microscopic, blade-like, diploid 
sporophyte alternates with a microscopic, Filamentous, haploid gametophyte. 
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, little difference was 
noted in preliminary response among various species. Data presented herein 
represent the responses of Fucus 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 
appear 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, 15 u porosity, and .22 u porosity pleated Gelman filters. All 
apparatus used in tests with both Fucus and Laminaria was plastic. 
102 
