Thesis (M.S.)--Humboldt State University, 2006. / Includes bibliographical references (40-42). Also available via Humboldt Digital Scholar.

No description available.

No description available.

No description available.

Barnacles are mostly sessile, hermaphroditic, internal-fertilizing and usually non-selfing crustaceans. They have the longest penis length, relative to body length, among all organisms. Because of their immobility, barnacles have to extend penes to reach mates and transfer the sperm. The longer the penis the more mates they can reach. However, maintaining long penes may be costly. How do barnacles allocate the reproductive investment and adjust the length of penes? Previous researches indicated that wave actions influenced the penis length of barnacles. Here we explore if biological factors are also involved in determining the penis length. Our hypotheses are that the penis length of Balanus amphitrite may be determined by (1) the presence of neighbors, (2) neighbor numbers, and (3) neighbor distance. Experimental results indicate that the neighbor distance could influence the penis length of B. amphitrite, and the penis length increase with increasing distance of neighbors. The neighbor numbers were not found to influence the penis length. In the treatment of lone individuals, the penis lengths first increased and then decreased, and they are significantly shorter than those in the treatment with neighbors. When neighbors exist, B. amphitrite detects the density by distance of neighbors. The greater the distance to neighbors, the lower the densities of neighbors. Because of the mates are enough to mate, the penes length decrease with increasing density to save cost. When neighbors do not exist, B. amphitrite may save cost by decreasing or not investing pens length . Our result shows that the plasticity of the penis length of B. amphitrite is an adaptation by natural selection.

Barnacles have the longest penis length, relative to body length, among all organisms. It is common for their penis length to be several times that of their bodies¡¦. One reason is that barnacles are immobile and they rely on penis to reach mates. Thus the longer the penis the more mates there may be. How do barnacles balance mate numbers and penis cost? In this investigation, we studied the possible relationship between local densities and penis lengths of barnacles. Our goal is to explain the high intraspecific variation in penis lengths of barnacles. First, we measured the Nearest Neighbor Distance(NND) and Morphological Index (MI), both indices of local barnacle densities, of individuals of Amphibalanus amphitrite at Tainan, Tetraclita kuroshioensis at Keelung and Kenting, and Tetraclitella chinensis at Penghu. The cirrus lengths were used as indices of body sizes. A high percentage of penis length variation could not be explained by body sizes in these barnacles. In A. amphitrite and T. kuroshioensis, a positive correlation between residue penis length, i.e., after deducting the effect of body size, and MI was found. Assuming no sperm competition, we found, through simulation, that the optimal penis length, is not related to local densities, whereas in the presence of sperm competition, the longer penis length the lower fitness.In lab experiment, however, penis length of A. amphitrite was found to increase with increasing number of neighbors.Under high densities, the shell base become relatively small (high MI) and the shell becomes elongated. Investment in eggs may be limited by space available for brooding, thus more energy is available to invest in male functions. Under the assumption of no sperm competition, penis length remains the only option for effective investment. The preliminary result here suggests that the penis length of barnacles is plastic and is influenced by the local density. In Tetraclitella chinensis, no correlation between local densities and penis lengths was found; the very flat shell morphology of the species may have contributed to this phenomenon.

Gooseneck barnacles (Pollicipes cornucopia) exceeding 4 cm in length are a favourite seafood in Spain. In 1978 the British Columbia seafood industry introduced the indigenous species Pollicipes polymerus into this potentially lucrative market. Due to the problems associated with this species its export was unsuccessful. Alternatively, to fill either the void left by Pollicipes pollymerus and/or future markets, the acquisition of seed and the subsequent suspended culture of the gooseneck barnacle, Lepas anatifera, were investigated. Lepas anatifera successfully colonized the cultch (oyster shells, wooden dowelling and rubber) that was deployed at two locations off the west coast of Vancouver Island. The success of the colonization of cultch and the information obtained from a previous survey suggested that the set occurs regularly between the middle of April and the end of May off the west coast of Vancouver Island. The suspended culture of Lepas anatifera indicated that growth may be site specific and that areas of a high phytoplankton/zooplankton ratio may be detrimental to growth and time to sexual maturation. At the densities studied, survival seems to be proportional to density. Capitulum growth and weight gain were significantly greater for Lepas anatifera protected from predation within lantern nets than for those grown exposed on lines of oyster shells and wooden doweling. The average total length (capitulum plus peduncle) exceeded 4cm within 17 to 23 weeks. / Land and Food Systems, Faculty of / Graduate

No description available.

Seasonal reproduction of marine sessile organisms may be an adaptation of seasonal variation in suitable substratum availability. This research is focused on how to quantfy the suitable substratum of marine sessile organisms. Then the potential seasonal change of suitable substrate availability can be assessed. We tested 1-1.5 meters scale is a population closed spatial scale. At this scale we try to find ¡§intensification phenomenon¡¨ using different-size panels. If intensification phenomenon dose exist at 1-1.5 meter scale, then the amount of the suitable substratum can be estimated. We also compared three different current environments at Tiaoshi area in Nan-wan-Bay, the 3rd Nuclear Power Plant Inlet and the Hobihu Yacht Wharf to find out if the intensification phenomenon exists at this different situations. Lastly, sand and reef area were compared. Since reef areas has more suitable natural substratum than sand areas. The intensification phenomenon at 1-meter scale was not found. The larval density in water column might be highly heterogeneous even in very small scale. On the other hand, we consistently found higher settlement density in sand areas than in reef areas. This phenomenon may well have been caused by the intensification phenomenon.

No description available.