Marine epibiosis

Summary Polysyncraton lacazei is a colonial tunicate (family didemnidae) living in the NW-mediterranean rocky sublitoral. A thorough scanning of numerous colonies revealed that in spite of an apparently heavy local fouling pressure only one fouling species — a kamptozoan — is encountered with some regularity on Polysyncraton. We try to define the epibiotic situation of sessile marine organisms as composed of four epibiotic parameters: longevity or exposure time (A), epibiont load (E), colonizer pool (CP) and fouling-period (FP). Subsequently, these factors are combined to propose an Antifouling Potential index: AFP=(1–E/CP)×A/(FP+A). This index is intended to permit evaluating the relative antifouling defense potency to be expected in a given organism in a given epibiotic situation and to compare different cases of epibiosis and fouling.     

Marine drugs--macrolactins

The increasing demands for new lead compounds in pharmaceutical and agrochemical industries have driven scientists to search for new bioactive natural products. Marine microorganisms are rich sources of novel, bioactive secondary metabolites, and have attracted much attention of chemists, pharmacologists, and molecular biologists. This mini-review mainly focuses on macrolactins, a group of 24-membered lactone marine natural products, aiming at giving an overview on their sources, structures, biological activities, as well as their potential medical applications.     

Marine pharmacology

Marine organisms have provided a large proportion of the bioactive natural products reported over the last 20 years, but none of these compounds have reached the pharmaceutical marketplace. This review describes current progress in the development of a selection of new antiinflammatory and anticancer agents, discusses some difficulties encountered during the development process and suggests how these difficulties may be overcome in the near future through applications of recent advances in biotechnology.     

History of American Marine Biology and Marine Biology Institutions Introduction: Origins of American Marine Biology

SYNOPSIS.In the 1840s and 1850s professional naturalists dredgedshallow sea-water on the eastern coast of the United Statesto obtain marine specimens for teaching and research. In 1871Spencer F. Baird, first U.S. Commissioner of Fish and Fisheries,organized amarine biological laboratory at Woods Hole, Massachusetts,for basic biological research as well as for practical fisherybiology. In 1873 Louis Agassiz established his summer marinestation for teachers on Penikese Island, which stimulated others,especially some of his former students, to do likewise alongthe eastern coast in subsequent years, culminating in the renownedMarine Biological Laboratory at Woods Hole (1888). On the Pacificcoast the pioneer marine laboratories were the Hopkins MarineLaboratory (1892) and the prestigious Scripps Institute of Oceanographyin California (1903), and the Puget Sound Biological Station,later known as the Friday Harbor Laboratories, in Washington(1903). Today, over 50 marine laboratories are in operationin the 21 contiguous coastal states for education and researchin marine biology     

Polar Marine Communities

SYNOPSIS. This paper offers a sweeping but very superficialreview of the marine biology of polar seas. The marine systemsin the Arctic and Antarctic have in common polar positions andcold temperatures, otherwise they are strikingly different.The Arctic has broad shallow continental shelves with seasonallyfluctuating physical conditions and a massive fresh water impactin the northern coastal zones. However, it has a low seasonalityof pack ice and little vertical mixing. In contrast, the Antarctichas over twice the oceanic surface area, deep narrow shelves,and, except for ice cover, a relatively stable physical environmentwith very little terrestrial input. The Antarctic has greatpack ice seasonality and much vertical mixing. Primary productivityin the polar areas tends to be strongly pulsed with the zooplanktonlagging behind; however there are many exceptions to such generalizations.Most recent research has focused on specific patterns and processesresulting in biological hot spots such as predictable leadsin the ice, polynyas, oceanographic fronts, areas of intensemixing, and the marginal ice zone. This review attempts to weavethese recent oceanographic studies into the geological historyof each habitat in an effort to develop a holistic understandingof the biological processes     

Marine mammal chemoreception

The presence or absence of a chemoreceptive capacity in marine mammals has drawn relatively little attention from the research community outside the Soviet Union. Toothed whales are typically labelled anosmic (lacking a sense of smell) since they do not have the peripheral olfactory structures typically associated with terrestrial mammals. Baleen whales are known to possess reduced olfactory tracts; their olfactory bulbs also may be reduced or absent. Although the neural structures that mediate taste in terrestrial mammals have been reported to be present in both groups of whales, cetaceans have been considered to have a poor sense of taste because typical mammalian taste receptors have been thought to be absent. Soviet researchers, however, recently have reported that gustatory receptors are present on some cetacean tongues and that the tongue of Tursiops truncatus appear to be well innervated. These workers also have been conducting investigations which seem to be aimed at describing a specialized gustatory capability in cetaceans. No experimental work has been reported by Western scientists. Little work has been done by either Western or Soviet researchers with regard to chemoreception among the other orders of marine mammals (Pinnipedia, Carnivora and Sirenia). Pinnipedia are typically labelled microsmatic (having a poor sense of smell); research has been restricted to histological examination of the nasal pathways, and neural anatomy. Sea otters are credited with a keen sense of smell, but no quantitative work has been reported. The chemosensory abilities of Sirenia remain unknown. The tongues of non-cetacean marine mammals have been histologically examined and found to resemble those of terrestrial mammals. No other investigations of gustation in non-cetacean marine mammals have been reported.     

Marine phage genomics

Marine phages are the most abundant biological entities in the oceans. They play important roles in carbon cycling through marine food webs, gene transfer by transduction and conversion of hosts by lysogeny. The handful of marine phage genomes that have been sequenced to date, along with prophages in marine bacterial genomes, and partial sequencing of uncultivated phages are yielding glimpses of the tremendous diversity and physiological potential of the marine phage community. Common gene modules in diverse phages are providing the information necessary to make evolutionary comparisons. Finally, deciphering phage genomes is providing clues about the adaptive response of phages and their hosts to environmental cues.     

Marine biodiversity characteristics

Oceans contain the largest living volume of the “blue” planet, inhabited by approximately 235–250,000 described species, all groups included. They only represent some 13% of the known species on the Earth, but the marine biomasses are really huge. Marine phytoplankton alone represents half the production of organic matter on Earth while marine bacteria represent more than 10%. Life first appeared in the oceans more than 3.8 billion years ago and several determining events took place that changed the course of life, ranging from the development of the cell nucleus to sexual reproduction going through multi-cellular organisms and the capture of organelles. Of the 31 animal phyla currently listed, 12 are exclusively marine phyla and have never left the ocean. An interesting question is to try to understand why there are so few marine species versus land species? This pattern of distribution seems pretty recent in the course of Evolution. From an exclusively marine world, since the beginning until 440 million years ago, land number of species much increased 110 million years ago. Specific diversity and ancestral roles, in addition to organizational models and original behaviors, have made marine organisms excellent reservoirs for identifying and extracting molecules (> 15,000 today) with pharmacological potential. They also make particularly relevant models for both fundamental and applied research. Some marine models have been the source of essential discoveries in life sciences. From this diversity, the ocean provides humankind with renewable resources, which are highly threatened today and need more adequate management to preserve ocean habitats, stocks and biodiversity.