ALBERT

Description: The cuttlefish ingests much skeleton from the crustaceans and fish it preys upon. The skeletal pieces are relatively large and their dimensions bear a close relationship to the length of the buccal mass and diameter of the oesophagus. The structures of the buccal mass are instrumental in the breakdown of prey and orientation of long pieces of skeleton to ensure their entry into the oesophagus. Many pieces of skeletal material present in the stomach contents still have attached muscles, showing that there is little, or no, external digestion. Skeletal material may be important for long-term maintenance of young Sepia in captivity.

Description: Benthic metabolism and standing stocks were investigated in the deep Red Sea between 21o and 27oN, Activity was assessed by the determination of respiration rates with a shipboard method and by calculating oxygen consumption from the activity in the electron transport system. We attempted to compare results from different latitudes within the warm Red Sea and with data from cold Atlantic environments. Our investigations were part of an environmental risk assessment to evaluate future mining of metalliferous sediments from the Atlantis II Deep.

Description: The diet of the king penguin Aptenodytes patagonicus at Marion Island was examined throughout the year by analysis of stomach samples. Fish accounted for 87% by wet mass, 75% by numbers and 69% by reconstituted mass. Their proportional importance by wet mass increased from 68% during winter to almost 100% in summer and probably reflects a real increase in their local availability. Squid comprised most of the remainder with crustaceans forming less than 1% of the diet by numbers. Prey items were generally small, the most abundant being three species of myctophid fish, Krefftichthys anderssoni, Protomyctophum tenisonì and Electrona carlsbergi, and a squid Kondakovia longimana. King penguins took both juvenile and adult Krefftichthys anderssoni and P. tenisoni, but only adult E. carlshergi. The juvenile and adult modal size classes of K. anderssoni and P. tenisoni increased from March through to February and the proportion of juvenile to adult fish increased in winter. The increase in the modal size class of the K. anderssoni/P. tenisoni complex during the year probably reflects growth of the fish, rather than movement of different populations in and out of the area exploited by king penguins. All squid consumed were probably juveniles. The modal size class of Kondakovia longimana increased from March to August, but in September to October smaller squid again formed a large proportion of the squid component of the diet. Numbers of measurable squid beaks recovered from November to February were low. This is the first time that mesopelagic myctophid fish have been shown to comprise a major component of the diet of a vertebrate predator in the Southern Ocean.

Description: In the animal kingdom evolutionary size changes involved increasing, decreasing and stationary patterns. Planktic and benthic Foraminifera chiefly increased their size during evolution. This increase, however, did not always occur gradually, but could be interrupted by periods when the animals maintained or even decreased in size. The rate of the size increase is different for the various species examined, some benthic forms grew only 10% during the Oligocene-Pleistocene interval, while for others this figure was up to 96%. Some benthic species increased in size in certain areas, but not in others. It is not improbable that some phylogenetic trends of planktic Foraminifera representing, according to stratigraphers, the evolution of one species into another, represent in reality, from the biological point of view, specimens of the same species which changed their size and in addition some minor morphological traits which are encompassed by the normal span of intraspecific variability. A comprehensive understanding and explanation of the size change of Foraminifera needs much additional research.

Description: Osmotic adaption by halophilic and halotolerant bacteria is generally achieved by the accumulation or synthesis of several organic solutes. Accumulation by uptake from the medium is preferred over biosynthesis. The chemical nature of the major solute is important in determining the degree of osmotolerance of the organism. Glycine betaine accumulation confers a greater degree of osmotolerance than proline, which in turn confers more osmotolerance than glutamate accumulation. The occurrence and uptake of these solutes in a variety of eubacteria is reviewed.

Description: Blidingia minima var. ramifera is reported for the first time in eastern North America. It occurs in the Gulf of St. Lawrence, Nova Scotia and in Maine. In the estuary of the West and Rights Rivers (Antigonish Harbour, Nova Scotia) it is the most common intertidal alga and during its maximum growth period (June‐August) covers 75–90% of the intertidal zone for several km of shoreline at the mouth of the Rights River. In culture, spore germination and early development were typical of the taxon as described from Europe. The taxon is raised to specific status as Blidingia ramifera stat. nov. Blidingia subsalsa is confirmed from New England based on observations of spore germination in plants from Maine and Connecticut.

Description: Intense bottom-ice algal blooms, often dominated by diatoms, are an important source of food for grazers, organic matter for export during sea ice melt, and dissolved organic carbon. Sea-ice diatoms have a number of adaptations, including accumulation of compatible solutes, that allows them to inhabit this highly variable environment characterized by extremes in temperature, salinity, and light. In addition to protecting them from extreme conditions, these compounds present a labile, nutrient-rich source of organic matter, and include precursors to climate active compounds (e.g., dimethyl sulfide [DMS]), which are likely regulated with environmental change. Here, intracellular concentrations of 45 metabolites were quantified in three sea-ice diatom species and were compared to two temperate diatom species, with a focus on compatible solutes and free amino acid pools. There was a large diversity of metabolite concentrations between diatoms with no clear pattern identifiable for sea-ice species. Concentrations of some compatible solutes (isethionic acid, homarine) approached 1 M in the sea-ice diatoms, Fragilariopsis cylindrus and Navicula cf. perminuta, but not in the larger sea-ice diatom, Nitzschia lecointei or in the temperate diatom species. The differential use of compatible solutes in sea-ice diatoms suggests different adaptive strategies and highlights which small organic compounds may be important in polar biogeochemical cycles.

Description: Petrographic, mineralogic, and geochemical data are reported for lavas from two of the major shield volcanoes of the Santorini volcanic complex (Skaros and Micro Profitis Ilias), both of which were active prior to the well-known Minoan eruption with associated caldera collapse. Field work and whole-rock chemical analyses indicate four cycles of eruptive activity within the Skaros sequence and three within the Micro Profitis Ilias (M P1) sequence. SiO2 and LIL-element contents decrease from the base to the top of all cycles except for the uppermost cycle of Skaros. Chemical variations within cycles are interpreted to result from eruption from compositionally and thermally zoned magma chambers. Major oxide data and the results of least-squares, mass balance modeling indicate that fractional crystallization played an important role in the development of the observed chemical variations. However, observed systematic variations in groundmass compositions within each cycle, observed irregular variations in total phenocryst content and the results of density calculations require that generation of the chemical zonation did not involve crystal settling but reflects unstable density stratification, probably resulting from sidewall crystallization. Some of the primitive lavas erupted on Santorini preserve phenocryst and xenocryst evidence for a stage of high-pressure fractional crystallization (involving removal of olivine, clinopyroxene, orthopyroxene, and Cr-spinel). Trace element data combined with petrographic data (i.e. the occurrence of abundant phenocrysts with resorption textures) is taken as evidence that magma mixing was also important in the development of cyclic variations. Most basaltic andesites from Skaros appear to be hybrids derived by mixing of basalt and andesite/dacite. Mineralogic data demonstrate that mixing was also important in the development of zonation in the chambers beneath MPI, but trace element data cannot be explained by combined fractionation and mixing alone. Specifically, incompatible, and compatible element abundances are lower than predicted if fractionation and mixing occurred and it is suggested that the anomalous trace element behaviour of especially LIL elements reflects the simultaneous operation of assimilation, for which there is support from isotopic studies. It is concluded that inter- cyclic chemical variations are explicable in terms of fractionation, mixing and assimilation. The LIL element and highly compatible element concentrations in the most primitive lavas erupted in each cycle of Skaros and MPI increase with time, indicating that mixing became more important with time.