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Cell densities of Parmales (a group of siliceous marine phytoplankton) were determined in 81 water samples from depths of 0–60 m on a monthly basis from October 2009 and October 2010 in Mag...

Rochin-Banaga, H.; Bollmann, J.; Cortes, M.Y., and Aguirre-Bahena, F., 2017. First account of Parmales (Chrysophyceae) in sediment trap samples from the Alfonso Basin, Gulf of California, Mexico. The flux of Parmales was analyzed from samples collected by a sediment trap deployed at 300 m depth in Alfonso Basin, Bay of La Paz. Twelve time-series samples were collected from September 2011 to September 2012 with a monthly resolution. Tetraparma insecta was the only species identified in this study. Its total fluxes varied considerably, with a minimum flux of 1 × 106 individuals m−2 d−1 in spring-summer and maximum flux of 66 × 106 individuals m−2 d−1 in autumn. The maximum flux was associated with warm water conditions (28°C). The observation of T. insecta in sediment traps suggests that this species might also be preserved in the sediment record at the Alfonso Basin.

We analysed the morphology of Emiliania huxleyi from globally distributed plankton samples and demonstrate that the size of E. huxleyi placoliths is highly correlated to in-situ sea surface water salinity. We used multiple linear regression analysis to link morphological parameters of E. huxleyi to in-situ salinity and in-situ temperature. The best multiple regression model yielded an R 2 = 0.84 with a standard residual error of 0.65 for in-situ salinity over a gradient from 32.6 to 38.8. No significant correlation existed with temperature. Our results suggest that the morphology of E. huxleyi placoliths of recent and ancient sediments may provide a robust method to reconstruct sea surface salinities. One caveat is that the plankton-derived multiple regression model for in-situ salinities is different from that reported from previous work on Holocene sediments. This discrepancy is most likely caused by taphonomic processes or from the biogeographically biased data sets which were used (open ocean versus near shore). The cause of the tight relation between salinity and morphological response is not well understood but may be related to cell turgor regulation that affects the size of the cell and thus the size of a single coccolith.

8 pages, 4 figures, 2 tables, A new species Formonsella pyramidosa gen. et sp. nov. is described to accommodate a widely distributed warm-water coccolithophore species that has previously been referred to as Pappomonas sp. 2. Formonsella differs from Pappomonas with respect to, in particular, the detailed structure of the rim on both calicate and non-calicate coccoliths. In Formonsella the rim comprises two cycles of rod-shaped elements. Although elements in the distal layer are higher at one end, giving this cycle a serrate outline, the overall appearance is very different from the Pappomonas rim which encompasses a distal cycle of pentagonal elements, giving the rim a very distinct toothed appearance. Inverted rectangular pyramidal structures terminate the calicate F. pyramidosa coccoliths. In non-calicate coccoliths the central area calcification comprises differently sized tile-shaped elements, mostly arranged along the longitudinal axis in a rather irregular way

J. BOLLMANN, M.Y. CORTES ,A. K LEIJNE, J.B. O STERGAARD ANDJ.R. YOUNG. 2006. Solisphaera gen. nov. (Prymnesiophyceae), a new coccolithophore genus from the lower photic zone. Phycologia 45: 465-477. DOI: 10.2216/05-14.1 Solisphaera gen. nov. (Prymnesiophyceae) is described from the lower photic zone of the Pacific Ocean, the North Atlantic Ocean and the Gulf of Mexico. Differences in coccolith morphology between Solisphaera and members of Rhabdosphaer- aceae are certainly substantial enough to warrant the erection of a separate genus that should probably be categorised as incertae sedis aff. Rhabdosphaeraceae. The new genus accommodates three new species, S. emidasia sp. nov., S. blagna- censis sp. nov. and S. helianthiformis sp. nov. and the presence of a corona of process-bearing coccoliths around the cell is a key feature that unites the three species in the new genus Solisphaera, while the shape of these coronal coccoliths provides the main character for separating them at species level. A remarkable feature of this genus is the tight interlocking of the coronal coccoliths, in almost all collapsed coccospheres the circle of coronal coccoliths remains intact. This is evidently due to the presence of notches at the base of the process into which the rims of adjacent coccoliths lock. All three species are restricted to the lower photic zone in the areas studied and apparent preferences for different depth levels of S. emidasia and S. blagnacensis, as well as their nutrient and light requirements, have to be confirmed by further analysis.

Detailed analysis of the morphology of Florisphaera profunda from plankton samples collected at three sites in the Atlantic and Pacific Oceans reveals wide variation in this deep ocean-dwelling coccolithophore. In addition to the two varieties described previously, we found a third distinctive form, Florisphaera profunda var. rhinocera var. nov. All three varieties occur at each of the sampling sites. The analysis of monthly samples from different levels in the lower photic zone (LPZ) (100–200 m) at the Hawaii Ocean Time series station suggests that the varieties have similar distributions, which are correlated to primary productivity and the availability of light. The analysis of coccolith and coccosphere size in F. profunda reveals the existence of several size modes in Florisphaera profunda var. profunda and F. profunda var. elongata. The biological significance of these modes, or morphotypes is not known. However, their co-occurrence in single samples from different oceanic areas suggests that they ar...

This paper discusses the techniques used to sample and analyse living marine calcareous phytoplankton. The various methods are described and tested within several research projects aimed at the determination of coccolithophore cell densities in seawater. In addition, the potential advantages and drawbacks associated with the application of light and scanning electron microscopic techniques to the quantitative analysis of coccolithophores are discussed. Several tests have been carried out in order to quantify potential errors related to: (1) homogeneity of material distribution on filter membranes; (2) use of different microscopes (scanning electron microscope versus light microscope); (3) use of different filter membranes (cellulose mixed-ester membranes versus polycarbonate membranes); and (4) Utermohl settling versus filtration method. These tests revealed that major errors in cell density calculations could result from the uneven distribution of coccolithophore specimens on a filter membrane. The error resulting from the use of a light microscope arises from its low resolution, which restricts the identification of species, especially of small coccospheres. The use of different filter membranes does not show a statistically significant difference in cell density calculations, although polycarbonate membranes can be examined much more efficiently with the scanning electron microscopy than cellulose mixed-ester membranes. The Utermohl method, however, gives lower cell densities consistently (several times) than the filtration method.

Processes of current and past global change have been successfully identified and modeled by treating the earth as a physical or chemical system. Quantitative characterization of global change in the biota lags far behind. Units of measurement include biomass, productivity, abundance, diversity and species longevity. The response time to forcings of the physical and chemical systems range from seasons to a few thousand years. Response times of quantifiable aspects of the biosphere, however, may range from the ecological time-scale of days up to the evolutionary time-scale of millions of years.

A quick new method is described for the quantification of absolute nannofossil proportions in deep-sea sediments. This method (SMS) is the combination of Spiking a sample with Microbeads and Spraying it on a cover slide. It is suitable for scanning electron microscope (SEM) analyses and for light microscope (LM) analyses. Repeated preparation and counting of the same sample (30 times) revealed a standard deviation of10.5%. The application of tracer microbeads with different diameters and densities revealed no statistically significant differences between counts. The SMS-method yielded coccolith numbers that are statistically not significantly different from values obtained from the filtration-method. However, coccolith counts obtained by the random settling method are three times higher than the values obtained by the SMS- and the filtration-method. © 1999 Elsevier Science B.V. All rights reserved.

This is the first description of a combination coccosphere of the heterococcolithophore species Coronosphaera mediterranea (Lohmann 1902) Gaarder in Gaarder & Heimdal (1977) and the holococcolithophore species Calyptrolithophora hasleana (Gaarder 1962) Heimdal in Heimdal & Gaarder (1980) (Figs 1, 2). A single specimen of this new combination coccosphere was found within 53000 analysed cells in one of 189 samples collected at the JGOFS time series station ALOHA, Hawaii, during 1993 to 1996. The specimen was in a sample collected during autumn 1996 at a water depth of 5 m at a temperature of 26·1 °C, salinity of 35·0 psu, phosphate of 0·002 μmol/kg and in nitrate-depleted water (for details see Cortes, 1998; Cortes et al., 2001).