Topic
Attheya septentrionalis
About: Attheya septentrionalis is a research topic. Over the lifetime, 7 publications have been published within this topic receiving 516 citations.
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TL;DR: A novel technique was developed for the flocculation of marine microalgae commonly used in aquaculture, and concentrates prepared from 1000 L Chaetoceros muelleri cultures were effective as supplementary diets to improve the growth of juvenile C. gigas and the scallop Pecten fumatus reared under commercial conditions.
412 citations
TL;DR: Ten new diatom strains isolated from coastal waters of Australia are shown to be alternative Australian strains with good nutritional value that could be utilised by oyster hatcheries or nurseries and could also prove useful feed species for other animal species grown in aquaculture such as abalone and scallops.
72 citations
TL;DR: All data suggest that the investigated Attheya species form a separate group of diatoms, and there is no indication that they belong to either the Chaetocerotophyc Families or the Biddulphiophycidae.
Abstract: The phylogenetic position of diatoms belonging to the genus Attheya is presently under debate. Species belonging to this genus have been placed in the subclasses Chaetocerotophycidae and Biddulphiophycidae, but published phylogenetic trees based on 18S rDNA, morphology, and sexual reproduction indicate that this group of diatoms may be a sister group of the pennates. To clarify the position of Attheya, we studied the morphology, 18S rDNA, 16S rDNA of the chloroplasts, the rbcL large subunit (LSU) sequences of the chloroplasts, and the sterol composition of three different strains of Attheya septentrionalis (Ostrup) R. M. Crawford and one strain of Attheya longicornis R. M. Crawford et C. Gardner. These data were compared with data from more than 100 other diatom species, covering the whole phylogenetic tree, with special emphasis on species belonging to the genera that have been suggested to be related to the genus Attheya. All data suggest that the investigated Attheya species form a separate group of diatoms, and there is no indication that they belong to either the Chaetocerotophycidae or the Biddulphiophycidae. Despite applying these various approaches, we were unable to determine the exact phylogenetic position of the investigated Attheya species within the diatoms.
32 citations
TL;DR: A monitoring programme was initiated in 1987 to study phytoplankton populations in the Western Isles region of the Bay of Fundy, southwest New Brunswick, and has taken a conservative approach and termed species reported for the first time since 1995 as “new” species.
Abstract: Martin, J. L., and LeGresley, M. M. 2008. New phytoplankton species in the Bay of Fundy since 1995. - ICES Journal of Marine Science, 65: 759-764.A monitoring programme was initiated in 1987 to study phytoplankton populations in the Western Isles region of the Bay of Fundy, southwest New Brunswick. Samples are collected weekly from May through October, and monthly during the remaining months, to determine phytoplankton distribution and abundance at Brandy Cove, Lime Kiln Bay, Deadmans Harbour, the Wolves Islands, and mid-Passamaquoddy Bay. Since the programme was initiated, several previously absent or non-indigenous species have been found, suggesting that new species may have been introduced to the area. In order to establish a baseline for species indigenous to Bay of Fundy waters, we have taken a conservative approach and termed species reported for the first time in the Bay of Fundy system since 1995 as “new” species. New species include the following: (dinoflagellates) Alexandrium pseudogonyaulax, Amphidinium carterae, A. sphenoides, Ceratium macroceros, Polykrikos schwartzii, Preperidinium meunieri, Protoperidinium crassipes, and Pyrocystis lunata; (diatoms) Attheya septentrionalis, Attheya longicornis, Chaetoceros radicans, Cylindrotheca gracilis, Grammatophora serpentina, Lithodesmium undulatum, Mediopyxis helysia, Membraneis challengeri, Neodenticula seminae, Odontella sinensis, Proboscia eumorpha, Pseudo-nitzschia subpacifica, Pseudo-nitzschia fraudulenta, and Thalassiosira punctigera.
17 citations
TL;DR: A mathematical model revealed that both growth phase and salinity, alone and in combination, influenced the EPA content significantly, and might be related to a decreased silica content, an accumulation of storage lipids containing EPA, or both.
Abstract: Microalgae with a high content of the omega-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are of great demand for microalgae-based technologies. An Arctic strain of the diatom Attheya septentrionalis was shown in previous experiments to increase its EPA content from 3.0 to 4.6% of dry weight (DW) in the nutrient-replete exponential phase and nutrient-depleted stationary phase, respectively. In the present study, a factorial-design experiment was used, to investigate this effect in more detail and in combination with varying salinities and irradiances. A mathematical model revealed that both growth phase and salinity, alone and in combination, influenced the EPA content significantly. Maximum EPA values of 7.1% DW were obtained at a salinity of 22 and after 5 days in stationary phase, and might be related to a decreased silica content, an accumulation of storage lipids containing EPA, or both. However, growth rates were lower for low salinity (0.54 and 0.57 d-1) than high salinity (0.77 and 0.98 d-1) cultures.
13 citations