Journal of Phycology最新文献

{"title":"Species composition and abundance of crustose coralline algae and formation of Xinfeng algal reef in Northwestern Taiwan","authors":"Showe-Mei Lin,&nbsp;Li-Chia Liu,&nbsp;Jen-Chieh Shiao,&nbsp;Chih-Chien Huang,&nbsp;Li-Chun Tseng,&nbsp;Hsin Lee","doi":"10.1111/jpy.13537","DOIUrl":"10.1111/jpy.13537","url":null,"abstract":"<p>The composition and abundance of crustose coralline algae (CCA) have been documented in the Xinfeng algal reef (XAR). Eight CCA species were identified, including four in <i>Phymatolithon</i> (<i>P. margoundulatum</i>, <i>P. taiwanense</i>, <i>P. variabile</i>, and <i>Phymatolithon</i> sp.) and four only identified to the genus level (<i>Chamberlainium</i> sp. and three <i>Dawsoniolithon</i> spp.). <i>Chamberlainium</i> sp. was the most abundant species, while the three species of <i>Dawsoniolithon</i> were rarely observed. The CCA coverage varied from 18% ± 15% to 27% ± 21% in spring seasons of 2021–2024, but there were no significant differences. Based on carbon-14 dating, the CCA sediments in the XAR were estimated to be 5850–5990 years old. These CCA sediments were primarily composed of two paleo-CCA species, resembling modern <i>Chamberlainium</i> sp. and <i>Dawsoniolithon</i> sp. 1. However, the modern species of <i>Phymatolithon</i>, which are widespread and abundant in the algal reefs of northwestern Taiwan, were not observed in the CCA sediments. It is unclear whether their absence was due to fragile thalli after their death or their lack of occurrence, and this requires further investigation. The paleoenvironmental data and biogenic sediment composition analysis suggests that the XAR started to develop ~6000 years ago when the sea surface temperature began to decrease and seawater turbidity increased due to rainfall. Additional CCA sediment samples from this algal reef are needed to fully understand the historical changes in the paleo-environments in the XAR.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"132-143"},"PeriodicalIF":2.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142829080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Widespread distribution of chlorophyll f-producing Leptodesmis cyanobacteria","authors":"Li-Qin Shen,&nbsp;Zhong-Chun Zhang,&nbsp;Lu-Dan Zhang,&nbsp;Da Huang,&nbsp;Gongliang Yu,&nbsp;Min Chen,&nbsp;Renhui Li,&nbsp;Bao-Sheng Qiu","doi":"10.1111/jpy.13538","DOIUrl":"10.1111/jpy.13538","url":null,"abstract":"<p>Chlorophyll (Chl) <i>f</i> was reported as the fifth Chl in oxygenic photoautotrophs. Chlorophyll <i>f</i> production expanded the utilization of photosynthetically active radiation into the far-red light (FR) region in some cyanobacterial genera. In this study, 11 filamentous cyanobacterial strains were isolated from FR-enriched habitats, including hydrophyte, moss, shady stone, shallow ditch, and microbial mat across Central and Southern China. Polyphasic analysis classified them into the same genus of <i>Leptodesmis</i> and further recognized them as four new species, including <i>Leptodesmis atroviridis</i> sp. nov., <i>Leptodesmis fuscus</i> sp. nov., <i>Leptodesmis olivacea</i> sp. nov., and <i>Leptodesmis undulata</i> sp. nov. These cyanobacteria had absorption peaks beyond 700 nm due to Chl <i>f</i> production and red-shifted phycobiliprotein complexes under FR conditions. All but <i>L. undulata</i> produced phycoerythrin and showed varying degrees of a reddish-brown to dark green color under white light conditions. However, the phycoerythrin contents were sharply decreased under FR conditions, and these three <i>Leptodesmis</i> species appeared green. In summary, the <i>Leptodesmis</i> genus contains diverse species with the capacity to synthesize Chl <i>f</i> and is likely a ubiquitous group of Chl <i>f</i>-producing cyanobacteria.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"144-160"},"PeriodicalIF":2.8,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142824328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urea as a key nitrogen source for the invasion of the southern coast of Portugal by the brown seaweed Rugulopteryx okamurae (Dictyotales, Phaeophyceae)","authors":"Javier Jiménez Herrero,&nbsp;Ana Alexandre,&nbsp;João Silva,&nbsp;Rui Santos","doi":"10.1111/jpy.13534","DOIUrl":"10.1111/jpy.13534","url":null,"abstract":"<p>The invasive seaweed <i>Rugulopteryx okamurae</i>, native to East Asia, is spreading rapidly along the western Mediterranean and southern Portugal, severely affecting coastal biodiversity, ecosystem structure, and economic sectors such as fisheries and tourism. This study examined the nutrient uptake kinetics of <i>R. okamurae</i>, including ammonium, nitrate, urea, amino acids, and phosphate, and their role in nitrogen and phosphorus budgets based on laboratory growth rates. <i>R. okamurae</i> demonstrated the highest uptake for ammonium (V_max = 57.95 μmol · g⁻¹ DW · h⁻¹), followed by urea (7.74 μmol · g⁻¹ DW · h⁻¹), nitrate (5.37 μmol · g⁻¹ DW · h⁻¹), and amino acids (3.71 μmol · g⁻¹ DW · h⁻¹). The species showed higher uptake affinity for urea (α = 1.8), which accounted for 70% of nitrogen uptake. Phosphate uptake was low, and total nitrogen uptake exceeded growth requirements. These findings suggest that <i>R. okamurae</i> relies on organic nitrogen (urea) and may guide toward effective management strategies to mitigate its spread in coastal ecosystems.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"108-118"},"PeriodicalIF":2.8,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142824323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of temperature on rates of dissolved organic carbon (DOC) release by the kelp Ecklonia radiata (phylum Ochrophyta): Implications for the future coastal ocean carbon cycle","authors":"Eloise Bennett,&nbsp;Ellie R. Paine,&nbsp;Damon Britton,&nbsp;Jakop Schwoerbel,&nbsp;Catriona L. Hurd","doi":"10.1111/jpy.13518","DOIUrl":"10.1111/jpy.13518","url":null,"abstract":"<p>Dissolved organic carbon (DOC) released by macroalgae is an intrinsic component of the coastal ocean carbon cycle, yet knowledge of how future ocean warming may influence this is limited. Temperature is one of the primary abiotic regulators of macroalgal physiology, but there is minimal understanding of how it influences the magnitude and mechanisms of DOC release. To investigate this, we examined the effect of a range of temperatures on DOC release rates and physiological traits of <i>Ecklonia radiata</i>, the most abundant and widespread kelp in Australia that represents a potentially significant contribution to coastal ocean carbon cycling. Juvenile sporophytes were incubated at eight temperatures (4–28°C) for 14 days, after which time, DOC concentrations and physiological traits (growth, photosynthesis, respiration, <i>F</i>_v/<i>F</i>_m, photosynthetic pigment content, and carbon, and nitrogen content) were analyzed using thermal performance curves (TPCs) or regression analyses. Thermal optima were 15.63°C for growth and 25.84°C for photosynthesis, highlighting vulnerability to future ocean warming. Dissolved organic carbon concentrations increased when the temperature was above ~22°C, being greatest at the highest temperature tested (28°C), which was likely driven by photosynthetic overflow and thermal stress. Mean <i>F</i>_v/<i>F</i>_m, total chlorophyll, and total fucoxanthin content were lowest at 28°C. The C:N ratio of blades increased linearly with temperature from 23.9 ± 1.30 at 4°C to 33.0 ± 1.22 at 28°C. We demonstrate increased DOC release by <i>E. radiata</i> under elevated seawater temperatures and discuss potential implications for coastal carbon cycling under future ocean warming given the complex and uncertain fate of macroalgal DOC in the marine environment.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1471-1484"},"PeriodicalIF":2.8,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Weak effect of temperature fluctuations on the invasion of Raphidiopsis raciborskii (Cyanobacteria) in experimental plankton microcosms","authors":"Guntram Weithoff,&nbsp;Marley B. Stefan","doi":"10.1111/jpy.13536","DOIUrl":"10.1111/jpy.13536","url":null,"abstract":"<p>Biological invasions are a major threat for many aquatic ecosystems. In contrast to higher plants and animals, microbial invasions are less obvious and more difficult to detect. One of the most prominent microbial invaders is the cyanobacterium <i>Raphidiopsis raciborskii</i>. To better understand the environmental conditions favoring its invasion success, we studied invasion under three different temperature regimes (one constant and two variable) in experimental plankton communities by invader addition experiments. To account for intraspecific variation, we tested four different strains of <i>R. raciborskii</i> and the mixture of them. Invasion success of <i>R. raciborskii</i> was higher under constant temperature conditions than under fluctuations suggesting that the resident species responded faster to the environmental changes than the invaders. We observed a clear strain-specific effect, demonstrating that strain identity is an important determinant of invasion success. The interaction of temperature fluctuations and strain identity indicates that, among the tested strains, the response to the temperature regimes varied. The mixture of all four strains did not perform better than the best single strain showing no sign of a positive genetic diversity effect. In our experiment, environmental fluctuations did not widen a window of opportunity for the invasion of <i>R. raciborskii</i>.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 2","pages":"261-266"},"PeriodicalIF":2.8,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13536","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142801277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiological responses of the alien macroalga Rugulopteryx okamurae (Phaeophyceae, Heterokontophyta) to changes in nutrients and temperature","authors":"José Bonomi-Barufi,&nbsp;Félix L. Figueroa,&nbsp;Julia Vega,&nbsp;Rubén Huesa,&nbsp;Talissa B. Harb,&nbsp;Antonio Avilés,&nbsp;Jesús M. Mercado,&nbsp;Nathalie Korbee","doi":"10.1111/jpy.13528","DOIUrl":"10.1111/jpy.13528","url":null,"abstract":"<p>The Asian brown macroalga <i>Rugulopteryx okamurae</i> has invaded the oligotrophic areas of Mediterranean coasts since 2015, with drastic impacts on environmental conditions and socioeconomic activities in coastal areas in Europe. Therefore, it is intriguing how this species is able to grow and expand at the observed rates. In this context, the physiological responses of <i>R. okamurae</i> to changing nutrient concentrations and temperature were analyzed. Two experiments were conducted, evaluating six combinations of nitrate and phosphate concentrations and their potential interaction with temperature. Nutrient uptake efficiency (NUE) and rates (NUR), photosynthetic responses, growth rates, and biomass composition were evaluated. Photosynthesis parameters, soluble proteins, and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>N</mi>\u0000 <msubsup>\u0000 <mi>O</mi>\u0000 <mn>3</mn>\u0000 <mo>−</mo>\u0000 </msubsup>\u0000 </mrow>\u0000 </semantics></math>-NUR increased with increasing N:P ratio; however, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>P</mi>\u0000 <msubsup>\u0000 <mi>O</mi>\u0000 <mn>4</mn>\u0000 <mrow>\u0000 <mn>3</mn>\u0000 <mo>−</mo>\u0000 </mrow>\u0000 </msubsup>\u0000 </mrow>\u0000 </semantics></math>-NUR was very similar in all treatments. The species showed high capacity for nitrate assimilation, which was rapidly modulated by its external concentration and temperature (more than 90% of NO₃-NUE after 5 days in treatments with N:P rations of 5, 10, 16, 25, and 40 N to 1 P). Consequently, N-nutrients were removed from the water by <i>R. okamurae</i> and likely stored inside the cells. This process will allow the alga to maintain high growth rates if thalli are moved to oligotrophic areas, favoring its spreading to many marine environments. Additionally, fucoxanthin was the predominant carotenoid in this species, although its content was lower than in other brown macroalgae species (mean value of 0.51 ± 0.05 mg · g⁻¹ DW). However, since a huge amount of <i>R. okamurae</i> is observed recurrently on beaches, the use of this biomass might be proposed to compensate partially for its impacts.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"44-60"},"PeriodicalIF":2.8,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macro- and micronutrient effects on phytoplankton in Green Bay, Lake Michigan, and the western basin of Lake Erie","authors":"Jordyn T. Stoll,&nbsp;James H. Larson,&nbsp;Sean W. Bailey,&nbsp;Christopher B. Blackwood,&nbsp;David M. Costello","doi":"10.1111/jpy.13519","DOIUrl":"10.1111/jpy.13519","url":null,"abstract":"<p>Efforts to reduce the frequency, extent, and toxicity of harmful algal blooms (HABs) require knowledge about drivers of algal growth, toxin production, and shifts in phytoplankton community composition to cyanobacterial dominance. Although labile nitrogen (N) and phosphorus (P) fuel primary production, micronutrients also play roles as the enzymatic engines that facilitate rapid and efficient growth and toxin production. Macro- and micronutrient availability can shape community composition and function by selecting for particular taxa. To address how phytoplankton in two Great Lakes subbasins respond to macro- and micronutrients, we conducted bottle incubation enrichment experiments using water collected from two blooming and two nonblooming sites in Lakes Erie and Michigan during late summer (August). Three of the four sites exhibited multi-nutrient limitation of growth. Both blooming sites responded strongest to <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>NH</mi>\u0000 <mn>4</mn>\u0000 <mo>+</mo>\u0000 </msubsup>\u0000 </mrow>\u0000 </semantics></math> enrichment. Both nonblooming sites responded the strongest to <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>PO</mi>\u0000 <mn>4</mn>\u0000 <mrow>\u0000 <mn>3</mn>\u0000 <mo>−</mo>\u0000 </mrow>\u0000 </msubsup>\u0000 </mrow>\u0000 </semantics></math> enrichment, and three of the four sites responded in some way to a mix of micronutrients (Fe, Mn, Mo, Ni, and Zn). <i>Microcystis aeruginosa</i> relative abundance increased most with N enrichment, while P enrichment increased the abundance of diatoms and chlorophytes. At the Fox River, N-enriched communities grew 10%–20% more than non-N enriched communities (measured as chlorophyll <i>a</i>), and N-enriched communities had, on average, over twice as much microcystin (non-N communities average MC = 2.45 μg · L⁻¹, +N communities MC = 5.35 μg · L⁻¹). These overarching trends support the idea that control of HABs may not be effective with a P-only approach.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1514-1527"},"PeriodicalIF":2.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11670276/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142780513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of sterility of the male sporophytes of the brown alga Saccharina japonica (Phaeophyceae) in culture irrespective of their ploidy levels","authors":"Jing Li,&nbsp;Shaojun Pang","doi":"10.1111/jpy.13530","DOIUrl":"10.1111/jpy.13530","url":null,"abstract":"<p>Monoclonal female gametophytes of <i>Saccharina japonica</i>, when cultured independently, can develop into female sporophytes. Previous research has shown that the chromosomes in female sporophytes of <i>S. japonica</i> may naturally duplicate, forming diploids, and these diploid female sporophytes are capable of forming sori and releasing zoospores. In contrast, male sporophytes derived from culturing monoclonal male gametophytes failed to form sori and produce meiospores; thus, it was hypothesized that these male sporophytes are haploid and unable to perform meiotic division. In order to explore whether the chromosomes in male sporophytes can naturally duplicate and whether such diploid male sporophytes can effectively form sori and produce meiospores, we obtained 62 male sporophytes and cultivated them into adults. Only male-specific DNA markers were detected in all of these male sporophytes, indicating their male nature. Ten microsatellite markers were used to estimate the relatedness of the parental gametophytes and the corresponding sporophytes. Results revealed that the genotypes of the male sporophytes matched exactly with the corresponding male gametophytes. Both diploid and haploid sporophytes were detected in these 62 male sporophytes when analyzed by flow cytometry. After 16 months of cultivation, none of the male sporophytes formed sori regardless of their ploidy. As controls, both female and hybrid sporophytes developed sori and released viable zoospores. These findings suggest that the sterility of male sporophytes in <i>S. japonica</i> is not related to their ploidy; rather, it is attributed to the absence of essential elements for sori formation that may be present only in the female.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"241-249"},"PeriodicalIF":2.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142770052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of temperature and CO2 enrichment on the red seaweed Asparagopsis taxiformis from Southern California with implications for aquaculture","authors":"Hannah M. Resetarits,&nbsp;Gal Dishon,&nbsp;Vinayak Agarwal,&nbsp;Jennifer E. Smith","doi":"10.1111/jpy.13526","DOIUrl":"10.1111/jpy.13526","url":null,"abstract":"<p>The red alga <i>Asparagopsis taxiformis</i> has recently been recognized for its unique ability to significantly reduce methane emissions from ruminant animals when fed in small quantities. The main obstacle in using this seaweed as a methane-mitigating feed supplement is the lack of commercially available biomass. Little is known about how best to grow this red alga on a commercial scale, as there are few published studies that have investigated the factors that influence growth, physiology, and overall performance. This study examined the effects of temperature and CO₂ enrichment on the growth, photophysiology, and concentration of bromoform, the secondary metabolite largely responsible for methane reduction in <i>A. taxiformis</i>. A series of single and multifactor closed culture experiments were conducted on <i>A. taxiformis</i> collected, isolated, and cultured from populations in Southern California. We identified the optimal temperature range to be between 22 and 26°C, with significant short-term stress observed below 15°C and above 26°C. Carbon dioxide addition resulted in increased performance, when accounting for growth per CO₂ use. In general, we observed the highest bromoform concentrations in algae with the highest growth rates, but these results varied among experiments. These findings indicate that through environmental control and by addressing limiting resources, significant increases in biomass production and quality can be achieved.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1567-1584"},"PeriodicalIF":2.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11670279/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142770054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interactive effects of CO2, temperature, and nitrate limitation on the growth and physiology of strain CCMP 1334 of the marine cyanobacterium Synechococcus (Cyanophyceae)","authors":"Alyssa K. Sharbaugh,&nbsp;Edward A. Laws","doi":"10.1111/jpy.13531","DOIUrl":"10.1111/jpy.13531","url":null,"abstract":"<p>The marine cyanobacterium <i>Synecococcus</i> sp. (CCMP 1334) was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO₂ (400 and 1000 ppmv, respectively), nutrient availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21, 24, 28, 32, and 35°C. The maximum nutrient-replete growth rate was ~1.15 day⁻¹ at 32–35°C. Median nutrient-replete growth rates were higher at 1000 ppmv than at 400 ppmv pCO₂ at all temperatures. Carbon:nitrogen ratios were independent of pCO₂ at a fixed relative growth rate (i.e., growth rate ÷ nutrient-replete growth rate) but decreased with increasing temperature. Carbon:chlorophyll <i>a</i> ratios were decreased monotonically with increasing temperature and were higher under nitrate-limited than nutrient-replete conditions. Ratios of phycoerythrin to chlorophyll <i>a</i> were independent of growth conditions. Productivity indices were independent of temperature and nutrient limitation but were consistently higher at 1000 ppmv than 400 ppmv pCO₂. Both growth rates and dark respiration rates were positively correlated with temperature, and the associated <i>Q</i>₁₀ values were 2.2 and 2.3, respectively. A model of phytoplankton growth in which cellular carbon is allocated to structure, storage, or the light or dark reactions of photosynthesis accounted for the general patterns of cell composition and growth rate. This strain of <i>Synechococcus</i> appears well suited to changes in environmental conditions that are expected as the climate warms in response to anthropogenic emissions of CO₂.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"77-90"},"PeriodicalIF":2.8,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13531","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142770053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}