Journal of Phycology最新文献

The ecological, evolutionary, economic, and cultural importance of algae necessitates a continued integration of phycological research, education, outreach, and engagement. Here, we comment on several topics discussed during a networking workshop-Algae and the Environment-that brought together phycological researchers from a variety of institutions and career stages. We share some of our perspectives on the state of phycology by examining gaps in teaching and research. We identify action areas where we urge the phycological community to prepare itself to embrace the rapidly changing world. We emphasize the need for more trained taxonomists as well as integration with molecular techniques, which may be expensive and complicated but are important. An essential benefit of these integrative studies is the creation of high-quality algal reference barcoding libraries augmented with morphological, physiological, and ecological data that are important for studies of systematics and crucial for the accuracy of the metabarcoding bioassessment. We highlight different teaching approaches for engaging undergraduate students in algal studies and the importance of algal field courses, forays, and professional phycological societies in supporting the algal training of students, professionals, and citizen scientists.

This study investigated the changes in sea ice temperature, microalgae species distribution, shape changes, and photosynthetic activity observed in the first-year ice that forms in winter in Saroma-ko Lagoon, Hokkaido, Japan. Temperatures at the bottom of the ice remained constant at −1.7°C, near the freezing point, while they varied between −6 and −1°C with diel fluctuations at the surface layer. Carefully collected algal samples showed high photosynthetic quantum yield and acclimation to the light intensities of individual ice layers; this indicates that the algal photosynthetic activity responds to dynamic changes in the ice environment, such as variations in temperature, salinity, and brine space. The algal communities consisted of more than 95% diatoms. Smaller algal cells were distributed in the upper layer of the sea ice compared to the lower layers. Chaetoceros sp., the dominant small-cell species, was evenly distributed throughout the layers. In contrast, Detonula confervacea, the dominant large-cell species, was unevenly distributed in the lower layer, with smaller colony size and cell volume in the upper layer. The shape differences observed in this species were thought to be a response to the changing environment within the first-year sea ice.

This investigation reports the polyphasic characterization of six cyanobacterial strains that were isolated from Basantgarh village of district Udhampur in the union territory of Jammu and Kashmir, India. Morphological examination of the isolated strains indicated that the strains are members of the genus Nostoc or its morphotypes. Phylogenetic analyses using the 16S rRNA gene showed that five strains clustered in the Nostoc sensu stricto clade, whereas one strain clustered in the Desmonostoc clade. Further, comparative studies with their phylogenetically related taxa, based on morphology, folded secondary structures, phylogeny of the ITS rRNA region, and the percent genetic homology of 16S rRNA gene and ITS rRNA region clearly established the strains as novel taxa belonging to the genera Nostoc and Desmonostoc. Also, two strains 21A-PS and 2JNA-PS emerged as conspecific to each other, representing the same species of Nostoc. Hence, in accordance with the International code of Nomenclature for algae, fungi, and plants, this study describes Nostoc jammuense, Nostoc globosum, Nostoc breve, and Nostoc coriaceum, as novel species of the genus Nostoc, while Desmonostoc raii is described as a novel species of the genus Desmonostoc. This study adds novel species of Nostoc from Indian habitats and reinforces the need to explore the Nostoc sensu stricto clade for more novel taxa.

Seaweed farming is the single largest aquaculture commodity with >30 million tonnes produced each year. Furthermore, the restoration of lost seaweed forests is gaining significant momentum, particularly for kelps in warming temperate areas. Whether in aquaculture settings, following restoration practices, or in the wild, all seaweeds undergo biotic interactions with a diverse range of co-occurring or cocultured organisms. To date, most research assessing such biotic interactions has focused on the response of the organism interacting with seaweeds, rather than on the seaweeds themselves. However, understanding how seaweeds respond to other organisms, particularly on a molecular scale, is crucial for optimizing outcomes of seaweed farming or restoration efforts and, potentially, also for the conservation of natural populations. In this systematic review, we assessed the molecular processes that seaweeds undergo during biotic interactions and propose priority areas for future research. Despite some insights into the response of seaweeds to biotic interactions, this review specifically highlights a lack of characterization of biomolecules involved in the response to chemical cues derived from interacting organisms (four studies in the last 20 years) and a predominant use of laboratory-based experiments conducted under controlled conditions. Additionally, this review reveals that studies targeting metabolites (70%) are more common than those examining the role of genes (22%) and proteins (8%). To effectively inform seaweed aquaculture efforts, it will be crucial to conduct larger scale experiments simulating natural environments. Also, employing a holistic approach targeting genes and proteins would be beneficial to complement the relatively well-established role of metabolites.

Cryptophytes are abundant and ubiquitous microalgae that constitute a major plastid source for kleptoplastidic ciliates and dinoflagellates. Despite their ecological significance, the understanding of their light preferences and photophysiology remains limited. Here, we provide a comprehensive study of the response of the haploid strain Teleaulax amphioxeia (Cr10EHU) to varying light irradiance. This strain is capable of growing under a wide range of irradiance levels, notably by finely tuning the different pigments bound to the membrane light-harvesting proteins. Analysis of the luminal phycoerythrin content revealed remarkable flexibility, with phycoerythrin emerging as a pivotal protein facilitating acclimation to varying light levels. Detailed ultrastructure examinations unveiled that this adaptability was supported by the synthesis of large thylakoidal vesicles, likely enhancing the capture of green photons efficiently under low light, a phenomenon previously undocumented. Teleaulax amphioxeia Cr10EHU effectively regulated light utilization by using a cryptophyte state transition-like process, with a larger amplitude observed under high growth irradiance. Furthermore, our results revealed the establishment of growth irradiance-dependent non-photochemical quenching of fluorescence, likely inducing the dissipation of excess light. This study underscores the particularities and the significant photoadaptability of the plastid of the haploid form of T. amphioxeia. It constitutes a comprehensive photophysiological characterization of the Cr10EHU strain that paves the way for future studies of the kleptoplastidy process.

Culture collections such as the Blue Biotechnology and Ecotoxicology Culture Collection (LEGE-CC) hold approximately 1200 cyanobacterial strains and are critical community resources. However, many isolates in this and other collections have not been described with a polyphasic approach, and this limits further study. Here, we employed a polyphasic methodology that integrates 16S rRNA gene phylogenetic analyses, similarity (p-distance), 16S-23S ITS rRNA region secondary structures, morphological analyses, and habitat assessments to describe four novel cyanobacterial genera from the LEGE-CC, Portugal. Pseudolimnococcus planktonicus gen. et sp. nov. (Chroococcales) is phylogenetically and morphologically related to Limnococcus. The 16S rRNA gene similarity between the types of both genera is only 93.1%. Morphologically, Pseudolimnococcus cells do not reach the original spherical shape before the next division or have aerotopes and firm mucilage, while Limnococcus cells reach the original shape, lack aerotopes, and have diffluent mucilage. Eucapsopsis lusitanus gen. et sp. nov. (Chroococcales) is morphologically similar to Eucapsis but differs from it by having aerotopes and diffluent envelope. Eucapsis lacks aerotopes and has firm mucilaginous envelopes, rarely diffluent. Both genera are phylogenetically very distant from each other and have only 90.68% 16S rRNA gene similarity. Pseudoacaryochloris arrabidensis gen. et sp. nov. (Acaryochloridales) differs from Acaryochloris by the lack of mucilaginous envelope, which is present in Acaryochloris. Both genera are phylogenetically distant and have only 94.1% 16S rRNA gene similarity. Moreover, Acaryochloris is marine (sponge symbiont), while Pseudoacaryochloris is from freshwater. Vasconcelosia minhoensis gen. et sp. nov. (Nodosilineales) is phylogenetically related to Cymatolege but has only 94.3% similarity with this genus. Morphologically both genera are distinct. Vasconcelosia has a Romeria-like structure, while Cymatolege has a Phormidium-like structure. In all cases the 16S-23S ITS rRNA region secondary structures are in agreement with the other analyses. These novel genera expand the diversity of cyanobacteria in culture collections.

Climate change has profound effects on the distribution of kelp forests in the Arctic and sub-Arctic. However, studies on the responses of kelps to climate change, particularly along the sub-Arctic regions of the Alaska coast, are limited. Eualaria fistulosa is a foundational kelp species in the Aleutian Islands, with an east–west distribution that extends from Japan to southern southwest Alaska. In this study, we utilized a species distribution model (SDM) to explore changes in the future habitat suitability of E. fistulosa under contrasting Shared Socioeconomic Pathway (SSP) scenarios. Our model exhibited relatively high predictive performance, validating our SDM predictions. Notably, the SDM results indicate that minimum sea surface temperature, annual range in sea surface temperatures, and annual mean current velocities are the three most important predictor variables determining E. fistulosa's distribution. Furthermore, the projected geographic distribution of Eualaria is generally consistent with its observed occurrence records. However, under high emission scenarios (SSP5-8.5), E. fistulosa is predicted to contract its distribution range by 9.0% by 2100, with widespread disappearance along the southeast Alaskan coast and limited northward migration to Kamchatka Krai in Russia and Bristol Bay in Alaska. These findings contribute valuable insights for conservation strategies via addressing climate-induced alterations in sub-Arctic kelp distribution.

Mallomonas thrive primarily in freshwaters and dominate plankton communities, especially in oligotrophic waters. The cells have a siliceous cell covering of regularly arranged scales. Despite their ecological importance, the intricate structure and evolutionary significance of their silica scales are still unexplored. We investigated the nanopatterns on the scales and hypothesized that they may play a role in UV shielding. UVA and UVB exposure experiments were performed with 20 Mallomonas species, categorized into four groups based on the nanopattern of the scales (plain-scaled, meshed, striated, and papilliferous group); a fifth group consisted of the species that have extremely thick, robust scales regardless of the nanopattern. We revealed that thick scales were associated with enhanced UVB resistance, suggesting a protective role. No significant differences in UVA response were observed among the groups, except for the meshed group, which showed lower resistance, likely due to the less regular pattern on the shield. In conclusion, the scale case, composed of sufficiently silicified scales, provides effective UV protection in freshwater environments, regardless of the particular nanopattern. In increased UVB radiation, the thickness of the scales plays role. Contrary to expectations, cell size and phylogeny do not strongly predict UV resistance. The study highlights the diverse UV responses of Mallomonas, but further studies are needed to understand the role of scales/nanopatterns in the ecological adaptations of the species.

Lefler, F. W., Berthold, D. E., & Laughinghouse, H. D. IV (2021). The occurrence of Affixifilum gen. nov. and Neolyngbya (Oscillatoriaceae) in South Florida (USA), with the description of A. floridanum sp. nov. and N. biscaynensis sp. nov. Journal of Phycology, 57, 92–110. https://doi.org/10.1111/jpy.13065

In the Taxonomic description on page 101, the text “Material examined: strain BLCC-M54 (University of Florida/IFAS, FLREC, Davie, FL, USA) and strain ULC586 (Université de Liège, Liège, Belgium). Dried and preserved examined material: US 227641 (US National Herbarium, National Museum of Natural History, Washington DC, USA).” was incorrect. This should have read “Material examined: strain BLCC-M54 (University of Florida/IFAS, FLREC, Davie, FL, USA) and strain ULC586 (Université de Liège, Liège, Belgium). Dried and preserved examined material: US 227635 (US National Herbarium, National Museum of Natural History, Washington DC, USA).”

We apologize for this error.

Phaeocystis globosa is a marine phytoplankton species that forms deleterious blooms in temperate and tropical waters. In some locations, “giant” colonies form, although the controls on its size are unknown. During a “giant” colony bloom, measurements were completed to characterize photosynthesis–irradiance relationships, nitrogen uptake kinetics, and nitrogen–irradiance relationships of P. globosa colonies to understand its growth characteristics and their relationship to colony size. The photosynthetic capacity (F_v/F_m) varied from 0.65 to 0.68 among colony sizes ranging from 3.0 to 11.0 mm, indicating that all colonial cells were physiologically robust. The maximum chl a-specific photosynthetic rates ($��P_{\max }^B�$) ranged from 0.89 to 1.92 μg C · μg⁻¹ chl · h⁻¹, were maximal in the mid-sized colonies (5.5–6.5 mm) and decreased with size. The relatively low $��P_{\max }^B�$ values may be related to the high cellular chl a of colonial cells and their acclimation to in situ irradiance. Nitrate $��V_{\max }�$ and $��K_S�$ values were greater than those of ammonium, although N affinity was greater for ammonium. No differences in light-limited rates in either nitrate or ammonium uptake among colony sizes were observed, and no dark uptake occurred. Both ammonium and nitrate uptake showed a saturation response as a function of irradiance. While the driving forces for the formation of giant colonies remain unknown, their impacts on coastal systems are substantial and a further assessment of their growth is warranted.