scholarly journals The Genetic and Physiological Characteristics of the Symbiodinium spp. in the Endemic Anemone Anthopleura Aureoradiata

2021 ◽  
Author(s):  
◽  
Jennifer N. Howe
Keyword(s):  
New Zealand ◽  
Environmental Conditions ◽  
Rocky Shore ◽  
Temperature Adaptation ◽  
Symbiotic Relationship ◽  
Sea Anemones ◽  
Down Regulation ◽  
Symbiotic Relationships ◽  
Pam Fluorometer ◽  
The Tropics

<p>Photosynthetic dinoflagellates of the genus Symbiodinium form symbiotic relationships with many marine hosts, including cnidarian corals and sea anemones. This partnership is extremely successful in tropical waters leading to a great diversity of coral species and Symbiodinium types. Environmental condition in the tropics are stable, changes to which can lead to destabilization of the symbiotic interactions between the host and symbiont, which in turn can lead to total breakdown of the partnership and expulsion of the symbiont. Temperate symbiotic cnidarian species, especially sea anemones, are less common but locally abundant. Environmental conditions are highly variable with extreme differences in light and temperature. Adaptation to these conditions has led to the success of resilient partnerships, but also to less diversity of Symbiodinium types. This study looked at the relationship between the endemic New Zealand anemone, Anthopleura aureoradiata, and its symbiotic relationship with the Symbiodinium cells it harbours. The aim was to determine why and how this symbiotic relationship is so resilient to the temperate conditions by 1) determining the molecular identity of the Symbiodinium spp. within the anemone, throughout its latitudinal range and through the seasons, and whether any seasonal changes differed between two habitats, the rocky shore and mudflats; 2) comparing the identity of the Symbiodinium spp. in New Zealand with those from four species of anemones from Europe (Cereus pedunculatus, Anthopleura ballii and Anemonia viridis from the south-west of England and Aiptasia mutabilis from Brittany (France)) to establish any differences or similarities between the northern and southern hemispheres; 3) determining whether resilience to environmental conditions is attributed to the Symbiodinium photoprotective mechanisms. A. aureoradiata were collected in early autumn in five sites from the top (Parengarenga Harbour) to the bottom (Stewart Island) of New Zealand for the latitudinal study. Seasonal anemones were collected from a rocky shore in Wellington Harbour (Point Halswell, Kau Bay) and a mudflat at Pauatahanui Inlet. Symbiodinium types were identified to subcladal level using ITS2 sequencing. A low diversity of types was found, with all anemones harbouring algal cells identified as being similar, or identical to, Symbiodinium sp. Mediterranean clade A (Med clade A) and Symbiodinium sp. Amed (Amed). 96.55% of the anemones from the latitudinal study, all the winter anemones, 87.50% of the summer anemones and almost 78% of the autumn anemones harboured Symbiodinium cells most similar or identical to Med clade A. All Symbiodinium sequences from the European anemones also were identified as being similar or identical to Med clade A or Amed, suggesting that the Symbiodinium in A. aureoradiata are likely not endemic. It is not known whether anemones harbour both types simultaneously and whether a change in dominant symbiont type occurs with seasons within anemones by “shuffling”.  The photophysiology of the Symbiodinium cells isolated from the anemones was studied using an Imaging-PAM fluorometer whilst being maintained in six light and temperature treatments. The photosynthetic rate of PSII, energy quenching by NPQ, and photosystem recovery were measured to determine whether the Symbiodinium cells had a strong capacity for photoprotection and were able to down-regulate quickly to reduce photodamage to the chloroplast. The main outcome of this study is that the Symbiodinium cells within A. aureoradiata are very effective in protecting themselves against photo-damage by activating an efficient NPQ system. Down-regulation of the quantum efficiency of PSII under high light conditions appeared to cease altogether. Whether this was a true measurement of down-regulation to stop photodamage, or whether these clade A types use an alternative electron transport that bypasses PSII, and can therefore not be measured with the I-PAM fluorometer technique used, needs to be addressed in future studies.</p>

scholarly journals The Genetic and Physiological Characteristics of the Symbiodinium spp. in the Endemic Anemone Anthopleura Aureoradiata

2021 ◽  
Author(s):  
◽  
Jennifer N. Howe
Keyword(s):  
New Zealand ◽  
Environmental Conditions ◽  
Rocky Shore ◽  
Temperature Adaptation ◽  
Symbiotic Relationship ◽  
Sea Anemones ◽  
Down Regulation ◽  
Symbiotic Relationships ◽  
Pam Fluorometer ◽  
The Tropics

<p>Photosynthetic dinoflagellates of the genus Symbiodinium form symbiotic relationships with many marine hosts, including cnidarian corals and sea anemones. This partnership is extremely successful in tropical waters leading to a great diversity of coral species and Symbiodinium types. Environmental condition in the tropics are stable, changes to which can lead to destabilization of the symbiotic interactions between the host and symbiont, which in turn can lead to total breakdown of the partnership and expulsion of the symbiont. Temperate symbiotic cnidarian species, especially sea anemones, are less common but locally abundant. Environmental conditions are highly variable with extreme differences in light and temperature. Adaptation to these conditions has led to the success of resilient partnerships, but also to less diversity of Symbiodinium types. This study looked at the relationship between the endemic New Zealand anemone, Anthopleura aureoradiata, and its symbiotic relationship with the Symbiodinium cells it harbours. The aim was to determine why and how this symbiotic relationship is so resilient to the temperate conditions by 1) determining the molecular identity of the Symbiodinium spp. within the anemone, throughout its latitudinal range and through the seasons, and whether any seasonal changes differed between two habitats, the rocky shore and mudflats; 2) comparing the identity of the Symbiodinium spp. in New Zealand with those from four species of anemones from Europe (Cereus pedunculatus, Anthopleura ballii and Anemonia viridis from the south-west of England and Aiptasia mutabilis from Brittany (France)) to establish any differences or similarities between the northern and southern hemispheres; 3) determining whether resilience to environmental conditions is attributed to the Symbiodinium photoprotective mechanisms. A. aureoradiata were collected in early autumn in five sites from the top (Parengarenga Harbour) to the bottom (Stewart Island) of New Zealand for the latitudinal study. Seasonal anemones were collected from a rocky shore in Wellington Harbour (Point Halswell, Kau Bay) and a mudflat at Pauatahanui Inlet. Symbiodinium types were identified to subcladal level using ITS2 sequencing. A low diversity of types was found, with all anemones harbouring algal cells identified as being similar, or identical to, Symbiodinium sp. Mediterranean clade A (Med clade A) and Symbiodinium sp. Amed (Amed). 96.55% of the anemones from the latitudinal study, all the winter anemones, 87.50% of the summer anemones and almost 78% of the autumn anemones harboured Symbiodinium cells most similar or identical to Med clade A. All Symbiodinium sequences from the European anemones also were identified as being similar or identical to Med clade A or Amed, suggesting that the Symbiodinium in A. aureoradiata are likely not endemic. It is not known whether anemones harbour both types simultaneously and whether a change in dominant symbiont type occurs with seasons within anemones by “shuffling”.  The photophysiology of the Symbiodinium cells isolated from the anemones was studied using an Imaging-PAM fluorometer whilst being maintained in six light and temperature treatments. The photosynthetic rate of PSII, energy quenching by NPQ, and photosystem recovery were measured to determine whether the Symbiodinium cells had a strong capacity for photoprotection and were able to down-regulate quickly to reduce photodamage to the chloroplast. The main outcome of this study is that the Symbiodinium cells within A. aureoradiata are very effective in protecting themselves against photo-damage by activating an efficient NPQ system. Down-regulation of the quantum efficiency of PSII under high light conditions appeared to cease altogether. Whether this was a true measurement of down-regulation to stop photodamage, or whether these clade A types use an alternative electron transport that bypasses PSII, and can therefore not be measured with the I-PAM fluorometer technique used, needs to be addressed in future studies.</p>

scholarly journals Climate Change Leads to a Reduction in Symbiotic Derived Cnidarian Biodiversity on Coral Reefs

2021 ◽  
Vol 9 ◽  
Author(s):  
Tamar L. Goulet ◽  
Denis Goulet
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Coral Reefs ◽  
Environmental Conditions ◽  
Sea Anemones ◽  
Coral Reef Ecosystem ◽  
Symbiotic Relationships ◽  
Cascade Effect ◽  
Symbiotic Partner ◽  
Reef Ecosystem

Symbiotic relationships enable partners to thrive and survive in habitats where they would either not be as successful, or potentially not exist, without the symbiosis. The coral reef ecosystem, and its immense biodiversity, relies on the symbioses between cnidarians (e.g., scleractinian corals, octocorals, sea anemones, jellyfish) and multiple organisms including dinoflagellate algae (family Symbiodiniaceae), bivalves, crabs, shrimps, and fishes. In this review, we discuss the ramifications of whether coral reef cnidarian symbioses are obligatory, whereby at least one of the partners must be in the symbiosis in order to survive or are facultative. Furthermore, we cover the consequences of cnidarian symbioses exhibiting partner flexibility or fidelity. Fidelity, where a symbiotic partner can only engage in symbiosis with a subset of partners, may be absolute or context dependent. Current literature demonstrates that many cnidarian symbioses are highly obligative and appear to exhibit absolute fidelity. Consequently, for many coral reef cnidarian symbioses, surviving changing environmental conditions will depend on the robustness and potential plasticity of the existing host-symbiont(s) combination. If environmental conditions detrimentally affect even one component of this symbiotic consortium, it may lead to a cascade effect and the collapse of the entire symbiosis. Symbiosis is at the heart of the coral reef ecosystem, its existence, and its high biodiversity. Climate change may cause the demise of some of the cnidarian symbioses, leading to subsequent reduction in biodiversity on coral reefs.

scholarly journals Predicting photosynthesis and transpiration responses to ozone: decoupling modeled photosynthesis and stomatal conductance

2012 ◽  
Vol 9 (8) ◽  
pp. 3113-3130 ◽  
Author(s):  
D. Lombardozzi ◽  
S. Levis ◽  
G. Bonan ◽  
J. P. Sparks
Keyword(s):  
Carbon Dioxide ◽  
Stomatal Conductance ◽  
Primary Productivity ◽  
Environmental Conditions ◽  
Water Exchange ◽  
Global Scale ◽  
Community Land Model ◽  
Climate Regulation ◽  
The Tropics ◽  
Tulip Poplar

Abstract. Plants exchange greenhouse gases carbon dioxide and water with the atmosphere through the processes of photosynthesis and transpiration, making them essential in climate regulation. Carbon dioxide and water exchange are typically coupled through the control of stomatal conductance, and the parameterization in many models often predict conductance based on photosynthesis values. Some environmental conditions, like exposure to high ozone (O3) concentrations, alter photosynthesis independent of stomatal conductance, so models that couple these processes cannot accurately predict both. The goals of this study were to test direct and indirect photosynthesis and stomatal conductance modifications based on O3 damage to tulip poplar (Liriodendron tulipifera) in a coupled Farquhar/Ball-Berry model. The same modifications were then tested in the Community Land Model (CLM) to determine the impacts on gross primary productivity (GPP) and transpiration at a constant O3 concentration of 100 parts per billion (ppb). Modifying the Vcmax parameter and directly modifying stomatal conductance best predicts photosynthesis and stomatal conductance responses to chronic O3 over a range of environmental conditions. On a global scale, directly modifying conductance reduces the effect of O3 on both transpiration and GPP compared to indirectly modifying conductance, particularly in the tropics. The results of this study suggest that independently modifying stomatal conductance can improve the ability of models to predict hydrologic cycling, and therefore improve future climate predictions.

scholarly journals Modular marvels: The ecology, evolvability, and energetics of bryozoan polymorphism

2021 ◽  
Author(s):  
◽  
Carolann Schack
Keyword(s):  
New Zealand ◽  
Community Assembly ◽  
Environmental Conditions ◽  
Environmental Filtering ◽  
Classification Systems ◽  
Energetic Cost ◽  
Developmental Constraints ◽  
Mechanical Advantage ◽  
Colony Form ◽  
Hard Substrata

<p>Modularity is a fundamental concept in biology. Most taxa within the colonial invertebrate phylum Bryozoa have achieved division of labor through the development of specialized modules (polymorphs), and this group is perhaps the most outstanding exemplar of the phenomenon. This thesis addresses several gaps in the literature concerning the morphology, ecology, energetics, and evolvability of bryozoan polymorphism.  It has been over 40 years since the last review of bryozoan polymorphism, and here I provide a comprehensive update that describes the diversity, morphology, and function of bryozoan polymorphs and the significance of modularity to their evolutionary success. While the degree of module compartmentalization is important for the evolution of polymorphism in bryozoans, this does not appear to be the case for other colonial invertebrates.  To facilitate data collection, I developed a classification system for polymorphism in cheilostome bryozoans. While classification systems exist for bryozoan colony form, the system presented here is the first developed for polymorphism. This system is fully illustrated and non-hierarchical, enabling swift classification and statistical comparisons at many levels of detail.  Understanding community assembly is a key goal in community ecology, but previous work on bryozoan communities has focused on colony form rather than polymorphism. Environmental filtering influences community assembly by excluding ill-adapted species, resulting in communities with similar functional traits. An RLQ (a four-way ordination) analysis incorporating spatial data was run on a dataset of 642 species of cheilostomes from 779 New Zealand sites, to investigate environmental filtering of colony form and zooid polymorphism. This revealed environmental filtering of colony form: encrusting-cemented taxa were predominant in shallow environments with hard substrata (200 m). Furthermore, erect taxa found in shallow environments with high current speeds were typically jointed. Surprisingly, polymorphism also followed environmental gradients. External ovicells (brood chambers) were more common in deeper, low oxygen water than immersed and internal ovicells. This may reflect the oxygen needs of the embryo or increased predation intensity in shallow environments. Bryozoans with costae (rib-like spines) tended to be found in deeper water as well, while bryozoans with calcified frontal shields were found in shallow environments with a higher concentration of CaCO₃. Avicularia (defensive grasping structures) were not related to environmental conditions, and changes in pivot bar structure with depth likely represent a phylogenetic signal. Factors influencing community assembly were somewhat partitioned by levels of organization, since colony form responds to environmental conditions, while the effects of evolutionary history, predation, and environmental conditions were not well-separated for zooid-level morphology. Finally, rootlets may have been a key innovation that allowed cementing taxa to escape hard substrata, potentially contributing to the cheilostome radiation.  Despite the diversity of life on earth, many morphologies have not been achieved. Morphology can be limited by a variety of constraints (developmental, historical, biomechanical) and comparing the distribution of realized forms in a theoretical form-space (i.e. “morphospace”) can highlight which constraints are at play and potential functions. If traits cluster around biomechanical optima, then morphology may be shaped by strong selective pressures. In contrast, a well-explored (filled) morphospace suggests weak constraints and high morphological evolvability. Here, constraints on morphospace exploration were examined for 125 cheilostome bryozoan species from New Zealand. The mandible morphospaces for avicularia (beak-like polymorphs) were visualized using Coordinate-Point Extended Eigenshape analysis. Mechanical advantage, moment of inertia, drag, peak force, and rotational work required to close the mandible were calculated for theoretical (n=47) and real mandibles (n=224) to identify biomechanical optima. The volume and surface of area of the parcel of water passed through by the closing mandible (referred to as the “domain”) was also calculated. The theoretical morphospace of avicularia is well-explored, suggesting they are highly evolvable and have relaxed developmental constraints. However, there may be constraints within lineages. A well-developed fulcrum (complete pivot bar) may be an evolutionary pre/corequisite to evolving mandibles with extreme moments of inertia such as setose and highly spathulate forms. The most common mandible shape, triangular, represents a trade-off between maximizing domain size, minimizing energetic cost (force and construction material), and minimizing the potential for breakage. This suggests that they are well suited for catching epibionts, representing the first empirical evidence for avicularian function. Tendon length and mechanical advantage are limited by tendon width, which itself is constrained by the base width of the mandible. This explains the low mechanical advantage of setose mandibles and suggests that they are unable to grasp epibionts. The calories required to close the mandible of an avicularium (estimated from rotational work) are quite small (1.24 x 10⁻¹⁶ to 8.82 x 10⁻¹¹ cal).  Overall, this thesis highlights the complexity of bryozoan polymorphism and suggests cheilostome avicularia could provide a unique evolutionary system to study due to their apparent lack of strong developmental constraints. Future studies into the ecology of polymorphism should focus on the degree of investment (polymorph abundance within a colony) rather than presence or absence.</p>

scholarly journals First record of Calliactis tricolor (Le Sueur, 1817) (Cnidaria, Actiniaria, Hormathiidae) in the Veracruz reef system, southwestern Gulf of Mexico

Check List ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 617-629
Author(s):  
José Luis Tello-Musi ◽  
Ricardo González-Muñoz ◽  
Fabián H. Acuña ◽  
Nuno Simões
Keyword(s):  
Coral Reef ◽  
Gulf Of Mexico ◽  
Benthic Community ◽  
First Record ◽  
Hermit Crabs ◽  
Tropical Atlantic ◽  
Sea Anemones ◽  
Southwestern Part ◽  
Symbiotic Relationships ◽  
Reef System

The sea anemone Calliactis tricolor (Le Sueur, 1817) is an ecologically important member of the benthic community in coastal and coral reefs of the tropical Atlantic, particularly for their propensity to establish mutualistic symbiotic relationships with hermit crabs. This species is presumably distributed throughout the Gulf of Mexico; however, it had never been recorded in the southwestern part of the Gulf. Here we document the first record of C. tricolor in 2 coral reef localities of the Veracruz reef system, Mexico, and update the number of species of sea anemones known for the region.

Phragmidium acuminatum.

2021 ◽  
Author(s):  
Keyword(s):  
New Zealand ◽  
Environmental Conditions ◽  
Pathogenic Fungus ◽  
Plant Pathogenic Fungus ◽  
The World ◽  
Agricultural Plants

Abstract There is little published information on this plant pathogenic fungus, which is limited to parts of Asia, Europe and New Zealand. It attacks Rubus spp., among others, and as these hosts exist in other regions of the world with similar environmental conditions, this species may pose a threat to native or agricultural plants if introduced.

scholarly journals Genome analyses of a placozoan rickettsial endosymbiont show a combination of mutualistic and parasitic traits

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kai Kamm ◽  
Hans-Jürgen Osigus ◽  
Peter F. Stadler ◽  
Rob DeSalle ◽  
Bernd Schierwater
Keyword(s):  
Amino Acids ◽  
Environmental Conditions ◽  
Metabolic Pathways ◽  
Essential Amino Acids ◽  
Intracellular Bacteria ◽  
The Novel ◽  
Symbiotic Relationships ◽  
Genome Analyses ◽  
Growth And Reproduction

AbstractSymbiotic relationships between eukaryotic hosts and bacteria range from parasitism to mutualism and may deeply influence both partners’ fitness. The presence of intracellular bacteria in the metazoan phylum Placozoa has been reported several times, but without any knowledge about the nature of this relationship and possible implications for the placozoan holobiont. This information may be of crucial significance since little is known about placozoan ecology and how different species adapt to different environmental conditions, despite being almost invariable at the morphological level. We here report on the novel genome of the rickettsial endosymbiont of Trichoplax sp. H2 (strain “Panama”). The combination of eliminated and retained metabolic pathways of the bacterium indicates a potential for a mutualistic as well as for a parasitic relationship, whose outcome could depend on the environmental context. In particular we show that the endosymbiont is dependent on the host for growth and reproduction and that the latter could benefit from a supply with essential amino acids and important cofactors. These findings call for further studies to clarify the actual benefit for the placozoan host and to investigate a possible role of the endosymbiont for ecological separation between placozoan species.

scholarly journals A Worm's World: Ecological Flexibility Pays Off for Free-Living Nematodes in Sediments and Soils

BioScience ◽  
2019 ◽  
Vol 69 (11) ◽  
pp. 867-876 ◽  
Author(s):  
Michaela Schratzberger ◽  
Martijn Holterman ◽  
Dick van Oevelen ◽  
Johannes Helder
Keyword(s):  
Environmental Conditions ◽  
Food Sources ◽  
Polar Regions ◽  
Soil Processes ◽  
Free Living ◽  
Ecological Flexibility ◽  
Ecological Success ◽  
The Tropics ◽  
Animal Communities ◽  
The Impact

Abstract Free-living nematodes, an ancient animal phylum of unsegmented microscopic roundworms, have successfully adapted to nearly every ecosystem on Earth: from marine and freshwater to land, from the polar regions to the tropics, and from the mountains to the ocean depths. They are globally the most abundant animals in sediments and soils. In the present article, we identify the factors that collectively explain the successful ecological proliferation of free-living nematodes and demonstrate the impact they have on vital sediment and soil processes. The ecological success of nematodes is strongly linked to their ability to feed on various food sources that are present in both sediments and soils, and to proliferate rapidly and survive in contrasting environmental conditions. The adaptations, roles, and behaviors of free-living nematodes have important implications for the resilience of sediments and soils, and for emergent animal communities responding to human alterations to ecosystems worldwide.

Progeny Testing of Dairy Bulls at Different Levels of Management

1954 ◽  
Vol 1954 ◽  
pp. 83-85 ◽  
Author(s):  
I. L. Mason
Keyword(s):  
Dairy Cattle ◽  
Experimental Evidence ◽  
Environmental Conditions ◽  
The Other ◽  
Progeny Testing ◽  
Laboratory Mice ◽  
Dairy Bulls ◽  
The Tropics ◽  
Different Levels ◽  
European Cattle

There are two schools of thought concerning the most appropriate environment in which to select breeding animals. One says ‘ Always select animals under environmental conditions similar to those where they are to be used ‘. The other says ‘ Select breeding animals in the optimum environment so that they have the best chance of revealing their genetic capabilities ‘. Experiments on growth of laboratory mice and experience with European cattle in the tropics have shown the advisability of the first course in these cases. In regard to hill sheep and dairy cattle in Britain, on the other hand, practice favours the second course, but there is little experimental evidence to support it.

Population ecology of the intertidal anemone Actinia tenebrosa. IV. Growth rates and longevities

1980 ◽  
Vol 31 (3) ◽  
pp. 385 ◽  
Author(s):  
JR Ottaway
Keyword(s):  
New Zealand ◽  
Population Ecology ◽  
Growth Rates ◽  
Mortality Data ◽  
Column Diameter ◽  
Growth Data ◽  
Sea Anemones ◽  
Free Living ◽  
Growth Increments ◽  
Rocky Coast

In all, 82 adults and about 600 juvenile A tenebrosa were tracked for up to 3 years These intertidal sea anemones were free-living on the rocky coast at Kaikoura, New Zealand Regular measurements of column diameters were taken for 2 years Annual growth increments were small for all sizes of A. tenebrosa observed most increments were in the range -2 to 4 mm of column diameter per year, with the smallest anemones havmg the fastest relative mean growth rates From the growth data, A tenebrosa reaches a column diameter of 40 mm in 8-66 years after settlement From mortality data, the observed adults have a predicted mean longevity of at least 50 years and a predicted maximum longevity of at least 210 years.

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