scholarly journals The Ecological Role of a Common Seastar (Patiriella spp.) Within Intertidal Cobble Fields

2021 ◽  
Author(s):  
◽  
Shiree Palmer
Keyword(s):  
Intraspecific Competition ◽  
Feeding Habits ◽  
South Coast ◽  
Coralline Algae ◽  
Ecological Role ◽  
Crustose Coralline Algae ◽  
Wide Range ◽  
Significant Difference ◽  
Micro Organisms

<p>Intertidal cobble habitats are complex three-dimensional marine environments that are understudied despite having unique species assemblages and ecological patterns. New Zealand's common cushion star, Patiriella spp., is found in a wide range of coastal habitats, including intertidal cobble fields. This seastar is an omnivore that feeds predominantly on crustose coralline algae and micro-organisms, but also supplements its diet by scavenging on carrion. Study on the adult ecology of Patiriella spp. is limited and this thesis aims to expand on the knowledge of this species and its role in intertidal cobble communities. First, field surveys were conducted within intertidal cobble fields in Wellington Harbour and on the Wellington South Coast to determine density, size and feeding habits of Patiriella spp. and the density of associated organisms. Patiriella spp. were abundant at all sites, with no significant difference in density between Wellington Harbour and Wellington South Coast; however, feeding rates and sizes were significantly higher on the South Coast. Distribution of Patiriella spp. on cobbles was negatively correlated with the distribution of chitons, suggesting possible competition between these animals. Second, scavenging behaviour was examined in field and laboratory experiments. Patiriella spp. were readily attracted to mussel carrion bait in the field; however, whelks were the numerically dominant taxon attracted to bait and may therefore compete with Patiriella spp. for this resource. Laboratory results showed that movement towards carrion may be indicative of hunger and Patiriella spp. from Wellington Harbour and the Wellington South Coast reacted similarly to carrion, suggesting similar, limited levels, of carrion supply within these regions. The occurrence of interspecific feeding competition was tested in the laboratory by examining growth and mortality in response to varying densities of Patiriella spp. and a locally abundant chiton, and possible competitor, Chiton glaucus. Intraspecific competition was also tested in response to varying densities of Patiriella spp., with and without carrion supplementation and during spring and winter. No inter- or intraspecific competition was found for crustose coralline algae and micro-organisms and this food resource appears not to be limited. However, Patiriella spp. supplemented on mussel carrion had significantly higher growth rates than non-supplemented treatments and this was greater at lower densities, suggesting intraspecific competition for carrion. Increases in Patiriella spp. size and pyloric caeca weight were only observed for treatments supplemented with carrion. Therefore, carrion appears important for growth and reproduction and intraspecific competition for this resource may impact population sizes. Consequently, fluctuations in carrion supply have the potential to change the distribution and abundance of Patiriella spp., leading to changes in community dynamics. This study has provided baseline information on Patiriella spp. populations within intertidal cobble fields in Wellington Harbour and on the Wellington South Coast and also improved knowledge of the feeding behaviours and competitive interactions of this seastar; therefore, contributing to understanding of the ecological role of Patiriella spp. within intertidal cobble communities.</p>

scholarly journals The Ecological Role of a Common Seastar (Patiriella spp.) Within Intertidal Cobble Fields

2021 ◽  
Author(s):  
◽  
Shiree Palmer
Keyword(s):  
Intraspecific Competition ◽  
Feeding Habits ◽  
South Coast ◽  
Coralline Algae ◽  
Ecological Role ◽  
Crustose Coralline Algae ◽  
Wide Range ◽  
Significant Difference ◽  
Micro Organisms

<p>Intertidal cobble habitats are complex three-dimensional marine environments that are understudied despite having unique species assemblages and ecological patterns. New Zealand's common cushion star, Patiriella spp., is found in a wide range of coastal habitats, including intertidal cobble fields. This seastar is an omnivore that feeds predominantly on crustose coralline algae and micro-organisms, but also supplements its diet by scavenging on carrion. Study on the adult ecology of Patiriella spp. is limited and this thesis aims to expand on the knowledge of this species and its role in intertidal cobble communities. First, field surveys were conducted within intertidal cobble fields in Wellington Harbour and on the Wellington South Coast to determine density, size and feeding habits of Patiriella spp. and the density of associated organisms. Patiriella spp. were abundant at all sites, with no significant difference in density between Wellington Harbour and Wellington South Coast; however, feeding rates and sizes were significantly higher on the South Coast. Distribution of Patiriella spp. on cobbles was negatively correlated with the distribution of chitons, suggesting possible competition between these animals. Second, scavenging behaviour was examined in field and laboratory experiments. Patiriella spp. were readily attracted to mussel carrion bait in the field; however, whelks were the numerically dominant taxon attracted to bait and may therefore compete with Patiriella spp. for this resource. Laboratory results showed that movement towards carrion may be indicative of hunger and Patiriella spp. from Wellington Harbour and the Wellington South Coast reacted similarly to carrion, suggesting similar, limited levels, of carrion supply within these regions. The occurrence of interspecific feeding competition was tested in the laboratory by examining growth and mortality in response to varying densities of Patiriella spp. and a locally abundant chiton, and possible competitor, Chiton glaucus. Intraspecific competition was also tested in response to varying densities of Patiriella spp., with and without carrion supplementation and during spring and winter. No inter- or intraspecific competition was found for crustose coralline algae and micro-organisms and this food resource appears not to be limited. However, Patiriella spp. supplemented on mussel carrion had significantly higher growth rates than non-supplemented treatments and this was greater at lower densities, suggesting intraspecific competition for carrion. Increases in Patiriella spp. size and pyloric caeca weight were only observed for treatments supplemented with carrion. Therefore, carrion appears important for growth and reproduction and intraspecific competition for this resource may impact population sizes. Consequently, fluctuations in carrion supply have the potential to change the distribution and abundance of Patiriella spp., leading to changes in community dynamics. This study has provided baseline information on Patiriella spp. populations within intertidal cobble fields in Wellington Harbour and on the Wellington South Coast and also improved knowledge of the feeding behaviours and competitive interactions of this seastar; therefore, contributing to understanding of the ecological role of Patiriella spp. within intertidal cobble communities.</p>

Willows in the environment

1992 ◽  
Vol 98 ◽  
pp. 215-224 ◽  
Author(s):  
Alastair H. C. Sommerville
Keyword(s):  
Plant Communities ◽  
Ecological Role ◽  
Large Numbers ◽  
Wide Range

SynopsisThe ecological role of native willows is described in terms of the diverse structure of the species involved, the wide range of plant communities they form and the large numbers of invertebrates associated with them. The conservation importance of the genusSalixis discussed along with comments on the necessary management to retain willow habitats.

scholarly journals Coral larvae for restoration and research: a large-scale method for rearing Acropora millepora larvae, inducing settlement, and establishing symbiosis

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3732 ◽  
Author(s):  
F. Joseph Pollock ◽  
Sefano M. Katz ◽  
Jeroen A.J.M. van de Water ◽  
Sarah W. Davies ◽  
Margaux Hein ◽  
...  
Keyword(s):  
Large Scale ◽  
Larval Settlement ◽  
Larval Survival ◽  
Coralline Algae ◽  
Larval Rearing ◽  
Crustose Coralline Algae ◽  
Minimal Impact ◽  
Acropora Millepora ◽  
Wide Range ◽  
Order Of Magnitude

Here we describe an efficient and effective technique for rearing sexually-derived coral propagules from spawning through larval settlement and symbiont uptake with minimal impact on natural coral populations. We sought to maximize larval survival while minimizing expense and daily husbandry maintenance by experimentally determining optimized conditions and protocols for gamete fertilization, larval cultivation, induction of larval settlement by crustose coralline algae, and inoculation of newly settled juveniles with their dinoflagellate symbiont Symbiodinium. Larval rearing densities at or below 0.2 larvae mL−1 were found to maximize larval survival and settlement success in culture tanks while minimizing maintenance effort. Induction of larval settlement via the addition of a ground mixture of diverse crustose coralline algae (CCA) is recommended, given the challenging nature of in situ CCA identification and our finding that non settlement-inducing CCA assemblages do not inhibit larval settlement if suitable assemblages are present. Although order of magnitude differences in infectivity were found between common Great Barrier Reef Symbiodinium clades C and D, no significant differences in Symbiodinium uptake were observed between laboratory-cultured and wild-harvested symbionts in each case. The technique presented here for Acropora millepora can be adapted for research and restoration efforts in a wide range of broadcast spawning coral species.

scholarly journals Antagonism and synergism in Gardnerella vaginalis strains isolated from women with bacterial vaginosis

2010 ◽  
Vol 59 (8) ◽  
pp. 891-897 ◽  
Author(s):  
G. S. Teixeira ◽  
K. L. K. Soares-Brandão ◽  
K. M. G. R. Branco ◽  
J. L. M. Sampaio ◽  
R. M. D. Nardi ◽  
...  
Keyword(s):  
Bacterial Vaginosis ◽  
Chemical Nature ◽  
Growth Conditions ◽  
Antagonistic Activity ◽  
Gardnerella Vaginalis ◽  
Ecological Role ◽  
Micro Organisms

Antagonistic and synergistic substances are important for interactions between micro-organisms associated with human body surfaces, either in healthy or in diseased conditions. In the present study, such compounds produced by Gardnerella vaginalis strains isolated from women with bacterial vaginosis (BV) were detected in vitro and the antagonistic ones were partially characterized. Among 11 G. vaginalis strains tested, all showed antagonistic activity against at least one of the 22 indicator bacteria assayed. Interestingly, for some of these strains, antagonism reverted to synergism, favouring one of the indicator strains (Peptostreptococcus anaerobius) when the growth medium was changed. Partial characterization of antagonistic substances suggested a bacteriocin-like chemical nature. Depending on growth conditions, G. vaginalis isolated from women with BV produced antagonistic or synergistic compounds for other bacterial components of the vaginal ecosystem. This is the first report to our knowledge of the production of antagonistic and/or synergistic substances by G. vaginalis. This ability may be a pivotal factor in understanding BV and the ecological role of this bacterium in the vaginal environment.

scholarly journals New insight into the trophic position and ecological role of the European hake (Merluccius merluccius L., 1758) in Central and Southern Tyrrhenian Sea (Central Mediterranean Sea).

2021 ◽  
Author(s):  
Claudio D'Iglio ◽  
Nunziatina Porcino ◽  
Adriana Profeta ◽  
Anna Perdichizzi ◽  
Enrico Armeli Milicante ◽  
...  
Keyword(s):  
Trophic Position ◽  
Feeding Habits ◽  
Diet Shift ◽  
Tyrrhenian Sea ◽  
Ecological Role ◽  
Size Classes ◽  
Geographical Variations ◽  
Prey Composition ◽  
European Hake

This paper aims to investigate the ecological role of Merlucicius merluccius, Linnaeus, 1758, in the southern and central Tyrrhenian Sea (GSA 10, Resolution GFCM/33/2009/2 General Fisheries Commission for the Mediterranean), analysing ontogenetic diet shift, geographical variations on prey composition and feeding habits. A sample of 734 hake specimens between 6 cm and 73 cm of total length (TL) were collected in 2018. To value the ontogenetic shifts in prey composition, five size-classes were created from the sample and for each class were calculated quantitative feeding indices. The cluster and MDS analysis, based on the % IRI, resulted in three trophic groups of hake size classes. The most abundant preys for small hake (size class I) were the Euphausiids, Stylocheiron longicorne and Mysidacea, while for hake with size over 10.5 cm of TL were crustaceans and fish. Engraulis encrasicolus was the most abundant prey fish for hake, followed by Boops boops and Myctophids. The mesopelagic fauna had a relevant role in the European hake diet in the southern zone. The high presence of Euphausiids, Mysids, Myctophidae and Sternoptychidae in the gut content of juvenile hakes (6-23 cm) showed the importance of organic matter and energy flowed from the mesopelagic environment to the epipelagic. Important is also the presence of decapod crustaceans in hake with size over 36 cm TL considering that our study area includes an important Gulf for the fishing of decapod crustacea.

scholarly journals Recruitment of crustose coralline algae on tiles material for monitoring coral larvae settlement’s consolidators at Nature Reserve Pulau Sempu, East Java, Indonesia

2023 ◽  
Vol 83 ◽  
Author(s):  
Guntur ◽  
O.M. Luthfi ◽  
M. A. Asadi
Keyword(s):  
Calcium Carbonate ◽  
Marine Ecosystem ◽  
Seawater Temperature ◽  
Empty Space ◽  
Coralline Algae ◽  
Life History Stage ◽  
Crustose Coralline Algae ◽  
High Coverage ◽  
Significant Difference ◽  
Key Factor

Abstract Crustose coralline algae (Corallinophycideae) are red algae that produced calcium carbonate and are well recognized as foundation species in the epipelagic zone of the marine ecosystem. These algae induced settlement juvenile of coral by released chemical cues from bacterial communities on the surface of their colonies. Their extracellular calcium carbonate also can stabilize reef structure that influencing many invertebrate attaches and growth in the seabed. Crustose coralline algae (CCA) have obtained attention because of their distribution and health compromise to increasing seawater temperature, ocean acidification, and pollutant. As a cryptic species in the ecosystem, the presence of CCA recruit sometimes doesn’t have attention, especially on their capability to occupy the empty space. This study aimed to document coverage and number of CCA recruit in two different recruitment tile’s material. The highest CCA percentage of the cover was showed inside surface than others surface in all stations. Light intensity and low sedimentation were suggested as a key factor of success of high coverage. Overall, station higher CCA recruits have shown from Tiga Warna. Low sedimentation and protection from aerial exposure became the main reason for it. No significant difference number of CCA recruits between marble and sandstone in this study. Successful CCA recruitment in this study can give a wide picture that natural recruitment of coral and other reef biodiversity in Southern Malang might be will succeed because of the abundance of coralline algae that support their life history stage.

scholarly journals Ocean acidification does not affect magnesium composition or dolomite formation in living crustose coralline algae, <i>Porolithon onkodes</i> in an experimental system

2015 ◽  
Vol 12 (2) ◽  
pp. 1373-1404 ◽  
Author(s):  
M. C. Nash ◽  
S. Uthicke ◽  
A. P. Negri ◽  
N. E. Cantin
Keyword(s):  
Ocean Acidification ◽  
Experimental System ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Experimental Conditions ◽  
Pco2 Treatment ◽  
Wide Range ◽  
Dolomite Formation ◽  
Time Frames ◽  
Near Future

Abstract. There are concerns that Mg-calcite crustose coralline algae (CCA), which are key reef builders on coral reefs, will be most susceptible to increased rates of dissolution under higher pCO2 and ocean acidification. Due to the higher solubility of Mg-calcite, it has been hypothesized that magnesium concentrations in CCA Mg-calcite will decrease as the ocean acidifies, and that this decrease will make their skeletons more chemically stable. In addition to Mg-calcite, CCA Porolithon onkodes the predominant encrusting species on tropical reefs, can have dolomite (Ca0.5Mg0.5CO3) infilling cell spaces which increases their stability. However, nothing is known about how bio-mineralised dolomite formation responds to higher pCO2. Using P. onkodes grown for 3 and 6 months in tank experiments, we aimed to determine (1) if mol % MgCO3 in new crust and new settlement affected by increasing pCO2 levels (365, 444, 676 and 904 ppm), (2) whether bio-mineralised dolomite formed within these time frames, and (3) if so, whether this was effected by pCO2. Our results show there was no significant effect of pCO2 on mol % MgCO3 in any sample set, indicating an absence of a plastic response under a wide range of experimental conditions. Dolomite within the CCA cells formed within 3 months and dolomite abundance did not vary significantly with pCO2 treatment. While evidence mounts that climate change will impact many sensitive coral and CCA species, the results from this study indicate that reef-building P. onkodes will continue to form stabilising dolomite infill under near-future acidification conditions, thereby retaining its higher resistance to dissolution.

The rôle of fleshy macroalgae in the ecology of juvenile cod (Gadus morhua L.) in inshore waters off eastern Newfoundland

1987 ◽  
Vol 65 (1) ◽  
pp. 49-53 ◽  
Author(s):  
D. W. Keats ◽  
D. H. Steele ◽  
G. R. South
Keyword(s):  
Sea Urchin ◽  
Gadus Morhua ◽  
Coralline Algae ◽  
Benthic Organisms ◽  
Crustose Coralline Algae ◽  
Small Juvenile ◽  
Green Sea Urchin ◽  
Inshore Waters

Juvenile cod (Gadus morhua) were more abundant in inshore areas with abundant fleshy macroalgae (Desmarestia spp.) than they were in green sea urchin dominated areas with only crustose coralline algae. Small juvenile cod (<125 mm) fed mainly on small zooplankton, while larger juveniles fed mainly on benthic organisms. The contribution of epiphytic animals obtained from the macroalgae was low. We suggest that the juvenile cod were associated with the algae mainly for cover, and to a lesser degree for food obtained from the algae.

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