scholarly journals Facultative paedomorphosis as a mechanism promoting intraspecific niche differentiation

Oikos ◽  
2017 ◽  
Vol 127 (3) ◽  
pp. 427-439 ◽  
Author(s):  
Benjamin Lejeune ◽  
Nicolas Sturaro ◽  
Gilles Lepoint ◽  
Mathieu Denoël
Keyword(s):  
Niche Differentiation ◽  
Facultative Paedomorphosis

scholarly journals Non-Conventional Metal Ion Cofactor Requirement of Dinoflagellate Alkaline Phosphatase and Translational Regulation by Phosphorus Limitation

2019 ◽  
Vol 7 (8) ◽  
pp. 232 ◽  
Author(s):  
Xin Lin ◽  
Chentao Guo ◽  
Ling Li ◽  
Tangcheng Li ◽  
Senjie Lin
Keyword(s):  
Alkaline Phosphatase ◽  
Metal Ion ◽  
Translational Regulation ◽  
Organic Phosphorus ◽  
Niche Differentiation ◽  
Phosphorus Limitation ◽  
Marine Phytoplankton ◽  
Phosphate Limitation ◽  
Dissolved Organic Phosphorus ◽  
Metal Cofactor

Alkaline phosphatase (AP) enables marine phytoplankton to utilize dissolved organic phosphorus (DOP) when dissolved inorganic phosphate (DIP) is depleted in the ocean. Dinoflagellate AP (Dino-AP) represents a newly classified atypical type of AP, PhoAaty. Despite While being a conventional AP, PhoAEC is known to recruit Zn2+ and Mg2+ in the active center, and the cofactors required by PhoAaty have been contended and remain unclear. In this study, we investigated the metal ion requirement of AP in five dinoflagellate species. After AP activity was eliminated by using EDTA to chelate metal ions, the enzymatic activity could be recovered by the supplementation of Ca2+, Mg2+ and Mn2+ in all cases but not by that of Zn2+. Furthermore, the same analysis conducted on the purified recombinant ACAAP (AP of Amphidinium carterae) verified that the enzyme could be activated by Ca2+, Mg2+, and Mn2+ but not Zn2+. We further developed an antiserum against ACAAP, and a western blot analysis using this antibody showed a remarkable up-regulation of ACAAP under a phosphate limitation, consistent with elevated AP activity. The unconventional metal cofactor requirement of Dino-AP may be an adaptation to trace metal limitations in the ocean, which warrants further research to understand the niche differentiation between dinoflagellates and other phytoplankton that use Zn–Mg AP in utilizing DOP.

Habitat use and the coexistence of the sika deer and the Japanese serow, sympatric ungulates from Mt. Asama, central Japan

Mammalia ◽  
2020 ◽  
Vol 84 (6) ◽  
pp. 503-511
Author(s):  
Hayato Takada ◽  
Riki Ohuchi ◽  
Haruko Watanabe ◽  
Risako Yano ◽  
Risako Miyaoka ◽  
...  
Keyword(s):  
Habitat Use ◽  
Sika Deer ◽  
Cervus Nippon ◽  
Niche Differentiation ◽  
Ecological Niches ◽  
Dwarf Bamboo ◽  
Central Japan ◽  
Habitat Mosaic ◽  
The Japanese Archipelago ◽  
Japanese Serow

AbstractDifferential resource use allows for diverse species to specialize in ecological niches and thus coexist in a particular area. In the Japanese archipelago, increasing sika deer (Cervus nippon, Temminck 1836) densities have excluded the Japanese serow (Capricornis crispus, Temminck 1836), but in places where deer population densities are low, the two species coexist. We wanted to better understand their habitats and how these two ungulates manage to coexist. We evaluated the role of habitat use in the coexistence of these two sympatric ungulates on Mt. Asama, central Japan. Deer frequently used the dwarf bamboo-rich communities in autumn and winter, and their habitat use was not associated with topography. Serows frequently used deciduous broadleaf shrub-rich communities and steep slopes throughout the year. Consequently, their habitat use was significantly different in terms of vegetation and topography. Niche breadth suggests that deer tend to be generalists, whereas serows tend to be specialists. Niche differentiation in habitat use between deer and serows may make the coexistence of these similarly sized ungulates possible in Japanese mountainous zones. Therefore, the fine-grained habitat mosaic of different vegetation and topography areas might be the underlying feature that allows the coexistence of these two species.

scholarly journals Niches, rather than neutrality, structure a grassland pioneer guild

2005 ◽  
Vol 272 (1570) ◽  
pp. 1357-1364 ◽  
Author(s):  
Lindsay A Turnbull ◽  
Liz Manley ◽  
Mark Rees
Keyword(s):  
Seed Size ◽  
Adult Stage ◽  
Niche Differentiation ◽  
Competitive Dynamics ◽  
Similar Species ◽  
Adult Density ◽  
Pioneer Species ◽  
Trade Offs ◽  
Very High ◽  
Early Establishment

Pioneer species are fast-growing, short-lived gap exploiters. They are prime candidates for neutral dynamics because they contain ecologically similar species whose low adult density is likely to cause widespread recruitment limitation, which slows competitive dynamics. However, many pioneer guilds appear to be differentiated according to seed size. In this paper, we compare predictions from a neutral model of community structure with three niche-based models in which trade-offs involving seed size form the basis of niche differentiation. We test these predictions using sowing experiments with a guild of seven pioneer species from chalk grassland. We find strong evidence for niche structure based on seed size: specifically large-seeded species produce fewer seeds but have a greater chance of establishing on a per-seed basis. Their advantage in establishment arises because there are more microsites suitable for their germination and early establishment and not directly through competition with other seedlings. In fact, seedling densities of all species were equally suppressed by the addition of competitors' seeds. By the adult stage, despite using very high sowing densities, there were no detectable effects of interspecific competition on any species. The lack of interspecific effects indicates that niche differentiation, rather than neutrality, prevails.

scholarly journals Microbial niche differentiation explains nitrite oxidation in marine oxygen minimum zones

2021 ◽  
Author(s):  
Xin Sun ◽  
Claudia Frey ◽  
Emilio Garcia-Robledo ◽  
Amal Jayakumar ◽  
Bess B. Ward
Keyword(s):  
Nitrogen Loss ◽  
Niche Differentiation ◽  
Nitrite Reduction ◽  
Nitrite Oxidation ◽  
Fixed Nitrogen ◽  
Anoxic Waters ◽  
Biogeochemical Models ◽  
Nitrite Oxidizing Bacteria ◽  
Oxygen Addition ◽  
Oxygen Minimum

AbstractNitrite is a pivotal component of the marine nitrogen cycle. The fate of nitrite determines the loss or retention of fixed nitrogen, an essential nutrient for all organisms. Loss occurs via anaerobic nitrite reduction to gases during denitrification and anammox, while retention occurs via nitrite oxidation to nitrate. Nitrite oxidation is usually represented in biogeochemical models by one kinetic parameter and one oxygen threshold, below which nitrite oxidation is set to zero. Here we find that the responses of nitrite oxidation to nitrite and oxygen concentrations vary along a redox gradient in a Pacific Ocean oxygen minimum zone, indicating niche differentiation of nitrite-oxidizing assemblages. Notably, we observe the full inhibition of nitrite oxidation by oxygen addition and nitrite oxidation coupled with nitrogen loss in the absence of oxygen consumption in samples collected from anoxic waters. Nitrite-oxidizing bacteria, including novel clades with high relative abundance in anoxic depths, were also detected in the same samples. Mechanisms corresponding to niche differentiation of nitrite-oxidizing bacteria across the redox gradient are considered. Implementing these mechanisms in biogeochemical models has a significant effect on the estimated fixed nitrogen budget.

scholarly journals Foraging niche partitioning in sympatric seabird populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christina Petalas ◽  
Thomas Lazarus ◽  
Raphael A. Lavoie ◽  
Kyle H. Elliott ◽  
Mélanie F. Guigueno
Keyword(s):  
Interspecific Competition ◽  
Niche Partitioning ◽  
Niche Differentiation ◽  
Sympatric Species ◽  
Foraging Strategies ◽  
Gps Tracking ◽  
Seabird Species ◽  
Foraging Range ◽  
Common Murre ◽  
Prey Items

AbstractSympatric species must sufficiently differentiate aspects of their ecological niche to alleviate complete interspecific competition and stably coexist within the same area. Seabirds provide a unique opportunity to understand patterns of niche segregation among coexisting species because they form large multi-species colonies of breeding aggregations with seemingly overlapping diets and foraging areas. Recent biologging tools have revealed that colonial seabirds can differentiate components of their foraging strategies. Specifically, small, diving birds with high wing-loading may have small foraging radii compared with larger or non-diving birds. In the Gulf of St-Lawrence in Canada, we investigated whether and how niche differentiation occurs in four incubating seabird species breeding sympatrically using GPS-tracking and direct field observations of prey items carried by adults to chicks: the Atlantic puffin (Fratercula arctica), razorbill (Alca torda), common murre (Uria aalge), and black-legged kittiwake (Rissa tridactyla). Although there was overlap at foraging hotspots, all species differentiated in either diet (prey species, size and number) or foraging range. Whereas puffins and razorbills consumed multiple smaller prey items that were readily available closer to the colony, murres selected larger more diverse prey that were accessible due to their deeper diving capability. Kittiwakes compensated for their surface foraging by having a large foraging range, including foraging largely at a specific distant hotspot. These foraging habitat specialisations may alleviate high interspecific competition allowing for their coexistence, providing insight on multispecies colonial living.

Sign in / Sign up

Export Citation Format

Share Document