Ecological traits of benthic assemblages in shallow Antarctic waters: does ice scour disturbance select for small, mobile, secondary consumers with high dispersal potential?

Polar Biology ◽  
2008 ◽  
Vol 31 (10) ◽  
pp. 1225-1231 ◽  
Author(s):  
Dan A. Smale
Keyword(s):  
Benthic Assemblages ◽  
Ecological Traits ◽  
High Dispersal ◽  
Antarctic Waters ◽  
Dispersal Potential ◽  
Secondary Consumers

The Trophic Role of Marine Microorganisms Through Time

2002 ◽  
Vol 8 ◽  
pp. 69-92 ◽  
Author(s):  
Jere H. Lipps ◽  
Stephen J. Culver
Keyword(s):  
Trophic Structure ◽  
Mass Extinctions ◽  
Marine Microorganisms ◽  
Geologic History ◽  
Benthic Assemblages ◽  
Primary Producers ◽  
Early Diversification ◽  
History Of ◽  
Secondary Consumers ◽  
Extinction Events

Microorganisms (prokaryotes and protists) seldom fossilize, but they form much of the trophic structure in marine pelagic and benthic environments, chiefly as primary producers and secondary consumers. The fossil record of unskeletonized groups is meager or non-existent. Skeletonized groups have excellent records but represent a small portion of the total microbial diversity.The evolution of trophic structures and roles of microorganisms can be reconstructed broadly for most of geologic history. When life first evolved, it had a trophic structure. The first microbial fossils appear to be benthic mats; these are abundant in the Precambrian but sparse later; body fossils are very rare. The Archean saw pelagic and benthic prokaryotes and possibly protists later on. Proterozoic trophic structures became increasingly complex as protists entered pelagic environments. Benthic assemblages likewise became complex, as prokaryotes and protists formed mats and stromatolites in many environments. At the end of the eon, animals appeared; microbial primary producers and predation on microorganisms and among animals fueled these assemblages. The fundamental trophic structures that developed then persisted with modification into modern times. Phanerozoic ecosystems became very complex as skeletonized animals and protists evolved. Among the important trophic developments in the Phanerozoic history of microorganisms were the early diversification of phytoplankton and siliceous micro-zooplankton (Cambrian), algal endosymbiosis with benthic metazoans (Cambrian to Recent) and rock-forming foraminifera (late Paleozoic to Recent), the radiation of pelagic skeletal primary producers and micro-zooplankton (mid-Mesozoic), and radiations in the deep sea, reefs, and shallow areas (Mesozoic and Cenozoic). Each evolutionary change increased trophic complexity by adding more species at each level, while episodic mass extinctions decreased species diversity and trophic complexity.Marine trophic structures evolved over immense intervals of geologic time, growing complex and then suffering destruction at major extinction events. The effects of human impact on these structures should be examined, for without them, Earth may change dramatically.

The geographic scale of speciation in a marine snail with high dispersal potential

2011 ◽  
Vol 38 (6) ◽  
pp. 1016-1032 ◽  
Author(s):  
Martine Claremont ◽  
Suzanne T. Williams ◽  
Timothy G. Barraclough ◽  
David G. Reid
Keyword(s):  
Geographic Scale ◽  
Marine Snail ◽  
High Dispersal ◽  
Dispersal Potential

scholarly journals Evidence of high genetic connectivity for the longnose spurdog Squalus blainville in the Mediterranean Sea

2015 ◽  
Vol 17 (2) ◽  
pp. 371 ◽  
Author(s):  
V. KOUSTENI ◽  
P. KASAPIDIS ◽  
G. KOTOULAS ◽  
P. MEGALOFONOU
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Structure ◽  
Mediterranean Sea ◽  
Genetic Connectivity ◽  
Middle Pleistocene ◽  
Biological Knowledge ◽  
Shark Species ◽  
High Dispersal ◽  
Dispersal Potential ◽  
The Mediterranean

Squalus blainville is one of the least studied Mediterranean shark species. Despite being intensively fished in several locations, biological knowledge is limited and no genetic structure information is available. This is the first study to examine the genetic structure of S. blainville in the Mediterranean Sea. Considering the high dispersal potential inferred for other squalid sharks, the hypothesis of panmixia was tested based on a 585 bp fragment of the mitochondrial DNA cytochrome c oxidase subunit I gene from 107 individuals and six nuclear microsatellite loci from 577 individuals. Samples were collected across the Ionian, Aegean and Libyan Seas and off the Balearic Islands. Twenty three additional sequences of Mediterranean and South African origin were retrieved from GenBank and included in the mitochondrial DNA analysis. The overall haplotype diversity was high, in contrast to the low nucleotide diversity. Low and non-significant pairwise ΦST and FST values along with a Bayesian cluster analysis suggested high connectivity with subsequent genetic homogeneity among the populations studied, and thus a high dispersal potential for S. blainville similar to other squalids. The historical demography of the species was also assessed, revealing a pattern of population expansion since the middle Pleistocene. These findings could be considered in species-specific conservation plans, although sampling over a larger spatial scale and more genetic markers are required to fully elucidate the genetic structure and dispersal potential of S. blainville.

scholarly journals Climatic change drives dynamic source–sink relationships in marine species with high dispersal potential

2021 ◽  
Author(s):  
Catarina N. S. Silva ◽  
Emma F. Young ◽  
Nicholas P. Murphy ◽  
James J. Bell ◽  
Bridget S. Green ◽  
...  
Keyword(s):  
Climatic Change ◽  
Marine Species ◽  
High Dispersal ◽  
Dispersal Potential ◽  
Dynamic Source ◽  
Source Sink

scholarly journals Local and regional founder effects in lake zooplankton persist after thousands of years despite high dispersal potential

2014 ◽  
Vol 23 (5) ◽  
pp. 1014-1027 ◽  
Author(s):  
M. Ventura ◽  
A. Petrusek ◽  
A. Miró ◽  
E. Hamrová ◽  
D. Buñay ◽  
...  
Keyword(s):  
Founder Effects ◽  
High Dispersal ◽  
Dispersal Potential

scholarly journals DISPERSAL POTENTIAL OF HERBACEOUS SPECIES ACCORDING TO CLIMATE, LAND USE AND HABITAT CONDITIONS IN WEST AFRICAN SAVANNAH

2017 ◽  
Vol 332 ◽  
pp. 69-87 ◽  
Author(s):  
Issouf Zerbo ◽  
Karen Hahn ◽  
Markus Bernhardt-Römermann ◽  
Oumarou Ouédraogo ◽  
Adjima Thiombiano
Keyword(s):  
Land Use ◽  
Principal Component ◽  
Climatic Conditions ◽  
West African ◽  
Herbaceous Species ◽  
Dispersal Patterns ◽  
Herbaceous Vegetation ◽  
The North ◽  
High Dispersal ◽  
Dispersal Potential

According to environmental predictions, West Africa is becoming vulnerable to the adverse effects of climate change and land use dis- turbance. Herbaceous vegetation is the most sensitive to these effects. To assess the poten- tial of species to cope with these changes, this study investigated the dispersal potential of different herbaceous species. Data on her- baceous plant composition and environmen- tal parameters were collected along climate, land use and habitat gradients in West Afri- can savannah areas, as well as the diaspores of all herbaceous species encountered. Their traits were described in order to document the diversity of diaspore categories in herbaceous savannah vegetation. Based on an occurrence diagram, variations in dissemination patterns within families were identified. The dispersal potential of each species was determined on the basis of their patterns of dispersal. A hie- rarchical classification method was used to establish a dispersal typology, and principal component analysis was applied to identify the environmental conditions that account for their patterns of dispersal. The results show that the diaspores of herbaceous spe- cies can be classified according to fruit type, diaspore type, presence of heterodiaspory, exposure of diaspores, number of seeds per diaspore, diaspore morphology, shape of diaspores and pattern of dispersal. Poaceae, the most abundant family in savannah areas, have six patterns of dispersal. Most species have more than one pattern, and species with high dispersal potential (85.43%) dominate the herbaceous vegetation. Four groups of herbaceous species were identified according to their dispersal patterns. Potentially epizoo- chorous and anemochorous species (39.25% of the flora) were more related to village areas independently of climatic conditions and habi- tat types. Potentially endozoochorous and dysozoochorous species (31.06% of the flora) were more related to fresh and dry habitats in protected areas of the North and South Suda- nian zones. Potentially hydrochorous species (12.63% of the flora) were related to wet habi- tats but were more prominent in the Sahel, and potentially autochorous species (17.06% of the flora) were more related to bowé habi- tats in the southern Sudanian zone. Our study showed that all herbaceous species have good dispersal potential, which might enable them to persist in West African savannahs despite the severe climatic changes predicted.

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