scholarly journals Corrigendum: A New Method for Standardizing Inland Fish Community Surveys: Characterizing Habitat Associated With Small-Bodied Fish Species, Abundance, and Size Distribution in a Highly Modified Estuary

2021 ◽  
Vol 9 ◽  
Author(s):  
Joseph E. Merz ◽  
Meghan J. Camp ◽  
Juniper L. Simonis ◽  
Whitney Thorpe
Keyword(s):  
Size Distribution ◽  
Fish Species ◽  
Fish Community ◽  
Species Abundance ◽  
New Method ◽  
Community Surveys

scholarly journals The hydraulic management of the Barra Bonita reservoir (SP, Brazil) as a factor influencing the temporal succession of its fish community

2007 ◽  
Vol 67 (3) ◽  
pp. 433-445 ◽  
Author(s):  
ML. Petesse ◽  
M. Petrere Jr. ◽  
RJ. Spigolon
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
Abundant Species ◽  
Anthropogenic Stress ◽  
Reservoir Level ◽  
Species List ◽  
Adaptation Capacity ◽  
Reproductive Structures ◽  
Temporal Succession ◽  
Reproductive Compensation

The temporal succession of fish communities allows evaluating the environmental conditions and the adaptation capacity of the fish species to anthropogenic stress in reservoirs. The fish community at Barra Bonita reservoir was sampled in two different periods of the year (dry and rainy) and in three different areas of the reservoir (fluvial, transition, and lentic). The species list was compared to another four lists, trying to detect the transformations of the fish community for the last 15 years. In order to evaluate the adaptation of the present fish community to the hydraulic management of reservoir, the trophic and reproductive structures were studied. Temporal succession analysis shows little change in fish richness of the communities. The number of fish species varies between 23 and 39 for a total of 68 registered species. From this, 27 can be considered constant, 14 accessory and 27 accidental; the main differences observed were for Anostomidae, Loricariidae and Characidae families. In relation to the hydraulic management, we found a fish community stabilized and adapted to environmental stress. This is characterized by the dominance of small-sized fish species of opportunistic diet and high reproductive compensation (r-strategists). The overlap of biological cycles of the most abundant species with the reservoir level fluctuations points to the period from September to March-April as critical for reproductive success and only the species with partial reproductive strategy or parental care are best succeeded. These results, interpreted in the context of the reservoir aging process, indicate that Barra Bonita reservoir is entering a transition phase, between the colonization and aging stages.

scholarly journals The contribution of environmental factors to fish assemblages in the Río Acahuapa, a small drainage in Central America

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Francisco S. Álvarez ◽  
Wilfredo A. Matamoros ◽  
Francisco A. Chicas
Keyword(s):  
Fish Species ◽  
Habitat Structure ◽  
Fish Assemblages ◽  
Species Abundance ◽  
Main Channel ◽  
Estuarine Fish ◽  
Species Origin ◽  
High Temperature Water ◽  
Distribution Of Fish ◽  
Temperature Water

ABSTRACT The ichthyofauna of the Río Acahuapa was analyzed sampling 17 sites that included the basin main channel and its tributaries. Fish were collected using dip-nets, seine-nets and electrofishing. Fish standard length and species abundance were recorded. Species origin and salinity tolerance criteria were used to classify fish species. Water physicochemical variables, habitat structure and sampling sites elevation were recorded. A total of 33 fish species were registered, 12.1% are primary, 45.5% are secondary and 42.4% are of marine derivation. Fish species richness declined with increase of elevation (R2=0.55, p=0.0006). Two assemblages of fishes were identified: the first one associated to sites of low elevations (19-184 masl), composed mainly of secondary and marine-estuarine fish species related with high temperature, water velocity, river width, dissolved oxygen and low sand and silt substrate cover; the second one associated to sites of middle and higher elevations (185-519 masl), composed by primary and secondary freshwater fishes related with high pH, logs and rocks substrate cover. In summary, elevation and environmental variables contributed to the composition and distribution of fish in the Río Acahuapa.

Positronium Thermalization Process in Nanoporous Materials and its Influence on the Shape of PALS Spectrum

2008 ◽  
Vol 607 ◽  
pp. 39-41
Author(s):  
Jerzy Kansy ◽  
Radosław Zaleski
Keyword(s):  
Mesoporous Silica ◽  
Pore Size Distribution ◽  
Porous Materials ◽  
Pore Size ◽  
Size Distribution ◽  
Nanoporous Materials ◽  
New Method ◽  
New Model ◽  
Conventional Models ◽  
Mcm 41

A new method of analysis of PALS spectra of porous materials is proposed. The model considers both the thermalization process of positronium inside the pores and the pore size distribution. The new model is fitted to spectra of mesoporous silica MCM-41 and MSF. The resulting parameters are compared with parameters obtained from fitting the “conventional” models, i.e. a sum of exponential components with discrete or/and distributed lifetimes.

scholarly journals Demersal fish community on the inner shelf of Ubatuba, southeastern Brazil

1998 ◽  
Vol 46 (2) ◽  
pp. 93-109 ◽  
Author(s):  
Gecely R. A. Rocha ◽  
Carmen L. D. B. Rossi-Wongtschowski
Keyword(s):  
Continental Shelf ◽  
Coastal Water ◽  
Fish Community ◽  
Species Abundance ◽  
Fish Fauna ◽  
Sampling Period ◽  
Demersal Fish ◽  
Southeastern Brazil ◽  
Otter Trawl ◽  
South Atlantic Central Water

Fluctuations in the distribution and abundance of demersal fishes collected by otter trawl on the continental shelf of Ubatuba were examined over a two-year sampling period, in an area up to 50 m depth. A total of 111 species were collected. Seasonal and annual fluctuations in species abundance were related to differences in the distribution of Coastal Water and South Atlantic Central Water masses. The demersal fish fauna in the area was divided into three ecologically distinct communities: Tropical Sciaenid, Subtropical Sciaenid, and Gerreid-Haemulid. The most important one is the Tropical Sciaenid Community, characterized by Ctenosciaena gracilicirrhus, Paralonchurus brasiliensis, and Cynoscion jamaicensis.

A new method to measure the size distribution of insoluble submicron particles in water

1994 ◽  
Vol 25 (2) ◽  
pp. 345-354 ◽  
Author(s):  
A. Wiedensohler ◽  
M. Krämer ◽  
H.-C. Hansson
Keyword(s):  
Size Distribution ◽  
New Method ◽  
Submicron Particles

Documentation of potential courtship-behaviour in Periphylla periphylla (Cnidaria: Scyphozoa)

2008 ◽  
Vol 89 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Henry Tiemann ◽  
Ilka Sötje ◽  
Blair D. Johnston ◽  
Per R. Flood ◽  
Ulf Båmstedt
Keyword(s):  
Life History ◽  
Distribution Pattern ◽  
Size Distribution ◽  
Small Groups ◽  
Deep Sea ◽  
Species Abundance ◽  
Mating Strategy ◽  
Courtship Behaviour ◽  
Norwegian Fjord

The distribution pattern and nocturnal surface behaviour of the deep-sea medusa Periphylla periphylla in a Norwegian fjord was studied. Medusa abundance, size distribution and condition were determined, using surface collections, net tows and ROV-based video profiles. Only larger, mature medusae reached the surface and aggregated into small groups of both sexes, whereas juvenile medusae remained in deeper waters. Observations on the behaviour and cytology of aggregated medusae suggested a mating strategy. We hypothesize that this behaviour is the by-product of a holopelagic life history, developed in a more oceanic deep environment with low species abundance, as surface aggregation increases the chance of encounter and mating.

scholarly journals Shifting fish distributions in warming sub-Arctic oceans

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Steven E. Campana ◽  
Ragnhildur B. Stefánsdóttir ◽  
Klara Jakobsdóttir ◽  
Jón Sólmundsson
Keyword(s):  
Fish Species ◽  
Climate Warming ◽  
Large Scale ◽  
Linear Models ◽  
Three Dimensional ◽  
Species Abundance ◽  
Time Frame ◽  
Thermal Limits ◽  
Dimensional Distribution ◽  
Distribution Shifts

Abstract The distributional response of marine fishes to climate warming would be expected to be very different than that of homeothermic birds and mammals, due both to more direct thermal effects on poikilothermic fish physiology and on reduced habitat fragmentation. In this study, we use a combination of linear models and graphical tools to quantify three-dimensional distribution shifts in 82 fish species caught in 5390 standardized groundfish survey tows over a 22-year time frame in the highly-productive sub-Arctic waters around Iceland. Over a 1 °C range, temperature significantly modified the distributional centroids of 72% of all fish species, but had relatively little effect on diversity. Most of the geographic shifts were to the northwest, and there was no overall tendency to move to deeper waters. A doubling of species abundance significantly influenced the distribution of 62% of species, but lacked the poleward orientation observed with temperature increases. Stenothermal species, those near their upper or lower thermal limits, and those with restricted spatial ranges were most likely to shift their distribution in response to climate warming, while deepwater species were not. A 2–3 °C warming of marine waters seems likely to produce large-scale changes in the location of many sub-Arctic fisheries.

scholarly journals A New Method for Recording the Grain-Structure of Ice

1957 ◽  
Vol 3 (22) ◽  
pp. 131-132
Author(s):  
Keiji Higuchi
Keyword(s):  
Size Distribution ◽  
Replica Method ◽  
New Method ◽  
Grain Structure ◽  
Etch Pits ◽  
Etching Technique ◽  
Simple Operation ◽  
Individual Grains

AbstractSeparated etch pits can be produced by a simple operation using a plastic replica film. Combining this etching technique with Schaefer’s replica method, it is possible to record both the size distribution and the orientation of crystal axes of individual grains of ice.

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