Seasonal and diel comparisons of the diets of four dominant fish species within the main channel and flood-zone of a small intermittently open estuary in south-eastern Australia

2007 ◽  
Vol 58 (12) ◽  
pp. 1086 ◽  
Author(s):  
Alistair Becker ◽  
Laurie J. B. Laurenson
Keyword(s):  
Fish Species ◽  
Main Channel ◽  
Ecological Value ◽  
Flood Zone ◽  
Eastern Australia ◽  
Dominant Fish ◽  
Galaxias Maculatus ◽  
Significant Divergence ◽  
Feeding Behaviours ◽  
Prey Items

The diets of four highly-abundant, dominant fish species within the Surrey River, a small intermittently open estuary in south-east Australia, were examined from specimens collected between July 2004 and June 2005. These four, similar-sized species (Atherinosoma microstoma, Galaxias maculatus, Philypnodon grandiceps and Pseudogobius olorum) have limited ability to spatially segregate along the length of the estuary owing to its small size relative to other estuarine habitats. All four species fed on a variety of prey items including crustaceans, insects and detritus. Despite this parity, the four species were demonstrated to occupy differing dietary niches that were concluded to be responsible for reducing interspecific feeding competition. Seasonal variations in the diets were observed for A. microstoma and Philypnodon grandiceps, with these species also exhibiting contrasting diel feeding behaviours. The closure of the estuary mouth led to the flooding of its margins, resulting in an increase in the size of the estuary and providing alternative food resources for the fish to exploit. It appears the inundation of the flood-zone facilitated further significant divergence in the diets of the fish and is likely to be of high ecological value to the estuary.

Temporo-spatial heterogeneity of dominant fish species in the Jiaozhou Bay community

2017 ◽  
Vol 24 (5) ◽  
pp. 1091
Author(s):  
Jia WO ◽  
Binduo XU ◽  
Ying XUE ◽  
Yiping REN ◽  
Chongliang ZHANG
Keyword(s):  
Spatial Heterogeneity ◽  
Fish Species ◽  
Jiaozhou Bay ◽  
Dominant Fish

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.

scholarly journals Zooplankton composition and trophic status of hydrobionts of the Laptev and East Siberian seas

2019 ◽  
Vol 59 (6) ◽  
pp. 987-997
Author(s):  
K. M. Gorbatenko ◽  
S. I. Kiyashko
Keyword(s):  
Fish Species ◽  
Trophic Status ◽  
Northwestern Part ◽  
Gut Content Analysis ◽  
Boreogadus Saida ◽  
Gut Content ◽  
Summer Period ◽  
East Siberian Sea ◽  
Dominant Fish ◽  
The Laptev Sea

Species composition, density, biomass and distribution of zooplankton on shelf and slope of northwestern part of the Laptev Sea and shallow-water shelf of the East Siberian Sea were studied in 2015 summer period. Using analysis of stable isotopes of carbon (13 С) and nitrogen (15N), trophic status of abundant zooplankton and fish species, and their positions in food webs of these two seas, were compared. Gut content analysis, as well stable isotope data, showed mutual changes in the trophic status of dominant fish species arctic cod, Boreogadus saida, with age.

Skinks and burrowing crayfish as prey items of the Eastern Yellow Robin Eopsaltria australis in south-eastern Australia

2016 ◽  
Vol 33 ◽  
pp. 57-60 ◽  
Author(s):  
Valerie La May ◽  
Martin O’Brien ◽  
Con Boeke ◽  
Kathy Costello ◽  
Geoff Park ◽  
...  
Keyword(s):  
South Eastern ◽  
Eastern Australia ◽  
Prey Items ◽  
South Eastern Australia

scholarly journals Catch assessment of artisanal marine fishing gears in Cox’s Bazar and Teknaf of Bangladesh

2016 ◽  
Vol 27 (2) ◽  
pp. 228-234
Author(s):  
SK Ghosh ◽  
MK Ahsan ◽  
MK Ahmmed ◽  
SI Ahmed ◽  
MM Hasan ◽  
...  
Keyword(s):  
Fish Species ◽  
Fishing Gear ◽  
Catch Per Unit Effort ◽  
Beach Seine ◽  
Gill Net ◽  
Fishing Gears ◽  
Dominant Fish ◽  
Commercially Important ◽  
Marine Fishing ◽  
Harpadon Nehereus

Studies were conducted on catch assessment of some artisanal marine fishing gears operated in Cox’s Bazar and Teknaf areas from April 2014 to April 2015. Sixteen types of fishing gears were identified, of which gill net, beach seine net, estuarine set bag net, marine set bag net and trammel net occupy major fishing activities. Although estuarine set bag net (ESBN) is a legally restricted fishing gear recorded the highest catch per unit effort (CPUE) (110 kg/gear/day) in July followed by marine set bag net (MSBN) (105 kg/gear/day) in Cox’s Bazar and the highest CPUE was recorded 100 kg/gear/day by ESBN in June followed by MSBN (90 kg/gear/day) in Teknaf. Out of 52 species of fishes, the major fish species abundantly caught by these gears were Poa (Otolithoides argenteus), Churi (Trichiurus haumela), Loittya (Harpadon nehereus), Ranga choukha (Lutjanus johni), Lal poa (Johnius argentatus), Olua (Coilia dussumieri), Rup chanda (Stromateus chinensis), (Stromateus argenteus) and Ilish (Tenualosa ilisha). Besides these fish species, 10 commercially important shrimp species and 3 important crab species were also recorded during the study period. The peak season of availability of most fish species was June and July while lean season was December and January. This study indicated that Otolithoides argenteus) was the dominant fish species followed by Trichiurus haumela, Harpadon nehereus and Coilia dussumieri.Progressive Agriculture 27 (2): 228-234, 2016

Estuarine characteristics, water quality and heavy metal contamination as determinants of fish species composition in intermittently open estuaries

2017 ◽  
Vol 68 (5) ◽  
pp. 941 ◽  
Author(s):  
K. O'Mara ◽  
A. Miskiewicz ◽  
M. Y. L. Wong
Keyword(s):  
Water Quality ◽  
Species Composition ◽  
Fish Species ◽  
Metal Contamination ◽  
Fish Assemblages ◽  
Anthropogenic Activities ◽  
Estuarine Fish ◽  
Fish Diversity ◽  
Eastern Australia ◽  
Fish Species Composition

Estuaries are critical aquatic environments that are used by many fish during their life cycle. However, estuaries often suffer from poor water quality as a result of anthropogenic activities. Fish diversity studies in estuaries are common, although few have examined whether correlations exist between water quality, metal contamination and fish assemblages. In the present study we investigated the effect of abiotic conditions, heavy metals and estuary characteristics on the abundance, diversity and composition of fish in four intermittently open estuaries along the Illawarra coast of south-eastern Australia. The heterogeneity of environmental conditions was reflected in the fish assemblages in each estuary. Environmental variables predicted fish species composition, and estuaries in particularly poor condition contained few species (estuarine residents) in high abundance, indicating their ability to acclimatise and survive in conditions that are hostile to other species. Overall, these findings demonstrate that estuarine fish assemblages may be useful indicators of estuary condition and reveal the importance of managing anthropogenic activities in the surrounding catchment to improve water quality so that biodiversity of fish can be restored in these estuarine environments.

Potential competition between two top-order predators following a dramatic contraction in the diversity of their prey base

2011 ◽  
Vol 61 (1) ◽  
pp. 29-47 ◽  
Author(s):  
Raylene Cooke ◽  
Rohan Bilney ◽  
John White
Keyword(s):  
Habitat Management ◽  
Mammalian Species ◽  
Dietary Overlap ◽  
Study Region ◽  
Terrestrial Mammals ◽  
Potential Competition ◽  
European Settlement ◽  
Eastern Australia ◽  
Significant Divergence ◽  
Potential Resource

AbstractTwo sympatric native top-order predators, the sooty owl (Tyto tenebricosa tenebricosa) and powerful owl (Ninox strenua) coexist throughout much of their range in south-eastern Australia. Following European settlement, however, major changes in resource availability for these predators potentially resulted in increased competition, especially for food. This study examined ecological attributes of both species, including intersexual differences in the sooty owl, potential resource partitioning and whether competition may be occurring. Dietary overlap was high between female sooty owls and powerful owls (0.90), compared to overlap between male sooty owls and powerful owls (0.67), with three mammalian species contributing over 74% of their diets. Sooty and powerful owls coexisted throughout the study region, regularly roosting within the same vegetation types, and in similar locations, although microhabitat differences were apparent. Sooty owls displayed aseasonal breeding, although a peak in fledging in spring coincided with powerful owl breeding. Both species exclusively nested in similar size mountain grey gums (Eucalyptus cypellocarpa), however, hollow characteristics differed slightly. Significant divergence along a single niche dimension was not detected between powerful and sooty owls, as they had similar diets, habitat usage and activity times, potentially resulting in competition. Reproductive output was low for both species, however, the degree to which competitive interactions influenced this remains unknown. To minimise potential competition, longterm feral predator control and improved habitat management is recommended to increase the density and diversity of small terrestrial mammals, as this should result in diversification of the sooty owl diet, reducing dietary overlap with powerful owls.

scholarly journals FISH DIVERSITY OF GHODAGHODI LAKE IN KAILALI, FAR-WEST NEPAL

2017 ◽  
Vol 22 (1) ◽  
pp. 120-126
Author(s):  
Dipendra Joshi ◽  
Bijaya K. C.
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Fish Species ◽  
Diversity Index ◽  
Fish Diversity ◽  
Channa Striatus ◽  
Illegal Fishing ◽  
Dominant Fish ◽  
Fish Catch ◽  
Excessive Proliferation

Ghodaghodi Lake is an ox-bow perennial lake of Ghodaghodi Lake Complex, situated in Kailali district. The present study was conducted to understand the fish diversity, community structure and distribution pattern in Ghodaghodi Lake. A total of 13 fish species were recorded from the different section of Ghodaghodi Lake, belonging to five order, eight family and eleven genera. According to fish catch the dominant order and family of Ghodaghodi Lake were found to be Cypriniformes (40%) and Cyprinidae (40%) respectively. The dominant fish species of Ghodaghodi Lake was Labeo gonius followed by Mystus tengara, Nandus nandus and Channa striatus. The highest diversity index (2.46), species richness (6.14) and evenness (0.96) of fish were recorded from station III during the month of January. Lowest diversity index (1.75) and evenness (0.90) was found in station II and during the month of October (2.25 and 0.88). Similarly, lowest species richness was found in station I (3.91) and during the month of July (5.82). Fish diversity and number in Ghodaghodi Lake were found to have decreased. This could be due to pollution, illegal fishing and excessive proliferation of aquatic weeds.Journal of Institute of Science and TechnologyVolume 22, Issue 1, July 2017, page: 120-126

Abundance and biology of warty oreo (Allocyttus verrucosus) and spiky oreo (Neocyttus rhomboidalis) (Oreosomatidae) off south-eastern Australia

1997 ◽  
Vol 48 (2) ◽  
pp. 91 ◽  
Author(s):  
J. M. Lyle ◽  
D. C. Smith
Keyword(s):  
Continental Slope ◽  
Reproductive Biology ◽  
Size Structure ◽  
Depth Range ◽  
South Eastern ◽  
Species Overlap ◽  
Eastern Australia ◽  
Prey Items ◽  
South Eastern Australia ◽  
Depth Distributions

The distribution, abundance, size structure, reproductive biology and diet of warty oreo, Allocyttus verrucosus (Gilchrist), and spiky oreo, Neocyttus rhomboidalis (Gilchrist), from the continental slope region (400-1200 m depth) of south-eastern Australia are described. The depth distributions of the two species overlap, with spiky oreo being more abundant in intermediate depths (600-800 m) and warty oreo abundance peaking at greater depths (900-1200 m). There was evidence of size structuring with depth. Warty oreo juveniles and subadults were comparatively more abundant in depths of less than 1000 m and adults dominated at greater depths. In spiky oreo, juveniles were largely restricted to the depth range of 700-900 m. Size at 50% maturity in females was 28 and 35 cm for warty and spiky oreos, respectively. Males mature at slightly smaller sizes. Spawning occurs in May–June for warty oreo and between August and October for spiky oreo. Just prior to spawning in warty oreo the sexes appear to segregate by depth, with females becoming progressively more dominant with depth. Both species are benthopelagic feeders, consuming a range of prey items including crustaceans, fish and squid. Salps were also an important component of the diet of spiky oreo.

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