Factors influencing the diets of four morphologically divergent fish species in nearshore marine waters

The dietary compositions of Atherinomorus ogilbyi (Atherinidae), Sillago schomburgkii (Sillaginidae), Lesueurina platycephala (Leptoscopidae) and Ammotretis elongatus (Pleuronectidae) in three nearshore habitats on the lower west coast of Australia, which varied in their exposure to wave energy and the extent to which they contain sea grass, have been determined. The dietary compositions of these four abundant teleosts differed, reflecting marked differences between the location in the water column, head and mouth morphology and feeding behaviour of these species. Atherinomorus ogilbyi, which has a relatively high and large mouth, fed mainly on planktonic invertebrates in the water column, while S. schomburgkii ingested predominantly benthic prey, such as polychaetes and bivalves, which it extracted from the sediment using its downward-protruding mouth. Lesueurina platycephala employed its large mouth, cryptic coloration and ambush feeding to target relatively large teleosts and invertebrates, while the small mouth and flattened body of Ammotretis elongatus facilitated the ingestion of small crustacean prey, e.g. cumaceans and amphipods, which live on the substrate surface. Atherinomorus ogilbyi consumed predominantly calanoid copepods, cladocerans and insects during the day and mainly amphipods at night, when the latter taxon became abundant in the water column. The dietary composition of each species underwent a similar pattern of size-related change, being most pronounced in L. platycephala during the day. The diets of A. ogilbyi and S. schomburgkii, the two species for which the data were most comprehensive, differed among habitats and seasons, reflecting differences in the densities of their main prey. Comparisons between the day-time diets of the above four species with those recorded previously for a further four abundant species in the same habitats during the day, show that food resources are well distributed among the main fish species in nearshore waters along the lower west coast of Australia. This feature, together with the size-related changes in the diets of the different species, reduces the potential for inter- and intraspecific competition for food by fish species in this environment.

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Effect of extremely severe winters on under-ice phytoplankton development in a mesotrophic lake (Eastern Poland)

Oceanological and Hydrobiological Studies ◽

10.2478/s13545-014-0127-x ◽

2014 ◽

Vol 43 (2) ◽

Cited By ~ 4

Author(s):

Władysława Wojciechowska ◽

Tomasz Lenard

Keyword(s):

Water Column ◽

Dominant Species ◽

Biomass Concentration ◽

Thermal Conditions ◽

Ice Cover ◽

Abundant Species ◽

Blue Green Algae ◽

Cyanobacteria And Algae ◽

Taxonomic Groups ◽

The Vertical Distribution

AbstractThe research was carried out in a mesotrophic and dimictic lake during winters with ice cover. In the last forty years, the development of phytoplankton was analyzed in five extreme winter seasons. The studies of phytoplankton characteristics in the water column took into account values of biomass, concentration of chlorophyll-a and species composition, including dominant species. Differences in the vertical distribution of flagellate and non-flagellate species belonging to cyanobacteria and algae were analyzed in the gradient of light and thermal conditions. The phytoplankton biomass was low and vertically differentiated, with the lowest values at the deeper part of the water column. Flagellate species from the group of Cryptophyceae, Chrysophyceae and Dinophyceae were most abundant. Species biodiversity was low but every winter the dominant species represented different taxonomic groups. In some periods, larger non-motile phytoplankton species from green or blue-green algae dominated. The research proved that the development of phytoplankton under the ice cover was limited mainly by light and, to a lesser extent, by temperature.

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Diversity and abundance of cichlids in Ikere Gorge Reservoir, Iseyin, Oyo State, Nigeria

Zoologist (The) ◽

10.4314/tzool.v18i1.9 ◽

2021 ◽

Vol 18 (1) ◽

pp. 52-56

Author(s):

S.O. Ajagbe ◽

R.O. Ajagbe ◽

O.S. Ariwoola ◽

F.I. Abdulazeez ◽

O.O. Oyewole ◽

...

Keyword(s):

Fish Species ◽

Riparian Forest ◽

Abundant Species ◽

Freshwater Ecosystems ◽

Freshwater Species ◽

Fishing Villages ◽

Gorge Reservoir ◽

Commercially Important ◽

Sarotherodon Galilaeus ◽

Fish Species Diversity

Cichlids are highly abundant and commercially important fish in freshwater ecosystems in Nigeria. This study examined the diversity and abundance of cichlids in Ikere Gorge Reservoir. Four fishing villages were randomly selected from 12 fishing villages in Ikere Gorge Reservoir as sampling sites. Cichlids were sampled randomly and examined from fishermen catch in each selected fishing village; were identified with appropriate keys; the weight and abundance of the catches were recorded. The data obtained was subjected to descriptive statistical analysis using SPSS (Version 20.0) software to determine the abundance of fish species. Fish species diversity was carried out by using Palaeontological Statistics (PAST). Eight species of cichlids were sampled in Ikere Gorge but Sarotherodon galilaeus was the most abundant species while the least abundant species was Pelmatolapia mariae. It was observed that, cichlids were abundant in rainy season than in the dry season. Likewise, cichlids were abundant in Ikere-gorge reservoir but they have low diversity. This may be as a result of unsustainable fishing pressure and deforestation of riparian forest and sedimentation in Ikere-gorge reservoir. Therefore, to maintain sustainable fishing activities and improve cichlids population in Ikeregorge reservoir, unsustainable activities in and around Ikere Gorge reservoir should be put under control. Keywords: Cichlidae; freshwater species; dominant; Sarotherodon galilaeus; Pelmatolapia mariae.

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

Brazilian Journal of Biology ◽

10.1590/s1519-69842007000300008 ◽

2007 ◽

Vol 67 (3) ◽

pp. 433-445 ◽

Cited By ~ 17

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.

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Length-weight relationships of three fish species from Kerala waters, south-west coast of India

Journal of Applied Ichthyology ◽

10.1111/jai.13485 ◽

2017 ◽

Vol 33 (6) ◽

pp. 1308-1309 ◽

Cited By ~ 1

Author(s):

S. K. Roul ◽

A. R. Akhil ◽

T. B. Retheesh ◽

D. Prakasan ◽

U. Ganga ◽

...

Keyword(s):

Fish Species ◽

West Coast ◽

West Coast Of India ◽

South West ◽

South West Coast

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Suprabenthic crustacean fauna of a denseAmpeliscacommunity from the English Channel

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400040881 ◽

1996 ◽

Vol 76 (4) ◽

pp. 909-929 ◽

Cited By ~ 18

Author(s):

Jean-Claude Dauvin ◽

Souaad Zouhiri

Keyword(s):

Atlantic Ocean ◽

Water Column ◽

Vertical Migration ◽

Fine Sand ◽

Abundant Species ◽

Sexually Dimorphic ◽

English Channel ◽

Free Swimming ◽

Sea Bottom ◽

Sea Bed

Ninety-six species (97, 677individuals) were collected over the course of 6 h in five suprabenthic sledge hauls from a very denseAmpeliscafine sand community from the Bay of Morlaix (western English Channel). All the species migrated into the water column at night (98% of the specimens collected in the suprabenthos were found in the night hauls). The 23 most abundant species collected were classified into five groups based on their height within the water column, but two groups predominated: the upper suprabenthic species, abundant at 0–80–145 m above the sea-bed; and the lower suprabenthic species which were abundant only near the sea bottom (-0–1–0–75 m high). Three different patterns of nocturnal vertical migration were distinguished based on the timing of maximum swimming activity: at dusk; at the beginning of the night; or later in the night. Sexually dimorphic patterns of free-swimming behaviour was observed inAmpeliscaand some other species of Amphipoda (Bathyporeia teniupes, Metaphoxusfultoni), and Cumacea (Bodotria pulchella, Pseudocuma longicornis), with many more males than females migrating into the water column at night. Finally, the density of suprabenthic crustaceans in nocturnal hauls was amongst the highest reported from infralittoral or circalittoral suprabenthic studies on other parts of the Atlantic Ocean sampled during spring.

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