scholarly journals Diel variation of larval fish abundance in the Amazon and Rio Negro

2001 ◽  
Vol 61 (3) ◽  
pp. 357-362 ◽  
Author(s):  
C. A. R. M. ARAUJO-LIMA ◽  
V. V. da SILVA ◽  
P. PETRY ◽  
E. C. OLIVEIRA ◽  
S. M. L. MOURA
Keyword(s):  
Larval Fish ◽  
Fish Abundance ◽  
Large Rivers ◽  
Larval Abundance ◽  
Diel Variation ◽  
Larval Drift ◽  
Larval Distribution ◽  
Rio Negro ◽  
One Year

Many streams and large rivers present higher ichthyoplankton densities at night. However, in some rivers this does not occur and larvae are equally abundant during the day. Larval drift diel variation is an important information for planning sampling programs for evaluating larval distribution and production. The aim of this study was to test whether the abundance of larval fish was different at either period. We tested it by comparing day and night densities of characiform, clupeiform and siluriform larvae during five years in the Amazon and one year in Rio Negro. We found that larvae of three species of characiform and larvae of siluriform were equally abundant during day and night in the Amazon. Conversely, the catch of Pellona spp. larvae was significantly higher during the day. In Rio Negro, however, larval abundance was higher during the night. These results imply that day samplings estimate adequately the abundance of these characiform and siluriform larvae in the Amazon, but not Pellona larvae. Evaluations of larved densities of Rio Negro will have to consider night sampling.

Larval fish drift in the Valley River, Manitoba: influence of abiotic and biotic factors, and relationships with future year-class strengths

1995 ◽  
Vol 52 (11) ◽  
pp. 2423-2431 ◽  
Author(s):  
Thomas A. Johnston ◽  
Marc N. Gaboury ◽  
Richard A. Janusz ◽  
Laureen R. Janusz
Keyword(s):  
Larval Fish ◽  
Common Species ◽  
Mature Female ◽  
Larval Abundance ◽  
White Sucker ◽  
Catch Per Unit Effort ◽  
Larval Drift ◽  
Class Strength ◽  
Median Date ◽  
Valley River

We examined patterns in the spring drift of larval fishes in the Valley River, Manitoba. White sucker (Catostomus commersoni) and walleye (Stizostedion vitreum) were the most common species. The median date of larval drift for walleye was significantly earlier than for all other species. Capture rates of all species were significantly greater during the night than during the day. Larval abundance was positively related to river discharge in the 35 d preceding the median date of larval drift. Larval abundance was also positively related to mature female biomass in Dauphin Lake for walleye, but not for white sucker. Year-class strength of a cohort (catch per unit effort of 3- or 4-year-old fish) in Dauphin Lake was positively related to total larval drift of the same cohort (3 or 4 years earlier) in the Valley River for walleye, but not for white sucker. Our results suggest that the year-class strength of Dauphin Lake walleye is determined very early in the life history and that factors which enhance the natural production of walleye larvae will enhance walleye recruitment.

scholarly journals The Larval Fish Fauna of the “Canal de Santa Cruz” - Estuary in Northeast Brazil.

2001 ◽  
Vol 29 (2) ◽  
Author(s):  
Werner EKAU ◽  
Petra WESTHAUS-EKAU ◽  
Silvio José de MACÊDO ◽  
Christian von DORRIEN
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Fish Fauna ◽  
Taxonomic Composition ◽  
Larval Abundance ◽  
Nursery Ground ◽  
Geographical Patterns ◽  
Larval Distribution ◽  
High Concentrations ◽  
Inner Channel

was investigated. The larval distribution in the channel was analysed based on 187 samples from 9 stations collected from November 1993 to May 1994. 50 of these samples were used to investigate the taxonomic composition. Larval densities varied between 0 and 376 ind. per 50 m³. Seasonal and geographical patterns were found. Both in dry and rainy season larval abundance was low at the inner channel. Except a few hauls, most samples did not exceed densities of 25 or 45 ind./50 m³, respectively. High concentrations beyond 100 ind. per 50 m³ were found at station 2, 3 and once at station 8 in the northern part and at station 7 in the southern part of the channel. Engraulidae larvae and different types of Gobiidae were the dominant groups in the channel. These two families reached almost 76% of the whole ichthyoplankton in the catches. They are followed by Achiridae, Clupeidae, Terapontidae, Sciaenidae, Tetraodontoidei, Carangidae, Syngnathidae, Cottidae (?) and Blennioidei (summing up to 95% of the caught fish larvae in the channel). Nearly all groups are found as adults in the channel. Only five families are represented exclusively by larvae: Achiriidae, Cottidae, Terapontidae, Exocoetidae and Ephippidae. From the latter, only Exocoetidae form an oceanic group. Based on the taxa composition, it is assumed, that the importance of the estuary as nursery ground for shelf and oceanic fish is low. Key words: Ichthyoplankton; estuary; larval distribution;

Influence of the aquatic vegetation landscape on larval fish abundance

2015 ◽  
Vol 41 (3) ◽  
pp. 873-880 ◽  
Author(s):  
Philippe Massicotte ◽  
Andrea Bertolo ◽  
Philippe Brodeur ◽  
Christiane Hudon ◽  
Marc Mingelbier ◽  
...  
Keyword(s):  
Aquatic Vegetation ◽  
Larval Fish ◽  
Fish Abundance ◽  
Vegetation Landscape

scholarly journals Epilithic community development on artificial reefs deployed along a cross-shelf environmental gradient off Paraná state, southern Brazil

2011 ◽  
Vol 59 (spe1) ◽  
pp. 43-53 ◽  
Author(s):  
Frederico Brandini ◽  
Ariel Scheffer da Silva
Keyword(s):  
Large Scale ◽  
Diversity Index ◽  
Artificial Reef ◽  
Larval Abundance ◽  
Percent Cover ◽  
Southern Brazil ◽  
Factors Affecting ◽  
Hydrographic Conditions ◽  
One Year ◽  
General Community

Concrete modules were deployed on the bottom of the 11, 18 and 30 meters isobaths along a cross-shelf hydrographic gradient off Paraná State, Southern Brazil, with the purpose of studying the colonization of sessile epilithic macroinvertebrates on artificial surfaces. After one year of submersion a total of 63 species of epilithic organisms were identified, dominated by Ostrea puelchana, Chthamalus bisinuatus, Balanus cf spongicola, Astrangia cf rathbuni, Didemnum spp, poryphers and bryozoans. Diversity index and percent cover at reef stations placed at 11, 18 and 30 meters isobaths were respectively 2.28 and 66.7%, 2.79 and 96.6% and 1.66 and 77.4%. Differences of general community structure among the three assemblages were not clearly related to the general environmental conditions at the bottom layers near the reef stations. Turbidity and larval abundance are discussed as important factors affecting colonization processes. Results indicate that depths between 15-20 meters are more suitable for the implementation of large scale artificial reef systems in the inner shelf off Paraná and, possibly, throughout the inner shelves off southern Brazil with similar hydrographic conditions.

scholarly journals Coastal winds drive a recruitment mechanism for estuarine fisheries

2020 ◽  
Author(s):  
Hayden T. Schilling ◽  
Charles Hinchliffe ◽  
Jonathan P. Gillson ◽  
Anthony Miskiewicz ◽  
Iain M. Suthers
Keyword(s):  
Larval Fish ◽  
Future Research ◽  
Larval Abundance ◽  
Spawning Period ◽  
Onshore Wind ◽  
Larval Recruitment ◽  
Australian Region ◽  
Coastal Winds ◽  
Key Driver ◽  
Catch Rates

AbstractCoastal winds transport larval fish onshore or offshore which may contribute to estuarine recruitment, yet our understanding of the mechanism underlying this relationship is limited. Here, we show that larval abundance of coastally spawned species increased with weak to moderate upwelling favourable winds 14 days prior to sampling, reflecting increased nutrient and plankton availability for larval fish. A strong decline in larval abundance was observed following strong upwelling favourable winds while abundance increased with onshore (downwelling favourable) winds, in relation to offshore and onshore wind-driven transport. Subsequently, we show that effects of wind during the spawning period can be detected in lagged estuarine commercial fisheries catch rates of coastally spawned species (lagged by 2 – 8 years depending on species’ growth rates), representing the same mechanism proposed for larval fish. Upwelling favourable winds in the southeast Australian region have increased since 1850 while onshore winds have decreased, which may reduce larval recruitment to estuaries. Coastal winds are likely an important factor for estuarine recruitment in the east Australian region and future research on the estuarine recruitment of fish should incorporate coastal winds. As global winds are changing, it is important to investigate if this mechanism is applicable to other regions around the world where coastal winds are a key driver of upwelling.

Patterns in larval reef fish distributions and assemblages, with implications for local retention in mesoscale eddies

2018 ◽  
Vol 75 (2) ◽  
pp. 180-192 ◽  
Author(s):  
K. Shulzitski ◽  
S. Sponaugle ◽  
M. Hauff ◽  
K.D. Walter ◽  
E.K. D’Alessandro ◽  
...  
Keyword(s):  
Larval Fish ◽  
Current System ◽  
Age Distribution ◽  
Mesoscale Eddies ◽  
Larval Transport ◽  
Boundary Current ◽  
Straits Of Florida ◽  
Structuring Element ◽  
Larval Distribution ◽  
Species Specific

Benthic marine populations are often replenished by a combination of larvae from local and distant sources. To promote retention of locally spawned larvae in strong, unidirectional boundary current systems, benthic marine organisms must utilize biophysical mechanisms to minimize advective loss. We examined patterns in larval fish abundance, age distribution, and assemblage in relation to environmental variables in the Straits of Florida to better understand the factors underlying larval transport and retention in a boundary current system. Depth was the primary structuring element; larval assemblages were more distinct across vertical distances of tens of metres than they were over horizontal distances of tens to hundreds of kilometres. However, depth distributions were species-specific, and larval assemblages inside and outside of mesoscale eddies were distinct. Age distributions were consistent with the hypothesis that mesoscale eddies provide opportunities for retention. Our data indicate that the effect of eddies on larval retention is likely taxon-specific and temporally variable, as synchronization of reproductive output, larval distribution, and timing of eddy passage are prerequisite to entrainment and subsequent retention of locally spawned larvae.

Comparison of acoustic and Miller high-speed sampler estimates of larval fish abundance in Oneida Lake, New York

2002 ◽  
Vol 57 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Lars G. Rudstam ◽  
Anthony J. VanDeValk ◽  
Mark D. Scheuerell
Keyword(s):  
New York ◽  
High Speed ◽  
Larval Fish ◽  
Fish Abundance ◽  
Oneida Lake

Oceanographic scenario and fish larval distribution off Guinea-Bissau (north-west Africa)

2014 ◽  
Vol 95 (3) ◽  
pp. 435-452 ◽  
Author(s):  
M.P. Jiménez ◽  
R.F. Sánchez-Leal ◽  
C. González ◽  
E. García-Isarch ◽  
A. García
Keyword(s):  
Surface Waters ◽  
Larval Fish ◽  
Fish Larvae ◽  
Inner Shelf ◽  
North West ◽  
Guinea Bissau ◽  
Larval Distribution ◽  
Océanographic Survey ◽  
Continental Runoff ◽  
Abundance And Diversity

This paper describes the hydrography and the larval fish assemblage of Guinea Bissau waters, and analyses the spatial distribution of the main families in relation to the oceanographic features of the area. Data were obtained during an oceanographic survey, undertaken between October and November 2008. In addition to 98 demersal fishing hauls, a total of 33 stations, located between 20 and 1000 m depth, were sampled for hydrography and ichthyoplankton. Data showed that Guinea-Bissauan surface waters are characterized by a strong thermohaline front that flows parallel to the bathymetry of the area. Warm surface waters (SST > 29°C) occupy the inner shelf, and colder (SST < 26°C), chlorophyll-a-rich waters take over the shelf break. Continental runoff seems responsible for the low salinity of the inner-shelf waters whereas the colder types bear thermohaline features typical of tropical Atlantic waters. These features define a scenario which favours the development of fish early life stages, reflected in the high abundance and diversity of fish larvae recorded. A total of 84 taxa of fish larvae were identified. Only the family Clupeidae accounted for 54.8% of the sampled larvae. Other important families were Carangidae (8.8%), Sparidae (8.4%) and Myctophidae (5.9%).

Patterns of larval fish abundance in a bottomland hardwood wetland

Wetlands ◽  
1996 ◽  
Vol 16 (3) ◽  
pp. 288-295 ◽  
Author(s):  
K. Jack Killgore ◽  
John A. Baker
Keyword(s):  
Larval Fish ◽  
Fish Abundance ◽  
Bottomland Hardwood
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