scholarly journals La distribución del ictioplancton está directamente relacionada con la hidrodinámica de una región y el comportamiento de desove de los adultos. En este estudio buscamos mapear las zonas de mayor ocurrencia de ictioplancton observadas en la Bahía de São Marcos, que tiene una de las mayores amplitudes de marea en la Costa Amazónica, Brasil. El ictioplancton fue recolectado mediante una técnica de arrastre horizontal en la capa superficial, utilizando una red de rodillos cónicos con malla de 300 μm acoplada a un medidor de flujo, para estimar el volumen de agua filtrada en la Bahía de São Marcos (Complexo Estuarino de São Marcos - CESM, Maranhão) . La densidad se calculó a partir de la relación entre el número total de huevos y larvas en cada muestra y el volumen de agua filtrada. Las fuentes de Ictioplancton se consideraron continuas y se organizaron para representar de forma asincrónica las condiciones de distribución. Para ello se realizó utilizando el polígono de Voronoi para determinar la forma espacial del área de operación de todos los puntos de muestreo. El uso de CESM, como lugar de desove y cría de larvas de peces, se verificó en todas las épocas del año, con mayor densidad de huevos en la época de lluvias y mayor densidad de larvas durante la época seca. La ubicación de las mayores densidades de ictioplancton varió, con las concentraciones más altas más cerca del canal sureste del CESM en la estación seca, moviéndose hacia el centro en la estación lluviosa. El canal sureste del CESM era, por tanto, un área de cría de muchas especies de peces, lo que requería una acción prioritaria para la protección del medio ambiente.

2020 ◽  
Vol 9 (10) ◽  
pp. e9229109238
Author(s):  
Rômulo de Araújo Soares ◽  
Júlio Cesar Martins Ribeiro Júnior ◽  
Paula Cilene Alves da Silveira ◽  
Raimunda Fortes Carvalho Neta ◽  
Audalio Rebelo Torres Junior
Keyword(s):  
Fish Larvae ◽  
Central Area ◽  
Spawning Behavior ◽  
Dry Period ◽  
Management Actions ◽  
Spawning Site ◽  
Sampling Points ◽  
Spatial Shape ◽  
Para Determinar ◽  
Eggs And Larvae

The occurrence of ichthyoplankton is associated to the hydrodynamics and spawning behavior of adults. In this study we aimed to detect regions of concentration of ichthyoplankton in São Marcos Bay, which has macro tidal amplitudes in Amazon Coast, Brazil. Ichthyoplankton was acquired by way of drag technique, using with 300 μm mesh. The density was obtained considering the number of eggs and larvae in filtered water. The sources of Ichthyoplankton were defined continuous and organized to denote the asynchronously the distribution conditions. To this was done using Voronoi polygon to determine the spatial shape of the region of operation of all sampling points. The use of CESM, as a spawning site and breeding fish larvae, was verified at all times of the year, with a higher density of eggs in the wet period and a higher density of larvae during the dry period. The position of the higher ichthyoplankton densities varied, considering concentrations in the area at south-east channel of the CESM in the rainless period, going to the central area in the wet period. The southeast of CESM is, therefore, a nursery for fish, requiring environmental management actions.

Geographic and ontogenetic variations in parasite communities of intertidal fish species from the south-eastern Pacific coast

2020 ◽  
Vol 94 ◽  
Author(s):  
N.V. Leiva ◽  
G. Muñoz ◽  
M.T. González
Keyword(s):  
Fish Species ◽  
Parasite Species ◽  
Fish Larvae ◽  
Geographical Area ◽  
Central Area ◽  
Geographic Ranges ◽  
Northern Area ◽  
Parasite Communities ◽  
Intertidal Fish ◽  
Mature Fish

Abstract Parasite composition can be affected by physiological and ecological changes during host ontogeny. Intertidal fish do not travel long distances and live in the same area throughout their lifetimes, meaning that parasite communities can differ across geographic ranges. The objective of this study was to analyse the parasite communities of three fish species (Hypsoblennius sordidus, Helcogrammoides cunninghami and Scartichthys viridis) collected from the Chilean coast. The composition of parasite species was compared among host ontogenetic stages (larvae, juveniles and mature fish) and geographic areas. A total of 184 larval, 252 juveniles and 217 mature individuals were collected in the northern area (c. 24°S), and 186 larval, 192 juveniles and 112 mature individuals from the central area (c. 33°S). Ectoparasites were most prevalent in fish from the central area, whereas endoparasites were most prevalent in the northern area. The parasite species richness varied significantly between geographical areas for H. sordidus and H. cunninghami, but the parasite composition varied significantly between geographical areas for all fish species analysed. Therefore, the geographical area was the most important factor determining the parasite composition of intertidal fish species. The absence of endoparasites in fish larvae and the increased infestation in juvenile and mature fish may be explained by the shift in habitat from the water column to intertidal pools where prey abundance and availability are higher. On the other hand, hydrographic barriers affecting prey distributions may also offer an explanation as to the differences in parasite composition.

Influences of Anadromous Spawning Behavior and Optimal Environmental Conditions Upon Striped Bass (Morone saxatilis) Year-Class Success

1980 ◽  
Vol 37 (2) ◽  
pp. 143-154 ◽  
Author(s):  
R. E. Ulanowicz ◽  
T. T. Polgar
Keyword(s):  
Striped Bass ◽  
Environmental Conditions ◽  
Transport Model ◽  
Transition Probabilities ◽  
Morone Saxatilis ◽  
Spawning Behavior ◽  
Two Factors ◽  
Model Year ◽  
Eggs And Larvae ◽  
Potomac Estuary

An analysis of the spatial and temporal abundance patterns of developing striped bass (Morone saxatilis) ichthyoplankton stages in the Potomac Estuary, including a Markovian description of transport, indicates that annual differences in the distribution of spawning fish are not likely to account wholly for the wide fluctuations in year-class success. Year-class success can be decomposed into the product of two factors — one extrinsic, acting upon the eggs and larvae, and the other, a behavioral property of the adult stock. The effect of extrinsic environmental conditions upon year-class success can be measured relative to the maximum computed survival of eggs to post-finfold larvae among all locations and times during a given year. Apparently, the behavior of the spawning adult fish is not well matched with the environmental conditions favorable to ichthyoplankton survival, and therefore, the actual spawning distribution yields only a fraction (the spawning fitness) of the maximum production possible during that year. Spawning fitnesses were estimated to be small (< 0.02 out of 1.0) and varied by less than a factor of two over the three seasons observed. In contrast, the year-class success as measured by post-finfold production differed 35-fold over the same 3 yr. It appears most likely that the large range in success is due primarily to the extrinsic, density-independent environmental factors which determine the optimum survivals in combination with spawning behavior. However, no strong case can be made for behavioral compensation by spawning fish to offset changes in the annual optimum survival conditions for ichthyoplankton.Key words: anadromous, ichthyoplankton development, Markovian transition probabilities, optimal survival, spawning behavior, spawning fitness, striped bass, transport model, year-class success

Ichthyoplankton community of the Dardanelles Strait, Turkey

2017 ◽  
Vol 46 (3) ◽  
Author(s):  
İsmail Burak Daban ◽  
Ahsen Yüksek
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Teleost Fish ◽  
Dominant Species ◽  
Fish Larvae ◽  
The Other ◽  
Fish Eggs ◽  
One Year ◽  
Eggs And Larvae ◽  
Fish Eggs And Larvae

AbstractAn ichthyoplankton survey was conducted between March 2012 and February 2013 along the Anatolian coast of the Dardanelles Strait, with the aim of describing the species composition and temporal variation of fish eggs and larvae. For this purpose, monthly samples were collected at three sites using a WP-2 plankton net equipped with 500 µm mesh during a one-year period. Biodiversity indices were calculated to understand differences in biodiversity. A total of 50 teleost fish species belonging to 25 families and 7 orders were identified. The highest species richness of fish eggs was recorded in spring, whereas the highest species richness of fish larvae – in spring and summer. On the other hand, species richness of fish eggs and larvae were at a minimum in the fall. The most dominant species recorded in the Dardanelles were

Survival of Young Fish in the Discharge Canal of a Nuclear Power Plant

1971 ◽  
Vol 28 (7) ◽  
pp. 1057-1060 ◽  
Author(s):  
Barton C. Marcy Jr.
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Fish Larvae ◽  
Juvenile Fish ◽  
Water System ◽  
Cooling Water ◽  
Young Fish ◽  
Discharge Canal ◽  
Sampling Points

No young fish of nine species entrained in the condenser cooling-water system of a nuclear power plant survived passage to the lower end of the plant's 1.83-km (1.14-mile) discharge canal when water temperatures were above 30 C. Temperatures in the canal remained above 30 C during 95% of the period during which the fish larvae and juveniles were collected near the plant's intake. A field observation device was developed to keep alive for counting those larvae and juvenile fish that survived passage to sampling points in the system.

scholarly journals DUGAAN DAERAH PEMIJAHAN IKAN NAPOLEON (Cheilinus undulatus, RUPPELL, 1835) DI SEKITAR PERAIRAN KEPULAUAN ANAMBAS

2017 ◽  
Vol 22 (3) ◽  
pp. 147 ◽  
Author(s):  
Amran Ronny Syam ◽  
Mujiyanto Mujiyanto ◽  
Masayu Rahmia Anwar Putri
Keyword(s):  
Fish Larvae ◽  
Fish Population ◽  
Fish Abundance ◽  
Ocean Currents ◽  
Visual Census ◽  
Seed Collection ◽  
Spawning Site ◽  
Spawning Area ◽  
In The Wild ◽  
Net Cage

Kelimpahan ikan Napoleon di alam sangat rendah, namun larvanya muncul setiap tahun di sekitar perairan Kepulauan Anambas. Saat ini ikan Napoleon yang berukuran satu kilogram masih banyak ditemukan dari hasil pemeliharaan dalam Keramba Jaring Tancap dan Karamba Jaring Apung.  Kajian terhadap keberadaan larva/juvenil ikan Napoleon dan lokasi pemijahan di alam merupakan salah satu indikator dalam upaya mempertahankan keberlanjutan hidup populasi ikan napoleon. Tujuan penelitian ini adalah untuk menduga daerah pemijahan ikan Napoleon di alam berdasarkan ukuran larva/juvenil ikan Napoleon yang tertangkap di alam dan pola arus di sekitar perairan tersebut.  Metode yang digunakan adalah Sensus visual (UVC), enumerasi hasil tangkapan benih dan penentuan pola arus laut di sekitar daerah penangkapan benih. Daerah pemijahan ikan Napoleon belum diketahui pasti. Berdasarkan pola arus laut dan keberadaan larva ikan Napoleon yang berukuran 0,5 inci, dapat diduga pemijahan ikan Napoleon di alam berlangsung tidak jauh dari lokasi ditemukannya larva tersebut, yaitu 1. Tanjung Datuk, 2.Pulau Tembuk, 3. Tanjung Ikan, 4.Teluk Nipah, 5.Teluk Pau, dan 6. Tanjung Sing. Populasi ikan Napoleon dewasa di perairan sekitar Kabupaten Anambas tergolong rendah, namun kemunculan benih ikan Napoleon dapat terjadi setiap tahun terutama pada Oktober/Nopember atau Januari dan Februari. The adult of Napoleon wrasse fish abundance in nature is very low, but the larvae can be found almost at year-round  in the Anambas waters. Currently, napoleon wrasse of one kilogram weight is still found in the fixed net cage and floating net cage. Study on the larva/juvenile existence and spawning site in nature is one of the keys indicators to maintain the sustainability of fish population. The methods used were the visual census (UVC), enumerating the seed catch and identify the pattern of ocean currents around the seed collection area. Spawning area of Napoleon wrasse fish could not exactly be determined yet. Based on the pattern of ocean currents and the smallest size of fish larvae that were found, the spawning site of Napoleon wrasse fish in the wild was estimated to be in around the occurrence location of Napoleon wrasse larvae, namely 1. Tanjung Datuk, 2. Tembuk Island, 3 Tanjung Ikan, 4. Teluk Nipah, 5.Teluk Pau, and 6.Tanjung Sing. The population of adult Napoleon fish in the waters around Anambas was relatively low, but the emergence of Napoleon wrasse larvae can occurs annually, especially in October- November or January-February.  

scholarly journals Ichthyoplankton distribution and abundance off southeastern and southern Brazil

2004 ◽  
Vol 47 (4) ◽  
pp. 601-612 ◽  
Author(s):  
Débora Martins de Freitas ◽  
José Henrique Muelbert
Keyword(s):  
Coastal Waters ◽  
Fish Larvae ◽  
Bottom Layer ◽  
Brazilian Coast ◽  
Fish Eggs ◽  
Near Shore ◽  
Partial Overlap ◽  
Eggs And Larvae ◽  
Distribution Of Fish ◽  
Fish Eggs And Larvae

This study describes the distribution of fish eggs and larvae along the southeastern and southern Brazilian coast. Plankton samples were collected at 85 stations using a Bongo net, and water salinity and temperature were profiled with a CTD. Results showed that fish eggs and larvae, and zooplankton biovolume were distributed in coastal waters with mean temperature of 23ºC and salinity between 33 and 34. The largest egg abundance occurred along Iguape (24º'S) with a partial overlap with zooplankton biovolume and fish larvae were most abundant near shore close to Santos (24ºS). These protected coastal waters presented a surface layer with lower salinity and higher temperatures, while the bottom layer had cooler water. Ichthyoplankton abundance was low off Cabo Frio (22º'S), while a maximum in fish eggs occurred around Cabo Santa Marta Grande (28ºS).

scholarly journals Comparison of temporal and spatial variation of periphytic algal community in two urban lakes in Umuarama-PR (Brazil)

2020 ◽  
Vol 42 ◽  
pp. e94
Author(s):  
Rodrigo Felipe Bedim Godoy ◽  
Elias Trevisan ◽  
Enzo Luigi Crisiogiovanni ◽  
Matheus Haddad Nudi ◽  
Carlos Eduardo Porto ◽  
...  
Keyword(s):  
Water Resources ◽  
Water Sample ◽  
Spatial Variation ◽  
Algal Community ◽  
Ammoniacal Nitrogen ◽  
Dry Period ◽  
Temporal And Spatial Variation ◽  
Sampling Points ◽  
Temporal And Spatial ◽  
Living Organisms

Water resources are very important for all living organisms, and as being of vital importance need to be preserved. Thus, many water bodies are monitored as an essential strategy for identification of possible alterations over space and time. The analyses were performed in two different hydrological conditions, and water sample and rocks were collected in two different points at each lake. The results showed higher values of Ammoniacal Nitrogen in Aratimbó Lake, mainly during dry period (Ammoniacal Nitrogen = 4.2 mgL-1) at P1. However, P2 at Tucuruvi Lake presented higher concentration of Orthophosphate (2.24 mgL-1). Total Periphyton density also demonstrated variation among the different hydrological scenarios and lakes. The Highest density was of 385.30 10³ ind.cm-2at Aratimbó Lake and 180.43 10³ ind.cm-2at Tucuruvi Lake in rainy condition. Comparing the predominance of species, In Aratimbó Lake, Chlorophyceae class was predominant at P1, while Cyanophyceae class was predominant at P2. In dry period, Bacillarophyceae class was seen as the predominant class for both of lakes and for all sampling points. Differently from Aratimbó Lake, in Tucuruvi Lake Bacillarophyceae class was predominant in both of hydrological scenarios.

Summer ichthyoplankton, food supply of fish larvae and impact of invasive ctenophores on the nutrition of fish larvae in the Black Sea during 2000 and 2001

2005 ◽  
Vol 85 (3) ◽  
pp. 537-548 ◽  
Author(s):  
A.D. Gordina ◽  
Ju.A. Zagorodnyaya ◽  
A.E. Kideys ◽  
L. Bat ◽  
H.H. Satilmis
Keyword(s):  
Black Sea ◽  
Coastal Waters ◽  
Negative Impact ◽  
Fish Larvae ◽  
Late Summer ◽  
The Black Sea ◽  
Species Number ◽  
Mnemiopsis Leidyi ◽  
Short Period ◽  
Eggs And Larvae

Qualitative composition and abundance of both ichthyoplankton and small forms of zooplankton were evaluated by field studies in the northern (the Crimea near Sevastopol) and southern (Sinop region and TEEZ) Black Sea during the summers 2000 and 2001. A tendency of increasing the species richness, abundance of fish eggs and larvae as well as zooplankton (which is the food for fish larvae) was observed over a period of Mnemiopsis leidyi and Beroe ovata co-existence. The eggs and larvae of the Mediterranean migrants—bonito and bluefish appeared again in the coastal waters near Sevastopol, which testified to favourable conditions for the spawning and nutrition of these fish species and their larvae. Aborigen copepod Oithona nana was found in the Crimean coastal waters although earlier in the 1990s it had completely vanished. Although rare in the 1990s copepods Centropages ponticus and Paracalanus parvus appeared in inshore waters as well as Pontellids species. Observed increases in species number and abundance of both ichthyoplankton and small zooplankton (≤500 μm), which promoted survival and development of fish larvae, were attributed to reduced predatory impact of Mnemiopsis on prey zooplankton after the arrival of Beroe in the late 1990s. However, the influence of Mnemiopsis continued to be significant during the short period of its peak occurrence in late summer. When this period coincided with the appearance of fish larvae, a negative impact on their survival could be predicted due to a low concentration of food items for larvae feeding.

scholarly journals Spatial variability in the icthyoplankton structure of a subtropicalhypersaline lagoon

2016 ◽  
Vol 64 (2) ◽  
pp. 149-156 ◽  
Author(s):  
Judson da Cruz Lopes da Rosa ◽  
Mariana Dantas Alberto ◽  
Wanda Maria Monteiro Ribas ◽  
Maria Helena Campos Baeta Neves ◽  
Lohengrin Dias de A. Fernandes
Keyword(s):  
Spatial Variability ◽  
Fish Species ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
High Salinity ◽  
Fish Larvae ◽  
Reproductive Season ◽  
Uneven Distribution ◽  
Eggs And Larvae ◽  
Spatial And Temporal Analyses

Abstract The Lagoa de Araruama is a hypersaline ecosystem inhabited by distinct fish species, either permanently or during their reproductive season. Over recent years, some significant environmental changes have been observed in this ecosystem related to the sewage runoff, as salinity decrease (from 64 to 41 psu during the last 40 years) and nutrients increase. As both changes are thought to affect the ichthyoplankton assemblage, the present study aimed to evaluate all the potential relationships between salinity disruption and fish larvae distribution. Ichtyoplankton samples were collected monthly from January 2010 to March 2011 at eight sites in Araruama Lagoon by means of a WP2 plankton net equipped with a flowmeter. During this period, low egg densities were coincident with high salinity regions, suggesting that adults are avoiding to release their eggs under less favorable environmental conditions to the larvae. The uneven distribution of eggs and larvae inside the lagoon, as revealed by both spatial and temporal analyses lead us to suggest that changes in salinity have influenced the reproductive rhythms of those fish species that depend upon the Lagoa de Araruama.

scholarly journals Spatial distribution of dairy heifers’ dung in silvopastoral systems

2019 ◽  
Vol 49 (10) ◽  
Author(s):  
Roberta Aparecida Carnevalli ◽  
Andrea Cristina Tavares de Mello ◽  
Luciano Shozo ◽  
Steben Crestani ◽  
Admar Junior Coletti ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Transition Period ◽  
Central Area ◽  
Experimental Period ◽  
Dry Period ◽  
Mato Grosso ◽  
Rainy Period ◽  
Full Sunlight ◽  
Dairy Heifers ◽  
Distribution Mapping

ABSTRACT: Ruminants vary their walking trajectory according to the positioning of the trees in integrated systems, which can determine the concentration of dung deposition at certain locations. The aim of this study was to map the distribution of feces and the behavior of dairy heifers in sunny and shaded areas. This experiment was carried out in Mato Grosso, Brazil, where the main grazing conditioner is shade due to the presence of trees in the pastures. Shading levels used were: full sunlight (control), moderate shade (338 trees ha−1) and intensive shade (714 trees ha−1) in randomized complete blocks. The experimental period was divided into three evaluation periods based on rainfall distribution: rainy period = December 2012; transition period = March 2013 and dry period = June 2013. Animal behavior assessments and dung distribution mapping were performed. The full sunlight system displayed a higher concentration of feces patches at sites near the gate, cow drinkers and fences opposite the gate. Heifers picked shaded places for ruminating and idleness. The major concentration was reported in the central area and under trees, in shaded systems. There were places with greater feces concentrations, but when the pasture had trees, deposition did not only happen underneath trees but also in places under their influence. The distribution was more homogeneous when trees were present in large quantities. The shaded area available in pastures affects spatial distribution of dung, stimulating uniformity.

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