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Wyświetlanie 1-3 z 3
Tytuł:
Long term variation of sardine Sardina pilchardus spawning along the Atlantic coast of Northwest Africa (21–26°N): characterization and spatiotemporal variability in spawning habitat
Autorzy:
Abdelouahab, H.
Berraho, A.
Baibai, T.
Larissi, J.
Charib, S.
Agouzouk, A.
Makaoui, A.
Ettahiri, O.
Errhif, A.
Powiązania:
https://bibliotekanauki.pl/articles/2079005.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
pelagic fish
sardine
Sardina pilchardus
population dynamics
environment change
spawning
sea surface
temperature
Atlantic coast
Opis:
Small pelagic fish such as sardine show strong recruitment variability often associated with environmental changes influencing the spawning process and ultimately, affecting population dynamics. Sardine (Sardina pilchardus, Walbaum 1792) is one of the most exploited pelagic species along the northwest African coast. The main spawning occurs during the cold season (autumn—winter). A time-series autumn—winter surveys extending from 1994 to 2015 sampled sardine eggs, along the southern area of the Moroccan Atlantic coast (26°N—21°N) were analyzed. The present work focuses on examining the inter-annual variability of the spawning habitat by analyzing the spatial-temporal variability of sardine egg distribution and density extracted from the data collected over the period 1994—2015. Generalized additive models (GAM) were used to detect the relationships between the sardine distribution, expressed as egg density and the presence or absence data and relevant hydrobiological environmental variables, such as salinity, temperature and zooplankton biomass. The generalized additive models showed significant relationships between the environment variables (SST, SSS and Zooplankton biomass) and sardine density, but not with sardine presence. Given that the study area is characterized by high mesoscale features and significant upwelling activities, the variability of upwelling processes could explain the changes of spawning ground position and thermal window
Źródło:
Oceanologia; 2021, 63, 1; 1-11
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Annual reproductive cycle in two free living populations of three-spined stickleback (Gasterosteus aculeatus L.): patterns of ovarian and testicular development
Autorzy:
Sokolowska, E.
Kulczykowska, E.
Powiązania:
https://bibliotekanauki.pl/articles/47889.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
free living population
stickleback
gonad
environment change
reproductive cycle
wild population
Oliva Stream
natural habitat
fresh water
breeding
Vistula River
Gasterosteus aculeatus
spermatogenesis
vitellogenesis
Opis:
The annual reproductive cycle in two wild populations of three-spined stickleback was studied. Sticklebacks from the Dead Vistula River (Martwa Wisła) (brackish water) and the Oliva Stream (Potok Oliwski) (freshwater) were exposed to annual environmental changes in their natural habitats. Ovaries and livers (females), and testes and kidneys (males) were collected during 1–2 years. The gonadosomatic IG, hepatosomatic IH, nephrosomatic IN indices, kidney epithelium height (KEH) and size of oocytes were calculated. The number of mature oocytes and percentage of ovulating females were determined during the spawning season. Histological changes in the ovaries and testes were described throughout a year. Annual reproductive cycles were similar in both populations of sticklebacks. This is the first histological and morphological study carried out throughout a year, simultaneously in two wild populations of three-spined sticklebacks inhabiting different environments. An improved scale of gonadal development in conjunction with the determined indices and fecundity give a comprehensive description of the reproductive cycle. These newobserv ations, in combination with previously reported features, provide a universal scale that can be successfully used to distinguish all phases of gametogenesis in sticklebacks in different habitats.
Źródło:
Oceanologia; 2006, 48, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative studies on the morphometry and physiology of European populations of the lagoon specialist Cerastoderma glaucum (Bivalvia)
Autorzy:
Tarnowska, K.
Wolowicz, M.
Chenuil, A.
Feral, J.-P.
Powiązania:
https://bibliotekanauki.pl/articles/48074.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
ecophysiology
Baltic Sea
morphometry
bivalve
lagoon
European population
Cerastoderma glaucum
physiological parameter
seasonal change
adaptation
Mediterranean Sea
cockle
North Sea
Bivalvia
Opis:
Seasonal changes in the morphometric and physiological parameters of the cockle Cerastoderma glaucum (Bivalvia) from the Baltic Sea (GD), the North Sea (LV), and the Mediterranean Sea (BL) were investigated. The cockles from GD were much smaller than those from other populations due to osmotic stress. The female to male ratios did not differ significantly from 1 : 1. The northern populations (GD, LV) had a monocyclic reproductive pattern, whereas the southern population (BL) seemed to reproduce throughout the year. Seasonal changes in the contents of biochemical components appeared to be correlated with changes in trophic conditions and the reproductive cycle. Protein content was the highest in spring for all the populations. The highest lipid contents and lowest carbohydrate contents were noted in GD and BL in spring, while no marked differences were noted among seasons in LV (probably because the data from both sexes were pooled). Respiration rates in GD were the highest among the populations, which could have been due to osmotic stress. High metabolic rates expressed by high respiration rates in GD and LV in spring and autumn could have resulted from gamete development (in spring) and phytoplankton blooms (in spring and autumn).
Źródło:
Oceanologia; 2009, 51, 3; 437-458
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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