Search results for "Clupea"
showing 8 items of 18 documents
Seasonal dynamics of atlantic herring (Clupea harengus L.) populations spawning in the vicinity of marginal habitats
2014
Published version of an article from the journal PLoS One. Also available from the publisher: http://dx.doi.org/10.1371/journal.pone.0111985 Gillnet sampling and analyses of otolith shape, vertebral count and growth indicated the presence of three putative Atlantic herring (Clupea harengus L.) populations mixing together over the spawning season February–June inside and outside an inland brackish water lake (Landvikvannet) in southern Norway. Peak spawning of oceanic Norwegian spring spawners and coastal Skagerrak spring spawners occurred in March–April with small proportions of spawners entering the lake. In comparison, spawning of Landvik herring peaked in May–June with high proportions f…
Growth and emigration of third-stage larvae of Hysterothylacium aduncum (Nematoda: Anisakidae) in larval herring Clupea harengus
2000
The growth and emigration of Hystherothylacium aduncum in laboratory-reared herring larvae Clupea harengus was studied. Experimental infections of 36-day-old herring larvae resulted in 126 hosts infected with 306 H. aduncum larvae. Regression analyses showed a significant worm emigration from the rectum to the head of the fish, accompanied by an increase in worm body length. The emigration was independent of worm intensity, which suggests an ontogenetic process. Some worms departed from this pattern by moving posteriorly or by penetrating into the muscle, and in 5 cases, the larvae were observed to leave living fish. This individual variation has not been observed in previous studies and mi…
Reņģes (Clupea harengus) nobarotība un to ietekmējošie faktori Rīgas jūras līcī
2018
Pētījumā veikta reņģu (Clupea harengus) nobarotības un to ietekmējošo faktoru analīze Rīgas līcī, balstoties uz rūpnieciskajā zvejā ievāktajiem datiem no 1995. līdz 2016. gadam, kā arī no institūta BIOR ievāktajiem ūdens temperatūras un zooplanktona Eurytemora affinis biomasas datiem, un Starptautiskās jūras pētniecības padomes datiem par reņģu krājuma biomasu. Nobarotība reņģēm analizētajā periodā bija ļoti mainīga pa gadiem, jo to ietekmēja vairāki faktori - ūdens temperatūra un barības bāze bija vieni no galvenajiem faktoriem. Lielākās nobarotības izmaiņas bija novērojamas jaunākām un mazākām zivīm. Nobarotības pētījumi sniedz iespēju labāk raksturot reņģu krājumu stāvokli un to mijiedar…
Individual habitat transitions of Atlantic herring Clupea harengus in a human-modified coastal system
2015
Published version of an article from the journal: Marine Ecology Progress Series. Also available from Inter Research. Http://dx.doi.org/10.3354/meps11103 Pelagic marine fish often display highly dynamic migration patterns. However, such movement behaviour is usually studied at the population or school level, while less is known about individual movement characteristics and habitat transitions. During March 2012 to June 2013, we used acoustic tags and moored receivers to monitor the behaviour of Atlantic herring Clupea harengus L. (N = 47) throughout a range of habitats on the Skagerrak coast in southern Norway. Five of the tagged herring entered a former lake transformed into an artificial …
Sensitivity of different early developmental periods of Baltic herring (Clupea harengus) to water-accommodated fraction of crude oil
2013
The probability for the oil accident to occur at the Gulf of Finland has been increasing last ten years and it is predicted to continue so. The risk is high based on the accident probability and the probable harm caused; some spawning areas of the Baltic herring (Clupea harengus membras) are located in the vicinity of ports and ship fairways with heavy traffic, so any oil spillage there could affect recruitment of this commercially important species. In this study, newly fertilized embryos, the older embryos and the hatched larvae of Baltic herring were exposed to water-accommodated fraction (WAF) made from crude oil. Oil exposure increased most the mortality of the hatched larvae, and larv…
High Lipid Content of Prey Fish and n−3 PUFA Peroxidation Impair the Thiamine Status of Feeding-Migrating Atlantic Salmon (Salmo salar) and Is Reflec…
2022
Signs of impaired thiamine (vitamin B1) status in feeding-migrating Atlantic salmon (Salmo salar) were studied in three Baltic Sea areas, which differ in the proportion and nutritional composition of prey fish sprat (Sprattus sprattus) and herring (Clupea harengus). The concentration of n−3 polyunsaturated fatty acids (n−3 PUFAs) increased in salmon with dietary lipids and n−3 PUFAs, and the hepatic peroxidation product malondialdehyde (MDA) concentration increased exponentially with increasing n−3 PUFA and docosahexaenoic acid (DHA, 22:6n−3) concentration, whereas hepatic total thiamine concentration, a sensitive indicator of thiamine status, decreased with th…
Data from: Seasonal dynamics of Atlantic herring (Clupea harengus L.) populations spawning in the vicinity of marginal habitats
2015
Gillnet sampling and analyses of otolith shape, vertebral count and growth indicated the presence of three putative Atlantic herring (Clupea harengus L.) populations mixing together over the spawning season February–June inside and outside an inland brackish water lake (Landvikvannet) in southern Norway. Peak spawning of oceanic Norwegian spring spawners and coastal Skagerrak spring spawners occurred in March–April with small proportions of spawners entering the lake. In comparison, spawning of Landvik herring peaked in May–June with high proportions found inside the lake, which could be explained by local adaptations to the environmental conditions and seasonal changes of this marginal hab…
It takes time to see the menu from the body: an experiment on stable isotope composition in freshwater crayfishes
2015
For many applications and ecological studies in which wild individuals are brought to laboratory it would be essential to know accurately how fast novel diet is reflected in composition of different tissues. To study the effects of two different diets on the stable isotope composition of freshwater crayfish muscle and hemolymph, we conducted a three month experiment on noble crayfish (Astacus astacus) and signal crayfish (Pacifastacus leniusculus) by feeding them sweet corn (Zea mays) or Baltic herring (Clupea harengus membras) as novel food. During the experiment, the crayfish were given 0.4 g of selected food daily and the amount consumed was recorded. The samples for the stable isotope a…