Relationship between Food, Fat, Sexual Maturation, and Spawning Time of Baltic Herring (Clupea harengus membras) in the Archipelago Sea

1992 ◽  
Vol 49 (4) ◽  
pp. 644-654 ◽  
Author(s):  
Marjut Rajasilta

The effect of nutritional status on gonad maturation and timing of spawning was examined in the Baltic herring (Clupea harengus membras) in the Archipelago Sea. Fish were collected from overwintering areas in December and from the spawning grounds in May–July. Muscle fat content, amount of mesenteric fat, and condition factor were used as indicators of nutritional status of fish. In winter, fish were highly variable with substantial individual variation in nutritional status, gonad stage, gonad weight, and gonadosomatic index (GSI). Gonad weight was related to fat content, suggesting a close relationship with fish nutritional status and maturation rate. Spawning fish were separable into early and late spawners according to fat content, gonad weight, and GSI but not according to length. The spawning shoals consisted of mixtures of fish of all sizes. I concluded that in the study area, individual maturation cycles vary and timing of spawning is primarily determined by the feeding conditions prior to spawning.

2019 ◽  
Vol 76 (4) ◽  
pp. 576-585 ◽  
Author(s):  
Marjut Rajasilta ◽  
Jari Hänninen ◽  
Lea Laaksonen ◽  
Päivi Laine ◽  
Jukka-Pekka Suomela ◽  
...  

Global climate change can affect the energy content of fish by altering their lipid physiology and consumption. We investigated the effects of different environmental stressors on the lipid content of the Baltic herring (Clupea harengus membras) from spawning ground samples that were collected annually in the northern Baltic Sea. During 1987–2014, the average lipid content of herring muscle decreased from 5%–6% (wet mass) to 1.5% (wet mass). Generalized linear mixed models indicated that sea water salinity and the size of the herring stock explained best the declining trend of lipid content. We estimated that the amount of the lipid storage incorporated in the spawning stock decreased by approximately 45% during the study, with respective energy content decreases. Fatty acid composition analysis revealed that herring lipids contained a high proportion of EPA (eicosapentaenoic acid; 20:5n-3) and DHA (docosahexaenoic acid; 22:6n-3), which likely originated from its main summertime prey, Limnocalanus macrurus. The results illustrate various climate change-induced processes leading to changes in the lipid content of the Baltic herring and, consequently, to changes in the energy flows of the northern Baltic ecosystem.


2014 ◽  
Vol 71 (5) ◽  
pp. 1148-1152 ◽  
Author(s):  
M. Rajasilta ◽  
J. Hänninen ◽  
I. Vuorinen

Abstract The stomach contents of the herring (Clupea harengus membras L.) from the Bothnian Sea, northern Baltic, were analysed during spring 2011 and 2013. The stomachs were full of Limnocalanus macrurus in May and June, and an improvement in the condition of herring was observed when fish started to feed on this prey. The analyses showed that Limnocalanus is currently an important link between lower trophic levels and Baltic herring in the Bothnian Sea.


Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1631
Author(s):  
Robert Gustafsson ◽  
Ulrich Eckhard ◽  
Weihua Ye ◽  
Erik D. Enbody ◽  
Mats Pettersson ◽  
...  

Phosphoglucomutase 5 (PGM5) in humans is known as a structural muscle protein without enzymatic activity, but detailed understanding of its function is lacking. PGM5 belongs to the alpha-D-phosphohexomutase family and is closely related to the enzymatically active metabolic enzyme PGM1. In the Atlantic herring, Clupea harengus, PGM5 is one of the genes strongly associated with ecological adaptation to the brackish Baltic Sea. We here present the first crystal structures of PGM5, from the Atlantic and Baltic herring, differing by a single substitution Ala330Val. The structure of PGM5 is overall highly similar to structures of PGM1. The structure of the Baltic herring PGM5 in complex with the substrate glucose-1-phosphate shows conserved substrate binding and active site compared to human PGM1, but both PGM5 variants lack phosphoglucomutase activity under the tested conditions. Structure comparison and sequence analysis of PGM5 and PGM1 from fish and mammals suggest that the lacking enzymatic activity of PGM5 is related to differences in active-site loops that are important for flipping of the reaction intermediate. The Ala330Val substitution does not alter structure or biophysical properties of PGM5 but, due to its surface-exposed location, could affect interactions with protein-binding partners.


2013 ◽  
Vol 70 (6) ◽  
pp. 1108-1117 ◽  
Author(s):  
Tomas Gröhsler ◽  
Rainer Oeberst ◽  
Matthias Schaber ◽  
Niklas Larson ◽  
Georgs Kornilovs

Abstract Gröhsler, T., Oeberst, R., Schaber, M., Larson, N., and Kornilovs, G. 2013. Discrimination of western Baltic spring-spawning and central Baltic herring (Clupea harengus L.) based on growth vs. natural tag information. – ICES Journal of Marine Science, 70: 1108–1117. In the Baltic Sea, several stocks of herring (Clupea harengus L.) are surveyed and managed separately. For assessment purposes, a spatial stock separation based on ICES subdivisions is implemented. However, especially in the western Baltic, the distribution areas of two stocks, the western Baltic spring-spawning herring and the central Baltic herring, overlap. Results of regularly conducted surveys for assessment purposes indicated variable degrees of mixing of both stocks in the survey area, based on conspicuous differences in weights/lengths within certain age groups, especially in an area known for overlapping distribution of both stocks. At present, varying fractions of the central Baltic herring stock have not been taken into account during regular surveys conducted in the western Baltic, leading to possible undetected biases in assessment indices derived from these surveys. Additionally, methods otherwise applied for stock separation of Baltic herring so far are based on parameters that cannot readily be derived during regular surveys. In this paper, we present a simple and quick method to reliably allocate herring to either stock based on a separation function derived from survey-based length-at-age data, thus facilitating a more precise estimate of biomass and abundance indices from regular surveys and commercial fisheries.


2009 ◽  
Vol 57 (4) ◽  
pp. 263-272 ◽  
Author(s):  
Hilda Caramantin-Soriano ◽  
Luz Amelia Vega-Pérez ◽  
Miguel Ñiquen

The influence of the 1992-1993 El Niño events on the reproductive behavior of the Scomber japonicus peruanus (Chub mackerel) was studied from samples collected monthly, along the Peruvian coast (3º23'S-14º00'S), from January 1990 to December 1993. The monthly variation of the gonadosomatic index and the frequency of the periods of gonad maturation evidenced that the spawning of the species occurred all year long, being more intense in summer. The values of the gonadosomatic index were higher during the occurrence of the 1992-1993 El Niño, while the body weight and gonad weight decreased. Regarding the condition factor, its values decreased in females over 35 cm in fork length.


1992 ◽  
Vol 49 (10) ◽  
pp. 2045-2054 ◽  
Author(s):  
Rodney G. Bradford ◽  
Robert L. Stephenson

Egg weight varies among northwest Atlantic herring (Clupea harengus) populations that spawn in different seasons (n = 12), but the range in weights is less than half of that known for northeast Atlantic populations. Egg weights were similar for both spring (May–June)- and autumn (August–October)-spawning herring (1.06 ×) and most dissimilar between spring- and summer (July)-spawning herring (1.21 ×). Mean population egg weights were not correlated with temperature either at spawning or for the last 2 mo of the egg development period. The product of egg weight and fecundity (standardized to length) differed between spring- and autumn-spawning herring of the southern Gulf of St. Lawrence. Spring-spawners, particularly smaller fish [Formula: see text], have lower ripe ovary weights than do autumn-spawning herring. Differences between spawning seasons in the relative allocation of storage energy to gonad and metabolism, a process mediated by the duration of the gonad maturation period, are the likely basis for the observed patterns.


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