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Reproductive performance of farmed Arctic charr

Jeuthe, Henrik (2015). Reproductive performance of farmed Arctic charr. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2015:30
ISBN 978-91-576-8258-1
eISBN 978-91-576-8259-8
[Doctoral thesis]

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Abstract

The production of farmed Arctic charr (Salvelinus alpinus) has increased rapidly over the last decade, and the industry is predicted to continue to grow in the coming years. One major bottleneck for this future expansion concerns the supply of viable eggs and juveniles. Hatching rates of Arctic charr eggs in aquaculture are generally much lower than for other farmed salmonids, and exhibit a large variation between individuals and years. The aim of this thesis is to evaluate current hatchery conditions and to deepen the understanding on how environmental and biological factors affect the reproductive performance of Arctic charr in routine farming. The thesis comprises four separate studies.

In paper I, records of biological and environmental variables and individual egg survival data from an Arctic charr hatchery, covering a period of 12 years, were analysed in an attempt to find single and combined factors that can explain some of the variation in egg survival. Rearing temperature during summer was identified as the most critical factor for reproductive success of the current broodstock. The study also revealed strong positive relationships between female age, egg size, and egg viability, most likely enhanced by the thermal stress experienced by the broodstock.

Paper II assessed broodstock rearing temperature and egg viability over a period of 28 years with focus on thermal stress in a changing climate. Mean summer water temperatures in the hatchery increased by approximately 2°C from 1986 to 2010. The temperature increase was most evident in July but was also apparent in May, August, and September. Egg survival was most closely linked to September temperatures, which indicates that it is not necessarily the warmest days that are the most detrimental.

Paper III is a study on egg incubation temperature, and the first, to my knowledge, to show that the initial stages of embryogenesis in Arctic charr are much more cold-sensitive than later in the incubation period. Incubations initiated at low temperature (2.3°C to 2.8°C) resulted in significantly higher mortality and deformity rates.

Paper IV is a case study which assessed hormonal status and gamete quality of male and female Arctic charr during routine artificial fertilisation. Female plasma levels of maturation inducing hormone during stripping indicated that post-ovulation aging of oocytes can explain part of the egg loss. The results also suggest that the paternal effect on reproductive performance of the current broodstock is considerable.

Authors/Creators:Jeuthe, Henrik
Title:Reproductive performance of farmed Arctic charr
Series/Journal:Acta Universitatis agriculturae Sueciae (1652-6880)
Year of publishing :2015
Depositing date:14 April 2015
Volume:2015:30
Number of Pages:50
Papers/manuscripts:
NumberReferences
IJeuthe, H., Brännäs, E., Nilsson, J. (2013). Effects of egg size, maternal age and temperature on egg viability of farmed Arctic charr. Aquaculture 408-409, 70-77.
IIJeuthe, H., Brännäs, E., Nilsson, J. (2015) Thermal stress in Arctic charr Salvelinus alpinus broodstock: a 28-year case study. Journal of Fish Biology 83, 1139-1152.
IIIJeuthe, H., Brännäs, E., Nilsson, J. Effects of variable egg incubation temperatures on the embryonic development in Arctic charr Salvelinus alpinus (submitted manuscript).
IVJeuthe, H., Schmitz, M., Brännäs, E. A case study on hormonal status and gamete quality of Arctic charr Salvelinus alpinus broodstock at stripping (manuscript).
Place of Publication:Umeå
Publisher:Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-8258-1
ISBN for electronic version:978-91-576-8259-8
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L53 Animal physiology - Reproduction
M Aquatic sciences and fisheries > M12 Aquaculture production
M Aquatic sciences and fisheries > M40 Aquatic ecology
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Ecology
(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Developmental Biology
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Fish and Aquacultural Science
Agrovoc terms:salvelinus alpinus, aquaculture, animal breeding, reproduction, ova, embryonic development, viability, environmental factors, temperature
Keywords:Salmonidae, aquaculture, breeding, environmental factors, egg quality, sperm quality, fertilisation, embryogenesis
URN:NBN:urn:nbn:se:slu:epsilon-e-2562
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-2562
ID Code:12115
Faculty:S - Faculty of Forest Sciences
Department:(S) > Dept. of Wildlife, Fish and Environmental Studies
Deposited By: Henrik Jeuthe
Deposited On:14 Apr 2015 12:19
Metadata Last Modified:10 Feb 2016 08:14

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