Published 21.09.2023

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Publication details

Journal : Physiological Reports , vol. 11 , p. 1–12 , Thursday 21. September 2023

Publisher : John Wiley & Sons

International Standard Numbers :
Printed : 2051-817X
Electronic : 2051-817X

Publication type : Academic article

Contributors : Mlingi, Frank Thomas; Puvanendran, Velmurugu; Burgerhout, Erik; Tveiten, Helge; Tomkiewicz, Jonna; Kjørsvik, Elin; Mommens, Maren

Issue : 18

Research areas

Quality and measurement methods

Farmed fish

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Kjetil Aune
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The commercial farming of juvenile lumpfish requires monitoring of gonadal development to achieve synchronized production. Conventional methods such as gonadosomatic index (GSI), sex hormone analyses, gonadal histology, endoscopy, and gene expression analyses are costly, invasive, and often involve sacrificing the fish. We assessed the efficiency of ultrasound as a non-invasive method for monitoring gonadal development in lumpfish. Based on ultrasound observations, we categorized the fish into six stages; F0 to F5 for females and M0 to M5 for males, that represented maturity levels from immature to spent. Importantly, the ultrasound gonadal stages aligned with histological gonadal stages. Additionally, ultrasound stages aligned with profiles of GSI, testosterone (T), 11-ketotestosterone, and 17β-estradiol throughout gonadal development including the spawning period. Moreover, these parameters exhibited significant positive correlations with each other reflecting their parallel trends during gonadal development. To minimize the frequency of ultrasound usage and fish handling, we established F3 and M3/M4 as arbitrary thresholds for identifying ripe females and males, respectively. By using these thresholds, the need for regular ultrasound monitoring could be reduced during most of the rearing period. Ultrasound proves to be useful and reliable for monitoring gonadal development in lumpfish, enabling synchronized production of juvenile fish.


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