Prosjektnummer
900717
Understanding the reproductive cycle of the green sea urchin Strongylocentrotus droebachiensis in Norway: A guide for fishermen, aquaculturalists and researchers
Results achieved
The guidebook is intended to be used as a guide for anybody with a need to understand, or an interest, in the reproductive cycle of sea urchins. It includes the following:
• a description of the reproductive cycle of sea urchins;
• the factors that cause variations in the size and quality of the gonad; • methods for sampling sea urchin gonads; and
• a guide to reading the histology slides of sea urchin gonads in order to be able to classify them into the different stages of the reproductive cycle.
In order to further assist with this process Appendix One shows examples of histology slides taken from the two populations. These clearly show the general pattern associated with the reproductive cycle of sea urchins but also the enormous variation that can occur between populations.
The authors hope that this guide will enable those working with sea urchins to follow the reproductive cycle of selected populations and that it will contribute significantly to the knowledge of the reproductive cycle of sea urchins that occur in various populations around the coast of Norway.
In Norwegian
• a description of the reproductive cycle of sea urchins;
• the factors that cause variations in the size and quality of the gonad; • methods for sampling sea urchin gonads; and
• a guide to reading the histology slides of sea urchin gonads in order to be able to classify them into the different stages of the reproductive cycle.
In order to further assist with this process Appendix One shows examples of histology slides taken from the two populations. These clearly show the general pattern associated with the reproductive cycle of sea urchins but also the enormous variation that can occur between populations.
The authors hope that this guide will enable those working with sea urchins to follow the reproductive cycle of selected populations and that it will contribute significantly to the knowledge of the reproductive cycle of sea urchins that occur in various populations around the coast of Norway.
In Norwegian
Den ferdige håndboken er ment brukt som en veiledning for alle som har behov for å forstå eller har interesse av å lære om kråkebollenes reproduksjonssyklus. Følgende er omtalt:
• en beskrivelse av kråkebollenes reproduksjonssyklus
• faktorer som påvirker størrelses- og kvalitetsvariasjon på rognen
• metoder for å ta prøver av gonader og
• en innføring i hvordan man tolker histologiske snitt med tanke på å bestemme reproduksjonsstadier.
• en beskrivelse av kråkebollenes reproduksjonssyklus
• faktorer som påvirker størrelses- og kvalitetsvariasjon på rognen
• metoder for å ta prøver av gonader og
• en innføring i hvordan man tolker histologiske snitt med tanke på å bestemme reproduksjonsstadier.
For å kunne være til videre hjelp med dette har man i vedlegg 1 tatt med eksempler på histologiske snitt fra de to kråkebollepopulasjonene som er beskrevet. Disse viser tydelig hvordan både generelle sesongvariasjoner og variasjon mellom populasjoner påvirker reproduksjonssyklusen til kråkebollene.
Forfatterne håper at denne håndboken vil sette de som arbeider med kråkeboller i stand til å følge utvalgte kråkebollepopulasjoners reproduksjonssyklus og at den vil bidra til økt kunnskap om reproduksjonssyklusene til forskjellige populasjoner langs kysten av Norge.
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Sluttrapport: A Guide to the Sea Urchin Reproductive Cycle and Staging Sea Urchin Gonad Samples
Nofima. Av Philip James og Sten Siikavuopio.
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Sluttrapport: En innføring i kråkebollens reproduksjonssyklus og bestemmelse av reproduksjonsstadie basert på gonadeprøver
Nofima. Av Philip James og Sten Siikavuopio.
Background
An important aspect of fishing for wild sea urchins, enhancing the roe of wild caught sea urchins and growing sea urchins from eggs to market size is to have a thorough understanding of the reproductive cycle of the species. This allows fisherman and farmers to know when wild animals are in good condition for collection, export and roe enhancement. It also provides information on the timing of spawning events of both captive and wild stocks. This is essential as urchins cannot be collected and sold during the spawning period.
For sea urchin roe enhancement activities it is important to understand and control the reproductive cycle so that a consistent supply of sea urchin roe can be achieved throughout the year. For sea urchin farmers (rearing sea urchins from eggs to market) it is critical to follow the reproductive stage of the broodstock animals to provide continuity of gametes throughout the breeding season and possibly throughout the year.
For sea urchin roe enhancement activities it is important to understand and control the reproductive cycle so that a consistent supply of sea urchin roe can be achieved throughout the year. For sea urchin farmers (rearing sea urchins from eggs to market) it is critical to follow the reproductive stage of the broodstock animals to provide continuity of gametes throughout the breeding season and possibly throughout the year.
Because of the lack of a regular, consistent historical sea urchin fishery in Norway there is relatively little knowledge of the timing of the reproductive cycle of the various sea urchin populations along the Norwegian coastline. This includes such basic knowledge as the spawning periods for sea urchins along the latitudinal gradient found in Norway (i.e. spawning periods from south to north may differ significantly).
Currently in Norway there are two sea urchin facilities making regular gonad collections in order to monitor the reproductive cycle of sea urchins. These are Troms Kråkebolle AS and Norway Sea Urchin AS. Neither of the facilities have staff with the knowledge, or experience, to read the histology slides and assess the reproductive stage of sea urchins. Troms Kråkebolle AS has previously relied on overseas experts to read the slides, or, more recently Phil James from Nofima, Tromsø. Norway Sea Urchin has only just started collections and will also rely on Phil James to read the slides.
Objectives
To produce a small pamphlet that outlines the reproductive cycle of the green sea urchin and shows the various reproductive stages for male and female sea urchins.
Expected project impact
The result of this project would allow the current as well as any future sea urchin farmers, fishers or researchers to collect sea urchins, make histology slides and assess what reproductive stage the urchins are in and where they are in the reproductive cycle. Over time this will substantially increase the knowledge of spawning times, natural reproductive cycles and processes that control the reproductive cycle along the Norwegian coastline
Project design and implementation
As part of a two year Fellowship Phil James has collected a substantial number of sea urchin roe samples and most of these have now also been converted into histology slides as part of a separate project. In order to complete a series of slides covering the entire reproductive cycle there are still some slides that will need to be processed.
Dissemination of project results
The guide/pamphlet will be available in English and Norwegian versions from FHF's website and the Nofima Capture Based Aquaculture website.
The guide/pamphlet will be available in English and Norwegian versions from FHF's website and the Nofima Capture Based Aquaculture website.
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Sluttrapport: En innføring i kråkebollens reproduksjonssyklus og bestemmelse av reproduksjonsstadie basert på gonadeprøver
Nofima. Av Philip James og Sten Siikavuopio.
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Sluttrapport: A Guide to the Sea Urchin Reproductive Cycle and Staging Sea Urchin Gonad Samples
Nofima. Av Philip James og Sten Siikavuopio.