Short profile


FishEthoScore of the species

Abbreviated assessment of the species' likelihood and potential for fish welfare in aquaculture, based on ethological findings for 10 crucial criteria.

Criteria Li Po Ce
1 Home range ? ?
2 Depth range
3 Migration
4 Reproduction
5 Aggregation ? ?
6 Aggression ? ?
7 Substrate
8 Stress ? ?
9 Malformation
10 Slaughter ?
FishEthoScore 0 1 0
Li = Likelihood that the individuals of the species experience welfare under minimal farming conditions
Po = Potential overall potential of the individuals of the species to experience welfare under improved farming conditions
Ce = Certainty of our findings in Likelihood and Potential
 
                    ?     /  
  High    Medium     Low     Unclear  No findings
 
FishEthoScore = Sum of criteria scoring "High" (max. 10)



General remarks

Acipenser stellatus is found in the Black and Caspian seas and connecting rivers, to where it migrates for spawning in spring and summer. It is a critically endangered species [1], driven to near extinction by overfishing, habitat destruction, and disruption of river connectivity. Although it has been in the focus of aquaculture because it is the source of the sevruga caviar, there is a severe lack of knowledge concerning biology and behaviour in the wild (home range, aggregation, aggression for example) and also many aspects of farming (aggression, environmental enrichment, stress, and slaughter). This lack of knowledge not only severely hinders the assessment of its welfare state but also impedes almost any perspective for improvement.


1. Are minimal farming conditions likely to provide the home range of the species? What overall welfare potential can be achieved? How certain are these findings?

?
Likelihood
?
Potential
L
Certainty

LARVAE: WILD: no data found yet. FARM: rectangular troughs: ca 0.2 m3 [2]; ponds: 0.5 ha [3]. For sturgeons in general, rearing tanks or trays: 2-4 m2 [4]. Further research needed to determine whether this applies to A. stellatus as well.

JUVENILES: WILD: no data found yet. FARM: tanks: 25-70 m [5]; ponds: 15-25 ha [3]. For sturgeons in general, ponds: 1-4 ha [4]; cages: 20-100 m2 (15-20 m2 for overwintering) [4]. Further research needed to determine whether this applies to A. stellatus as well.

ADULTS: WILDno data found yet. FARM:  JUVENILES.

SPAWNERS: WILD: no data found yet. FARM: maturation ponds: 0.1 ha [6]. For sturgeons in general, pre-spawn holding in "Kazansky" type earthen ponds: 120-130 m [4] or "Kurinsky" type earthen ponds: 30-60 x 12 m [4]; long-term holding in concrete tanks: 30-50 m2 [4] or cages: 20-100 m2 [4]; overwintering of breeders in plastic and concrete tanks: >40 m3 [4] or "Kurinsky" type concrete ponds: 105 x 17 m or 1,000-4,000 ha separated into different compartments [4]. Further research needed to determine whether this applies to A. stellatus as well.


2. Are minimal farming conditions likely to provide the depth range of the species? What overall welfare potential can be achieved? How certain are these findings?

L
Likelihood
L
Potential
M
Certainty

Eggs: WILD and FARM: no data found yet.

LARVAE: WILD: no data found yet. FARM: tanks: ca 0.2 m3 [2], <50 cm [5]; ponds: 1.8 m [3].

JUVENILES: WILD: shallow habitats during first summer [7]: 3-5 m, winter: 10-80 m [8]. FARM: tanks: <1.5 m [5]; ponds: 1.5-1.8 m [3]. For sturgeons in general, ponds: 2.3-2.5 m [4]; cages: 2.5-3.5 m [4]. Further research needed to determine whether this applies to A. stellatus as well.

ADULTS: WILD: in the sea 3-4 m [9] but can remain at 80-300 m [8] [10], especially in winter [9]. FARM:  JUVENILES.

SPAWNERS: WILD: 4-8 m [11]-[12]. FARM: maturation ponds: 1.2-1.7 m [6]. For sturgeons in general, pre-spawn holding in "Kazansky" type earthen ponds: 0.5-2.5 m [4] or "Kurinsky" type earthen ponds: 1.5-2.5 m [4]; long-term holding in concrete tanks: 2 m [4] or cages: 3-3.5 m [4]; overwintering of breeders in plastic and concrete tanks: >1.5 m [4]. Further research needed to determine whether this applies to A. stellatus as well.


3. Are minimal farming conditions compatible with the migrating or habitat-changing behaviour of the species? What overall welfare potential can be achieved? How certain are these findings?

L
Likelihood
L
Potential
L
Certainty

ANADROMOUS [7].

LARVAE: WILD: riverine habitats, drift downriver with current [7]FARM: fresh water [2] [3]. For details of holding systems  crit. 1 and 2.

JUVENILES: WILD: overwinter in river deltas [13] or migrate to sea during first year, remain there until maturity [7]FARM: fresh water [3] [5]. For details of holding systems  crit. 1 and 2.

ADULTS: WILD: live at sea outside of breeding season [7]FARM: fresh water [5]. For details of holding systems  crit. 1 and 2.

SPAWNERS: WILD: migrate to spawn upriver [7] at 7.5 km/day upstream, and 10-20 km/day downstream when spawning finishes [14]FARM: fresh water [6] [5]. For details of holding systems  crit. 1 and 2.


4. Is the species likely to reproduce in captivity without manipulation? What overall welfare potential can be achieved? How certain are these findings?

L
Likelihood
L
Potential
M
Certainty

WILD: first reproduction at the age of 6-12 years for males, 8-14 for females [8]. Males spawn every 2-3 years, females 3-4 years, in spring-summer and only under stable current conditions [8] [9]. For spawning substrate crit. 7. FARM: hormonal induction of final maturation [6].


5. Is the aggregation imposed by minimal farming conditions likely to be compatible with the natural behaviour of the species? What overall welfare potential can be achieved? How certain are these findings?

?
Likelihood
?
Potential
L
Certainty

LARVAE: WILD: no data found yet. FARM: tanks: ca 6,000-8,000 IND/m3 [2]; ponds: 5,000 IND/ha [3].

JUVENILES: WILD: no data found yet. FARM: ponds: 50-73 IND/ha [3], 10 kg/m3 in high-standard farms. Increasing density does not seem to affect growth but apparently decreases immune response and survival [15]; further research needed to confirm poor quality data.

ADULTS: WILDno data found yet. FARM JUVENILES.

SPAWNERS: WILD: no data found yet. FARM: maturation ponds: ca 1 IND/m2 divided by sex [6].


6. Is the species likely to be non-aggressive and non-territorial? What overall welfare potential can be achieved? How certain are these findings?

?
Likelihood
?
Potential
L
Certainty

LARVAE: cannibalism at 8,000 IND/m3, but not at 6,000 IND/m3 [2].

JUVENILES: no data found yet.

ADULTS: no data found yet.

SPAWNERS: no data found yet.


7. Are minimal farming conditions likely to match the natural substrate and shelter needs of the species? What overall welfare potential can be achieved? How certain are these findings?

L
Likelihood
M
Potential
M
Certainty

Eggs: WILD: adhesive, laid on beds of scattered stones, pebbles, and gravel [7] [10] or in its absence over sand [10] or clay [7]. FARM: undergo a mechanical de-adhesion process [4].

LARVAE: WILD: PELAGIC while in yolk-sac phase (2-3 days), then settle in coarse substrate [9]. FARM: no shelter or enrichment reported in literature; bottom grids in hatching trays may mimic natural conditions [5].

JUVENILES: WILD: at sea use substrate to prey on benthic animals [7], prefer silt and sand [16]FARM: for details of holding systems crit. 1 and 2. Ponds are able to provide natural substrate [5].

ADULTS: JUVENILES.

SPAWNERS: WILD: use substrate to spawn [7], mainly on stony ridges on the riverbed [16]FARM: ponds are able to provide natural substrate [5].


8. Are minimal farming conditions (handling, confinement etc.) likely not to stress the individuals of the species? What overall welfare potential can be achieved? How certain are these findings?

?
Likelihood
?
Potential
L
Certainty

Eggs and LARVAE: no data found yet.

JUVENILES: for stress and stocking density crit. 5.

ADULTS: no data found yet.

SPAWNERS: no data found yet.


9. Are malformations of this species likely to be rare under farming conditions? What overall welfare potential can be achieved? How certain are these findings?

L
Likelihood
M
Potential
M
Certainty

Eggs: morphological deformations, structural malformations of envelope and yolk with overall frequency of 50-100% [17]. Frequencies can be expected to decrease with increasing farming experience [18].

LARVAE: malformations in body shape, internal and external organs, tissue and functional abnormalities, mechanical damages with overall frequency 20-100% [17]. Frequencies can be expected to decrease with increasing farming experience [18].

JUVENILES: structural abnormalities in external organs, internal tissues and structural deformities occur with undescribed frequency [17]. Frequencies can be expected to decrease with increasing farming experience [18].

ADULTS: no data found yet.


10. Is a humane slaughter protocol likely to be applied under minimal farming conditions? What overall welfare potential can be achieved? How certain are these findings?

?
Likelihood
H
Potential
L
Certainty

Common slaughter method: no data found yet. High-standard slaughter method: percussive stunning through manual spiking or percussive gun performed by experienced staff, followed by bleeding [19].


Side note: Domestication

DOMESTICATION LEVEL 4 [20], level 5 being fully domesticated.


Side note: Feeding without components of forage fishery

All age classes: WILD: carnivorous [12] [10] [7] [9]. FARM: fed with live feed supplements, dislike pellets [3]. No replacement of fish meal and fish oil reported in literature. 


Glossary

ADULTS = mature individuals, for details Findings 10.1 Ontogenetic development
ANADROMOUS = migrating from the sea into fresh water to spawn
DOMESTICATION LEVEL 4 = entire life cycle closed in captivity without wild inputs [20]
FARM = setting in farm environment
IND = individuals
JUVENILES = fully developed but immature individuals, for details Findings 10.1 Ontogenetic development
LARVAE = hatching to mouth opening, for details Findings 10.1 Ontogenetic development
PELAGIC = living independent of bottom and shore of a body of water
SPAWNERS = adults that are kept as broodstock
WILD = setting in the wild


Bibliography

[1] Qiwei, W. 2010. Acipenser stellatus. The IUCN Red List of Threatened Species. International Union for Conservation of Nature. https://doi.org/10.2305/IUCN.UK.2010-1.RLTS.T229A13040387.en.
[2] Oprea, Daniel, and Lucian Oprea. 2009. Acquired Results on Rearing of Sevruga Larvae (Acipenser stellatus–Pallas, 1771) in Superintensive System. Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Animal Science and Biotechnologies 66.
[3] Patriche, Neculaí, Constantin Pecheanu, Mircea Vasile, Marlena Talpes, Dan Mirea, María Fetecau, Victor Cristea, and Roland Billard. 2002. Rearing the Stellate Sturgeon Acipenser stellatus in Mono- and Polyculture with Chinese and Common Carps in Ponds. International Review of Hydrobiology 87: 561–568. https://doi.org/10.1002/1522-2632(200211)87:5/6561::AID-IROH5613.0.CO;2-W.
[4] Chebanov, Mikhail S., and Elena V. Galich. 2011. Sturgeon hatchery manual. FAO Fisheries and Aquaculture Technical Paper 558. Ankara: Food and Agriculture Organization of the  United Nations.
[5] Saraiva, João L. 2018. Personal communication.
[6] Semenkova, T., I. Barannikova, D. E. Kime, B. G. McAllister, L. Bayunova, V. Dyubin, and N. Kolmakov. 2002. Sex steroid profiles in female and male stellate sturgeon (Acipenser stellatus Pallas) during final maturation induced by hormonal treatment. Journal of Applied Ichthyology 18: 375–381. https://doi.org/10.1046/j.1439-0426.2002.00368.x.
[7] Kottelat, Maurice, and Jörg Freyhof. 2007. Handbook of European freshwater fishes. Publications Kottelat.
[8] Khodorevskaya, R. P., and Ye. V. Krasikov. 1999. Sturgeon abundance and distribution in the Caspian Sea. Journal of Applied Ichthyology 15: 106–113. https://doi.org/10.1111/j.1439-0426.1999.tb00218.x.
[9] Reinartz, Ralf. 2002. Sturgeons in the Danube river: biology, status, conservation; literature study. IAD.
[10] FAO. 2017. FAO Fisheries Aquaculture - Species Fact Sheets - Acipenser stellatus (Pallas, 1771).
[11] Veshchev, PV. 1994. The Scale of Natural Reproduction of Volga Starred Sturgeon under Current Environmental Conditions. Ekologiya: 59–68.
[12] Zykova, G.F., and Yu. A. Kim. 2017. Acipenser stellatus, Pallas. http://archive.iwlearn.net/www.caspianenvironment.org/www.caspianenvironment.org/CaspBIS/Taxons/Taxon010f.html?taxonid=6. Accessed November 14.
[13] Nelson, Troy C., Phaedra Doukakis, Steven T. Lindley, Andrea D. Schreier, Joseph E. Hightower, Larry R. Hildebrand, Rebecca E. Whitlock, and Molly A. H. Webb. 2013. Research Tools to Investigate Movements, Migrations, and Life History of Sturgeons (Acipenseridae), with an Emphasis on Marine-Oriented Populations. PLOS ONE 8: e71552. https://doi.org/10.1371/journal.pone.0071552.
[14] Kynard, B., R. Suciu, and M. Horgan. 2002. Migration and habitats of diadromous Danube River sturgeons in Romania: 1998–2000. Journal of Applied Ichthyology 18: 529–535. https://doi.org/10.1046/j.1439-0426.2002.00404.x.
[15] Dicu, Maria D, Victor Cristea, Marilena Maereanu, Lorena Dediu, SM Petrea, and others. 2013. The effect of stocking density on growth performance and hematological profile of stellate sturgeon (A. stellatus, Pallas, 1771) fingerlings reared in an industrial ‘flow-through’aquaculture system. Bulletin UASVM Animal Science and Biotechnologies 70: 244–254.
[16] Palatnikov, GM, and RU KASIMOV. 2010. Sturgeons–Contemporaries of Dinosaurs. Baku.
[17] Ruban, G. I., N. V. Akimova, V. B. Goriounova, E. V. Mikodina, M. P. Nikolskaya, V. G. Shagayeva, M. I Shatunovsky, and S. A. Sokolova. 2006. Abnormalities in Sturgeon gametogenesis and postembryonal ontogeny. Journal of Applied Ichthyology 22: 213–220. https://doi.org/10.1111/j.1439-0426.2007.00954.x.
[18] Ruban, G. I., N. V. Akimova, V. B. Goriounova, E. V. Mikodina, M. P. Nikolskaya, A. V. Novosadova, H. K. Rosenthal, S. A. Sokolova, V. G. Shagayeva, and M. I. Shatunovsky. 2015. Atlas of abnormalities in gametogenesis and early life stages of sturgeons. Vol. 7. Special Publication. World Sturgeon Conservation Society.
[19] Anonymous farmers. 2018. Personal communication.
[20] Teletchea, Fabrice, and Pascal Fontaine. 2012. Levels of domestication in fish: implications for the sustainable future of aquaculture. Fish and Fisheries 15: 181–195. https://doi.org/10.1111/faf.12006.