Reviews in Aquaculture (2014) 6, 1–21 doi: 10.1111/raq.12068 Rearing European brown shrimp (Crangon crangon, Linnaeus 1758): a review on the current status and perspectives for aquaculture Daan Delbare1, Kris Cooreman1 and Guy Smagghe2 1 Animal Science Unit, Research Group Aquaculture, Institute for Agricultural and Fisheries Research (ILVO), Ostend, Belgium 2 Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium Correspondence Abstract Daan Delbare, Animal Science Unit, Research Group Aquaculture, Institute for Agricultural The European brown shrimp, Crangon crangon, is a highly valued commercial and Fisheries Research (ILVO), Ankerstraat 1, species fished in the north-eastern Atlantic, especially the North Sea. The shrimp 8400 Ostend, Belgium. fisheries are mainly coastal and exert high pressures on the local ecosystems, Email: [email protected] including estuaries. The culture of the species provides an alternative to supply a niche market (large live/fresh shrimps) in a sustainable manner. However, after Received 5 February 2014; accepted 5 June more than a century of biological research on this species, there is still little 2014. knowledge on its optimal rearing conditions. C. crangon remains a difficult spe- cies to keep alive and healthy for an extended period of time in captivity. This review is based on a comprehensive literature search and reflects on the current status of experimental rearing techniques used for this species, identifies the prob- lems that compromise the closing of the life cycle in captivity and provides exam- ples on how these problem issues were solved in the culture of commercial shrimp species or other crustaceans. The ability to consistently produce high- quality offspring could initiate the commercial production of this valuable shrimp. A further advantage of the ability to consistently produce high-quality offspring of this species would facilitate research on the development of new bio- assays with this ecologically and economically important species in a wide variety of biochemical and physiological studies. Key words: cannibalism, Crangon crangon, disease, formulated feed, nutritional requirements, production techniques. reach 80 individuals per m2 in intertidal pools and shallow Introduction water; Boddeke et al. 1986) and as epibenthic predator on a The European brown shrimp, Crangon crangon, is an omni- wide range of organisms, such as worms, amphipods, present inhabitant of the shallow coastal shelf region in the schizopods, copepods, cyprid larvae of Balanus, snails, north-eastern Atlantic from northern Norway to the Atlan- young mussels and even juvenile fish (Ehrenbaum 1890; tic coast of Morocco, including the White Sea, the Baltic Herdman 1892; Havinga 1930; Plagmann 1939; Van der Sea, the Mediterranean Sea and the Black Sea (Plagmann Veer & Bergman 1987). 1939; Tiews 1970; Kuipers & Dapper 1984; Gibson et al. Crangon crangon is also economically a valuable target 1995; Spaargaren 2000). Recently (first observations in species. A fishing fleet of more than 600 vessels from six 2003), C. crangon has also colonized the west and south countries (Belgium, Denmark, France, Germany, the Neth- coasts of Iceland (Gunnarsson et al. 2007). erlands and the UK) lands annually more than 30 000 tons Crangon crangon is ecologically an important species, of commercial shrimp (>50 mm total length, TL), repre- due to its central place in the food web: as prey organism senting approximately € 100 million (Hufnagl 2009; FAO for many marine species and birds within its distribution 2013). The primary product is shrimp that was boiled on area (Herdman 1892; Gilis 1952; Kuhl€ 1956, 1961, 1963a,b, board in a traditional way in sea water with addition of salt, 1964a,b; Tiews 1965), as competitor for spawning area, subsequently resulting in a limited product range (boiled food supply and shelter space (juvenile abundance can shrimp) which is very sensitive to spoilage and has a short © 2014 Wiley Publishing Asia Pty Ltd 1 D. Delbare et al. shelf life. Traditional peeling is carried out on a small-scale, ing water temperature (Fig. 1) within the range of 6–21°C local and immediately transported for consumption, but (Wear 1974). the bulk of the boiled product is transported for peeling The duration of the larval development is also positively (using hand or peeling machine) within or outside Europe. correlated with the water temperature. But according to The processed shrimp require therefore a thorough conser- Criales and Anger (1986), this is only true for temperatures vation treatment to prolong the shelf life (Broekaert et al. between 9 and 18°C. They observed that at 9°C, the survival 2011). The processed product is sold at a retail price rate was 32% with a moulting frequency of 5 times, while À between 21.1 and 39.9 € kg 1 in Belgium, the Netherlands at 15°C, it took between 5 and 9 moults before reaching the and Luxembourg (Aviat et al. 2011). first juvenile stage with a survival of 70%, but with Despite the high commercial value of the species, little increased frequency of stunted forms. attention has been given to improve the breeding tech- niques. This paper reviews the current status of rearing Salinity C. crangon, by combining the existing knowledge on its Although C. crangon is generally considered as an euryha- reproduction biology and breeding techniques. We also line species, this is only true for the juveniles (75% sur- tried to identify gaps of knowledge and major problems to vival at a salinity of 5 ppt; Cieluch et al. 2004) and succeed in closing the life cycle in captivity, and where pos- adults. Hagerman (1970) observed that the haemolymph sible, we provided solutions by proposing techniques and of adult C. crangon was almost iso-osmotic with the med- husbandry strategies that are used in the intensive culture ium at a salinity of 21–23 ppt. On the other hand, larvae of commercial crustaceans. The aquaculture production of exhibit a much narrower salinity tolerance, with high sur- C. crangon has the opportunity to continuously supply the vival rates between 17 and 32 ppt. Slower development market with big size and high-quality live specimens in a rates were observed at salinities below 25 ppt (Criales & sustainable manner. Anger 1986) and survival decreased rapidly in media below 10 ppt (Cieluch et al. 2004). According to Criales and Anger (1986), the optimum salinity for larvae at Husbandry conditions 12°C was 32 ppt, while survival was significant lower and Water quality and light regime the periods between development stages longer at 25 and 37 ppt, respectively. Temperature The maturation process is also influenced by the salinity. Temperature has a major influence on the development In experiments carried out by Gelin et al. (2001), adult and metabolic rate of poikilothermal organisms, such as females reared at 25 ppt became ovigerous after 32 days, crustaceans, with higher metabolic rates at higher tempera- while it took 80 days at 15 ppt and no female became ovi- tures, within an optimal range. Subsequently, temperature gerous at 5 ppt. The fecundity was also higher in females significantly influences embryogenesis, larval and juvenile reared at 25 ppt, compared with specimens reared at growth, feeding incidence, moulting, reproduction and sur- 15 ppt. vival. As in most crustaceans, copulation takes place just after the female has moulted (Nouvel 1939; Lloyd & Yonge 1947; Tiews 1954). Subsequently, the frequency of moulting and its incubation period will determine the number of spawns within the breeding period. Meixner (1966) observed that females can spawn up to five times (with an average of 3.6 times) within 5 months in captivity at a constant water temperature of 14°C. Hufnagl and Temming (2011) found a clear relation between the moult interval (mi), tempera- ture (T,in°C) and total length (TL, in mm) under labora- tory conditions: 0:7364 0:09363T mi ¼ 5:7066TL e ð1Þ During spawning, the female transfers the fertilized eggs from the genital opening to the pleopods (Lloyd & Yonge Figure 1 Incubation period of C. crangon eggs in relation to tempera- 1947), where the eggs are kept until hatching. The length of ture (after (♦) Havinga 1930; (○) Tiews 1954; (●) Meixner 1969 and (■) the incubation period decreases exponentially with increas- Redant 1978). Reviews in Aquaculture (2014) 6, 1–21 2 © 2014 Wiley Publishing Asia Pty Ltd Rearing techniques for Crangon crangon pH that this can also result in gas bubble disease in crustaceans Studies on effects of abnormal pH values on the develop- (Weitkamp & Katz 1980). ment of crustaceans are scarce. At increased pCO2 levels (1200 latm and pH below 7.8), larvae of Homarus gamma- Light rus (Linnaeus 1758) showed significant higher number of Crangon crangon is mainly active during the night, espe- deformities, such as curled carapace and bent rostrum cially at dusk and dawn (Pihl & Rosenberg 1984; Feller (Agnalt et al. 2013). Under the same conditions, the calcifi- 2006). Dalley (1980) investigated the influence of a circa- cation rate in the larval stages 3 and 4 was significantly dian (12L/12D) and two non-circadian (8L/8D and LD reduced, although there was no direct effect on growth random) light–dark cycles on C. crangon from hatching to (Arnold et al. 2009). As growth in crustaceans occurs the late juvenile stage and observed that during the larval directly after moulting, after which the new shell hardens phase, the survival under non-circadian regimes was signif- with the deposition of calcium carbonate (CaCO3) and icantly lower, 45.6% and 20.8%, respectively, vs. 52.1% at magnesium carbonate (MgCO3), deformities of the cara- circadian regime. This observation supports the hypothesis pace and extremities could be caused by changes in energy that light is an important factor in various physiological fluxes to maintain homoeostasis, which disrupt the normal processes within the animal. There was, however, no evi- deposition of these salts.