Aquaculture Europe 2023

September 18 - 21, 2023


Add To Calendar 20/09/2023 14:30:0020/09/2023 14:45:00Europe/ViennaAquaculture Europe 2023PHYSIOLOGICAL EFFECTS OF Gymnodinium catenatum AND Skeletonema marinoi BLOOMS ON THE OYSTER Magallana angulata AN AQUACULTURE PERSPECTIVESchubert 4The European Aquaculture Societywebmaster@aquaeas.orgfalseDD/MM/YYYYaaVZHLXMfzTRLzDrHmAi181982


Rui Cereja1,2*, Joana P.C. Cruz1 , Joshua Heumüller1 , Bernardo Vicente1 , Ana Amorim1,3 , Frederico Carvalho1 , Sara Cabral1 , P aula Chainho1,4 , A na C. Brito1,3 , Inês Ferreira5,6 , M ário S. Diniz5,7.


 1 – MARE—Marine and Environmental Science Centre, ARNET—Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal

2 – IPMA, Division of Aquaculture, Upgrading and Bioprospection (DivAV ), Portuguese Institute for the Sea and Atmosphere (IPMA, I.P.), Av. Doutor Alfredo Magalhães Ramalho 6, 1495-165, Lisboa, Portugal

3 – Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal

4 – CINEA-ESTSetubal, Instituto Politécnico de Setúbal, 2914-508 Setúbal, Portugal

 5 - UCIBIO – Applied Molecular Biosciences Unit, Department of Chemistry, School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal

 6- LAQV-REQUIMTE, Chemistry Department, NOVA School of Science and Technology, Caparica , Portugal

 7- Associate Laboratory i4HB – Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal

*Presenting author: Rui Cereja,



 Bivalves are usually cultured in land tanks connected directly to estuarine and coastal waters. This type of aquaculture exposes the cultured species to possible toxic blooms  that  often  affect these natural ecosystems .  The effects of toxic algae on humans have been  the subject of many studies. However, information on the effects of  these toxic species on bivalve species have been less explored.

Gymnodinium catenatum is a dinoflagellate which produces a saxitoxin like compound, being responsible for paralytic shellfish poisoning. It has been  shown  to cause an increase in antioxidant enzyme activities and oxidative stress in some bivalve species after exposures of 6-12 hours. However, the effect of such  contaminants to short-time exposures has not been  extensively studied . Shorter exposure times are important  to evaluate possible effects into aquacultures, as these types of systems usually allow to close the connection with external water,  thereby reducing the exposure of the  cultured animals .

 Besides toxic algae , o ther species  can  negatively affect  the reared  species. Algae like Skeletonema  spp. Are known  to damage the gills, leading to several health complications in marine animals (Esenkulova et al., 2022) .  In addition to  physical damage, Skeletonema marinoi produces polyunsaturated aldehydes (PUA) when exposed to grazing (Vidoudez et al., 2011) which are toxic to many marine species  (Romano et al., 2011; Tosti et al., 2003) . Nevertheless,  S. marinoi  is commonly used to feed bivalves in aquacultures (Guéguen et al., 2008).

 It has been observed that antioxidant  enzymes  respond  to several contaminants (Cereja et al., 2018; Dias et al., 2019) including algae toxins (Cao et al., 2018) and thus can be used as a physiological stress  indicator  for to toxic algae exposure.

 The  aim  of this study  was to assess the physiological effect  of  short-term  exposure to  G. catenatum and  S. marinoi  in cultured Magallana angulata.

Material and methods

Oysters were collected at an aquaculture farm in the Sado Estuary, Portugal and carried to MARE facilities where they were  allowed  to acclimate in 70L tanks. During the acclimatization period, all oysters were fed with ≈2*109 cells L-1 of a mixture of Tetraselmis sp. and Phaeodactylum sp. For the exposure treatments, both Gymnodinium catenatum and Skeletonema marinoi , were obtained from the algae culture collection  of the Lisbon University (ALISU).

In the experiment, ≈2x107 cells L-1 of Tetraselmis sp. for the control group, ≈4x107 cells L-1 of S. marinoi and ≈1x104 cells L-1 of  G. catenatum for the exposure treatments were added to three tanks, each containing 6 oysters , and allowed  to filter for two hours. Afterwards,  the  six  organisms of each treatment were opened by cutting the adductor muscle. The gills, the digestive gland and the adductor muscle were removed  and  stored at -80 oC.

Subsequently, the s amples were homogenized in PBS buffer saline solution, centrifuged (15 min, 10,000×g at 4°C) and the supernatants used to quantify superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) , acetylcholinesterase (AChE) and total ubiquitin (UBI) and the data was  analysed  using a PerMANOVA.


The results showed significant differences  in both treatments: tissues and treatments.  Gills were the tissue  showing higher biomarkers while the adductor muscle had the lowest levels .  Regarding  the  comparison between treatments, the control treatment presented higher levels of the analysed biomarkers.  S. marinoi treatment presented higher CAT and GST than  G. catenatum treatment.


 The higher biomarker levels  determined  in the control treatment were hypothesized  to  be a consequence of reduced metabolic rates in the two other treatments, although such relation must be confirmed in future studies . The higher CAT and GST activities determined  in the  G. catenatum treatment in comparison to the  S. marinoi treatment was hypothesized to result from detoxication process. These results  suggest  that  G. catenatum may affect the physiology of  M. angulata even in short-term exposures and that live  S. marinoi , which is usually used as aquaculture feed, may also impact  the  M. angulata physiology, probably due to the production of PUA. Further studies must be performed to confirm this  possibility  and if such effect is also  observed  when using dead  S. marinoi as PUA production may differ.


 Cao, R., Wang, D., Wei, Q., Wang, Q., Yang, D., Liu, H., Dong, Z., Zhang, X., Zhang, Q., & Zhao, J. (2018). Integrative Biomarker Assessment of the Influence of Saxitoxin on Marine Bivalves: A Comparative Study of the Two Bivalve Species Oysters, Crassostrea gigas, and Scallops, Chlamys farreri . Frontiers in Physiology , 9.

 Cereja, R., Mendonça , V., Dias, M., Vinagre , C., Gil, F., & Diniz , M. (2018). Physiological effects of cymothoid parasitization in the fish host Pomatoschistus microps (Krøyer , 1838) under increasing ocean temperatures. Ecological Indicators , 95, 176–182.

 Dias, M., Madeira, C., Jogee , N., Ferreira, A., Gouveia, R., Cabral, H., Diniz, M., & Vinagre, C. (2019).  Oxidative stress on scleractinian coral fragments following exposure to high temperature and low salinity. Ecological Indicators , 107, 105586.

Esenkulova , S., Neville, C., DiCicco, E., & Pearsall, I. (2022). Indications that algal blooms may affect wild salmon in a similar way as farmed salmon. Harmful Algae , 118, 102310.

Guéguen , M., Bardouil , M., Baron, R., Lassus , P., Truquet , P., Massardier , J., & Amzil , Z. (2008). Detoxification of Pacific oyster Crassostrea gigas fed on diets of Skeletonema costatum with and without silt, following PSP contamination by Alexandrium minutum . Aquatic Living Resources , 21(1), 13–20.

 Romano, G., Costantini , M., Buttino , I., Ianora , A., & Palumbo, A. (2011). Nitric Oxide Mediates the Stress Response Induced by Diatom Aldehydes in the Sea Urchin Paracentrotus lividus . PLoS ONE , 6(10), e25980.

Tosti , E., Romano, G., Buttino , I., Cuomo, A., Ianora , A., & Miralto , A. (2003).  Bioactive aldehydes from diatoms block the fertilization current in ascidian oocytes. Molecular Reproduction and Development , 66(1), 72–80.

Vidoudez , C., Nejstgaard , J. C., Jakobsen, H. H., & Pohnert , G. (2011). Dynamics of Dissolved and Particulate Polyunsaturated Aldehydes in Mesocosms Inoculated with Different Densities of the Diatom Skeletonema marinoi . Marine Drugs , 9(3), 345–358.