In vivo exposure to northern diatoms arrests sea urchin embryonic development

• Published in: Toxicon (Oxford) Vol. 109; pp. 63 - 69
• Main Authors: Gudimova, Elena, Eilertsen, Hans C., Jørgensen, Trond Ø., Hansen, Espen
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2016; Elsevier
• Subjects: Animals; Attheya; Biomedical materials; Chaetoceros furcellatus; Chaetoceros socialis; Diatoms; Echinoidea; Echinus acutus; Embryonic Development; Embryos; Exposure; In vivo testing; In vivo tests; Marine; Medical disciplines: 700; Mortality; Northern diatoms; Porosira glacialis; Sea urchin embryo development; Sea urchins; Sea Urchins - embryology; Strongylocentrotus droebachiensis; Surgical implants; Thalassiosira gravida; Toxicity; VDP; Northern diatoms; Toxicity; Sea urchin embryo development
• ISSN: 0041-0101; 1879-3150; 1879-3150
• DOI: 10.1016/j.toxicon.2015.11.001

There are numerous reports indicating that marine diatoms may act harmful to early developmental stages of invertebrates. It is believed that the compounds responsible for these detrimental effects are oxylipins resulting from oxidized polyunsaturated fatty acids, and that they may function as grazing deterrents. Most studies reporting these effects have exposed test organisms to diatom extracts or purified toxins, but data from in vivo exposure to intact diatoms are scarce. We have conducted sea urchin egg incubation and plutei feeding experiments to test if intact diatom cells affected sea urchin embryo development and survival. This was done by exposing the common northern sea urchins Strongylocentrotus droebachiensis and Echinus acutus to northern strains of the diatoms Chaetoceros socialis, Skeletonema marinoi, Chaetoceros furcellatus, Attheya longicornis, Thalassiosira gravida and Porosira glacialis. The intact diatom cell suspensions were found to inhibit sea urchin egg hatching and embryogenesis. S. marinoi was the most potent one as it caused acute mortality in S. droebachiensis eggs after only four hours exposure to high (50 μg/L Chla) diatom concentrations, as well as 24 h exposure to normal (20 μg/L Chla) and high diatom concentrations. The second most potent species was T. gravida that caused acute mortality after 24 h exposure to both diatom concentrations. A. longicornis was the least harmful of the diatom species in terms of embryo development arrestment, and it was the species that was most actively ingested by S. droebachiensis plutei. •Intact common northern diatom cells affects sea urchin embry development and survival.•Diatom cell suspensions inhibited egg hatching and embryogenesis in both Strongylocentrotus droebachiensis and Echinus acutus.•The most toxic species were Skeletonema costatum and Thalassiosira gravida and the least toxic one was Attheya longicornis.•It is believed that the compounds responsible for these detrimental effects are oxylipins.