Potential chemical defenses of Antarctic sponges against sympatric microorganisms

Cytotoxic Activity of Antarctic Benthic Organisms Against the Common Sea Urchin Sterechinus neumayeri

“…Similar toxicity results have been observed in mycalosides isolated from congeneric Caribbean sponge M. laxissima, which inhibited the fertilization of eggs by sperm of the sea urchin Strongylocentrotus nudus [61]. On the other hand, other studies carried out by Peters and collaborators [19] showed that M. acerata inhibited the growth of the bacteria Alteromonas elyakovi. Moreover, different species of the genera Iophon and Isodictya caused mortality in diatoms.…”

“…Although this group is also an important source of natural products with pharmaceutical properties [23], few studies have focused on the chemical interactions that these compounds play in the ecosystems [19,30,33,64,72,73]. In particular, some colonial and solitary ascidians possess chemical defenses to protect them from predators [20,64,72].…”

“…Below anchor ice and ice scour (<30 m), the particular physical environment of these communities is relatively constant, being these benthic organisms structured mainly by biological factors, such as predation and competition [8,11]. All this makes it likely that many of the organisms inhabiting these waters have evolved chemical mechanisms to avoid predation [12][13][14][15], competition for space or food [16,17] and fouling [18][19][20][21][22], thus creating a complex chemical ecological network [23][24][25].…”

Algicidal activity and potential antifouling defenses in macroalgae from the western Antarctic Peninsula including probable synergistic effects of multiple compounds

“…The strain utilized has also been used in several related studies with extracts of algae and invertebrates collected from the Antarctic Peninsula (McClintock et al 2004, Amsler et al 2005b, Peters et al 2010, Koplovitz et al 2011 ) and was chosen because small pennate diatoms are commonly observed epibionts on macroalgae and invertebrates in these communities (C. Amsler, personal observations). Only the seawater insoluble component of the lipophilic extract was assayed from Gymnogongrus turquetii because the hydrophilic extract was lost during preparation.…”

“…Bioassays were performed using Falcon 3070 96-well, culture treated plates (Becton, Dickinson and Company, Franklin Lakes, NJ, USA). In order to avoid drying of extract onto the vertical surfaces of the wells, solubilized extracts were transferred to the well in multiple aliquots that covered only the bottom (Peters et al 2010, Koplovitz et al 2011. Each aliquot was dried under reduced air pressure before the next aliquot was applied.…”