Growth dynamics and bioactivity variation of the Mediterranean demosponges Agelas oroides (Agelasida, Agelasidae) and Petrosia ficiformis (Haplosclerida, Petrosiidae)

Abstract

Growth dynamics and bioactivity variation of the Mediterranean demosponges Agelas oroides and Petrosia ficiformis were investigated over 15 months at Paraggi and Colombara within the Marine Reserve of Portofino Promontory (Mediterranean Sea, Ligurian Sea, Italy). For both species, growth rates varied between individuals and were unaffected by initial sponge size. The two species showed a different trend in growth pattern: A. oroides did not vary significantly between seasons, sites and depths; in contrast, some individuals of P. ficiformis showed a seasonal pattern, shrinking during winter as water temperature decreased and growing during summer when water temperature increased. Differences in growth between the two species may result from different reproductive cycles, food availability, species‐specific thermophily and patterns of spatial competition. Moreover, spatial competition probably induced sponges to produce bioactive secondary molecules. Spatial and temporal variation of bioactivity of both species was examined for the first time by studying its effect on human neuroblastoma cells. The bioactivity of A. oroides extracts differed significantly between seasons, sites and depths, whereas the cytotoxicity of P. ficiformis differed significantly between seasons and depths (differences for sites were not determined). These results suggest the possible influence of environmental factors on bioactive metabolite biosynthesis.

Biochemical Trade-Offs: Evidence for Ecologically Linked Secondary Metabolism of the Sponge Oscarella balibaloi

“…On the other hand, two other common Mediterranean species, Agelas oroides and Petrosia ficiformis , displayed also a higher bioactivity in winter whereas in summer the bioactivity was lower or absent [18]. It was often hypothesized, but never proved, that variations of sponge chemical defenses can be driven by internal physiological factors, thus resulting from trade-offs with primary biological functions such as growth and/or reproduction [2], [9], [10], [18], [19], [27], [48], [49]. These “internal” factors may act together with other biotic factors, such as competition for space [20], [21], [22], [23], and a number of abiotic factors (i.e.…”

“…Measurements of the bioactivity were often used as indicators in order to determine the baseline variations of the secondary metabolism [13], [14]. Spatial and temporal variations of bioactivity and concentrations of some secondary metabolites were already documented in few sponges, ascidians, and other sessile marine invertebrates [9], [15], [16], [17], [18], [19]. Natural variations were mostly explained by ecological and environmental factors, like biotic interactions [20], [21], [22], [23], habitat type, temperature, depth or salinity [15], [16], [18], [24], [25], [26], whereas the link with the organisms' life cycle (growth, reproduction) or its physiological state was rarely investigated [2], [9], [18], [27], [28].…”

Phylogeny Drives Large Scale Patterns in Australian Marine Bioactivity and Provides a New Chemical Ecology Rationale for Future Biodiscovery

“…Previous workers have sought to relate specific bioactivity to ecological function and small scale environmental gradients [47], [48] and use ecology and biology to explain intraspecific variability [33], [47], [48], [49], [50], [51], [52], [53]. However, there are no published studies that comprehensively integrate a diverse range of biodiversity and bioactivity measurements across vast bioregional and phylogenetic gradients.…”

Marine Microorganism-Invertebrate Assemblages: Perspectives to Solve the “Supply Problem” in the Initial Steps of Drug Discovery

“…Attempts to enhance secondary metabolism in mariculture included stress treatments, which were successfully applied to increase the production of avarol [80] and latrunculin B [81]. Other factors reported to influence metabolite concentration include location, depth and seasonality [82,83]. …”