The aim of our research is to design tank systems to culture Dysidea avara for the production of avarol. Flow information was needed to design culture tanks suitable for effective production. Water flow regimes were characterized over a 1-year period for a shallow rocky sublittoral environment in the Northwestern Mediterranean where D. avara sponges are particularly abundant. Three-dimensional Doppler current velocities at 8–10-m depths ranged from 5 to 15 cm/s over most seasons, occasionally spiking to 30–66 cm/s. A thermistor flow sensor was used to map flow fields in close proximity (≈2 cm) to individual sponges at 4.5-, 8.8-, and 14.3-m depths. These “proximal flows” averaged 1.6 cm/s in calm seas and 5.9 cm/s during a storm, when the highest proximal flow (32.9 cm/s) was recorded next to a sponge at the shallowest station. Proximal flows diminished exponentially with depth, averaging 2.6 cm/s ± 0.15 SE over the entire study. Flow visualization studies showed that oscillatory flow (0.20–0.33 Hz) was the most common regime around individual sponges. Sponges at the 4.5-m site maintained a compact morphology with large oscula year-around despite only seasonally high flows. Sponges at 8.8 m were more erect with large oscula on tall protuberances. At the lowest-flow 14.3-m site, sponges were more branched and heavily conulated, with small oscula. The relationship between sponge morphology and ambient flow regime is discussed.

The present publication presents oxygen properties and pumping behaviour of Dysidea avara. Oxygen profiles were measured near and inside the atrial space of the osculum with a Clark-type micro-electrode. Pumping sponges had profiles with oxygen concentrations marginally lower than that of the aquarium water. In contrast, diffusive profiles, with a clear boundary layer above the sponge surface, and oxygen penetrating only 0.5 mm into the sponge tissue, were typically that of a sponge which was not pumping. Diffusive oxygen flux at the sponge surface was 4.2 μmol O2 cm –2 d–1 and the calculated volumetric filtration rate was 0.3 cm3 water cm–3 sponge min–1. The oxygen concentration in the osculum was temporally f luctuating between 95 and 59% saturation at a frequency of approximately once per minute. The combination of static oxygen microelectrode measurements and particle tracking velocimetry (PTV) allowed us to simultaneously observe finescale oxygen fluxes and oscular f low patterns in active sponges, even at extremely low pumping rates. Oscular oxygen concentration and flow were correlated but not always synchronous to the second. Particle tracking velocimetry was used to visualize the f low field around the sponge and to distinguish sponge-generated flow from the unidirectional current in a f low-cell.

The present publication presents oxygen properties and pumping behaviour of Dysidea avara. Oxygen profiles were measured near and inside the atrial space of the osculum with a Clark-type micro-electrode. Pumping sponges had profiles with oxygen concentrations marginally lower than that of the aquarium water. In contrast, diffusive profiles, with a clear boundary layer above the sponge surface, and oxygen penetrating only 0.5 mm into the sponge tissue, were typically that of a sponge which was not pumping. Diffusive oxygen flux at the sponge surface was 4.2 μmol O2 cm2 d1 and the calculated volumetric filtration rate was 0.3 cm3 water cm3 sponge min1. The oxygen concentration in the osculum was temporally fluctuating between 95 and 59% saturation at a frequency of approximately once per minute. The combination of static oxygen micro-electrode measurements and particle tracking velocimetry (PTV) allowed us to simultaneously observe fine-scale oxygen fluxes and oscular flow patterns in active sponges, even at extremely low pumping rates. Oscular oxygen concentration and flow were correlated but not always synchronous to the second. Particle tracking velocimetry was used to visualize the flow field around the sponge and to distinguish sponge-generated flow from the unidirectional current in a flow-cell.

Marine sponges are known to produce an overwhelming array of secondary metabolites with pharmaceutical potential. The technical and economical potential of using marine sponges for large-scale production of these compounds was assessed for two cases: the anticancer molecule halichondrin B from a Lissodendoryx sp., and avarol from Dysidea avara for its antipsoriasis activity. An economic and technical analysis was done for three potential production methods: mariculture, ex situ culture (in tanks), and cell culture. We concluded that avarol produced by mariculture or ex situ culture could become a viable alternative to currently used pharmaceuticals for the treatment of psoriasis. Production of halichondrin B from sponge biomass was found to not be a feasible process, mainly due to the extremely low concentration of the compound in the sponge. Technical feasibility was also analyzed for five alternatives: chemical synthesis, wild harvest, primmorph culture, genetic modification and semi-synthesis. It was concluded that the latter two approaches could prove to be valuable methods for the production of pharmaceuticals, based on chemical structures of secondary metabolites present in trace amounts in marine sponges. (c) 2005 Wiley Periodicals, Inc.

The marine sponges Dysidea avara and Chondrosia reniformis (globular forms) were cultured in the laboratory on a diet of viable Phaeodactylum tricornutum cells and dissolved nutrients (algae and fish powders). Our growth data were combined with literature data for Pseudosuberites andrewsi (a globular sponge) and for the encrusting sponges Oscarella lobularis, Hemimycale columella, and Crambe crambe. The suitability of three growth models-linear, exponential, and radial accretive-for describing the growth of globular and encrusting sponges was assessed. Radial accretive growth was determined to be the best model to describe growth of both encrusting and globular sponges. Average growth rates of 0.051+/-0.016 and 0.019+/-0.003 mm/day (calculated as the increase of the radius of the sponge per day) were obtained experimentally for D. avara and C. reniformis, respectively.

Large-scale, renewable supplies of chemical constituents derived from marine invertebrates have limited development of potential new natural product drugs. This paper describes the development of two in-sea aquaculture systems designed and engineered for production of large quantities of biomass for two species of marine invertebrates desired for their natural product chemical constituents. The two invertebrates and their products were: (1) the cosmopolitan, arborescent bryozoan Bugula neritina (Phylum Bryozoa) for its anticancer chemical constituent bryostatin 1; and (2) Ecteinascidia turbinate (Phylum Tunicata) the source of anticancer ecteinascidin 743. For the third invertebrate Phylum Porifera, and its representative sponge Acanthella cavernosa (desired for its anti-parasitic and anti-infective kalihinols) in-sea systems were not developed in favor of controlled environment tank aquaculture systems. For the bryozoan and tunicate, projected economics for commercial-scale in-sea production proved cost effective. This was in contrast to the controlled environment sponge culture tank system, which did not prove to be economical due to inherent slow growth and low natural product yields of the sponge in culture. A non-destructive method for "milking" natural product chemicals from sponges was tested and is described.