Environmental Flow Regimes for Dysidea avara Sponges

Abstract

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.

Competition in benthic marine invertebrates: the unrecognized role of exploitative competition for oxygen

“…For example, there are indications that oxygen is limited in corals (at night) and among sponges (Osinga et al 1999, Dodds et al 2007, raising the potential for oxygen competition. Furthermore, rocky subtidal habitats can have flow rates similar to those measured in our study (Mendola et al 2008). Conversely, it seems unlikely that water flows in exposed habitats such as rocky intertidal reefs will ever be so low as to result in oxygen limitation and therefore competition for oxygen is unlikely.…”

How do environmental factors influence life cycles and development? An experimental framework for early‐diverging metazoans

“…Reciprocal transplantation of intertidal sponges between high and low wave action environments indicate that sponges rapidly initiate production of stiffer and stronger tissues in high wave energy environments but delay formation of new, less robust, tissues in calm habitats [56]. Moreover, as in corals, the gross morphology (body shape) of many sponges is affected by the environment, individuals exposed to higher flow rates being more compact than those growing in more sheltered locations [57,58] (Fig. 3F and G).…”

“…Reproduced with permission from Zoe Richards. F and G: Typical morphotypes of Dysidea avara sponges from depth sites of 8.8 m (F) and 14.3 m (G); pictures from Mendola et al . H: Hydra vulgaris under normal culture conditions.…”

Genetic diversity of the imperilled bath sponge Spongia officinalis Linnaeus, 1759 across the Mediterranean Sea: patterns of population differentiation and implications for taxonomy and conservation

“…The above observations allow us to assume that the morphological variability characterizing S. officinalis is not linked to underlying genetic differentiation, at least associated to the examined markers, and does not correspond to discrimination of subspecies. Phenotypic plasticity has been acknowledged as an inherent trait for several sponges and evidently connected with abiotic and biotic factors, such as flow regime (Mendola et al 2008), substratum (Mercurio et al 2006) or symbiotic relationships (Carballo et al 2006). Very few studies, however, demonstrate lack of genetic differentiation between acknowledged morphotypes or distinct sponge species (Ló pez-Legentil et al 2010).…”