The Effect of Depth on the Morphology, Bacterial Clearance, and Respiration of the Mediterranean Sponge Chondrosia reniformis (Nardo, 1847)

Abstract

<jats:p>To support the successful application of sponges for water purification and collagen production, we evaluated the effect of depth on sponge morphology, growth, physiology, and functioning. Specimens of Eastern Mediterranean populations of the sponge Chondrosia reniformis (Nardo, 1847) (Demospongiae, Chondrosiida, Chondrosiidae) were reciprocally transplanted between 5 and 20 m depth within the Kaş-Kekova Marine Reserve Area. Control sponges at 5 m had fewer but larger oscula than their conspecifics at 20 m, and a significant inverse relationship between the osculum density and size was found in C. reniformis specimens growing along a natural depth gradient. Sponges transplanted from 20 to 5 m altered their morphology to match the 5 m control sponges, producing fewer but larger oscula, whereas explants transplanted from 5 to 20 m did not show a reciprocal morphological plasticity. Despite the changes in morphology, the clearance, respiration, and growth rates were comparable among all the experimental groups. This indicates that depth-induced morphological changes do not affect the overall performance of the sponges. Hence, the potential for the growth and bioremediation of C. reniformis in mariculture is not likely to change with varying culture depth. The collagen content, however, was higher in shallow water C. reniformis compared to deeper-growing sponges, which requires further study to optimize collagen production.</jats:p>

Filtering Activity and Nutrient Release by the Keratose Sponge Sarcotragus spinosulus Schmidt, 1862 (Porifera, Demospongiae) at the Laboratory Scale

“…Although the comparison of the CR between different sponge species is challenging due to the intraspecies variability, the effect of sponge size, the morpho-physiological features, and the different units in which CR are expressed [4,25,73], our results are comparable with those reported for other Mediterranean species ( Supplementary Table S1). A careful analysis of the results requires further considerations related to the characteristics of the tested sponge.…”

“…The importance of free bacteria in the diet of sponges [16] and the ability to concentrate and digest large numbers of microorganisms suggested that sponges could be effective in reducing bacterial abundance, including microbial pollution, caused by sewage in coastal areas [17], such as near mariculture facilities where bacteria, including potentially pathogenic species, are often abundant [18][19][20][21][22][23][24][25][26][27][28][29][30].…”

“…sponge cultivation may be suitable for the eco-sustainable supply chain of biomass for certain target species [27,41,46,47]. The sponge biomass obtained in polyculture systems has considerable potential from a commercial point of view, having good appeal for hobbyists as well as cosmetic and natural bioactive compound companies (e.g., [25]).…”

“…To find sustainable solutions to these issues, recently an in situ innovative integrated multitrophic aquaculture (IMTA) system in a Mediterranean fish farm, in which explants of the keratose sponge Sarcotragus spinosulus Schmidt 1862 (Porifera, Demospongiae) were co-cultured, showed promising survival and growth performances with a doubling of the sponge biomass after one year of rearing [49]. To date, no studies are available on the filtering performance and nutrient release [15,25], despite representing a deeply studied species in the research of basic and applied biology (e.g., microbiology, mariculture and the extraction of bioactive compounds) [50][51][52]. Conversely, the natural products that can be extracted from this species are well-known (e.g., polyprenylhydroquinones) [53] and have drawn particular attention due to the wide spectrum of their antibacterial, antiviral, anti-inflammatory, and cytotoxic activities [52].…”

An Innovative IMTA System: Polychaetes, Sponges and Macroalgae Co-Cultured in a Southern Italian In-Shore Mariculture Plant (Ionian Sea)

“…As concerns sponges, findings obtained from about 20 years of field and laboratory research on more than 30 sponge species by Italian and international researcher teams suggest that in situ sponge-culture may be suitable for the eco-sustainable supply chain of sponge biomass for some target species [44,[53][54][55][56][57]. The sponge biomass obtained in polyculture systems has considerable potential from a commercial point of view, having good appeal for cosmetic or hobbyist production of natural biocides, or for the pharmaceutical industry thanks to their bioactive compounds.…”