2024-03-28T07:58:18Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1780522020-12-13T09:10:27Zcom_10261_123com_10261_8com_10261_88col_10261_502col_10261_467
Morganti, T.
Coma, Rafael
Yahel, G.
Ribes, Marta
2019-03-18T08:17:45Z
2019-03-18T08:17:45Z
2017-06-25
10th Sponge World Conference: 134-135 (2017)
http://hdl.handle.net/10261/178052
10.13140/RG.2.2.34685.87528
http://dx.doi.org/10.13039/501100003329
http://dx.doi.org/10.13039/501100003176
ponges are commonly divided into High (HMA) and Low (LMA) Microbial- Abundance species according to the bacterial biomass in their tissue. These two groups reflect distinct aquiferous structures and feeding strategies. In the NW Mediterranean coralligenous community HMA and LMA sponges are often packed in dense, multispecies assemblages that cover many pinnacles and overhangs. This dense packing together with a developed concentration boundary layer with near-bottom plankton depletion suggests that competition for space and access to unfiltered water should be intense among these closely related suspension feeders. We investigated the metabolism of three HMA (Chondrosia reniformis, Agelas oroides, Petrosia ficiformis) and two LMA (Dysidea avara and Crambe crambe) species that cohabitate the coralligenous community by using a direct in situ technique (VacuSIP). Simultaneous sampling of the water inhaled and exhaled by undisturbed animals sharing the same rocky wall in the NW Mediterranean allowed us to measure plankton uptake and the fluxes of dissolved organic (DON and DOC) and inorganics (NH4+, NOx-) mediated by the sponges. Sponges consumed plankton, DOC, and ammonium in relation to their abundance in ambient water. The plankton retention efficiency was high for all species. When DOC concentration was high (>80 μmol L-1), it accounted for ~90% of carbon intake from the examined sources for the three HMA sponges and D. avara. Nitrogen fluxes markedly differed between the two groups: plankton was the main source of nitrogen for LMAs that excreted DON and ammonium. The nitrogenous waste products of LMAs were found to be the major source of nitrogen (up to 97%) for HMAs that efficiently removed DON and ammonium and excreted nitrate. The estimated areal fluxes indicated that the N excreted by LMAs might potentially account for N needs of coexistence HMAs. This illustrates a phenomenon in which a metabolic end-product of the LMA species become a resource for the HMA species. The different capacity of both sponge strategies to use dissolved resources suggests a partial trophic niche separation related to HMA-LMA dichotomy as a mechanism facilitating their dense coexistence in the community. Our findings suggest that a mixed assemblage of sponges (and their associated microbes) is able to utilize the suspended particulate and dissolved material more efficiently than a single species population and may contribute to the understanding of the phenomena of the stability and diversity of dense sponge assemblages in oligotrophic habitats
eng
openAccess
A Trophic Niche Separation May Explain the Tight Coexistence of High (HMA) and Low (LMA) Microbial-Abundance Sponges
póster de congreso