Experimental silicon demand by the sponge Hymeniacidon perlevis reveals chronic limitation in field populations

Abstract

Dissolved silicon (DSi) is a key marine nutrient. Sponges and diatoms are relevant DSi consumers, but sponges appear to have a less efficient uptake system that requires higher ambient DSI concentrations for maximum uptake. We experimentally tested whether a sponge adapted to live at the intertidal (Hymeniacidon perlevis) also shows such a need for high DSi. Under laboratory conditions, sponges were exposed to both the natural DSi concentration (10 lM) and much higher levels (25, 40, and 70 lM) for 36 h, being water samples taken at 6 h intervals to infer DSi uptake. Uptake rates shifted over time (particularly in high DSi treatments) and showed moderate interindividual variability. Average DSi uptake rate at 70 lM was twice higher than those at 40 and 25 lM, which in turn were not significantly different from each other, but were twice higher than the uptake rate at 10 lM. Therefore, H. perlevis needs, for efficient uptake, ambient DSi concentrations two to four times higher than the maximum available in its natural habitat. From an eco-physiological point of view, it means that the skeletal growth in the populations of H. perlevis is chronically limited by DSi availability, a limitation that may favor sponge evolution toward skeletal slimming.

Silicon consumption kinetics by marine sponges: An assessment of their role at the ecosystem level

“…In agreement with all previous sponge studies (Frøhlich and Barthel ; Reincke and Barthel ; Maldonado et al , ; López‐Acosta et al ), our results show important levels of between‐individual variability in the DSi consumption responses. While in the demosponges Axinella spp., T. citrina , and H. perlevis (Maldonado et al ; López‐Acosta et al ), the between‐individual variability was significantly related to sponge size and/or the particular physiological stage (i.e., reproductive vs. nonreproductive condition), a similar pattern has not been retrieved herein.…”

Silicon consumption in two shallow-water sponges with contrasting biological features

“…The results for H. perlevis in our study contrast with those obtained for intertidal individuals of this same species in the Yellow Sea (Dalian, China). When exposed at 10 (field DSi concentration), 25, 40, and 70 μM DSi during 36 h (Maldonado et al ), the Yellow Sea individuals showed consumption rates 3.3–5.7 times higher than the ones expected according to the H. perlevis kinetic equation obtained from the Brest population. In the current stage of knowledge, local adaptations in the performance of the sponge DSi utilization systems cannot be ruled out.…”

Discordance between morphological and molecular species boundaries among Caribbean species of the reef sponge Callyspongia

“…Maldonado et al. (, ) showed that spicule morphology and the presence or absence of a particular spicule type are influenced by seawater chemistry and the availability of nutrients such as silicic acid. Although microhabitat data were not collected as part of this study, we documented differences in spicule size among four different geographic locations, indicating environment plays a role in determining spicule morphology in Callyspongia .…”