Biogenic Fish-gut Calcium Carbonate is a Stable Amorphous Phase in the Gilt-head Seabream, Sparus aurata

Abstract

The main source of calcium carbonate (CaCO3) in the ocean comes from the shells of calcifying planktonic organisms, but substantial amounts of CaCO3 are also produced in fish intestines. The precipitation of CaCO3 assists fish in intestinal water absorption and aids in whole body Ca2+ homeostasis. Here we report that the product formed in the intestinal lumen of the gilt-head seabream, Sparus aurata, is an amorphous calcium carbonate (ACC) phase. With FTIR spectroscopy and SEM imaging, our study shows that the fish-derived carbonates from S. aurata are maintained as a stable amorphous phase throughout the intestinal tract. Moreover, intestinal deposits contained up to 54 mol% Mg2+, the highest concentration yet reported in biogenic ACC. Mg is most likely responsible for stabilizing this inherently unstable mineral. The fish carbonates also displayed initial rapid dissolution when exposed to seawater, exhibiting a significant increase in carbonate concentration.

A Story Told by a Single Nanoparticle in the Body Fluid: Demonstration of Dissolution-Reprecipitation of Nanocrystals in a Biological System

“…Using a similar precipitation method, we showed previously that various ions interact with organic moieties to form mineralo-organic NPs in biological fluids [1][2][3]10,11]. The mineral NPs produced this way were highly similar to the mineral particles detected in human calcified tissues [26,40,41] and other living organisms [42,43], results that confirm the physiological relevance of this approach.…”

Reef fish carbonate production assessments highlight regional variation in sedimentary significance

“…This is reflected in our model outputs, which indicate that relatively stable calcites collectively average 16-30% of overall production (29-39% of known products) across all reef systems except Dampier (offshore Western Australia; 52% of known products), whereas ACMC averages at least 24-62% (42-70% of known products). At least some ACMC produced by fish is known to dissolve within a few hours of excretion (Foran et al, 2013), and if such dissolution is pervasive it would result in average losses from our test reefs of at least 0.6-4.6 g m -2 yr -1 , leaving up to 1.2-5.0 g m -2 yr -1 of more stable fish carbonate (primarily LMC and HMC) to accumulate as sediment. In addition to the evident sedimentary implications, this potential for extensive dissolution raises an intriguing possibility that fish carbonates y = 15.5x have important roles in the regulation of both sediment pore-water chemistry and diel cycles in coral reef carbonate chemistry (e.g., Albright et al, 2015).…”

Ceramics from the Alcazar Palace in Seville (Spain) dated between the 11th and 15th centuries: Compositions, technological features and degradation processes

“…The position of the bands also depends on the type of cations surrounding the corresponding ions. Displacements in the position of the fundamental vibrational bands to lower wavenumber are related to the presence of higher atomic weight cations [74,75]. In the analysed spectra, a double contribution is clearly observed in the band of higher intensity of ion [CO 3 ] 2− .…”