石首鱼科(Sciaenidae)三种鱼耳石CaCO_3晶相结构分析

软骨及硬骨鱼以及其它高等脊椎动物耳石中,CaCO_3占绝大部分.本文主要以X射线衍射分析对白姑鱼,大黄鱼,小黄鱼三种石首鱼科鱼类耳石作了分析,发现CaCO_3结晶均为霰石结构.依文献,对耳石晶相结构在动物分类上的意义作了初步讨论.     

Crystallization, stability, and enzymatic degradation of poly(L-lactide) thin film

Poly(L-lactide) (PLLA) thin film with 100 nm thickness was crystallized at 160 degreesC for 20 min from the melt obtained at 220 degreesC. Hexagonal crystals with three types of growth (derivative growth lamellae, overgrowth multistacked lamellae, and undergrowth multistacked lamellae) were simultaneously observed by atomic force microscopy (AFM). These phenomena are due to the differences of the formative points of secondary crystal nuclei against the basal lamella. Enzymatic degradation of PLLA thin film revealed two types of amorphous regions. These regions were identified as the free amorphous region around the crystals and the restricted amorphous region between the crystal and glass substrate. In situ observation of thermal behavior of lamellar crystals was performed to understand the correlation between the chain folding and stability of the crystal by using temperature-controlled AFM. The morphology of the sectors with [100] growth plane had changed to a comblike morphology despite the fact that the [110] growth plane remained unchanged, suggesting that the stability of the chain folding and the chain-packing state affected the thermal behavior.     

Identification of a novel matrix protein contained in a protein aggregate associated with collagen in fish otoliths

In the biomineralization processes, proteins are thought to control the polymorphism and morphology of the crystals by forming complexes of structural and mineral-associated proteins. To identify such proteins, we have searched for proteins that may form high-molecular-weight (HMW) aggregates in the matrix of fish otoliths that have aragonite and vaterite as their crystal polymorphs. By screening a cDNA library of the trout inner ear using an antiserum raised against whole otolith matrix, a novel protein, named otolith matrix macromolecule-64 (OMM-64), was identified. The protein was found to have a molecular mass of 64 kDa, and to contain two tandem repeats and a Glu-rich region. The structure of the protein and that of its DNA are similar to those of starmaker, a protein involved in the polymorphism control in the zebrafish otoliths [S?llner C, Burghammer M, Busch-Nentwich E, Berger J, Schwarz H, Riekel C & Nicolson T (2003) Science302, 282-286]. (45)Ca overlay analysis revealed that the Glu-rich region has calcium-binding activity. Combined analysis by western blotting and deglycosylation suggested that OMM-64 is present in an HMW aggregate with heparan sulfate chains. Histological observations revealed that OMM-64 is expressed specifically in otolith matrix-producing cells and deposited onto the otolith. Moreover, the HMW aggregate binds to the inner ear-specific short-chain collagen otolin-1, and the resulting complex forms ring-like structures in the otolith matrix. Overall, OMM-64, by forming a calcium-binding aggregate that binds to otolin-1 and forming matrix protein architectures, may be involved in the control of crystal morphology during otolith biomineralization.     

Morphometry and composition of aragonite and vaterite otoliths of deformed laboratory reared juvenile herring from two populations

Vaterite otoliths were sampled from two reared populations (Celtic and Clyde Seas) of juvenile herring Clupea harengus. The crystallography, elemental composition and morphometry were analysed and compared with those of normal aragonite otoliths. The incidence of vaterite otoliths in the juveniles sampled (n = 601) ranged from 7·8% in the Clyde population to 13·9% in the Celtic Sea population, and was 5·5% in the small sample (n = 36) of wild adults examined. In all but one case fish had only one vaterite otolith; the corresponding otolith of the pair was completely aragonite. Although the majority of the juveniles sampled showed craniofacial deformities, there was no link between the skull or jaw malformation and the incidence of vaterite otoliths. All vaterite otoliths had an aragonite inner area, and vaterite deposition began sometime after the age of 90 days. The vaterite otoliths were larger and lighter than their corresponding aragonite partners, and were less dense as a consequence of the vaterite crystal structure. The vaterite areas of the otoliths were depleted in Sr, Na and K. Concentrations of Mn were higher in the vaterite areas. The transition between the aragonite inner areas and the vaterite areas was sharply delineated. Within a small spatial scale (20 μm³) in the vaterite areas, however, there was co‐precipitation of both vaterite and aragonite. The composition of the aragonite cores in the vaterite otoliths was the same as in the cores of the normal aragonite otoliths indicating that the composition of the aragonite cores did not seed the shift to vaterite. Vaterite is less dense than aragonite, yet the concentrations of Ca analysed with wavelength‐dispersive spectrometry (WDS) were the same between the two polymorphs, indicating that Ca concentrations measured with WDS are not a good indicator of hypermineralized zones with high mineral density. The asymmetry in density and size of the otoliths may cause disruptions of hearing and pressure sensitivity for individual fish with one vaterite otolith, however, the presence of vaterite otoliths did not seem to affect the growth of these laboratory reared juvenile herring.     

In situ observation of crystal growth for poly[(S)-lactide] by temperature-controlled atomic force microscopy

The crystallization behavior and crystalline morphologies of poly[(S)-lactide] (P[(S)-LA]) in thin films crystallized isothermally at over 160 degrees C were characterized by transmission electron microscopy and atomic force microscopy (AFM). The dendritic crystal and hexagonal crystal were formed in thin film with thicknesses below 30 nm or over 50 nm, respectively. The crystal structures of dendritic and hexagonal crystals were identical, suggesting that the crystalline morphology of P[(S)-LA] is strongly dependent upon the film thickness. In situ observation of the crystal growth in the P[(S)-LA] thin film at 165 degrees C from the melt was carried out by using temperature-controlled AFM equipped with a heating stage. The initial stage of crystallization and development of lamellae were successfully observed during isothermal crystallization at 165 degrees C. The first forming crystal showed the edge-on orientation, and grew to S-shaped edge-on lamellae. Dendritic flat-on crystals were developed from the S-shaped edge-on lamellae. The growth rates of flat-on and edge-on lamellae were almost identical.     

Exposure to thyroid hormone in ovo affects otolith crystallization in rainbow trout Oncorhynchus mykiss

Calcareous otoliths in the inner ears of fishes are necessary for proper hearing and vestibular function. Sagittal otoliths are usually composed of the calcium carbonate polymorph aragonite but may contain the polymorph vaterite, a phenomenon called otolith crystallization. The causes of otolith crystallization are poorly understood. Thyroid hormone (TH) can influence the chemical microenvironment and structure of the inner ear, suggesting that TH may influence otolith crystallization. The present study examined the effect of exogenous TH treatment on sagittal otolith crystallization and growth in larval and juvenile rainbow trout, Oncorhynchus mykiss. In the first experiment, 110?C179?day-old fish raised from TH-treated oocytes had significantly fewer sagittal otoliths containing the crystalline calcium carbonate polymorph vaterite as compared to untreated fish. Vaterite-containing otoliths were significantly longer than those containing the typical polymorph aragonite, although there was no effect of TH treatment on otolith length. In the second experiment, juveniles immersed in an exogenous solution of TH for 6?weeks had slightly longer otoliths (relative to fish length) than age-matched controls, but this effect was not significant. This juvenile population had a very high percentage (88.3?%) of vaterite sagittae overall and this percentage did not change significantly with treatment, suggesting the switch from aragonite to vaterite occurred prior to inclusion of the fish in the study. These results suggest that early manipulation of TH levels may affect calcium carbonate deposition on the otolith but that later TH exposure is unable to restore typical otolith composition.     

Analysis of the soluble matrix of vaterite otoliths of juvenile herring (Clupea harengus): do crystalline otoliths have less protein?

Otoliths are calcium carbonate concretions laid down in the inner ear of fish and used in fish age estimation. Otoliths precipitate in the form of aragonite but aberrant precipitation may result in vaterite formation instead of aragonite. Vaterite otoliths are more translucent than aragonite. The quantity of HCl-soluble proteins (SP) was measured in the vaterite otoliths and their aragonite pairs of one year old reared herring Clupea harengus to assess the changes induced by the precipitation of vaterite in the amount of soluble proteins in the otolith. Results showed that vaterite otoliths had as much soluble proteins as their aragonite pairs (p>0.05). Due to the lower density of the vaterite, vaterite otoliths were lighter than their aragonite pairs (p<0.05) which explained that protein concentrations were significantly higher (p<0.05) than in aragonite otoliths. These results indicate that the precipitation of vaterite in otoliths did not affect the inclusion of soluble proteins. Furthermore, they suggest that soluble proteins do not affect the translucent or opaque appearance of otoliths. Differences in translucency may instead be caused by the amounts of insoluble proteins or by differences in the physical properties of proteins. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of the otolith proteins revealed two bands at 50 and 62 kDa in both aragonite and vaterite otoliths suggesting that the precipitation of vaterite in the otolith is not controlled by either of these two proteins present in the otolith.     

Scanning electron microscopic and X-ray diffraction studies of otoconia in the lizard Podarcis s. sicula

Summary The otoliths of embryos and young animals of the lizard Podarcis s. sicula were studied by X-ray diffraction and scanning electron microscopy. Two types of crystal that give different X-ray diffraction patterns were found in the membranous labyrinth of Podarcis. The crystals consist of calcite or aragonite and are easily distinguished by scanning electron microscopy because of their different morphology. The two calcium carbonate crystal forms are not mixed at random but are present in the embryo from the very beginning in specific sites. The endolymphatic sac contains aragonite crystals while the saccule contains calcite crystals adjacent to the wall, in addition to a preponderance of aragonite crystals. The utricle and lagena contain only calcite crystals. The presence of two crystal forms of calcium carbonate in the membranous labyrinth are discussed in terms of differing genetic and functional significance.     

High incidence of otolith abnormality in juvenile European flounder Platichthys flesus from a tidal freshwater area

Otolith abnormality has been reported for a wide range of freshwater and marine fish species. In this study, the sagittal otolith morphology and mineralogy of juvenile European flounder, Platichthys flesus, were examined to describe the incidence and types of structural deformities in this species. Juvenile flounder were collected over the years 2013–2015 in the tidal freshwater section of an estuarine nursery (Minho estuary, NW Portugal). Otolith abnormality was found in 43% of the individuals and, in most cases, occurred in both otoliths. Despite an abnormal mineralogy confirmed by scanning electron microscopy, the morphometry and the mineral polymorph composition of abnormal otoliths did not differ from normal ones (i.e. aragonite). This contrasts with other studies where vaterite and/or calcite were found to replace aragonite in abnormal otoliths. Further studies are needed to elucidate whether abrupt salinity changes associated with habitat transitions may have played a role in the abnormal otolith biomineralization in this species.     

Specific adsorption of osteopontin and synthetic polypeptides to calcium oxalate monohydrate crystals

Protein-crystal interactions are known to be important in biomineralization. To study the physicochemical basis of such interactions, we have developed a technique that combines confocal microscopy of crystals with fluorescence imaging of proteins. In this study, osteopontin (OPN), a protein abundant in urine, was labeled with the fluorescent dye AlexaFluor-488 and added to crystals of calcium oxalate monohydrate (COM), the major constituent of kidney stones. In five to seven optical sections along the z axis, scanning confocal microscopy was used to visualize COM crystals and fluorescence imaging to map OPN adsorbed to the crystals. To quantify the relative adsorption to different crystal faces, fluorescence intensity was measured around the perimeter of the crystal in several sections. Using this method, it was shown that OPN adsorbs with high specificity to the edges between {100} and {121} faces of COM and much less so to {100}, {121}, or {010} faces. By contrast, poly-L-aspartic acid adsorbs preferentially to {121} faces, whereas poly-L-glutamic acid adsorbs to all faces approximately equally. Growth of COM in the presence of rat bone OPN results in dumbbell-shaped crystals. We hypothesize that the edge-specific adsorption of OPN may be responsible for the dumbbell morphology of COM crystals found in human urine.     

On the role of the central nervous system in regulating the mineralisation of inner-ear otoliths of fish

Summary. Stato- or otoliths are calcified structures in the organ of balance and equilibrium of vertebrates, the inner ear, where they enhance its sensitivity to gravity. The compact otoliths of fish are composed of the calcium carbonate polymorph aragonite and a small fraction of organic molecules. The latter form a protein skeleton which determines the morphology of an otolith as well as its crystal lattice structure. This short review addresses findings according to which the brain obviously plays a prominent role in regulating the mineralisation of fish otoliths and depends on the gravity vector. Overall, otolith mineralisation has thus been identified to be a unique, neuronally guided biomineralisation process. The following is a hypothetical model for regulation of calcification by efferent vestibular neurons: (1) release of calcium at tight junctions in the macular epithelia, (2) macular carbonic anhydrase activity (which in turn is responsible for carbonate deposition), (3) chemical composition of matrix proteins. The rationale and evidence that support this model are discussed. Correspondence and reprints: Zoological Institute, University of Hohenheim, Garbenstrasse 30, 70593 Stuttgart, Federal Republic of Germany.     

Fusion of Otoconia: a Stage in the Development of the Otolith in the Evolution of Fishes

Abstract The rigid, polycrystalline otolith of teleosts is a side-branch of the general evolution of endolymphatic otoconia that extends from the sharks and rays to the higher vertebrates including man. The transition from the otoconial mass found in the endolymphatic sac of sharks and rays to the rigid polycrystalline otolith of teleosts probably occurred by progressive fusion of otoconia from a loose aggregate to a semi-rigid mass. Traces of the primitive fused otoconia type of otolith still occur in the otherwise polycrystalline otoliths of some teleosts, and a few species of fish retain otoliths that are probably similar to the primitive fused otoconia type of otolith. The morphology of the fusion of otoconia varies according to the polymorph of calcium carbonate that is involved, as well as the particular crystal habit of the polymorph. Analyses of the size distributions of the polymorph-specific morphologies and crystal structure of otoconia suggest that three physical chemical processes, Ostwald ripening, Keith-Padden spherulitic growth and carbonate cementation are significant in the chemistry of fusion of otoconia in the evolution of the aragonite teleost otolith. Predictions of otoconia growth rate from the theory of Ostwald ripening can be compared with predictions from the Keith-Padden theory of spherulitic growth.     

Crystalline otoliths in teleosts: Comparisons between hatchery and wild coho salmon (<Emphasis Type="Italic">Oncorhynchus kisutch</Emphasis>) in the Strait of Georgia

Otoliths, or ‘ear stones’, are calcium carbonate structures found in all vertebrates. In teleosts, they have a number of sensory functions, including hearing. Daily growth increments of these structures have permitted advanced age and population studies of teleosts. Whereas ‘normal’ otoliths are composed of crystals imbedded within a protein matrix as aragonite, a ‘crystalline’ form of calcium carbonate termed vaterite is also found. A review of the otolith literature demonstrates a significant level of understanding of the structure and function of otoliths, but the cause for crystalline otolith structure remains speculative. Pairs of otoliths from hatchery and wild juvenile and adult coho salmon (Oncorhynchus kisutch) were examined visually for determination of otolith microstructure type. The vateritic or crystalline otoliths were found in much higher percentages in juvenile hatchery-reared coho salmon than in juvenile wild coho salmon, supporting previous studies. There did not seem to be any negative impact on size or survival. There was also no correlation between crystalline otoliths and premature maturation in coho males. A preliminary study of adult coho salmon returning to Big Qualicum and Chilliwack hatcheries showed even higher ratios of vateritic otoliths than observed in juveniles.     

Ultrastructure of otolith increments and checks in the teleost fish Oreochromis niloticus

An otolith increment is composed of an incremental zone and a discontinous zone. Observation of the otoliths of Oreochromis niloticus with transmission and scanning electron microscopy reveals that organic fibers are concentrated in the discontinuous zone and are relatively scarce in the incremental zone. On the other hand, calcium carbonate crystals are chiefly packed in the incremental zone and are less dense in the discontinuous zone. Both fibers and crystals are oriented perpendicular to the growth increments. Otolith checks, or discontinuities, contain even denser fibers and fewer fine crystals than does the discontinuous zone. A higher proportion of individual fibers is prominently stained in the discontinuous zone and check than in the incremental zone. Other features of individual fibers appear to be the same among the three zones. The crystals on either side of a check or a discontinuous zone resemble each other both in size and orientation. Zonation of protein and mineral components of otoliths can be understood in terms of both incremental growth and the daily cycle of deposition.     

Microtexture of larval shell of oyster,Crassostrea nippona: A FIB-TEM study

The initial formation and subsequent development of larval shells in marine bivalve, Crassostrea nippona were investigated using the FIB-TEM technique. Fourteen hours after fertilization (the trochophore stage), larvae form an incipient shell of 100–150 nm thick with a columnar contrast. Selected-area electron diffraction analysis showed a single-crystal aragonite pattern with the c-axis perpendicular to the shell surface. Plan-view TEM analysis suggested that the shell contains high density of {110} twins, which are the origin of the columnar contrast in the cross-sectional images. 72 h after fertilization (the veliger stage), the shell grows up to 1.2–1.4 μm thick accompanying an additional granular layer between the preexisting layer and embryo to form a distinctive two-layer structure. The granular layer is also composed of aragonite crystals sharing their c-axes perpendicular to the shell surface, but the crystals are arranged with a flexible rotation around the c-axes and not restricted solely to the {110} twin relation. No evidence to suggest the existence of amorphous calcium carbonate (ACC) was found through the observation. The well-regulated crystallographic properties found in the present sample imply initial shell formation probably via a direct deposition of crystalline aragonite.     

Significance of otolith calcium carbonate crystal structure diversity to microchemistry studies

Otoliths, calcium carbonate (CaCO₃) ear stones of fish, contain a wealth of information about fish life and environmental history yet the CaCO₃ polymorph form the otolith is made of is a critical, but seldom considered, piece of information during otolith analysis. Otolith trace element chemistry data increasingly informs management decisions, but recent work has shown that CaCO₃ polymorphs—aragonite, vaterite, and calcite—can bear on incorporation of trace elements in a non-trivial way. Most fishes are thought to have otoliths of the aragonite CaCO₃ form, but this construct is potentially outdated with many recent literature reports showing otherwise. Our study used previously unpublished neutron diffraction data and reports from published literature to address three objectives: (1) summarize the relative effects of otolith CaCO₃ polymorphism on otolith microchemistry, (2) summarize reports of otolith polymorphs to gain a better understanding of the extent of non-aragonite otoliths among fishes, (3) outline future research needed to align interpretations of microchemistry with our current understanding of otolith polymorph diversity. We found that while aragonite otoliths are the most common, so are exceptions. For example, the ostensibly rare (among species) CaCO₃ form vaterite was reported in at least some otoliths of 40% of the species surveyed. Our work suggests that examination of the CaCO₃ polymorph composition of otoliths should become more common particularly in studies where results will or may be used to inform management decisions. Future research should work to attribute controls on otolith CaCO₃ polymorph expression using a combination of -omics and material characterization approaches to enrich the life history and environmental information output from otoliths and increase our understanding of the assumptions made in otolith trace element chemistry studies.

     

几种生物CaCO3霰石结晶的取向性

CaCO3结晶广泛分布于生物界,其主要结晶形式为方解石、霰石及球霰石。用X－射线衍射法对三角帆蚌及合浦珍珠母贝的珍珠层、墨鱼骨和大黄鱼耳石的CaCO3结晶进行测定,发现各样品均有一定取向性,以三角帆蚌和合浦珍珠母贝珍珠层的取向性为最强,墨鱼骨的取向性次之,大黄鱼耳石的取向性最小,以上材料粉末样的衍射分析表明,各样品对应d值间差异极小,均为X射线衍射卡（5－0453）所表征的CaCO3霰石结构。     

几种生物CaCO_3霰石结晶的取向性

ＣａＣＯ３结晶广泛分布于生物界,其主要结晶形式为方解石、霰石及球霰石。用Ｘ－射线衍射法对三角帆蚌及合浦珍珠母贝的珍珠层、墨鱼骨和大黄鱼耳石的ＣａＣＯ３结晶进行测定,发现各样品均有一定取向性,以三角帆蚌和合浦珍珠母贝珍珠层的取向性为最强,墨鱼骨的取向性次之,大黄鱼耳石的取向性最小,以上材料粉末样的衍射分析表明,各样品对应ｄ值间差异极小,均为Ｘ射线衍射卡（５—０４５３）所表征的ＣａＣＯ３霰石结构。     

Relationships between fish size and otolith size of four bathydemersal fish species from the south eastern Arabian Sea,India

The objective of this study was to estimate a prey body size from the hard parts (e.g. otoliths) of a fish species frequently found in the guts of predators. Length–weight relationships between otolith size (length, height, weight and aspect ratio) and fish size (total length and weight) were determined for four fish species captured in the Arabian Sea by bottom trawl (2015 survey on‐board FORV Sagar Sampada, 200–300 m depth), off the west coast of India: Psenopsis cyanea, Pterygotrigla hemisticta, Bembrops caudimacula and Hoplostethus rubellopterus. No significant differences were noted between the size of the left and right otoliths (t test) in any of the four species. The length–weight relationship of the otolith in all four species showed a negative allometric growth pattern (t test, p < .05). The data fitted well to the regression model for otolith length (OL), otolith height (OH) and otolith weight (OW) to total length (TL) and total weight (TW). Results showed that these relationships are a helpful tool in predicting fish size from the otoliths and in calculating the biomass of these less‐studied fish species during feeding studies and palaentology.     

Otolith size trends in marine fish communities from different depth strata

A comparison of 681 saccular otoliths (sagitta) from 134 species belonging to six demersal communities from different depth strata and the epipelagic community from the north-western Mediterranean Sea was made in order to study otolith relative size and function related morphologies. A relationship between otolith size composition, habitat and depth was found. The epipelagic community was characterized by species with very small and small otolith sizes (68% of the epipelagic species). In the demersal communities, the proportion of species with large sagitta increased with depth until 750 m (reached 50% of the species of the upper slope). The abyssal community (between 1000 and 2000 m), however, was characterized by a decrease in the mean otolith size and an increase in the proportion of species with very small otoliths. With exception of the abyssal community, endogenous causes (a mixture of geneaology, plesiomorph characters shared by the all species of the taxonomic group and recent adaptive ones) may be even more important than exogenous factors in determining the otolith relative size. Within the endogenous causes that condition sagitta size, the adaptive features associated with specialization in acoustic communication are relevant.