scholarly journals Morphology and evolutionary significance of phosphatic otoliths within the inner ears of cartilaginous fishes (Chondrichthyes)

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Lisa Schnetz ◽  
Cathrin Pfaff ◽  
Eugen Libowitzky ◽  
Zerina Johanson ◽  
Rica Stepanek ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Chemical Properties ◽  
Organic Matrix ◽  
Evolutionary Significance ◽  
Crown Group ◽  
Bony Tissue ◽  
Skeletal Tissue ◽  
Bony Fishes ◽  
Close Relationship ◽  
Cartilaginous Fishes

Abstract Background Chondrichthyans represent a monophyletic group of crown group gnathostomes and are central to our understanding of vertebrate evolution. Like all vertebrates, cartilaginous fishes evolved concretions of material within their inner ears to aid with equilibrium and balance detection. Up to now, these materials have been identified as calcium carbonate-bearing otoconia, which are small bio-crystals consisting of an inorganic mineral and a protein, or otoconial masses (aggregations of otoconia bound by an organic matrix), being significantly different in morphology compared to the singular, polycrystalline otolith structures of bony fishes, which are solidified bio-crystals forming stony masses. Reinvestigation of the morphological and chemical properties of these chondrichthyan otoconia revises our understanding of otolith composition and has implications on the evolution of these characters in both the gnathostome crown group, and cartilaginous fishes in particular. Results Dissections of Amblyraja radiata, Potamotrygon leopoldi, and Scyliorhinus canicula revealed three pairs of singular polycrystalline otolith structures with a well-defined morphology within their inner ears, as observed in bony fishes. IR spectroscopy identified the material to be composed of carbonate/collagen-bearing apatite in all taxa. These findings contradict previous hypotheses suggesting these otoconial structures were composed of calcium carbonate in chondrichthyans. A phylogenetic mapping using 37 chondrichthyan taxa further showed that the acquisition of phosphatic otolith structures might be widespread within cartilaginous fishes. Conclusions Differences in the size and shape of otoliths between taxa indicate a taxonomic signal within elasmobranchs. Otoliths made of carbonate/collagen-bearing apatite are reported for the first time in chondrichthyans. The intrinsic pathways to form singular, polycrystalline otoliths may represent the plesiomorphic condition for vertebrates but needs further testing. Likewise, the phosphatic composition of otoliths in early vertebrates such as cyclostomes and elasmobranchs is probably closely related to the lack of bony tissue in these groups, supporting a close relationship between skeletal tissue mineralization patterns and chemical otolith composition, underlined by physiological constraints.

scholarly journals Cartilaginous fishes (Class Chondrichthyes) from the Ichthyological Collection at the Federal University of Paraíba, Brazil

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Sarah TFL Viana ◽  
Danilo Lima ◽  
Katherine Viana ◽  
Antônio Felinto ◽  
Ricardo de Souza Rosa
Keyword(s):  
Fish Fauna ◽  
Public Consultation ◽  
Type Collection ◽  
Neotropical Fish ◽  
Full List ◽  
Bony Fishes ◽  
Fish Collection ◽  
Cartilaginous Fishes ◽  
Geographical Scope ◽  
Amazonian Region

Federal University of Paraíba (UFPB) ichthyological collection comprises over 11,000 lots of species of cartilaginous and bony fishes from marine, estuarine and freshwater realms. Due to the collection size, rarity of some specimens, taxonomic and geographical scope, this collection represents a substantial archive of the Neotropical fish fauna, especially concerning the Northeast Brazilian region. Currently, UFPB fish collection is under bioinformatization and curatorial transitions. Hence, the present study aimed to provide a detailed analysis of the Chondrichthyan collection database in which the systematic, spatial and chronological coverages are discussed. Full list of collection objects, updated nomenclature and type collection extent are given for public consultation. There are 504 lots of sharks, batoids and chimaeras that are classified within 10 orders, 22 families, 34 genera, and 64 species. Myliobatiformes and Carcharhiniformes represent taxa with higher number of lots in which freshwater stingrays (Potamotrygonidae) and requiem sharks (Carcharhinidae) stand out. Specimens were mostly collected in the marine coastline off Paraíba state and lower Amazonian region, which set UFPB fish collection as an outstanding scientific collection of the regional genetic heritage. 

Functional analyses of chitinolytic enzymes in the formation of calcite prisms inPinctada fucata

2019 ◽  
Author(s):  
Hiroyuki Kintsu ◽  
Alberto Pérez-Huerta ◽  
Shigeru Ohtsuka ◽  
Taiga Okumura ◽  
Shinsuke Ifuku ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Crystal Growth ◽  
Calcium Carbonate ◽  
Small Angle ◽  
Organic Matrix ◽  
Pinctada Fucata ◽  
Prismatic Layer ◽  
Chitinolytic Enzymes ◽  
Organic Matrices

Abstract Background: The mollusk shells present distinctive microstructures that are formed by small amounts of organic matrices controlling the crystal growth of calcium carbonate. These microstructures show superior mechanical properties such as strength or flexibility. The shell of Pinctada fucata has the prismatic layer consisting of prisms of single calcite crystals. These crystals contain small-angle grain boundaries caused by a dense intracrystalline organic matrix network to improve mechanical strength. Previously, we identified chitin and chitinolytic enzymes as components of this intracrystalline organic matrix. In this study, we analyzed the function of those organic matrices in calcium carbonate crystallization by in vitro and in vivo experiments.Results: We analyzed calcites synthesized in chitin gel with or without chitinolytic enzymes by using transmission electron microscope (TEM) and atom probe tomography (APT). TEM observations showed that grain boundary was more induced as concentration of chitinolytic enzymes increased and thus, chitin became thinner. In an optimal concentration of chitinolytic enzymes, small-angle grain boundaries were observed. APT analysis showed that ion clusters derived from chitin were detected. In order to clarify the importance of chitinolytic enzymes on the formation of the prismatic layer in vivo , we performed the experiment in which chitinase inhibitor was injected into a living Pinctada fucata and then analyzed the change of mechanical properties of the prismatic layer. The hardness and elastic modulus increased after injection of chitinase inhibitor. Electron back scattered diffraction (EBSD) mapping data showed that the spread of crystal orientations in whole single crystal also increased by the effect of inhibitor injections.Conclusion: Our results suggested that chitinolytic enzymes may function cooperatively with chitin to regulate the crystal growth and mechanical properties of the prismatic layer, and chitinolytic enzymes are essential for the formation of the normal prismatic layer of P. fucata.

scholarly journals Tides: A key environmental driver of osteichthyan evolution and the fish-tetrapod transition?

2020 ◽  
Vol 476 (2242) ◽  
pp. 20200355
Author(s):  
H. M. Byrne ◽  
J. A. M. Green ◽  
S. A. Balbus ◽  
P. E. Ahlberg
Keyword(s):  
Weight Bearing ◽  
Evolutionary Significance ◽  
Late Devonian ◽  
Crown Group ◽  
Tidal Model ◽  
Intertidal Zones ◽  
Terrestrial Environments ◽  
Environmental Driver ◽  
Tidal Pools ◽  
Early Late

Tides are a major component of the interaction between the marine and terrestrial environments, and thus play an important part in shaping the environmental context for the evolution of shallow marine and coastal organisms. Here, we use a dedicated tidal model and palaeogeographic reconstructions from the Late Silurian to early Late Devonian (420 Ma, 400 Ma and 380 Ma, Ma = millions of years ago) to explore the potential significance of tides for the evolution of osteichthyans (bony fish) and tetrapods (land vertebrates). The earliest members of the osteichthyan crown-group date to the Late Silurian, approximately 425 Ma, while the earliest evidence for tetrapods is provided by trackways from the Middle Devonian, dated to approximately 393 Ma, and the oldest tetrapod body fossils are Late Devonian, approximately 373 Ma. Large tidal ranges could have fostered both the evolution of air-breathing organs in osteichthyans to facilitate breathing in oxygen-depleted tidal pools, and the development of weight-bearing tetrapod limbs to aid navigation within the intertidal zones. We find that tidal ranges over 4 m were present around areas of evolutionary significance for the origin of osteichthyans and the fish-tetrapod transition, highlighting the possible importance of tidal dynamics as a driver for these evolutionary processes.

scholarly journals Roles of larval sea urchin spicule SM50 domains in organic matrix self-assembly and calcium carbonate mineralization

2013 ◽  
Vol 183 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Ashit Rao ◽  
Jong Seto ◽  
John K. Berg ◽  
Stefan G. Kreft ◽  
Martin Scheffner ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Sea Urchin ◽  
Self Assembly ◽  
Organic Matrix

scholarly journals The Transport System of Nacre Components through the Surface Membrane of Gastropods

2016 ◽  
Vol 672 ◽  
pp. 103-112 ◽  
Author(s):  
Elena Macías-Sánchez ◽  
Antonio G. Checa ◽  
Marc G. Willinger
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Calcium Carbonate ◽  
Lamellar Structure ◽  
Surface Membrane ◽  
Organic Matrix ◽  
X Ray ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Electron Energy Loss

The surface membrane is a lamellar structure exclusive of gastropods that is formed during the shell secretion. It protects the surface of the growing nacre and it is located between the mantle epithelium and the mineralization compartment. At the mantle side of the surface membrane numerous vesicles provide material, and at the nacre side, the interlamellar membranes detach from the whole structure. Components of nacre (glycoproteins, polysaccharides and calcium carbonate) cross the structure to reach the mineralization compartment, but the mechanism by which this occurs is still unknown. In this paper we have investigated the ultrastructure of the surface membrane and the associated vesicle layer by means of Transmission Electron Microscopy. Electron Energy Loss Spectroscopy and Energy-dispersive X-ray Spectroscopy were used for elemental analysis. The analyses revealed the concentration of calcium in the studied structures: vesicles, surface membrane, and interlamellar membranes. We discuss the possible linkage of calcium to the organic matrix.

scholarly journals The role of chitin-rich skeletal organic matrix on the crystallization of calcium carbonate in the crustose coralline alga Leptophytum foecundum

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
M. Azizur Rahman ◽  
Jochen Halfar ◽  
Walter H. Adey ◽  
Merinda Nash ◽  
Carlos Paulo ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Organic Matrix ◽  
Crustose Coralline Alga ◽  
Coralline Alga

scholarly journals The early elasmobranch Phoebodus : phylogenetic relationships, ecomorphology and a new time-scale for shark evolution

2019 ◽  
Vol 286 (1912) ◽  
pp. 20191336 ◽  
Author(s):  
Linda Frey ◽  
Michael Coates ◽  
Michał Ginter ◽  
Vachik Hairapetian ◽  
Martin Rücklin ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Time Scale ◽  
Body Shape ◽  
Skeletal Remains ◽  
Late Devonian ◽  
Crown Group ◽  
Anatomical Knowledge ◽  
Close Relationship ◽  
Stem Lineage ◽  
Fin Spines

Anatomical knowledge of early chondrichthyans and estimates of their phylogeny are improving, but many taxa are still known only from microremains. The nearly cosmopolitan and regionally abundant Devonian genus Phoebodus has long been known solely from isolated teeth and fin spines. Here, we report the first skeletal remains of Phoebodus from the Famennian (Late Devonian) of the Maïder region of Morocco, revealing an anguilliform body, specialized braincase, hyoid arch, elongate jaws and rostrum, complementing its characteristic dentition and ctenacanth fin spines preceding both dorsal fins. Several of these features corroborate a likely close relationship with the Carboniferous species Thrinacodus gracia , and phylogenetic analysis places both taxa securely as members of the elasmobranch stem lineage. Identified as such, phoebodont teeth provide a plausible marker for range extension of the elasmobranchs into the Middle Devonian, thus providing a new minimum date for the origin of the chondrichthyan crown-group. Among pre-Carboniferous jawed vertebrates, the anguilliform body shape of Phoebodus is unprecedented, and its specialized anatomy is, in several respects, most easily compared with the modern frilled shark Chlamydoselachus . These results add greatly to the morphological, and by implication ecological, disparity of the earliest elasmobranchs.

scholarly journals Comparisons between combine-drilling and broadcasting muriate of potash for spring barley

1959 ◽  
Vol 53 (1) ◽  
pp. 10-16 ◽  
Author(s):  
F. V. Widdowson ◽  
A. Penny ◽  
R. J. B. Williams ◽  
G. W. Cooke
Keyword(s):  
Calcium Carbonate ◽  
Small Proportion ◽  
Spring Barley ◽  
Average Level ◽  
Exchangeable Potassium ◽  
Close Relationship ◽  
Mineral Soils ◽  
Muriate Of Potash

1. Twelve experiments were carried out in Bedfordshire and Hertfordshire in 1955–57 to compare combine-drilling and broadcasting muriate of potash for barley. Ordinary mineral soils were used and only one contained more than 25% of calcium carbonate.2. On average of all the experiments in each year 0·25 cwt. K2O/acre drilled with the seed gave higher yields than 0·5 cwt. K2O/acre broadcast and worked into the seedbed. The average extra yields of barley from combine-drilling, as compared with broadcasting, were 1·2 cwt./acre when 0·25 cwt. K2O/acre was applied and 2·0 cwt./acre of grain when twice as much K2O was given. In twenty-one of the total of twenty-four comparisons drilling gave higher yields than broadcasting and in onethird of these comparisons the effects were significant. Combine-drilling gave higher average yields of straw than broadcasting.3. The average level of response was not great, the low and high rates of combine-drilled muriate of potash increasing yields by 13 and 16%, respectively. Only a small proportion of the applied potassium was taken up by the crops; apparent recoveries by grain plus straw averaged 11% of the light-drilled dressing and 8% of the heavy dressing.4. The level of response to potassium varied from year to year, but was much greater on average in the 1955 experiments than in 1956 and 1957. There was no close relationship between the degree of response and values for dilute hydrochloric-acidsoluble potassium or exchangeable potassium in the soils used.

scholarly journals Using bacteria to make improved, nacre-inspired materials

MRS Advances ◽  
2016 ◽  
Vol 1 (8) ◽  
pp. 559-564 ◽  
Author(s):  
Dominik T. Schmieden ◽  
Anne S. Meyer ◽  
Marie-Eve Aubin-Tam
Keyword(s):  
Composite Material ◽  
Calcium Carbonate ◽  
Organic Matrix ◽  
Layered Material ◽  
New Materials ◽  
Biotechnological Production ◽  
High Toughness ◽  
Sheet Structure ◽  
Ureolytic Bacteria

ABSTRACTNacre (mother of pearl) is an attractive model for the development of new materials. Its sheet structure of alternating layers of calcium carbonate and an organic matrix confers it highly desirable properties such as high toughness and strength. In this study, we produce a nacre-inspired composite material using only bacterially-produced components. Calcium carbonate is crystallized via the action of ureolytic bacteria. After each crystallization event, we apply bacterially produced γ-polyglutamate (PGA) to the sample, which promotes layering compared to the PGA-free control. We show that the combination of these two compounds yields a layered material reminiscent of nacre, showing a way towards the biotechnological production of new, nacre-inspired materials.

Sign in / Sign up

Export Citation Format

Share Document