Search

In the earliest published account of fish otoliths, Swedish physician and naturalist Magnus von Bromell (1679–1731) produced a brief but nonetheless remarkable publication titled 'De piscium lapillis', in which he declared 'fish pebbles' or 'ichthyoliths' (now known as otoliths) to be of great interest and strongly encouraged their study. A transcription and English translation of the original Latin is provided, with a discussion of the impact his study had on subsequent research. [ABSTRACT FROM AUTHOR]

Molecular phylogenies suggest some major radiations of open-ocean fish clades occurred roughly coincident with the Cretaceous-Palaeogene (K/Pg) boundary, however the timing and nature of this diversification is poorly constrained. Here, we investigate evolutionary patterns in ray-finned fishes across the K/Pg mass extinction 66 million years ago (Ma), using microfossils (isolated teeth) preserved in a South Pacific sediment core spanning 72-43 Ma. Our record does not show significant turnover of fish tooth morphotypes at the K/Pg boundary: only two of 48 Cretaceous tooth morphotypes disappear at the event in the South Pacific, a rate no different from background extinction. Capture-mark-recapture analysis finds two pulses of origination in fish tooth morphotypes following the mass extinction. The first pulse, at approximately 64 Ma, included short-lived teeth, as well as forms that contribute to an expansion into novel morphospace. A second pulse, centred at approximately 58 Ma, produced morphotype novelty in a different region of morphospace from the first pulse, and contributed significantly to Eocene tooth morphospace occupation. There was no significant increase in origination rates or expansion into novel morphospace during the early or middle Eocene, despite a near 10-fold increase in tooth abundance during that interval. Our results suggest that while the K/Pg event had a minor impact on fish diversity in terms of extinction, the removal of the few dominant Cretaceous morphotypes triggered a sequence of origination events allowing fishes to rapidly diversify morphologically, setting the stage for exceptional levels of ray-finned fish diversity in the Cenozoic.

Ray-finned fishes (Actinopterygii) comprise nearly half of all modern vertebrate diversity, and are an ecologically and numerically dominant megafauna in most aquatic environments. Crown teleost fishes diversified relatively recently, during the Late Cretaceous and early Paleogene, although the exact timing and cause of their radiation and rise to ecological dominance is poorly constrained. Here we use microfossil teeth and shark dermal scales (ichthyoliths) preserved in deep-sea sediments to study the changes in the pelagic fish community in the latest Cretaceous and early Paleogene. We find that the Cretaceous-Paleogene (K/Pg) extinction event marked a profound change in the structure of ichthyolith communities around the globe: Whereas shark denticles outnumber ray-finned fish teeth in Cretaceous deep-sea sediments around the world, there is a dramatic increase in the proportion of ray-finned fish teeth to shark denticles in the Paleocene. There is also an increase in size and numerical abundance of ray-finned fish teeth at the boundary. These changes are sustained through at least the first 24 million years of the Cenozoic. This new fish community structure began at the K/Pg mass extinction, suggesting the extinction event played an important role in initiating the modern "age of fishes."

A new, diverse and complex Early Triassic assemblage was recently discovered west of the town of Paris, Idaho (Bear Lake County), USA. This assemblage has been coined the Paris Biota. Dated earliest Spathian (i.e., early late Olenekian), the Paris Biota provides further evidence that the biotic recovery from the end-Permian mass extinction was well underway ca. 1.3 million years after the event. This assemblage includes mainly invertebrates, but also vertebrate remains such as ichthyoliths (isolated skeletal remains of fishes). Here we describe first fossils of Chondrichthyes (cartilaginous fishes) from the Paris Biota. The material is composed of isolated teeth (mostly grinding teeth) preserved on two slabs and representing two distinct taxa. Due to incomplete preservation and morphological differences to known taxa, the chondrichthyans from the Paris Biota are provisionally kept in open nomenclature, as Hybodontiformes gen. et sp. indet. A and Hybodontiformes gen. et sp. indet. B, respectively. The present study adds a new occurrence to the chondrichthyan fossil record of the marine Early Triassic western USA Basin, from where other isolated teeth (Omanoselache , other Hybodontiformes) as well as fin spines of Nemacanthus (Neoselachii) and Pyknotylacanthus (Ctenachanthoidea) and denticles have been described previously. [ABSTRACT FROM AUTHOR]

Native fish populations have been strongly impacted by fishing, habitat alteration and the introduction of invasive species. Understanding the dynamics of native fish populations prior to commercial fishing can be problematic, but provides critical baseline data for fish conservation, rehabilitation and management. We combined fish size, age and growth data, as well as month of catch data, from archaeological fish otoliths (1670–1308 cal BP to 409–1 cal BP), historical anecdotes (CE 1871–1999), and contemporary data sources (CE 1984–2014) to examine changes to mulloway, Argyrosomus japonicus , populations in the waters of eastern South Australia. We found that the data from the three different sources – archaeological, historical and contemporary – corroborate each other in many aspects. The time of catch for all three datasets was seasonal, with increases evident during the summer months. No significant changes in fish length over time were evident over the time span of the three data sources. Given the impact that fishing in the region is regarded to have had, this may imply that while the maximum recorded sizes of the species have remained stable, the abundance of these large specimens may have declined. [ABSTRACT FROM AUTHOR]

Copyright of Philosophy & History of Biology / Filosofia e História da Biologia is the property of Associacao Brasileira de Filosofia e Historia da Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Large‐scale, comparative studies of morphological variation are rare due to the time‐intensive nature of shape quantification. This data gap is important to address, as intraspecific and interspecific morphological variation underpins and reflects ecological and evolutionary processes. Here, we detail a novel software package, AutoMorph, for high‐throughput object and shape extraction. AutoMorph can batch image many types of organisms (e.g. foraminifera, molluscs and fish teeth), allowing for rapid generation of assemblage‐scale morphological data. We used AutoMorph to image and generate 2D and 3D morphological data for >100,000 marine microfossils in about a year. Our collaborators have used AutoMorph to process >12,000 patellogastropod shells and >50,000 fish teeth. AutoMorph allows users to rapidly produce large amounts of morphological data, facilitating community‐scale evolutionary and ecological studies. To hasten the adoption of automated approaches, we have made AutoMorph freely available and open source. AutoMorph runs on all UNIX‐like systems; future versions will run across all platforms. [ABSTRACT FROM AUTHOR]

Five types of coprolites, represented by 40 specimens from the Cambrian (Series 2-3) Burgess Shale-type deposits in the Pioche Shale of Nevada and the Spence Shale of Utah, are described. They are preserved in finely laminated deep-water calcareous mudstones. Round to ellipsoid features 13-42 mm in diameter consisting of black carbon film and variable amounts of skeletal fragments are interpreted as coprolites that were originally deposited in a burrow. Two kinds of elongated coprolites are also preserved and either consist of small pellets or skeletal debris. The pellets are typically 0.5 to 2mmacross and have a round to ellipsoid outline. Two different types of pellet-filled burrows are also present. The presence of organic tissue and skeletal fragments in some coprolites provides direct evidence of predatory or scavenging activity, and may advance understanding of the food chain in these Cambrian deposits. [ABSTRACT FROM AUTHOR]

As sessile, benthic filter feeders, brachiopods share an intimate relationship with their chosen substrate. Individuals of Micromitra burgessensis in the Burgess Shale Formation are preserved in life position, attached to a range of hard substrates, including skeletal debris, conspecific brachiopods, sponges and enigmatic tubes. Here we investigate the phenotypic variability of M. burgessensis associated with differing substrate attachments. We apply geometric morphometrics to test for variation by plotting landmarks on the exterior of ventral and dorsal valves of M. burgessensis specimens that are preserved attached to different substrates. Using principal component, canonical variate analyses and anova, we determine that there is some variation in shape related to substrate. Canonical variate analyses, for ventral valves and dorsal valves, indicate that specimens attached to the same substrate are recognizable in shape from specimens attached to other substrate types. The strength of differentiation however, is not robust and combined with our discriminate analysis of separate populations suggests that there is the potential for substrates to exercise only weak control over the morphology of Brachiopoda. [ABSTRACT FROM AUTHOR]

The first articulated fossil fishes (Actinopterygii) unequivocally discovered in the United States were collected in the Early Jurassic lacustrine deposits of the Newark Supergroup. They were reported in 1816 by Benjamin Silliman (1779-1864), the founder of the American Journal of Science, in Parker Cleaveland (1780-1858)'s Elementary treatise on mineralogy and geology. These fossils were found in Westfield, near Middletown, Connecticut. Shortly thereafter, Edward Hitchcock (1793-1864) also reported the discovery of fossil fishes in Sunderland, Massachusetts. Up to now, these specimens seemed to be lost or impossible to pinpoint in American museums. Some of them also found their way to France. In October 1818 and August 1821, Silliman sent several of these fossil fish slabs to the French geologist Alexandre Brongniart (1770-1847). Searches in French institutional paleontological collections that hold scattered parts of Brongniart's collection made it possible to rediscover these historical fossils that went completely unnoticed so far. A specimen, identified as Redfieldius sp., from Westfield (Hartford Basin, Connecticut), is one of the very first authenticated fossil bony fishes ever reported in the United States. Eight slabs with "ichthyolites" (fossil fishes) collected in Sunderland (Deerfield Basin, Massachusetts) by Edward Hitchcock in or before April 1821 have also been rediscovered. Three of them contain type material (lectotype and paralectotype) of Semionotus fultus (Agassiz, 1833), the first scientifically named fossil fish from the Newark Supergroup. The other five slabs contain Semionotus sp. and Semionotus tenuiceps (Agassiz, 1835). This paper presents the historical context surrounding these early discoveries in the light of the correspondence between Hitchcock, Silliman and Brongniart. This study highlights an early example of transatlantic scientific exchange in geosciences at the beginning of the nineteenth century. [ABSTRACT FROM AUTHOR]

The Chinese sturgeon, Acipenser sinensis, is a large member of Acipenseridae now found only in the Yangtze River and the Yellow and East China seas. The goal of this paper was to describe the skull of A. sinensis in the context of recent anatomical and systematic studies of sturgeons. Five specimens (354-670 mm standard length) were prepared as skeletons. The left and right parietals and frontals are broadly separated by a median fontanelle. The lateral-most lateral extrascapular variably supports the confluence of the supratemporal, occipital and trunk lateral lines. There is no distinct ventral supraorbital process as found in other sturgeons. The anterodorsal portion of the snout is unique among Acipenseridae by having a single large anamestic dorsal rostral bone instead of a series of separate dorsal rostral bones. There are 0-2 lateral rostral bones on each side positioned anterior to but not in contact with the horizontal arm of the jugal. The dorsal surface of the neurocranium lacks a pineal opening, and its anterior tip is sharply pointed in the smaller specimens examined and gently curved in larger specimens. The anteromedial arm of the palatopterygoid is broad relative to other acipenserids. These new morphological data are discussed and compared among Acipenseridae. [ABSTRACT FROM AUTHOR]

While the history of taxonomic diversification in open ocean lineages of ray-finned fish and elasmobranchs is increasingly known, the evolution of their roles within the open ocean ecosystem remains poorly understood. To assess the relative importance of these groups through time, we measured the accumulation rate of microfossil fish teeth and elasmobranch dermal denticles (ichthyoliths) in deep-sea sediment cores from the North and South Pacific gyres over the past 85 million years (Myr). We find three distinct and stable open ocean ecosystem structures, each defined by the relative and absolute abundance of elasmobranch and ray-finned fish remains. The Cretaceous Ocean (pre-66 Ma) was characterized by abundant elasmobranch denticles, but lowabundances of fish teeth. The Palaeogene Ocean (66-20 Ma), initiated by the Cretaceous/Palaeogene mass extinction, had nearly four times the abundance of fish teeth compared with elasmobranch denticles. This Palaeogene Ocean structure remained stable during the Eocene greenhouse (50 Ma) and the Eocene-Oligocene glaciation (34 Ma), despite large changes in the overall accumulation of both groups during those intervals, suggesting that climate change is not a primary driver of ecosystem structure. Dermal denticles virtually disappeared from open ocean ichthyolith assemblages approximately 20 Ma, while fish tooth accumulation increased dramatically in variability, marking the beginning of the Modern Ocean. Together, these results suggest that open ocean fish community structure is stable on long timescales, independent of total production and climate change. The timing of the abrupt transitions between these states suggests that the transitions may be due to interactions with other, non-preserved pelagic consumer groups. [ABSTRACT FROM AUTHOR]

Fish skeletal muscle is often used to monitor mercury concentrations and is used by regulatory agencies to develop fish consumption advisories. However, the distribution of mercury species (MeHg and THg) in muscle tissue and other organs is not well understood in a number of fish species. Here we evaluate the spatial distribution of THg and MeHg in skeletal muscle and internal organs (heart, liver, and kidney) of 19 sculpin representing three species: Myoxocephalus scorpius (shorthorn sculpin n = 13), Myoxocephalus jaok (plain sculpin, n = 4), and Megalocottus platycephalus (belligerent sculpin, n = 2). Four subsamples of muscle were taken along the lateral aspect of each fish, from muscle A (cranial) to muscle D (caudal). Using Games-Howell post hoc procedure to compare mean concentrations of all tissues, muscle samples were significantly different from internal organs, although there was no difference between muscle-sampling locations. THg concentrations (ww) were higher in muscle (muscle A through D mean ± SD, 0.30 ± 0.19 mg/kg) than that in heart (0.06 ± 0.05 mg/kg), kidney (0.08 ± 0.06 mg/kg), and liver (0.09 ± 0.08 mg/kg). Percent MeHg decreased with age in both skeletal muscle and organs ( p < 0.05). In contrast to some previous reports for other fish species, this study found significantly higher THg concentrations in muscle than in the liver. This study highlights the importance of using muscle samples when evaluating potential Hg exposure in risk assessments for piscivorous wildlife and human populations, and assumptions related to organ mercury concentrations should be examined with care. [ABSTRACT FROM AUTHOR]

Ray-finned fishes (Actinopterygii) comprise nearly half of all modern vertebrate diversity, and are an ecologically and numerically dominant megafauna in most aquatic environments. Crown teleost fishes diversified relatively recently, during the Late Cretaceous and early Paleogene, although the exact timing and cause of their radiation and rise to ecological dominance is poorly constrained. Here we use microfossil teeth and shark dermal scales (ichthyoliths) preserved in deep-sea sediments to study the changes in the pelagic fish community in the latest Cretaceous and early Paleogene. We find that the Cretaceous–Paleogene (K/Pg) extinction event marked a profound change in the structure of ichthyolith communities around the globe: Whereas shark denticles outnumber ray-finned fish teeth in Cretaceous deep-sea sediments around the world, there is a dramatic increase in the proportion of ray-finned fish teeth to shark denticles in the Paleocene. There is also an increase in size and numerical abundance of ray-finned fish teeth at the boundary. These changes are sustained through at least the first 24 million years of the Cenozoic. This new fish community structure began at the K/Pg mass extinction, suggesting the extinction event played an important role in initiating the modern "age of fishes." [ABSTRACT FROM AUTHOR]

The interrelationships between major living vertebrate, and even chordate, groups are now reasonably well resolved thanks to a large amount of generally congruent data derived from molecular sequences, anatomy and physiology. But fossils provide unexpected combinations of characters that help us to understand how the anatomy of modern groups was progressively shaped over millions of years. The dawn of vertebrates is documented by fossils that are preserved as either soft-tissue imprints, or minute skeletal fragments, and it is sometimes difficult for palaeontologists to tell which of them are reliable vertebrate remains and which merely reflect our idea of an ancestral vertebrate. [ABSTRACT FROM AUTHOR]

The article discusses the study by E. C. Sibert and L. D. Rubin which discovered a wholesale extinction of shark lineages in the pelagic ocean, the largest ecosystem on Earth, during early Miocene. Topics covered include the use of ichthyoliths in the study, how the loss of shark diversity is directly linked to overfishing and the ecological consequences of the loss of sharks.

The incidence of skeletal anomalies could be used as an indicator of the “quality” of rearing conditions as these anomalies are thought to result from the inability of homeostatic mechanisms to compensate for environmentally-induced stress and/or altered genetic factors. Identification of rearing conditions that lower the rate of anomalies can be an important step toward profitable aquaculture as malformed market-size fish have to be discarded, thus reducing fish farmers’ profits. In this study, the occurrence of skeletal anomalies in adult rainbow trout grown under intensive and organic conditions was monitored. As organic aquaculture animal production is in its early stages, organic broodstock is not available in sufficient quantities. Non-organic juveniles could, therefore, be used for on-growing purposes in organic aquaculture production cycle. Thus, the adult fish analysed in this study experienced intensive conditions during juvenile rearing. Significant differences in the pattern of anomalies were detected between organically and intensively-ongrown specimens, although the occurrence of severe, commercially important anomalies, affecting 2–12.5% of individuals, was comparable in the two systems. Thus, organic aquaculture needs to be improved in order to significantly reduce the incidence of severe anomalies in rainbow trout. [ABSTRACT FROM AUTHOR]

The skeleton of a natural whale fall discovered in the Southern Ocean at 1,445 m was densely covered by one small, janirid isopod. Jaera tyleri sp. nov. is the first of its genus found in the southern hemisphere and in the deep sea and is described herein. Morphological and molecular investigations revealed the systematic position of this species new to science. Phylogenetic analysis of the 18S locus confirms that this species falls in a strongly supported monophyletic clade of Jaera species. The whale bone habitat of J. tyleri sp. nov. is quite different from those of other species of the genus Jaera. The analysis of bathymetric and distribution patterns of the Janiridae in general and Jaera specifically confirm the unusualness of the habitat for this isopod species. The abundance of J. tyleri sp. nov. on the whale bones and its absence from other nearby habitats suggests it to be a whale-fall specialist. The analysis of the size-frequency distributions of J. tyleri sp. nov. suggests multimodal population structure with continuous breeding activity throughout the year. The fecundity of the species is low but in line with reduced fecundity observed in polar and small-sized isopods. [ABSTRACT FROM AUTHOR]

A concentration of fish remains found in a single room of a fortified building at Mleiha (United Arab Emirates) is presented here. Part of it was probably the filling of a bag or an organic container that fell from a bench onto the floor of the room. The various species recovered from these contexts, dating to the second to mid-third centuries AD, are briefly described. Particular attention is paid to the skeletal elements by which the fish are represented and to the corresponding lengths of the animals, as these allow the proposition that the fish had been dried on the seashore before being carried to the site inland. The data from building H will be compared to those from previously studied contexts at Mleiha (Gautier & Van Neer ; Mashkour & Van Neer ). In addition the ichthyofauna from ed-Dur (Van Neer & Gautier ), a coastal site that is partially contemporaneous with the contexts from building H, will be considered. [ABSTRACT FROM AUTHOR]

Gladbachus adentatusis a putative chondrichthyan, known only from the holotype specimen, which comprises an articulated endoskeleton complete from head to pelvic region with the squamation also preserved. The scales superficially resemble those of placoderms more than sharks, in having a similar gross morphology, lamellar cellular bone forming the base and upright dentinous tubercles comprising the crown. The odontocytic mesodentine in the tubercles is comparable to that in the Osteostraci and in some acanthodian taxa, known only from isolated scales, and is probably the plesiomorphic form of dentine for Gnathostomata. [ABSTRACT FROM AUTHOR]

Abstract: The oxygen isotopic compositions of Carboniferous conodonts and fish microfossils (ichthyoliths), from identical samples, were analysed in tandem in order to test whether these phosphatic media can be reliably used for palaeoclimatic reconstruction. The structure of conodonts and of most ichthyoliths analysed are somewhat analogous to the enamel and dentine/bone tissue, respectively, of modern mammals. Therefore, the diagenetic susceptibilities of the taxa analysed may provide important clues to other palaeoclimatic studies utilising a variety of biogenic apatite. Thermal maturation indices and scanning electron microscopy were used to characterise the preservation of biogenic apatite. Despite a high conodont colour alteration index (CAI) of ~5.5, conodont elements appear to have been only mildly affected by diagenetic alteration. In contrast, ichthyoliths were commonly recrystallised and exhibited diagenetic apatitic overgrowths containing amorphous pyrolytic carbon, interpreted as indicating that at least some overgrowth material derived from the original biogenic apatite. Diagenetic alteration has resulted in ichthyolith δ18O values being systematically lower by, on average, 2.9‰ (1σ=±0.3) relative to conodont apatite. Conodont samples yielded regionally correlatable isotope values, which can be interpreted in terms of more palaeoenvironmentally sensible palaeotemperatures relative to ichthyolith values. Densely crystalline, enamel-like conodont elements are interpreted as the more robust phosphatic medium to preserve original isotopic compositions. The strong correlation (r=0.8) of the δ18O values of the more structurally pristine conodont and commonly recrystallised ichthyolith apatite, indicates that (i) despite diagenetic lowering of absolute isotope values, original palaeoenvironmental records may be preserved and (ii) diagenetic overprinting may result in a stable offset, and therefore be correctable, locally. [Copyright &y& Elsevier]

Abstract: A screenwashed microvertebrate site, the Mile 175 locality, in the Morrison Formation of Wyoming has yielded more than 3000 elements of actinopterygian fish and indicates that fish were not as rare in some parts of the formation as previously supposed. Actinopterygians are represented by diverse teeth and tooth-bearing bone fragments, fin elements, and thousands of scales and scale fragments that can be divided into three distinct morphotypes. Lungfish are rare, represented by nine toothplates and toothplate fragments that are provisionally assigned to Potamoceratodus. Tetrapods recovered from the Mile 175 locality include indeterminate salamanders, turtles, choristoderes, a squamate, goniopholid crocodyliforms, theropod and ornithopod dinosaurs, and several mammals, including Docodon and indeterminate multituberculates. Salamanders are represented by just a few indeterminate vertebrae. The turtle fauna includes numerous small shell fragments and limb elements. The authors assign a tooth-bearing jaw fragment and several vertebrae to the choristodere Cteniogenys, whereas a sole vertebra is the only squamate fossil recovered. Theropod dinosaurs are well represented by several teeth, as is the ornithopod dinosaur Othnielosaurus. Similarly, several mammalian tooth and jaw fragments can be referred to either Docodon or Multituberculata indet. Dominance of the sample by aquatic and semi-aquatic taxa suggests the paleodepositional environment was a permanent water source. Many of the specimens appear to represent small and presumably ontogenetically young individuals of larger, known taxa in the Morrison Formation, and the site includes the northernmost occurrences of several taxa in the formation. Screenwashing efforts at several other previously quarried large-vertebrate sites in the Morrison Formation have shown promising results for recovering previously unidentified taxa. [Copyright &y& Elsevier]

Abstract: Coral skeletons are composite acellular structures, in which organic macromolecules are intimately associated with mineral phases. Previous studies focussed on proteins and sugars of the soluble organic matrices extracted from the skeletons. Here we report the occurrence of diverse lipids which were extracted from the aragonitic skeletons of seven modern coral species. Using thin layer chromatography, we show that these lipids differ in quantity and composition between the species. Higher proportions of sterols and sterol esters in skeleton extracts as compared to a much higher abundance of waxes and triglycerides in previously studied extracts from scleractinian soft tissues suggest a specific, although not yet determined, role in biomineralisation. The occurrence of intraskeletal lipids along with other organic components should also be taken into account when using coral skeletons as bone allografts, as well as in fossilisation processes. [ABSTRACT FROM AUTHOR]

Tropomyosins from fish skeletal muscle show high amino acid sequence homology, although their thermal stability is clearly different among species. In order to determine the regions that are responsible for the stability of this protein, five synthetic peptides of 30mer were synthesized by Fmoc method, based on the sequence of walleye pollack Theragra chalcogramma fast skeletal muscle tropomyosin, namely, N terminal Met1-Lys30, the variable region Asp84-Leu113, the middle region Val128-Ala157, the region containing the conservative Cys (Leu176-Lys205), and C terminal Asp255-Ile284. The thermal stability of these peptides was measured by circular dichroism and differential scanning calorimetry. The helical contents of these peptides were decreased in a temperature-dependent manner, although they showed no clear melting temperature, suggesting that the enthalpy necessary for the complete denaturation of these peptides was low. Peptides Asp255-Ile284 and Asp84-Leu113 showed the highest and second highest α-helical contents, respectively, and the other peptides gave rise to lower α-helical contents. [ABSTRACT FROM AUTHOR]

Pharyngeal foreign bodies are common problems seen at emergency rooms or ENT outpatient clinics, and fish bones are the most common foreign bodies encountered in East Asia and in Korea. One of the rare complications of a swallowed sharp fish bone is its migration from the site of entry into the subcutaneous tissues of the neck. We present four unusual cases of ingested fish bones that migrated out of the upper digestive tract to the neck. In the first case, this caused a recurrent deep neck infection for 2 years; in the second case, there was penetration of the facial artery; in the third case, there was a hematoma of the floor of the mouth; in the fourth case, there was a retropharyngeal abscess. [ABSTRACT FROM AUTHOR]

Abstract: Antioxidative activity and properties of bigeye snapper and brownstripe red snapper skin gelatin-based films incorporated with BHT (butylated-hydroxy-toluene) or α-tocopherol were investigated. Changes in FTIR spectra of fish skin gelatin films were observed when BHT or α-tocopherol at a level of 200ppm was incorporated, suggesting some interaction occurred between gelatin molecules and the antioxidants added. Incorporation of BHT generally increased tensile strength (TS) and elongation at break (EAB) of film from bigeye snapper skin gelatin, but decreased EAB of film from brownstripe red snapper skin gelatin (P<0.05). Addition of α-tocopherol (200ppm) decreased TS and EAB of film from brownstripe red snapper skin gelatin, and lowered EAB of film from bigeye snapper skin gelatin (P<0.05). Both BHT and α-tocopherol decreased water vapor permeability (WVP) of resulting film from skin gelatin of both species (P<0.05) but affected the transparency differently, depending upon gelatin source. During storage, all films had an increase in TS with a coincidental decrease in EAB (P<0.05). Antioxidative activity of fish skin gelatin films incorporated with BHT or α-tocopherol increased markedly with increasing storage time as indicated by the increase in DPPH radical scavenging activity (P<0.05). Films without and with BHT or α-tocopherol incorporated showed a preventive effect on lard oxidation as evidenced by the retardation of thiobarbituric acid reactive substances (TBARS) and peroxide formation. [Copyright &y& Elsevier]

Teeth of Polyacrodus contrarius are reported from the Anisian/Carnian of the Guanling area, as well as a tooth of ?Parvodus from the Anisian, and a tooth of an indeterminate elasmobranch, possibly with neoselachian affinity, from the Ladinian/Carnian. Dermal denticles similar to Arctacanthus are also relatively common in the Ladinian/Carnian interval. They are much smaller than the Permian Arctacanthus, and the structure of their root prevent them for being hybodont cephalic spines. They might represent frontal clasper denticles of a holocephalan. This fauna confirms the survival of Palaeozoic chondrichthyan lineages into the Triassic. [ABSTRACT FROM AUTHOR]

Five new late Eocene – Pliocene ichthyolith zones are defined based on indigenous faunal occurrences in strata that outcrop along western Vancouver Island and samples from six offshore Tofino Basin wells. Five new interval zones are each defined based on distinct transported ichthyolith assemblages. Results are correlated within the framework of established Cenozoic west coast and Arctic foraminifer zones and ichthyolith occurrences in deep-sea core samples and Cretaceous Queen Charlotte Group and Nanaimo Group strata of coastal British Columbia. The use of multiple data sets was important to interpret complex active tectonic margin sedimentation and structures. The integrated ichthyolith and foraminifer biostratigraphy allowed an interpretation of well log data and lithology reports. Also, we reassessed previous offshore seismic data, evaluated fossil preservation and thermal alteration, and distinguished transported from indigenous ichthyolith occurrences. These data allowed a reinterpretation of tectonic segments and associated strata of the Pacific Rim and Crescent terranes and the Cascadia Accretionary Complex onshore and offshore Vancouver Island. Tectonically active phases during the Eocene and Oligocene – early Miocene resulted in transport of Cretaceous to Eocene ichthyoliths from structural highs to lows, indicating proximity of the Pluto I-87 and Zeus D-14 wells to the Tofino Fault between the Pacific Rim and Crescent terranes and suggesting derivation with coeval Hesquiat Peninsula strata. An unconformity above the Eocene Crescent Formation volcanics in Prometheus H-68 and Zeus D-14 wells is correlated with the Pluto I-87 and Apollo J-14 well stratigraphy. An upper Miocene unconformable surface coincides with accretion and uplift of the Cascadia Accretionary Complex. [ABSTRACT FROM AUTHOR]

We analyzed 87Sr/86Sr ratios in foraminifera, pore fluids, and fish teeth for samples ranging in age from Eocene to Pleistocene from four Ocean Drilling Program sites distributed around the globe: Site 1090 in the Cape Basin of the Southern Ocean, Site 757 on the Ninetyeast Ridge in the Indian Ocean, Site 807 on the Ontong-Java Plateau in the western equatorial Pacific, and Site 689 on the Maud Rise in the Southern Ocean. Sr isotopic ratios for dated foraminifera consistently plot on the global seawater Sr isotope curve. For Sites 1090, 757, and 807 Sr isotopic values of the pore fluids are generally less radiogenic than contemporaneous seawater values, as are values for fossil fish teeth. In contrast, pore fluid 87Sr/86Sr values at Site 689 are more radiogenic than contemporaneous seawater, and the corresponding fish teeth also record more radiogenic values. Thus, Sr isotopic values preserved in fossil fish teeth are consistently altered in the direction of the pore fluid values; furthermore, there is a correlation between the magnitude of the offset between the pore fluids and the seawater curve, and the associated offset between the fish teeth and the seawater curve. These data suggest that the hydroxyfluorapatite of the fossil fish teeth continues to recrystallize and exchange Sr with its surroundings during burial and diagenesis. Therefore, Sr chemostratigraphy can be used to determine rough ages for fossil fish teeth in these cores, but cannot be used to fine-tune age models. In contrast to the Sr isotopic system, our Nd concentration data, combined with published isotopic and rare earth element data, suggest that fish teeth acquire Nd during early diagenesis while they are still in direct contact with seawater. The concentrations of Nd acquired at this stage are extremely high relative to the concentrations in surrounding pore fluids. As a result, Nd isotopes are not altered during burial and later diagenesis. Therefore, fossil fish teeth from a variety of marine environments preserve a reliable and robust record of deep seawater Nd isotopic compositions from the time of deposition. [Copyright &y& Elsevier]

Cenozoic pelagic (‘red’) clays of predominantly eolian and hydrogenous origin blanket much of the central North Pacific ocean basin. The eolian component is a key indicator of past paleoclimatic conditions; thus, Cenozoic atmospheric circulation can potentially be reconstructed through provenance studies of Pacific red clays, provided there are precise age controls. Methods commonly employed in the past to date red clay cores have included cobalt accumulation rates, ichthyolith biostratigraphy, magnetostratigraphy, and ichthyolith strontium isotope stratigraphy. The first two dating methods yield ages with large uncertainties, while magnetostratigraphy is only relevant to cores with accumulation rates in excess of 1 mm/kyr. Ichthyolith strontium isotope stratigraphy has shown promise as a chronological tool in marine studies, but has been only sparingly employed in the dating of marine red clay sequences. In this study, we present a complete age–depth profile for a large diameter piston core from the central North Pacific Ocean (EW9709 PC-01, 32.5°N, 141.2°W), consisting of 11 m of primarily wind-deposited dust. To generate this age–depth profile, strontium isotopic compositions were determined on fish teeth ichthyoliths previously cleaned of contaminants using a newly modified reductive cleaning procedure. Ages were determined by reference to the recently refined Sr isotope curve for Neogene seawater. Comparison with nearby giant piston core LL44-GPC3 reinforces the accuracy of our methods. The data for EW9709 PC-01 indicate a fairly constant sediment accumulation rate of ∼0.45 mm/kyr over most of the 24 Myr time period represented by this core. [Copyright &y& Elsevier]

Ichthyols are sulfated shale oils with well-known anti-inflammatory effects in dermatologic diseases. Their possible mechanisms of action were studied by measuring chemotactic factor release from peripheral human leukocytes in vitro. Ichthyols caused no release of such factors by themselves but inhibited ionophore-induced release. After elution of the cell supernatants on reverse-phase high-pressure liquid chromatography, followed by analysis of the fractions in the chemotaxis assay and the radioimmunoassay, lchthyols caused a reduction of lipids at marker positions for leukotriene B4 (LTB4) and 20-COOH-LTB4. The inhibition was also evident in the LTB4 radioimmunoassay, was dose- and time-dependent, and occurred in noncytotoxic concentrations of the agents. Ichthyols also inhibit the chemotactic response of neutrophils toward LTB4 and the unstimulated migration of cells. These inhibitory effects of Ichthyols on secretion of chemotactic arachidonate metabolites from leukocytes and on cell migration provide a plausible explanation for their anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

Molecular phylogenies suggest some major radiations of open-ocean fish clades occurred roughly coincident with the Cretaceous-Palaeogene (K/Pg) boundary, however the timing and nature of this diversification is poorly constrained. Here, we investigate evolutionary patterns in ray-finned fishes across the K/Pg mass extinction 66 million years ago (Ma), using microfossils (isolated teeth) preserved in a South Pacific sediment core spanning 72-43 Ma. Our record does not show significant turnover of fish tooth morphotypes at the K/Pg boundary: only two of 48 Cretaceous tooth morphotypes disappear at the event in the South Pacific, a rate no different from background extinction. Capture-mark-recapture analysis finds two pulses of origination in fish tooth morphotypes following the mass extinction. The first pulse, at approximately 64 Ma, included short-lived teeth, as well as forms that contribute to an expansion into novel morphospace. A second pulse, centred at approximately 58 Ma, produced morphotype novelty in a different region of morphospace from the first pulse, and contributed significantly to Eocene tooth morphospace occupation. There was no significant increase in origination rates or expansion into novel morphospace during the early or middle Eocene, despite a near 10-fold increase in tooth abundance during that interval. Our results suggest that while the K/Pg event had a minor impact on fish diversity in terms of extinction, the removal of the few dominant Cretaceous morphotypes triggered a sequence of origination events allowing fishes to rapidly diversify morphologically, setting the stage for exceptional levels of ray-finned fish diversity in the Cenozoic., (© 2018 The Author(s).)

We report the collection, and provide a description, of the first Great Barracuda, Sphyraena barracuda, in Canadian waters based on a partial skeleton from Country Island, Nova Scotia. [ABSTRACT FROM AUTHOR]