Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 328
Filtrar
1.
Environ Sci Pollut Res Int ; 28(38): 54161-54169, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34402011

RESUMO

This study investigated 20 elements in the muscle of 11 cephalopod species caught in the Canary Islands inhabiting from coastal to meso-bathypelagic habitats. Among them, trace element contents from large and elusive cephalopods such as Architeuthis dux, Taningia danae, Lepidoteuthis grimaldii, and Haliphron atlanticus were determined. Statistically significant differences in element concentration were found among class sizes and habitat. Large species that are inhabiting in deepest waters such as Loligo forbesii, A. dux, T. danae, H. atlanticus, and L. grimaldii showed a high load and variability in Fe and Al, while coastal species were characterized by a homogeneous element composition, being the Zn loads highest than other elements. Metal contents in large and elusive cephalopod species were dominated by Fe, Ni, Al, Zn, and Sr, with these species being able to carry important amounts of these elements to predators such as deep-diving odontocetes that reside around the Canary waters.


Assuntos
Cefalópodes , Oligoelementos , Animais , Tamanho Corporal , Ecossistema , Espanha , Oligoelementos/análise
2.
BMC Ecol Evol ; 21(1): 133, 2021 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-34174830

RESUMO

BACKGROUND: Expression of sexual dimorphism is recognised in various fossil groups of molluscs such as the Ammonoidea, an extinct group of shelled cephalopods. During the Mesozoic, the best-documented sexual dimorphic examples are seen in the Jurassic superfamily Perisphinctoidea. It is usually expressed by distinct adult size and apertural modifications between the antidimorphs. Putative males (otherwise referred to as microconch) are small in size and develop lappets at the end of the shell while the females (macroconch) are larger and bear a simple peristome. Dubious cases are, however, known in that superfamily, which often relate to taxonomic biases or lack of diagnostic characters, and some others expose ontogenetic anomalies illustrated by 'sex reversals' in the shell morphology and ornamentation. RESULTS: The discovery of two specimens of the Callovian Aspidoceratidae Peltoceras athleta (Phillips), having both female and male features, questions the significance and causes of 'sex reversals' in the Ammonoidea. The two specimens have started with the macroconch ontogeny of Peltoceras athleta and show an apparent change toward maleness in the adult, as illustrated by their rounded whorl section, ribs retroversion, fading of the tubercles and lappets typical of the microconchs. Few other cases of female-to-male, as well as male-to-female 'sex reversal', are known in the fossil record, all belonging to the Jurassic Perisphinctoidea (families Perisphinctidae or Aspidoceratidae). Since all Jurassic Perisphinctoidea are strictly gonochoristic, these 'sex reversals' are pathological in nature and are herein referred to as a new forma-type pathology: namely "forma hermaphrodita". CONCLUSIONS: In the absence of any clear evidence of injury or parasitism, we hypothesize that such "forma hermaphrodita" individuals illustrate pathologic cases of intersexuality. Little is known about the ammonoid soft parts, and it is not possible to determine which internal sexual organs occur in specimens having both male and female external shell features. Abnormal feminisation and/or masculinisation also occur in modern cephalopods, the latter also grouping only gonochoric species. This phenomenon is similarly illustrated by a change in the adult body size and a mixing of both female and male structures. In that case, intersexuality is either advantageous in the population or caused sterility. The causes of intersexuality are not clearly established but environmental pollutants are evoked in modern cephalopods because they act as endocrine disrupters. 'Sex reversals' and/or non-functional reproductive abnormalities have also been caused by endocrine disrupters in various gonochoric gastropods species, but infestation, genetic abnormalities, temperature fluctuations or viruses are multiple causes, which can stimulate or inhibit neural-endocrinal activity by direct gonadal influence, and ultimately lead to feminisation or masculinisation in fishes, isopods, crustaceans, and gastropods as well. Regardless of whether "forma hermaphrodita" is due to an exogenic or endogenic cause, the record of intersex Perisphinctoidea in the Jurassic can be explained by the ready recognition of dimorphic pairs, and the easy collection of large and sufficiently preserved fossil palaeopopulations in which intersex specimens have statistically more chance to be found.


Assuntos
Cefalópodes , Transtornos do Desenvolvimento Sexual , Animais , Crustáceos , Feminino , Fósseis , Humanos , Masculino , Moluscos
3.
J Exp Biol ; 224(13)2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34100547

RESUMO

Projected future carbon dioxide (CO2) levels in the ocean can alter marine animal behaviours. Disrupted functioning of γ-aminobutyric acid type A (GABAA) receptors (ligand-gated chloride channels) is suggested to underlie CO2-induced behavioural changes in fish. However, the mechanisms underlying behavioural changes in marine invertebrates are poorly understood. We pharmacologically tested the role of GABA-, glutamate-, acetylcholine- and dopamine-gated chloride channels in CO2-induced behavioural changes in a cephalopod, the two-toned pygmy squid (Idiosepius pygmaeus). We exposed squid to ambient (∼450 µatm) or elevated (∼1000 µatm) CO2 for 7 days. Squid were treated with sham, the GABAA receptor antagonist gabazine or the non-specific GABAA receptor antagonist picrotoxin, before measurement of conspecific-directed behaviours and activity levels upon mirror exposure. Elevated CO2 increased conspecific-directed attraction and aggression, as well as activity levels. For some CO2-affected behaviours, both gabazine and picrotoxin had a different effect at elevated compared with ambient CO2, providing robust support for the GABA hypothesis within cephalopods. In another behavioural trait, picrotoxin but not gabazine had a different effect in elevated compared with ambient CO2, providing the first pharmacological evidence, in fish and marine invertebrates, for altered functioning of ligand-gated chloride channels, other than the GABAAR, underlying CO2-induced behavioural changes. For some other behaviours, both gabazine and picrotoxin had a similar effect in elevated and ambient CO2, suggesting altered function of ligand-gated chloride channels was not responsible for these CO2-induced changes. Multiple mechanisms may be involved, which could explain the variability in the CO2 and drug treatment effects across behaviours.


Assuntos
Dióxido de Carbono , Cefalópodes , Animais , Canais de Cloreto , Cloretos , Ligantes , Receptores de GABA-A
4.
Mar Pollut Bull ; 168: 112408, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33965692

RESUMO

Mercury (Hg) concentrations have significantly increased in oceans during the last century. This element accumulates in marine fauna and can reach toxic levels. Seafood consumption is the main pathway of methylmercury (MeHg) toxicity in humans. Here, we analyzed total Hg (T-Hg) concentrations in two oceanic squid species (Ommastrephes bartramii and Thysanoteuthis rhombus) of an increasing commercial interest off Martinique, French West Indies. Stable isotope ratios reveal a negative linear relationship between δ15N or δ13C in diamondback squid samples. No significant trend was observed between δ34S values and T-Hg concentrations, contrasting with the sulfate availability and sulfide abundance hypotheses. This adds to a growing body of evidence suggesting Hg methylation via sulfate-reducing bacteria is not the main mechanism driving Hg bioavailability in mesopelagic organisms. All squid samples present T-Hg levels below the maximum safe consumption limit (0.5 ppm), deeming the establishment of a commercial squid fishery in the region safe for human consumption.


Assuntos
Cefalópodes , Mercúrio , Compostos de Metilmercúrio , Poluentes Químicos da Água , Animais , Região do Caribe , Monitoramento Ambiental , Humanos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Oceanos e Mares , Poluentes Químicos da Água/análise , Índias Ocidentais
5.
Commun Biol ; 4(1): 388, 2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33758350

RESUMO

Although an early Cambrian origin of cephalopods has been suggested by molecular studies, no unequivocal fossil evidence has yet been presented. Septate shells collected from shallow-marine limestone of the lower Cambrian (upper Terreneuvian, c. 522 Ma) Bonavista Formation of southeastern Newfoundland, Canada, are here interpreted as straight, elongate conical cephalopod phragmocones. The material documented here may push the origin of cephalopods back in time by about 30 Ma to an unexpected early stage of the Cambrian biotic radiation of metazoans, i.e. before the first occurrence of euarthropods.


Assuntos
Cefalópodes/ultraestrutura , Fósseis/ultraestrutura , Animais , Evolução Biológica , Cefalópodes/classificação , Microscopia Eletrônica de Varredura , Terra Nova e Labrador
6.
ACS Nano ; 15(2): 3509-3521, 2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33528244

RESUMO

Biological skin systems can perceive various external stimuli through ion transduction. Especially, the skin of some advanced organisms such as cephalopods can further promptly change body color by manipulating photonic nanostructures. However, the current skin-inspired soft iontronics lack the rapid full-color switching ability to respond to multiple stimuli including tension, pressure, and temperature. Here, an intelligent chromotropic iontronics with these fascinating functions is developed by constructing a biomimetic ultrastructure with anisotropic electrostatic repulsion. This skin-like chromotropic iontronics can synchronously realize electrical response and optical visualization to mechanical strain and tactile sensation by adjusting the ultrastructure in cooperation with ionic mechanotransduction. Notably, it can perform instantaneous geometric changes to thermal stimuli via an anisotropic electrostatic repulsion interior. Such a capability allows bionic skin to transduce temperature or infrared light into ionic signals and color changes in real time. The design of anisotropic photonic nanostructures expands the intelligent application for soft iontronics at higher levels, providing a concise, multifunctional, interactive sensing platform that dynamically displays stimuli information on its body.


Assuntos
Cefalópodes , Animais , Biomimética , Mecanotransdução Celular , Pele , Tato
7.
J Food Sci ; 86(3): 1153-1161, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33580563

RESUMO

Seafood is capable of bioaccumulating heavy metals (HM), making it a potentially major dietary source of HM for humans. Presently, little data exists on seafood from the eastern-most boundary of the Mediterranean Sea. This study aims to provide exposure insight of the Israeli population to HM through the consumption of locally caught seafood by assessing the levels of arsenic, mercury, cadmium, and lead in raw tissues of seafood. A wide survey of local fisheries was conducted providing 296 samples from 11 different species, including seven fish, two crustacean, and two cephalopod species. Total arsenic, cadmium, and lead were analyzed by graphite-furnace atomic absorption. Total mercury was measured by cold-vapor mercury analyzer. Arsenic speciation was performed by anion chromatography-inductively coupled plasma sector field mass spectrometry. Results suggested that the total arsenic concentrations were significantly higher in crustaceans and cephalopods than fish. Arsenic speciation revealed two samples that exceed 1 mg/kg of inorganic arsenic, whereas methylated arsenic was below the detection limit. Elevated mercury levels were detected in the commercial benthic species Mullus barbatus (red mullet), cadmium was detected in one-third of the samples, and lead detected in eight samples. Comparing the results to health guidelines, 99.4% of seafood tested in this study abide with acceptable levels of heavy metals in seafood, as defined by both Israeli and European Union guidelines.


Assuntos
Arsênio/análise , Cádmio/análise , Cefalópodes/metabolismo , Decápodes/metabolismo , Peixes/metabolismo , Contaminação de Alimentos/análise , Mercúrio/análise , Animais , Humanos , Mar Mediterrâneo
8.
J Synchrotron Radiat ; 28(Pt 1): 28-35, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33399549

RESUMO

A mid-infrared free-electron laser (MIR-FEL) is a synchrotron-radiation-based femto- to pico-second pulse laser. It has unique characteristics such as variable wavelengths in the infrared region and an intense pulse energy. So far, MIR-FELs have been utilized to perform multi-photon absorption reactions against various gas molecules and protein aggregates in physical chemistry and biomedical fields. However, the applicability of MIR-FELs for the structural analysis of solid materials is not well recognized in the analytical field. In the current study, an MIR-FEL is applied for the first time to analyse the internal structure of biological materials by using fossilized inks from cephalopods as the model sample. Two kinds of fossilized inks that were collected from different strata were irradiated at the dry state by tuning the oscillation wavelengths of the MIR-FEL to the phosphoryl stretching mode of hydroxyapatite (9.6 µm) and to the carbonyl stretching mode of melanin (5.8 µm), and the subsequent structural changes in those materials were observed by using infrared microscopy and far-infrared spectroscopy. The structural variation of these biological fossils is discussed based on the infrared-absorption spectral changes that were enhanced by the MIR-FEL irradiation, and the potential use of MIR-FELs for the structural evaluation of biomaterials is suggested.


Assuntos
Cefalópodes/ultraestrutura , Fósseis/ultraestrutura , Lasers , Animais , Elétrons , Raios Infravermelhos
9.
ACS Appl Mater Interfaces ; 13(11): 12735-12745, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33390008

RESUMO

Cephalopods use chromatophores distributed on their soft skin to change skin color and its pattern. Each chromatophore consists of a central sac containing pigment granules and radial muscles surrounding the sac. The contraction of the radial muscle causes the central sac to expand in area, making the color of the pigment more visible. With the chromatophores actuating individually, cephalopods can create extremely complex skin color patterns, which they utilize for exquisite functions including camouflage and communication. Inspired by this mechanism, we present an artificial chromatophore that can modulate its color pattern in response to light. Multimaterial projection microstereolithography is used to integrate three functional components including a photoactive hydrogel composite with polydopamine nanoparticles (PDA-NPs), acrylic acid hydrogel, and poly(ethylene glycol) diacrylate. In order to generate light-driven actuation of the artificial chromatophore, the photothermal effect of the PDA-NPs, light-responsive deformation of the photoactive hydrogel composite, and the produced mechanical stresses are studied. Mechanical properties and interfacial bonding strengths between different materials are also investigated to ensure structural integrity during actuation. We demonstrate pattern modulation of the light-responsive artificial chromatophores (LACs) with the projection of different light patterns. The LAC may suggest a new concept for various engineering applications such as the camouflage interface, biophotonic device, and flexible display.


Assuntos
Materiais Biomiméticos/química , Hidrogéis/química , Indóis/química , Nanopartículas/química , Polímeros/química , Materiais Inteligentes/química , Animais , Cefalópodes/química , Cromatóforos/química , Luz , Polietilenoglicóis/química , Impressão Tridimensional
10.
Mol Phylogenet Evol ; 155: 106972, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33035681

RESUMO

A central question in the evolution of life-histories is whether organisms reproduce once or repeatedly. For cephalopods, the main differences between semelparous and iteroparous are based on ovulation pattern and spawning type. The different reproductive strategies in coleoid cephalopods could be related to the habitat in which the species dwell (coastal vs. oceanic) and/or to environmental forces, thus, both aspects should be quantitatively evaluated under an evolutionary perspective to reconstruct: (a) the ancestral ovulation type of coleoid cephalopods, and (b) the potential of correlated evolution between ovulation type versus habitat and environment. Ancestral states of ovulation type were estimated using stochastic mapping based on literature data (i.e. synchronous or asynchronous), and this information was combined with a new molecular phylogeny including 165 species. The evolutionary correlation between ovulation type, habitat, and environment was estimated by means of the Markov model comparing the rates of gain and loss. The estimates of ancestral states of ovulation type for coleoid cephalopods resulted in a high probability that Octopodiformes evolved from synchronous ovulation type, and Decapodiformes from asynchronous ovulation type. The three traits evaluated presented phylogenetic signal, although no correlation was found between habitat and ovulation type. Overall, species in stable environments showed a tendency towards synchronous ovulation type, while the asynchronous ovulation pattern was found more frequently in species that live in unstable environments, being this last trait also responsible for triggering the change of ovulation type in some species throughout evolution.


Assuntos
Cefalópodes/classificação , Cefalópodes/fisiologia , Filogenia , Animais , Ecossistema , Feminino , Modelos Teóricos , Ovulação/fisiologia , Reprodução/fisiologia
11.
Biosensors (Basel) ; 10(12)2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33255443

RESUMO

A colorimetric assay, exploiting the combination of loop-mediated isothermal amplification (LAMP) with DNA barcoding, was developed to address the authentication of some cephalopod species, a relevant group in the context of seafood traceability, due to the intensive processing from the fishing sites to the shelf. The discriminating strategy relies on accurate design of species-specific LAMP primers within the conventional 5' end of the mitochondrial COI DNA barcode region and allows for the identification of Loligo vulgaris among two closely related and less valuable species. The assay, coupled to rapid genomic DNA extraction, is suitable for large-scale screenings and on-site applications due to its easy procedures, with fast (30 min) and visual readout.


Assuntos
Cefalópodes/genética , Colorimetria , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Animais , Código de Barras de DNA Taxonômico , Primers do DNA
12.
Sci Rep ; 10(1): 21506, 2020 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-33299075

RESUMO

Trophic niche and diet comparisons among closely sympatric marine species are important to understand complex food webs, particularly in regions most affected by climate change. Using stable isotope analyses, all ontogenetic stages of three sympatric species of Arctic cephalopods (genus Rossia) were studied to assess inter- and intraspecific competition with niche and diet overlap and partitioning in West Greenland and the Barents Sea. Seven traits related to resource and habitat utilization were identified in Rossia: no trait was shared by all three species. High boreal R. megaptera and Arctic endemic R. moelleri shared three traits with each other, while both R. megaptera and R. moelleri shared only two unique traits each with widespread boreal-Arctic R. palpebrosa. Thus all traits formed fully uncrossing pattern with each species having unique strategy of resource and habitat utilization. Predicted climate changes in the Arctic would have an impact on competition among Rossia with one potential 'winner' (R. megaptera in the Barents Sea) but no potential 'losers'.


Assuntos
Decapodiformes/metabolismo , Animais , Regiões Árticas , Cefalópodes/metabolismo , Mudança Climática , Decapodiformes/genética , Dieta , Ecossistema , Cadeia Alimentar , Especiação Genética , Estado Nutricional , Simpatria/genética
13.
Mar Environ Res ; 161: 105049, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33070930

RESUMO

Cephalopods represent an important pathway for mercury transfer through food webs. Due to the general difficulties in capturing oceanic squid, beaks found in the diet of top predators can be used to study their life-cycles and ecological role. Using upper beaks of the giant warty squid Moroteuthopsis longimana (major prey in the Southern Ocean), we describe a method to assess mercury concentrations along the life of cephalopods through the segmentary analysis of beak sections (i.e. tip of the rostrum and subsections along the hood). Distinct total mercury concentrations in the different subsections support that beaks can be used to study mercury levels in different periods of cephalopods' life-cycle. Mercury values in the anterior (1.3-7.9 µg kg-1 dw) and posterior (7.8-12.5 µg kg-1 dw) subsections of the hood reflect juvenile and adult stages, respectively. Furthermore, these results confirm that mercury bioaccumulates continuously throughout the individuals' life, with adults doubling their mercury concentrations to juveniles.


Assuntos
Cefalópodes , Mercúrio , Poluentes Químicos da Água , Animais , Bico/química , Decapodiformes , Cadeia Alimentar , Humanos , Mercúrio/análise , Oceanos e Mares , Poluentes Químicos da Água/análise
14.
Proc Biol Sci ; 287(1937): 20202055, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33081641

RESUMO

The cephalopod visual system is an exquisite example of convergence in biological complexity. However, we have little understanding of the genetic and molecular mechanisms underpinning its elaboration. The generation of new genetic material is considered a significant contributor to the evolution of biological novelty. We sought to understand if this mechanism may be contributing to cephalopod-specific visual system novelties. Specifically, we identified duplications in the Krüppel-like factor/specificity protein (KLF/SP) sub-family of C2H2 zinc-finger transcription factors in the squid Doryteuthis pealeii. We cloned and analysed gene expression of the KLF/SP family, including two paralogs of the DpSP6-9 gene. These duplicates showed overlapping expression domains but one paralog showed unique expression in the developing squid lens, suggesting a neofunctionalization of DpSP6-9a. To better understand this neofunctionalization, we performed a thorough phylogenetic analysis of SP6-9 orthologues in the Spiralia. We find multiple duplications and losses of the SP6-9 gene throughout spiralian lineages and at least one cephalopod-specific duplication. This work supports the hypothesis that gene duplication and neofunctionalization contribute to novel traits like the cephalopod image-forming eye and to the diversity found within Spiralia.


Assuntos
Cefalópodes/fisiologia , Visão Ocular/fisiologia , Animais , Decapodiformes , Evolução Molecular , Duplicação Gênica , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Transcrição Kruppel-Like/metabolismo , Filogenia , Sensibilidade e Especificidade , Fatores de Transcrição
15.
Proc Biol Sci ; 287(1936): 20201919, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33049174

RESUMO

The shells of ammonoid cephalopods are among the most recognizable fossils, whose fractally folded, internal walls (septa) have inspired many hypotheses on their adaptive value. The enduring explanation for their iterative evolution is that they strengthen the shell against pressure at increasing water depths. The fossil record does not definitively support this idea and much of the theoretical mechanical work behind it has suffered from inaccurate testing geometries and conflicting results. By using a different set of mathematical methods compared with previous studies, I generate a system of finite-element models that explore how different parameters affect the shell's response to water pressure. Increasing the number of initial folds of the septa ultimately has little to no effect on the resulting stress in the shell wall or the septum itself. The introduction of higher-order folds does reduce the tensile stress in the shell wall; however, this is coupled with a higher rate of increase of tensile stress in the septum itself. These results reveal that the increase in complexity should not be expected to have a significant effect on the shell's strength and suggests that the evolution of ammonitic septa does not reflect a persistent trend towards deeper-water habitats.


Assuntos
Adaptação Fisiológica , Exoesqueleto/fisiologia , Cefalópodes/fisiologia , Exoesqueleto/anatomia & histologia , Animais , Evolução Biológica
16.
J Anim Ecol ; 89(11): 2692-2703, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32895913

RESUMO

Individual body size strongly influences the trophic role of marine organisms and the structure and function of marine ecosystems. Quantifying trophic position-individual body size relationships (trophic allometries) underpins the development of size-structured ecosystem models to predict abundance and the transfer of energy through ecosystems. Trophic allometries are well studied for fishes but remain relatively unexplored for cephalopods. Cephalopods are important components of coastal, oceanic and deep-sea ecosystems, and they play a key role in the transfer of biomass from low trophic positions to higher predators. It is therefore important to resolve cephalopod trophic allometries to accurately represent them within size-structured ecosystem models. We assessed the trophic positions of cephalopods in an oceanic pelagic (0-500 m) community (sampled by trawling in a cold-core eddy in the western Tasman Sea), comprising 22 species from 12 families, using bulk tissue stable isotope analysis and amino acid compound-specific stable isotope analysis. We assessed whether ontogenetic trophic position shifts were evident at the species-level and tested for the best predictor of community-level trophic allometry among body size, taxonomy and functional grouping (informed by fin and mantle morphology). Individuals in this cephalopod community spanned two trophic positions and fell into three functional groups on an activity level gradient: low, medium and high. The relationship between trophic position and ontogeny varied among species, with the most marked differences evident between species from different functional groups. Activity-level-based functional group and individual body size are best explained by cephalopod trophic positions (marginal R2  = 0.43). Our results suggest that the morphological traits used to infer activity level, such as fin-to-mantle length ratio, fin musculature and mantle musculature are strong predictors of cephalopod trophic allometries. Contrary to established theory, not all cephalopods are voracious predators. Low activity level cephalopods have a distinct feeding mode, with low trophic positions and little-to-no ontogenetic increases. Given the important role of cephalopods in marine ecosystems, distinct feeding modes could have important consequences for energy pathways and ecosystem structure and function. These findings will facilitate trait-based and other model estimates of cephalopod abundance in the changing global ocean.


Assuntos
Cefalópodes , Ecossistema , Animais , Organismos Aquáticos , Cadeia Alimentar , Estado Nutricional , Oceanos e Mares
17.
Curr Biol ; 30(17): R986-R988, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32898496

RESUMO

Cephalopods fascinate us but have been out of the reach of experimental manipulations at the genetic level. A new study describes editing of a gene in a squid using CRISPR.


Assuntos
Cefalópodes , Edição de Genes , Animais , Biologia , Cefalópodes/genética , Decapodiformes/genética , Pigmentação
18.
PLoS One ; 15(8): e0235180, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760063

RESUMO

Nipponites is a heteromorph ammonoid with a complex and unique morphology that obscures its mode of life and ethology. The seemingly aberrant shell of this Late Cretaceous nostoceratid seems deleterious. However, hydrostatic simulations suggest that this morphology confers several advantages for exploiting a quasi-planktic mode of life. Virtual, 3D models of Nipponites mirabilis were used to compute various hydrostatic properties through 14 ontogenetic stages. At each stage, Nipponites had the capacity for neutral buoyancy and was not restricted to the seafloor. Throughout ontogeny, horizontally facing to upwardly facing soft body orientations were preferred at rest. These orientations were aided by the obliquity of the shell's ribs, which denote former positions of the aperture that were tilted from the growth direction of the shell. Static orientations were somewhat fixed, inferred by stability values that are slightly higher than extant Nautilus. The initial open-whorled, planispiral phase is well suited to horizontal backwards movement with little rocking. Nipponites then deviated from this bilaterally symmetric coiling pattern with a series of alternating U-shaped bends in the shell. This modification allows for proficient rotation about the vertical axis, while possibly maintaining the option for horizontal backwards movement by redirecting its hyponome. These particular hydrostatic properties likely result in a tradeoff between hydrodynamic streamlining, suggesting that Nipponites assumed a low energy lifestyle of slowly pirouetting in search for planktic prey. Each computed hydrostatic property influences the others in some way, suggesting that Nipponites maintained a delicate hydrostatic balancing act throughout its ontogeny in order to facilitate this mode of life.


Assuntos
Exoesqueleto/crescimento & desenvolvimento , Evolução Biológica , Cefalópodes/fisiologia , Movimento/fisiologia , Exoesqueleto/anatomia & histologia , Animais , Cefalópodes/anatomia & histologia , Pressão Hidrostática , Modelos Anatômicos
19.
Sci Rep ; 10(1): 11303, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32647209

RESUMO

We compiled an updated global catalogue of parasites in cephalopods. Data were used to assess changes in taxonomic distinctness of parasites over two centuries and across the world's oceans, to quantify turnover and nestedness components of parasite ß-diversity, and to attempt estimating their γ-diversity at a global scale. A total of 309 parasites infecting 164 cephalopods were found. We hypothesize that this diversity counts for less than half the potential parasite richness in this molluscan taxon. Taxonomic breadth of parasites was significantly above expectations from null models for Mediterranean Sea and NE Atlantic Ocean, whereas the opposite occurred for NW Pacific Ocean, where a few closely related genera characterized the parasite pool. ß-diversity of parasites was very high and dominated by turnover, except for the Atlantic Ocean where a nested pattern among sub-basins emerged. Taxonomic relatedness of parasite species remained substantially unchanged through time, but species replacements largely occurred over the last two centuries. Our findings highlighted potential hotspots of taxonomic distinctness in cephalopod parasites, geographic regions deserving future research, and the need for a deeper understanding of the magnitude of marine parasite diversity, their biogeography, and their role in marine ecosystems. Our global overview may represent a baseline step for future advances in this direction.


Assuntos
Cefalópodes/parasitologia , Doenças dos Peixes/parasitologia , Parasitos/classificação , Animais , Biodiversidade , Bases de Dados Factuais , Interações Hospedeiro-Parasita
20.
Int J Biol Macromol ; 163: 1223-1232, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32652154

RESUMO

Angiotensin converting enzyme (ACE) is a multifunctional enzyme involved in translation of angiotensin-I (AngI) to vasoconstrictor angiotensin-II (AngII). A sulfated N-acetylglucosamino-glucuronopyranosyl-arabinopyranan characterized as poly-[(2-methoxy-ß-arabinopyranosyl)-(1 â†’ 3)-(ß-glucurono)-(1 â†’ 4)-(2-acetamido-2-deoxy-3,6-di-O-sulfonato-ß-glucopyranose)] was purified and reported first time from the edible portion of Amphioctopus neglectus and evaluated for various pharmacological properties. The polysaccharide exhibited potential ACE attenuation property (IC50 0.11 mg mL-1), whereas molecular docking simulations displayed its efficient binding at the ACE active site with lesser inhibitory constant (Ki) of 17.36 nM and binding energy (-10.59 kcal mol-1). The in-vitro analysis showed that the studied polysacharide attenuated AngII prompted cardiac hypertrophy at 50 µg mL-1 in the cardiomyoblast cells, whereas 48% reduction in cellular surface area with extended viability could be correlated with anti-hypertrophic properties of the studied polysaccharide. The sulfated N-acetylglucosamino-glucuronopyranosyl-arabinopyranan purified from A. neglectus could function as a prospective functional lead against the pathophysiological conditions leading to hypertension.


Assuntos
Acetilglucosamina/química , Acetilglucosamina/farmacologia , Alimentos Marinhos/análise , Sulfatos/química , Acetilglucosamina/isolamento & purificação , Angiotensina II/efeitos adversos , Angiotensina II/metabolismo , Animais , Anti-Hipertensivos/química , Anti-Hipertensivos/isolamento & purificação , Anti-Hipertensivos/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Cardiomegalia/tratamento farmacológico , Cardiomegalia/etiologia , Cardiomegalia/metabolismo , Cefalópodes/química , Suscetibilidade a Doenças , Humanos , Espectroscopia de Ressonância Magnética , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Monossacarídeos/química , Peptidil Dipeptidase A/metabolismo , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...