Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.644
Filtrar
1.
Nat Commun ; 13(1): 2390, 2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35501345

RESUMO

Innovations relating to the consumption of hard prey are implicated in ecological shifts in marine ecosystems as early as the mid-Paleozoic. Lungfishes represent the first and longest-ranging lineage of durophagous vertebrates, but how and when the various feeding specializations of this group arose remain unclear. Two exceptionally preserved fossils of the Early Devonian lobe-finned fish Youngolepis reveal the origin of the specialized lungfish feeding mechanism. Youngolepis has a radically restructured palate, reorienting jaw muscles for optimal force transition, coupled with radiating entopterygoid tooth rows like those of lungfish toothplates. This triturating surface occurs in conjunction with marginal dentition and blunt coronoid fangs, suggesting a role in crushing rather than piercing prey. Bayesian tip-dating analyses incorporating these morphological data indicate that the complete suite of lungfish feeding specializations may have arisen in as little as 7 million years, representing one of the most striking episodes of innovation during the initial evolutionary radiations of bony fishes.


Assuntos
Ecossistema , Dente , Animais , Teorema de Bayes , Peixes/anatomia & histologia , Fósseis
2.
Vet Parasitol ; 303: 109667, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35124292

RESUMO

Trichodinids are problematic ectoparasites for intensive arapaima fish farming, which can make their breeding costly and unprofitable. The search for effective and safe therapeutic molecules is constant, and chloramine-T has stood out as an effective biocide to treat various pathogens in aquaculture. Here we investigated the acute toxicity (LC50-4h) of chloramine-T and its behavioural, morphological, histological, physiological, and antiparasitic effects on the control of trichodinids in arapaima juveniles. Initially arapaima were exposed to chloramine-T (0, 10, 20, 40, 50, 60, 80, 100 mg L-1) for 4 h. During this period, behavioural, morphological, and mortality changes were recorded. Immediately after a toxicity test, gills were collected for the histological analysis. The LC50-4h was calculated at 23.8 mg L-1 of chloramine-T. Behavioural changes like erratic swimming, loss of balance, gasping at the water surface, excessive mucus, jumping at the water surface, lethargy and gill hyperventilation, and morphological changes like loss of scales, ocular opacity, and skin darkening, were considered mild in arapaima exposed to 10 and 20 mg L-1 of chloramine-T for 4 h. The arapaima gills exposed to 10, 20 and, 40 mg L-1 of chloramine-T presented epithelial hyperplasia, dilated venous sinus and eosinophilic infiltrate, but they were reversible and of a low pathological degree. Based on the acute toxicity test (LC50-4h) results, concentrations were defined for the in vivo efficacy test, during which arapaima were exposed to 0, 10, 15, and 20 mg L-1 of chloramine-T for 1 h. After a therapeutic bath, physiological and parasitological analyses were performed. The use of 20 mg L-1 of chloramine-T significantly reduced (p < 0.05) parasitism by Trichodina sp. with an efficacy of 50.27 % and 53.23 % in gills and on the body surface, respectively. Chloramine-T did not change haematological parameters (erythrogram and thrombogram) or the biochemical parameters of arapaima after 1 h of exposure. However, monocytosis and neutrophilia were noted at slightly higher concentrations (15 and 20 mg L-1), but changes in fish homeostasis were not characterised. Thus, we demonstrate that the application of a therapeutic bath with 20 mg L-1 of chloramine-T for 1 h reduces parasitism by trichodinids and does not affect general arapaima juvenile health.


Assuntos
Peixes , Brânquias , Animais , Aquicultura , Cloraminas , Peixes/anatomia & histologia , Peixes/fisiologia , Brânquias/parasitologia , Compostos de Tosil
3.
Bioinspir Biomim ; 17(3)2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35073526

RESUMO

Remora suckerfish (Echeneis naucrates) can perform skimming and sliding motions on the surfaces of moving hosts to optimize adhesion positions. We found that remora achieve skimming and sliding motions through coordinated movement of the suction disc's lamellae and lip locomotion through live animal observations. We implemented an integrated biomimetic remora suction disc based on morphological and kinematic data of biological remoras. With soft actuators enabling 'compression-rotation' and 'compression-extension', the biomimetic disc controls the disc lip and lamellar movement under driving with only one degree of freedom, and can switch freely between three states: zero, low-friction, and robust adhesion. Then we investigate the effects of the biomimetic suction-disc soft-lip material, preload, and lamellar movement on the tangential friction force (both forward and backward) under different adhesion states. This biomimetic suction disc with a low-modulus soft lip can adhere to a smooth surface under 0.1 N preload and achieve normal adhesion-force and tangential frictional-force control ranges spanning ∼10-1to ∼102N and ∼10-1to ∼101N, respectively. The results reveal how remora disc achieved fast, tunable adhesion for skimming and sliding on surfaces. Furthermore, we demonstrate a bio-inspired robot capable of attachment, detachment, skimming, and sliding motions with the aiding of simple biomimetic pectoral-fin flapping. This study lays a foundation for future integrated applications of underwater adhesion robots and related biomechanical exploration.


Assuntos
Biomimética , Perciformes , Animais , Fenômenos Biomecânicos , Peixes/anatomia & histologia , Fenômenos Físicos
4.
PLoS One ; 17(1): e0262281, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34995331

RESUMO

Ensuring the accuracy of age estimation in fisheries science through validation is an essential step in managing species for long-term sustainable harvest. The current study used Δ14 C in direct validation of age estimation for queen triggerfish Balistes vetula and conclusively documented that triggerfish sagittal otoliths provide more accurate and precise age estimates relative to dorsal spines. Caribbean fish samples (n = 2045) ranged in size from 67-473 mm fork length (FL); 23 fish from waters of the southeastern U.S. (SEUS) Atlantic coast ranged in size from 355-525 mm FL. Otolith-based age estimates from Caribbean fish range from 0-23 y, dorsal spine-based age estimates ranged from 1-14 y. Otolith-based age estimates for fish from the SEUS ranged from 8-40 y. Growth function estimates from otoliths in the current study (L∞ = 444, K = 0.13, t0 = -1.12) differed from spined-derived estimates in the literature. Our work indicates that previously reported maximum ages for Balistes species based on spine-derived age estimates may underestimate longevity of these species since queen triggerfish otolith-based ageing extended maximum known age for the species by nearly three-fold (14 y from spines versus 40 y from otoliths). Future research seeking to document age and growth population parameters of Balistes species should strongly consider incorporating otolith-based ageing in the research design.


Assuntos
Peixes/fisiologia , Membrana dos Otólitos/química , Envelhecimento , Animais , Radioisótopos de Carbono/análise , Pesqueiros , Peixes/anatomia & histologia , Peixes/crescimento & desenvolvimento , Longevidade , Membrana dos Otólitos/anatomia & histologia , Datação Radiométrica
5.
Science ; 375(6576): 101-104, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34990239

RESUMO

Climate change is expected to result in smaller fish size, but the influence of fishing has made it difficult to substantiate the theorized link between size and ocean warming and deoxygenation. We reconstructed the fish community and oceanographic conditions of the most recent global warm period (last interglacial; 130 to 116 thousand years before present) by using sediments from the northern Humboldt Current system off the coast of Peru, a hotspot of small pelagic fish productivity. In contrast to the present-day anchovy-dominated state, the last interglacial was characterized by considerably smaller (mesopelagic and goby-like) fishes and very low anchovy abundance. These small fish species are more difficult to harvest and are less palatable than anchovies, indicating that our rapidly warming world poses a threat to the global fish supply.


Assuntos
Mudança Climática , Ecossistema , Peixes , Sedimentos Geológicos , Oxigênio/análise , Água do Mar , Animais , Tamanho Corporal , Peixes/anatomia & histologia , Oceano Pacífico , Paleontologia , Peru , Água do Mar/química , Temperatura
6.
J Fish Biol ; 100(2): 519-531, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34822177

RESUMO

The pearlside Maurolicus stehmanni is one of the most abundant mesopelagic fishes off south-eastern Brazil and plays a key role in the regional ecosystem. However, its early life history remains poorly understood. This study examined the M. stehmanni early life stages, from eggs to juveniles, including all developmental changes in external morphology. Larvae are simple in morphology and lack specialized larval structures. Notochord flexion begins at ~5.15 mm body length (BL) and larvae ≥5.95 mm BL are flexed. The relative growth of seven measured larval characters (head length, body depth, snout length, eye diameter, pre-dorsal length, pre-ventral length and pre-anal length) have transition points (allometric inflexion points), indicating biphasic growth patterns which are likely related to shifts in habitat use, feeding and behaviour. Larval development is similar to that of other Maurolicus species. The relatively fast development of the fins, photophores, swimbladder and pigmentation suggests a precocious adoption of a micronektonic lifestyle in the mesopelagic environment.


Assuntos
Ecossistema , Peixes , Nadadeiras de Animais , Animais , Brasil , Peixes/anatomia & histologia , Larva
7.
J Comp Neurol ; 530(8): 1231-1246, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34729771

RESUMO

Although all vertebrate cerebella contain granule cells, Purkinje cells, and efferent neurons, the cellular arrangement and neural circuitry are highly diverse. In amniotes, cerebellar efferent neurons form clusters, deep cerebellar nuclei, lie deep in the cerebellum, and receive synaptic inputs from Purkinje cells but not granule cells. However, in the cerebellum of teleosts, the efferent neurons, called eurydendroid cells, lie near the cell bodies of Purkinje cells and receive inputs both from axons of Purkinje cells and granule cell parallel fibers. It is largely unknown how the cerebellar structure evolved in ray-finned fish (actinopterygians). To address this issue, we analyzed the cerebellum of a bichir Polypterus senegalus, one of the most basal actinopterygians. We found that the cell bodies of Purkinje cells are not aligned in a layer; incoming climbing fibers terminate mainly on the basal portion of Purkinje cells, revealing that the Polypterus cerebellum has unique features among vertebrate cerebella. Retrograde labeling and marker analyses of the efferent neurons revealed that their cell bodies lie in restricted granular areas but not as deep cerebellar nuclei in the cerebellar white matter. The efferent neurons have long dendrites like eurydendroid cells, although they do not reach the molecular layer. Our findings suggest that the efferent system of the bichir cerebellum has intermediate features between teleosts and amniote vertebrates, and provides a model to understand the basis generating diversity in actinopterygian cerebella.


Assuntos
Cerebelo , Células de Purkinje , Animais , Axônios , Peixes/anatomia & histologia , Neurônios
8.
J Morphol ; 283(3): 255-272, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34951741

RESUMO

Rhyacichthys aspro is a "basal" taxon in the Suborder Gobioidei of the teleost order Gobiiformes. We provide detailed descriptions of the reproductive morphology of adult males and females to assess the diagnostic reproductive morphological characters of this speciose clade of bony fishes. Female R. aspro are asynchronous spawners: they are able to spawn more than once in a breeding season. Oocytes are inferred to have short attachment filaments. A conspicuous feature of the external anatomy of the reproductive system (RSy) of female R. aspro is an ornate fimbriate pad upon which the urogenital papilla rests. The male reproductive system is characterized by an intralobar collection system in both the testicular and secretory lobes, termed the "sperm-collecting canal" and "milt-collecting canal," respectively. These may provide additional storage for sperm and milt. The spermatogenic lobe, or testis, is that portion of the male gobioid RSy comprising seminiferous lobules and separate from other RSy components. The secretory lobe is that portion of the male gobioid reproductive system that consists of secretory lobules and is separated from other components of the male RSy. The secretory lobe has also been called, in English, the sperm-duct gland, accessory gonadal structure, or seminal vesicle, and is endorsed as a synapomorphy of gobioid fishes.


Assuntos
Perciformes , Animais , Feminino , Peixes/anatomia & histologia , Gônadas , Masculino , Espermatozoides , Testículo/anatomia & histologia
9.
J Anat ; 240(1): 34-49, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34423431

RESUMO

Ancestors of the Antarctic icefishes (family Channichthyidae) were benthic and had no swim bladder, making it energetically expensive to rise from the ocean floor. To exploit the water column, benthopelagic icefishes were hypothesized to have evolved a skeleton with "reduced bone," which gross anatomical data supported. Here, we tested the hypothesis that changes to icefish bones also occurred below the level of gross anatomy. Histology and micro-CT imaging of representative craniofacial bones (i.e., ceratohyal, frontal, dentary, and articular) of extant Antarctic fish species specifically evaluated two features that might cause the appearance of "reduced bone": bone microstructure (e.g., bone volume fraction and structure linear density) and bone mineral density (BMD, or mass of mineral per volume of bone). Measures of bone microstructure were not consistently different in bones from the icefishes Chaenocephalus aceratus and Champsocephalus gunnari, compared to the related benthic notothenioids Notothenia coriiceps and Gobionotothen gibberifrons. Some quantitative measures, such as bone volume fraction and structure linear density, were significantly increased in some icefish bones compared to homologous bones of non-icefish. However, such differences were rare, and no microstructural measures were consistently different in icefishes across all bones and species analyzed. Furthermore, BMD was similar among homologous bones of icefish and non-icefish Antarctic notothenioids. In summary, "reduced bone" in icefishes was not due to systemic changes in bone microstructure or BMD, raising the prospect that "reduced bone" in icefish occurs only at the gross anatomic level (i.e., smaller or fewer bones). Given that icefishes exhibit delayed skeletal development compared to non-icefish Antarctic fishes, combining these phenotypic data with genomic data might clarify genetic changes driving skeletal heterochrony.


Assuntos
Densidade Óssea , Perciformes , Animais , Regiões Antárticas , Peixes/anatomia & histologia , Perciformes/anatomia & histologia
10.
Proc Natl Acad Sci U S A ; 118(49)2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34853171

RESUMO

Fishes exhibit an astounding diversity of locomotor behaviors from classic swimming with their body and fins to jumping, flying, walking, and burrowing. Fishes that use their body and caudal fin (BCF) during undulatory swimming have been traditionally divided into modes based on the length of the propulsive body wave and the ratio of head:tail oscillation amplitude: anguilliform, subcarangiform, carangiform, and thunniform. This classification was first proposed based on key morphological traits, such as body stiffness and elongation, to group fishes based on their expected swimming mechanics. Here, we present a comparative study of 44 diverse species quantifying the kinematics and morphology of BCF-swimming fishes. Our results reveal that most species we studied share similar oscillation amplitude during steady locomotion that can be modeled using a second-degree order polynomial. The length of the propulsive body wave was shorter for species classified as anguilliform and longer for those classified as thunniform, although substantial variability existed both within and among species. Moreover, there was no decrease in head:tail amplitude from the anguilliform to thunniform mode of locomotion as we expected from the traditional classification. While the expected swimming modes correlated with morphological traits, they did not accurately represent the kinematics of BCF locomotion. These results indicate that even fish species differing as substantially in morphology as tuna and eel exhibit statistically similar two-dimensional midline kinematics and point toward unifying locomotor hydrodynamic mechanisms that can serve as the basis for understanding aquatic locomotion and controlling biomimetic aquatic robots.


Assuntos
Peixes/anatomia & histologia , Peixes/fisiologia , Natação/fisiologia , Nadadeiras de Animais/anatomia & histologia , Animais , Biodiversidade , Fenômenos Biomecânicos/fisiologia , Comportamento Cooperativo , Peixes/classificação , Hidrodinâmica , Locomoção/fisiologia , Especificidade da Espécie
11.
PLoS One ; 16(7): e0246466, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34319974

RESUMO

Badis kaladanensis, a new percoid fish is described from the Kaladan basin of Mizoram, northeast India. It belongs to the Badis badis species group but can be easily distinguished from its congeners, except from B. kanabos and B. tuivaiei, in having a dark blotch on the dorsal fin between the base of 3rd to 5th spines. It is further distinguished from B. kanabos in having more scales in lateral row (27-30 vs. 25-26), more circumpeduncular scale rows (18-20 vs. 16-17) and smaller eye (7.5-8.9% SL vs. 9.5-12.7); and from B. tuivaiei in having fewer vertebrae (28-29 vs. 30-31) and more rakers on the first gill arch (9 vs. 6-8). The analysis of the mitochondrial DNA (coi and cytb) revealed the distinctness of B. kaladanensis from all other Badis species with the interspecific distance ranges from 5.4-20.4%. (coi) and 5.1-26.3% (cytb).


Assuntos
Peixes/anatomia & histologia , Animais , Tamanho Corporal , Índia , Tamanho do Órgão , Rios
12.
Zool Res ; 42(4): 492-501, 2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34235898

RESUMO

Fish morphological phenotypes are important resources in artificial breeding, functional gene mapping, and population-based studies in aquaculture and ecology. Traditional morphological measurement of phenotypes is rather expensive in terms of time and labor. More importantly, manual measurement is highly dependent on operational experience, which can lead to subjective phenotyping results. Here, we developed 3DPhenoFish software to extract fish morphological phenotypes from three-dimensional (3D) point cloud data. Algorithms for background elimination, coordinate normalization, image segmentation, key point recognition, and phenotype extraction were developed and integrated into an intuitive user interface. Furthermore, 18 key points and traditional 2D morphological traits, along with 3D phenotypes, including area and volume, can be automatically obtained in a visualized manner. Intuitive fine-tuning of key points and customized definitions of phenotypes are also allowed in the software. Using 3DPhenoFish, we performed high-throughput phenotyping for four endemic Schizothoracinae species, including Schizopygopsis younghusbandi, Oxygymnocypris stewartii, Ptychobarbus dipogon, and Schizothorax oconnori. Results indicated that the morphological phenotypes from 3DPhenoFish exhibited high linear correlation (>0.94) with manual measurements and offered informative traits to discriminate samples of different species and even for different populations of the same species. In summary, we developed an efficient, accurate, and customizable tool, 3DPhenoFish, to extract morphological phenotypes from point cloud data, which should help overcome traditional challenges in manual measurements. 3DPhenoFish can be used for research on morphological phenotypes in fish, including functional gene mapping, artificial selection, and conservation studies. 3DPhenoFish is an open-source software and can be downloaded for free at https://github.com/lyh24k/3DPhenoFish/tree/master.


Assuntos
Peixes/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/veterinária , Software , Animais , Peixes/classificação , Imageamento Tridimensional/métodos , Reprodutibilidade dos Testes , Especificidade da Espécie
13.
Sci Rep ; 11(1): 13878, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34230512

RESUMO

Changes to calcium carbonate (CaCO3) biomineralization in aquatic organisms is among the many predicted effects of climate change. Because otolith (hearing/orientation structures in fish) CaCO3 precipitation and polymorph composition are controlled by genetic and environmental factors, climate change may be predicted to affect the phenotypic plasticity of otoliths. We examined precipitation of otolith polymorphs (aragonite, vaterite, calcite) during early life history in two species of sturgeon, Lake Sturgeon, (Acipenser fulvescens) and White Sturgeon (A. transmontanus), using quantitative X-ray microdiffraction. Both species showed similar fluctuations in otolith polymorphs with a significant shift in the proportions of vaterite and aragonite in sagittal otoliths coinciding with the transition to fully exogenous feeding. We also examined the effect of the environment on otolith morphology and polymorph composition during early life history in Lake Sturgeon larvae reared in varying temperature (16/22 °C) and pCO2 (1000/2500 µatm) environments for 5 months. Fish raised in elevated temperature had significantly increased otolith size and precipitation of large single calcite crystals. Interestingly, pCO2 had no statistically significant effect on size or polymorph composition of otoliths despite blood pH exhibiting a mild alkalosis, which is contrary to what has been observed in several studies on marine fishes. These results suggest climate change may influence otolith polymorph composition during early life history in Lake Sturgeon.


Assuntos
Carbonato de Cálcio/metabolismo , Dióxido de Carbono/farmacologia , Peixes/crescimento & desenvolvimento , Peixes/metabolismo , Membrana dos Otólitos/química , Temperatura , Animais , Peixes/anatomia & histologia
14.
Sci Rep ; 11(1): 11812, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083600

RESUMO

The positive correlation between speciation rates and morphological evolution expressed by body size is a macroevolutionary trait of vertebrates. Although taxic diversification and morphological evolution are slow in coelacanths, their fossil record indicates that large and small species coexisted, which calls into question the link between morphological and body size disparities. Here, we describe and reassess fossils of giant coelacanths. Two genera reached up to 5 m long, placing them among the ten largest bony fish that ever lived. The disparity in body size adjusted to taxic diversity is much greater in coelacanths than in ray-finned fishes. Previous studies have shown that rates of speciation and rates of morphological evolution are overall low in this group, and our results indicate that these parameters are decoupled from the disparity in body size in coelacanths. Genomic and physiological characteristics of the extant Latimeria may reflect how the extinct relatives grew to such a large size. These characteristics highlight new evolutionary traits specific to these "living fossils".


Assuntos
Biodiversidade , Variação Biológica Individual , Tamanho Corporal , Peixes/anatomia & histologia , Peixes/classificação , Animais , Evolução Biológica , Fósseis
15.
Zootaxa ; 4975(2): 389396, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34186558

RESUMO

The new sardine Sardinella ventura n. sp. (Teleostei: Clupeiformes: Clupeidae) is described on the basis of 10 specimens collected from Mauritius. The new species is most similar to Sardinella dayi Regan 1917 in having non-deciduous scales with pores and discontinuous striae, a dark spot on the dorsal-fin origin, the pelvic fin with 8 rays, and similar number of gill rakers, in addition to very similar numbers of keeled scutes. However, the new species is distinguished from S. dayi by having a shorter caudal peduncle [6.27.6% SL (mean 7.0%) vs. 8.212.0% (9.2%) in S. dayi], larger eye [8.49.9% (9.0%) vs. 6.88.0% (7.4%)] and orbit [9.612.3% (10.7%) vs. 8.510.2% (9.3%)], longer pectoral [21.022.7% (21.5%) vs. 17.021.0% (19.8%)] and pelvic fins [12.513.5% (12.8%) vs. 10.412.2% (11.2%)], and a greater numbers of pseudobranchial filaments [1719 (modally 17) vs. 1822 (19)], lateral scale rows in longitudinal series [4143 (41) vs. 3842 (40)] and transverse scales [11 or 12 (12) vs. 11]. There were significant differences in seven meristic and 14 morphometric characters between the two species.


Assuntos
Peixes/anatomia & histologia , Peixes/classificação , Animais , Brânquias , Maurício
16.
Zootaxa ; 4981(1): 123136, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34186952

RESUMO

A new endemic species of triplefin Ruanoho scurra is described from deep water (108216 m) on the shelf region around coastal New Zealand (Northland to Stewart Island). It is differentiated from its congeners by the combination of fresh colour (bright yellow spots on the head and anterior body, oblique lines on the dorsal and anal fins, and sub-vertical lines on the caudal) as well as some proportional measurements. Comments are made on the relationship with its congeners, and evolutionary history of the family in New Zealand waters, along with observations on the habitat in which this new species is found. This paper formally describes the species first mentioned in Stewart Clements 2015:1523 as the polkadot triplefin.


Assuntos
Peixes/anatomia & histologia , Peixes/classificação , Animais , Ecossistema , Nova Zelândia
17.
Integr Comp Biol ; 61(2): 550-572, 2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34114010

RESUMO

Fishes are the longest persisting living vertebrates and as such, display an incredible array of diversity. Variation in the tail, or caudal fin, is often a reflection of a fish's environment, and affects movement, predation, defense, and reproduction. Previous literature has discussed many aspects of caudal fin form and function in particular taxonomic groups; however, no previous work has synthesized these studies in order to detail how the caudal fin is structured, and what purpose this structure serves, throughout the phylogeny of fishes. This review examines the caudal fin throughout the main lineages of fish evolution, and highlights where changes in shape and usage have occurred. Such novelties in form and function tend to have far-reaching evolutionary consequences. Through integration of past and present work, this review creates a coherent picture of caudal fin evolution. Patterns and outliers that demonstrate how form and function of this appendage are intertwined can further inform hypotheses that fill critical gaps in knowledge concerning the caudal fin.


Assuntos
Nadadeiras de Animais/anatomia & histologia , Peixes , Animais , Peixes/anatomia & histologia , Peixes/genética , Filogenia , Comportamento Predatório
18.
Proc Natl Acad Sci U S A ; 118(25)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34140413

RESUMO

Multicontrast X-ray imaging with high resolution and sensitivity using Talbot-Lau interferometry (TLI) offers unique imaging capabilities that are important to a wide range of applications, including the study of morphological features with different physical properties in biological specimens. The conventional X-ray TLI approach relies on an absorption grating to create an array of micrometer-sized X-ray sources, posing numerous limitations, including technical challenges associated with grating fabrication for high-energy operations. We overcome these limitations by developing a TLI system with a microarray anode-structured target (MAAST) source. The MAAST features an array of precisely controlled microstructured metal inserts embedded in a diamond substrate. Using this TLI system, tomography of a Drum fish tooth with high resolution and tri-contrast (absorption, phase, and scattering) reveals useful complementary structural information that is inaccessible otherwise. The results highlight the exceptional capability of high-resolution multicontrast X-ray tomography empowered by the MAAST-based TLI method in biomedical applications.


Assuntos
Tomografia Computadorizada por Raios X , Animais , Análise de Dados , Eletrodos , Peixes/anatomia & histologia , Imageamento Tridimensional , Interferometria , Iluminação , Dente/anatomia & histologia , Dente/diagnóstico por imagem
19.
Appl Opt ; 60(17): 5227-5235, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34143092

RESUMO

In this paper, we present the imaging formation process of the piecewise mirror eyes of the deep-sea spookfish, which has a strange combination of refractive and reflective eyes. The biological reflective eye structure is formulated to the curved surface's flat mirror array. Zemax is utilized to evaluate optical features such as the modulation transfer function, distortion, and imaging performances. However, the natural images are highly distorted, and the resolution is lower than expected. Therefore, we increase the number of piecewise mirrors of the fisheye to see higher quality images, which can be improved entirely by the mirror shapes. Finally, the fisheye's imaging analysis reveals the deep-sea creature's resolution limit and also shows the possibility of artificial and biomimetic camera applications.


Assuntos
Olho/anatomia & histologia , Peixes/anatomia & histologia , Imagem Óptica/instrumentação , Animais , Biomimética , Desenho de Equipamento , Modelos Teóricos , Oceanos e Mares , Fenômenos Ópticos , Visão Ocular/fisiologia
20.
PLoS One ; 16(6): e0252780, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34115773

RESUMO

Body and head shape among fishes both vary between environments influenced by water velocity and across ontogeny. Although the shape changes associated with variation in average water velocity and ontogeny are well documented, few studies have tested for the interaction between these two variables (i.e., does ontogenetic shape variation differ between velocity environments). We use geometric morphometrics to characterize shape differences in Trichomycterus areolatus, a freshwater catfish found in high and low-velocity environments in Chile. We identify a significant interaction between velocity environment and body size (i.e., ontogeny). Ontogenetic patterns of shape change are consistent with other studies, but velocity environment differentially affects the ontogenetic trajectory of shape development in T. areolatus. Shape change over ontogeny appears more constrained in high-velocity environments compared to low-velocity environments.


Assuntos
Ecossistema , Peixes/fisiologia , Somatotipos , Adaptação Fisiológica , Animais , Peixes/anatomia & histologia , Hidrodinâmica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...