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1.
Arq. bras. med. vet. zootec. (Online) ; 72(1): 285-289, Jan.-Feb. 2020. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1088930

RESUMO

As águas do rio Tocantins têm sofrido descargas de dejetos tóxicos que ameaçam a biota aquática. Para tanto, a investigação das brânquias de peixes atua como biomonitoramento, visto que esses órgãos respondem por meio de adaptações a xenobióticos. Este trabalho teve como objetivo avaliar a ocorrência de alterações morfológicas das espécies de Psectrogaster amazonica, Pimelodina flavipinnis e Pimelodus blochii. As coletas ocorreram nas estações chuvosa e seca. As brânquias de todos os espécimes coletados foram processadas de acordo com metodologia específica para protocolo de hematoxilina e eosina. As principais alterações histológicas observadas no período chuvoso foram: hiperplasia, destacamento do epitélio filamentar, fusão parcial e total das lamelas secundárias, congestão, aneurisma e encurtamento das lamelas respiratórias. Em relação ao período seco, as principais lesões observadas foram: ruptura do epitélio, aneurisma, hiperplasia e necrose. Considerando a diversidade ictiológica do rio Tocantins, o presente estudo propiciará o conhecimento da condição das brânquias, órgão imprescindível para a saúde do peixe, e consequentemente a compreensão das implicações sobre a qualidade das águas do rio Tocantins.(AU)


Assuntos
Animais , Peixes-Gato/anatomia & histologia , Caraciformes/anatomia & histologia , Brânquias/anatomia & histologia , Brasil , Água Doce
2.
Zootaxa ; 4571(3): zootaxa.4571.3.12, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-31715812

RESUMO

Mostly, gills are simple lamellate structures, but in decapods they can assume three elaborate morphologies: trichobranchiate, phyllobranchiate and dendrobranchiate. The dendrobranchiate gill, typically found among the suborder Dendrobranchiata, primarily consists of a long central axis, from which arises a series of paired secondary branches. Each secondary branch is subdivided into smaller fingerlike tertiary processes, and each fingerlike process is also branched (dendritic). The family Solenoceridae is known for having the dendrobranchiate type. Examen of 50 species of Solenoceridae from all nine genera, revealed a new pattern to the classic dendrobranchiate type in 14 species of Solenocera and in Mesopenaeus tropicalis. This new pattern consists of the flattening of the secondary and tertiary processes, with tertiary processes also having a wide, flattened, lamella-like base. This new pattern is herein described as a dendrolamellate gill.


Assuntos
Brânquias , Animais , Brânquias/anatomia & histologia
3.
PLoS One ; 14(7): e0217915, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31291277

RESUMO

Knodus nuptialis n. sp. is described from the Rio Curuá drainage, Rio Xingu basin, Brazil. It can be diagnosed from its congeners by having dentary teeth decreasing gradually in size posteriorly, outer premaxillary teeth row with five cusps, 12-15 branched anal-fin rays and a single humeral spot. The species presents notable sexual dimorphism consisting of densely concentrated nuptial tubercles on head, body, and fins, gill-gland, and bony hooks in the anal fin of mature males. It was found that these sexually dimorphic features are useful and functional in males of the new species only during the reproductive season and after this period, they become atrophied, and eventually disappear. The list of characiform species presenting breeding tubercles is updated and nine species and two genera of the Characidae, Deuterodon and Bryconacidnus, are for the first time reported to have breeding tubercles.


Assuntos
Characidae/anatomia & histologia , Characidae/classificação , Nadadeiras de Animais/anatomia & histologia , Animais , Characidae/fisiologia , Feminino , Brânquias/anatomia & histologia , Masculino , Caracteres Sexuais
4.
J Fish Biol ; 95(3): 802-811, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31192469

RESUMO

In order to assess the accuracy and reliability of age estimates from calcified structures in the three-spined stickleback Gasterosteus aculeatus, we evaluated intra and inter-reader repeatability from three structures: otoliths, gill covers and pelvic spines). Average age estimates were also compared between the structures. The overall intra-reader repeatability of age estimates were highest for otoliths (69%), lowest for gill covers (53%) and intermediate for spine cross-sections (63%). Although four of the seven readers had the highest intra-reader repeatability score for spine cross-sections, the inter-reader variance in this structure was much higher than in others. Otoliths were the easiest in terms of their pre-analysis treatment and exchange of materials (as digital images) between readers. In addition, otoliths are more well-studied compared with the other structures with respect to their development through ontogenesis; hence, age estimates based on otoliths should be the most reliable. Therefore, our recommendation is that whenever possible, analysis of otoliths should be the preferred approach for aging G. aculeatus.


Assuntos
Brânquias/anatomia & histologia , Membrana dos Otólitos/anatomia & histologia , Smegmamorpha/crescimento & desenvolvimento , Animais , Reprodutibilidade dos Testes , Smegmamorpha/anatomia & histologia
5.
J Fish Dis ; 42(9): 1259-1270, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31197843

RESUMO

In this study, we describe an abnormal ectopically mineralized structure (EMS) that was found inside the skull of a juvenile Sparus aurata that also showed a bilateral opercular deformation. The overall phenotype and tissue composition were studied using micro-CT scanning and histological analyses. The ectopic structure occupies a large volume of the brain cavity, partially extruding into the gill cavity. It shows a dense mineralization and an extracellular matrix-rich phenotype, with variation in both the morphology and size of the cell lacunae, combined with an irregular fibre organization inside the matrix. This study is the first to report such an EMS in a juvenile teleost fish, where the tissue does not resemble any other connective tissue type described in bony fish so far. The tissue phenotype seems to rule out that the EMS corresponds to a tumorous cartilage. Yet, it is rather reminiscent of a highly mineralized structure found in cartilaginous fish, where it is suggested to be associated with damage repair.


Assuntos
Calcificação Fisiológica , Brânquias/anatomia & histologia , Dourada/anormalidades , Animais , Brânquias/fisiologia , Dourada/anatomia & histologia , Dourada/fisiologia , Microtomografia por Raio-X/veterinária
6.
J Fish Biol ; 95(2): 502-509, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31073988

RESUMO

Deep sea habitats tend to favor species with low energetic demands, and therefore we predict that deep sea fishes will have behavioral and morphological specializations of the gill ventilatory system to reduce the energetic cost of pumping water across the gills. However, it is difficult to study functional morphology of deep sea fishes due the lack of ability to conduct laboratory experiments with living fishes. For this study, we combined analysis of publicly available video recorded by remote-operated vehicles (ROV) with detailed anatomical study of museum specimens to document the functional morphology of the massive gill chambers that are observed in coffinfishes (Lophiiformes: Chaunacidae). Chaunacids, like other lophiiforms, exhibit highly specialised ventilatory anatomy such as an enlarged branchiostegal apparatus and restricted gill openings, but videos show them using this anatomy in a new and unusual way. We observed eight individuals ventilating extremely slowly at rates of 0.03-0.004 Hz, during which the gill chambers were full yet we saw no inhalation or exhalation for periods of 26 to 245 s. This holding breath behaviour has not been observed in any other fishes and is probably highly energetically efficient. This inflation of the gill chambers also increases body volume by up to 30%, making them more globose and difficult to be taken as prey, much like stomach inflation in pufferfishes (Tetraodontidae). We also used micro computed-tomography (CT) scans to document the enormous branchiostegal rays and associated muscles that support this unique behaviour.


Assuntos
Peixes/fisiologia , Brânquias/fisiologia , Animais , Suspensão da Respiração , Metabolismo Energético , Peixes/anatomia & histologia , Brânquias/anatomia & histologia , Comportamento Predatório
7.
Integr Comp Biol ; 59(2): 394-409, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31004486

RESUMO

Suction feeding and gill ventilation in teleosts are functionally coupled, meaning that there is an overlap in the structures involved with both functions. Functional coupling is one type of morphological integration, a term that broadly refers to any covariation, correlation, or coordination among structures. Suction feeding and gill ventilation exhibit other types of morphological integration, including functional coordination (a tendency of structures to work together to perform a function) and evolutionary integration (a tendency of structures to covary in size or shape across evolutionary history). Functional coupling, functional coordination, and evolutionary integration have each been proposed to limit morphological diversification to some extent. Yet teleosts show extraordinary cranial diversity, suggesting that there are mechanisms within some teleost clades that promote morphological diversification, even within the highly integrated suction feeding and gill ventilatory systems. To investigate this, we quantified evolutionary integration among four mechanical units associated with suction feeding and gill ventilation in a diverse clade of benthic, primarily suction-feeding fishes (Cottoidei; sculpins and relatives). We reconstructed cottoid phylogeny using molecular data from 108 species, and obtained 24 linear measurements of four mechanical units (jaws, hyoid, opercular bones, and branchiostegal rays) from micro-CT reconstructions of 44 cottoids and 1 outgroup taxon. We tested for evolutionary correlation and covariation among the four mechanical units using phylogenetically corrected principal component analysis to reduce the dimensionality of measurements for each unit, followed by correlating phylogenetically independent contrasts and computing phylogenetic generalized least squares models from the first principle component axis of each of the four mechanical units. The jaws, opercular bones, and branchiostegal rays show evolutionary integration, but the hyoid is not positively integrated with these units. To examine these results in an ecomorphological context, we used published ecological data in phylogenetic ANOVA models to demonstrate that the jaw is larger in fishes that eat elusive or grasping prey (e.g., prey that can easily escape or cling to the substrate) and that the hyoid is smaller in intertidal and hypoxia-tolerant sculpins. Within Cottoidei, the relatively independent evolution of the hyoid likely has reduced limitations on morphological evolution within the highly morphologically integrated suction feeding and gill ventilatory systems.


Assuntos
Comportamento Alimentar , Brânquias/anatomia & histologia , Arcada Osseodentária/anatomia & histologia , Perciformes/fisiologia , Animais , Evolução Biológica , Fenômenos Biomecânicos , Brânquias/fisiologia , Arcada Osseodentária/fisiologia , Perciformes/anatomia & histologia , Filogenia , Respiração , Crânio/anatomia & histologia , Sucção
8.
Fish Physiol Biochem ; 45(2): 743-752, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30758701

RESUMO

Two-dimensional gel electrophoresis (2-DE) was combined with liquid chromatography-mass spectrometry (LC-MS/MS) to identify the differential proteomics of grass carp gills after hypoxic stress to better understand the roles of proteins in the hypoxic response and to explore the possible molecular mechanisms. Protein spots were obtained from a hypoxia-stressed group (372 ± 11 individuals) and a control group (406 ± 14 individuals) using the lmage Master 2D Platinum 7.0 analysis software. Fifteen protein spots were expressed differentially in the hypoxia-stressed group and varied significantly after exposure to the hypoxic conditions. In addition, these differential proteins were identified by mass spectrometry and then searched in a database. We found the expression and upregulation of the toll-like receptor 4, ephx1 protein, isocitrate dehydrogenase, L-lactate dehydrogenase, GTP-binding nuclear protein Ran, and glyceraldehyde-3-phosphate dehydrogenase; however, the expression of the keratin type II cytoskeletal 8, type I cytokeratin, ARP3 actin-related protein 3 homolog, thyroid hormone receptor alpha-A, ATP synthase subunit beta, citrate synthase, tropomyosin 2, and tropomyosin 3 were downregulated. Six proteins were found in the hypoxia-inducible factor-1 (HIF-1) signaling pathway. We concluded that the grass carp gill is involved in response processes, including energy generation, metabolic processes, cellular structure, antioxidation, immunity, and signal transduction, to hypoxic stress. To our knowledge, this is the first study to conduct a proteomics analysis of expressed proteins in the gills of grass carp, and this study will help increase the understanding of the molecular mechanisms involved in hypoxic stress responses in fish at the protein level.


Assuntos
Carpas/metabolismo , Proteínas de Peixes/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Brânquias/anatomia & histologia , Brânquias/metabolismo , Oxigênio/administração & dosagem , Adaptação Fisiológica , Animais , Proteínas de Peixes/genética , Fator 1 Induzível por Hipóxia/genética , Fator 1 Induzível por Hipóxia/metabolismo , Oxigênio/química , Oxigênio/farmacologia , Transdução de Sinais/efeitos dos fármacos , Água/química
9.
Acta Trop ; 191: 155-161, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30611713

RESUMO

A new species of black fly, Simulium (Simulium) luculentum, is described from specimens collected in Thailand, and is assigned to the Simulium variegatum species-group of the subgenus Simulium Latreille. This new species is distinguished from most members of this species group in the female by the mid femur and tibia entirely yellowish; and in the pupa by the gill with six filaments, which are somewhat inflated basally. This species represents the fifth member of the S. variegatum species-group recorded from Thailand.


Assuntos
Brânquias/anatomia & histologia , Larva/anatomia & histologia , Pupa/anatomia & histologia , Simuliidae/anatomia & histologia , Simuliidae/classificação , Animais , Feminino , Masculino , Tailândia
10.
Sci Total Environ ; 648: 90-101, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30114592

RESUMO

Changes in water temperature and pH levels have substantial adverse effects on aquatic organisms, hence causing physiological constraint on their well-being. To understand the physiological responses of Chondrostoma regium to temperature or pH changes, standard metabolic rate (SMR), maximum metabolic rate (MMR), absolute and factorial aerobic scope (AS&FAS) as well as the specific rate of ammonia excretion (Jamm) were measured at following temperatures: acute low (3.5-4.5 °C), 24 h low (5.5-6.5 °C), 7 d low (5.5-6.5 °C), acute high (30-31 °C), 24 h high (29-30 °C), 7 d high (28-29 °C), and different pH treatments: acute low (4.3-4.4), 24 h low (4.3-4.4), 7 d low (6.3-6.4), acute high (9.8-9.9), 24 h high (9.8-9.9), 7 d high (8.8-8.9). A control group was also assigned to optimum temperature = 22-23 °C and pH = 7.8-7.9. These experimental ranges for each treatment were obtained based on critical thermal and pH thresholds, i.e., 1.9 to 31.7 °C and 2.7 to 11.1, respectively. SMR was enhanced significantly (P < 0.05) following pH treatments, except for 24 h low pH treatment. Results showed significant (P < 0.05) changes in both SMR and MMR at low and high temperature treatments. The AS was elevated following pH treatments except for acute low pH treatment in which AS significantly was declined (P < 0.05). Low temperature treatments resulted in lower AS while no significant changes in AS were observed in high temperatures. In all treatments, FAS value did not differ significantly from control, except for acute and 24 h low treatments of both temperature and pH. All high pH and temperature treatments showed a significant increase (P < 0.05) in Jamm. Histopathological results of gills indicated hyperplasia and fusion of secondary lamella and kidneys histopathology revealed necrosis and loss of tubular lumen in the most treatments. Results indicated that increases in water temperature or pH are more stressful than the lower ranges of them, suggesting higher capability of fish to adjust to the low levels of temperature or pH.


Assuntos
Metabolismo Basal , Cyprinidae/metabolismo , Água Doce/química , Nitrogênio/metabolismo , Amônia/metabolismo , Animais , Brânquias/anatomia & histologia , Concentração de Íons de Hidrogênio , Rim/anatomia & histologia , Temperatura
11.
J Fish Biol ; 95(1): 222-227, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30141196

RESUMO

This study describes the cephalic and trunk lateral line systems in Patagonian blenny Eleginops maclovinus juveniles, providing morphological details for pores, canals and neuromasts. Eleginops maclovinus juveniles possess a complete laterodorsal lateral line that extends from the upper apex of the gill opening along the trunk as far as the caudal fin. The lateral line was ramified through pores and canals. The following pores were recorded: four supraorbital pores, with two along the eye border and two on the snout; seven infraorbital pores, with three on the lacrimal bone and four being infraorbital; five postorbital pores, with three along the preopercular border (upper preoperculum branch) and two on the bone curvature (inferior preoperculum branch); and four mandibular pores aligned along the jaw. Furthermore, five narrow-simple and interconnected canals were found (i.e. preopercular, mandibular, supraorbital and infraorbital canals). Histologically, the dorsal lateral line presented thin neuromasts (350 µm) with short hair cells. By contrast, the cranial region presented long, thick neuromasts. Infraorbital and mandibular neuromasts had a major axis length of 260 µm and respective average diameters of 200 and 185 µm. Sensory system variations would be due to a greater concentration of neuromasts in the cranial region, allowing for a greater perception of changes in water pressure. Scarce morphological information is available for the lateral sensory system in Eleginopsidae, particularly compared to Channichthyidae, Bovichthydae, Artedidraconidae and Bathydraconidae. Therefore, the presented results form a fundamental foundation of knowledge for the lateral-line system in juvenile E. maclovinus and provide a basis for future related research in this taxon as well as within the Notothenioidei suborder.


Assuntos
Sistema da Linha Lateral/anatomia & histologia , Perciformes/anatomia & histologia , Animais , Brânquias/anatomia & histologia , Sistema da Linha Lateral/fisiologia , Mecanorreceptores , Mecanotransdução Celular , Perciformes/crescimento & desenvolvimento , Perciformes/fisiologia , Crânio
12.
J Fish Biol ; 95(1): 311-323, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30198213

RESUMO

An ontogenetic analysis of the olfactory organ and the number and distribution of internal taste buds was carried out in two neon gobies (Elacatinus lori and Elacatinus colini) with the goal of revealing morphological trends that might inform an understanding of the roles of olfaction and taste in larval orientation behaviour. The pattern of development of the olfactory organ is unremarkable and enclosure of the olfactory epithelium occurs concurrently with metamorphosis and settlement in both species. Like other gobies, juvenile and adult E. lori and E. colini lack complex olfactory lamellae, and lack the accessory nasal sacs present in some adult gobies that could facilitate active olfactory ventilation (i.e., sniffing). A small number of internal taste buds are present at hatch with most found in the caudal region of the buccal cavity (on gill arches, roof of buccal cavity). As taste bud number increases, they demonstrate an anterior spread to the lips, buccal valves and tongue (i.e., tissue covering the basihyal). In the absence of an active ventilatory mechanism for the olfactory organs, the water that moves through the buccal cavity with cyclic gill ventilation may provide chemical cues allowing the internal taste buds to play a role in chemical-mediated orientation and reef-seeking behavior in pelagic larval fishes.


Assuntos
Comportamento Animal , Recifes de Corais , Peixes/fisiologia , Animais , Sinais (Psicologia) , Peixes/anatomia & histologia , Peixes/crescimento & desenvolvimento , Brânquias/anatomia & histologia , Brânquias/crescimento & desenvolvimento , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Larva/fisiologia , Metamorfose Biológica , Mucosa Olfatória/anatomia & histologia , Mucosa Olfatória/crescimento & desenvolvimento , Olfato , Paladar , Papilas Gustativas/anatomia & histologia
13.
Biol Rev Camb Philos Soc ; 94(2): 539-554, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30251433

RESUMO

Ontogenetic dietary shifts (ODSs), the changes in diet utilisation occurring over the life span of an individual consumer, are widespread in the animal kingdom. Understanding ODSs provides fundamental insights into the biological and ecological processes that function at the individual, population and community levels, and is critical for the development and testing of hypotheses around key concepts in trophic theory on model organisms. Here, we synthesise historic and contemporary research on ODSs in fishes, and identify where further research is required. Numerous biotic and abiotic factors can directly or indirectly influence ODSs, but the most influential of these may vary spatially, temporally and interspecifically. Within the constraints imposed by prey availability, we identified competition and predation risk as the major drivers of ODSs in fishes. These drivers do not directly affect the trophic ontogeny of fishes, but may have an indirect effect on diet trajectories through ontogenetic changes in habitat use and concomitant changes in prey availability. The synthesis provides compelling evidence that ODSs can have profound ecological consequences for fish by, for example, enhancing individual growth and lifetime reproductive output or reducing the risk of mortality. ODSs may also influence food-web dynamics and facilitate the coexistence of sympatric species through resource partitioning, but we currently lack a holistic understanding of the consequences of ODSs for population, community and ecosystem processes and functioning. Studies attempting to address these knowledge gaps have largely focused on theoretical approaches, but empirical research under natural conditions, including phylogenetic and evolutionary considerations, is required to test the concepts. Research focusing on inter-individual variation in ontogenetic trajectories has also been limited, with the complex relationships between individual behaviour and environmental heterogeneity representing a particularly promising area for future research.


Assuntos
Dieta/veterinária , Peixes/fisiologia , Animais , Tamanho Corporal , Comportamento Competitivo , Dieta/tendências , Ecossistema , Comportamento Alimentar , Peixes/crescimento & desenvolvimento , Peixes/metabolismo , Cadeia Alimentar , Trato Gastrointestinal/anatomia & histologia , Brânquias/anatomia & histologia , Comportamento Predatório , Natação/fisiologia
14.
Biol Trace Elem Res ; 187(2): 526-535, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29948908

RESUMO

Gobionellus oceanicus is a species widely distributed on the Atlantic coast and may be susceptible to anthropic effects. This study evaluated the morphology and the Na+/K+-ATPase activity of G. oceanicus gills considering the concentration of metals in the fish and Subaé River estuary. Although the metal concentrations detected in the water and sediment did not exceed certain limits, CONAMA (Brazilian Environment Council), TEL (Threshold Effect Level), and PEL (Probable Effect Level), the metals levels in gills plus muscle and skin of G. oceanicus were above the permitted setting of the Ministry of Health, Brazil. The pavement epithelial cells (PVC) of the gill filament was observed that there were long microridges either in the apical surface or in the lamella; especially, microridges degeneration was shown in some PVC from filament epithelium. The number of ionocyte and the volume density were (0.02 ± 0.001)/µm and (0.38 ± 0.27) %, respectively. The activity of Na+/K+-ATPase was 1.13 ± 0.76 µM Pi mg protein-1 h-1. We describe the volume density and number of ionocytes and Na+/K+-ATPase enzymatic activity in G. oceanicus for the first time, which is useful for basic and comparative future studies to support aquatic biomonitoring.


Assuntos
Estuários , Proteínas de Peixes/metabolismo , Brânquias/enzimologia , Perciformes/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Brasil , Água Doce/química , Geografia , Sedimentos Geológicos/química , Brânquias/anatomia & histologia , Brânquias/metabolismo , Transporte de Íons , Metais/análise , Concentração Osmolar , Perciformes/anatomia & histologia , Água do Mar/química
15.
Zoology (Jena) ; 130: 6-18, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30502840

RESUMO

The respiratory organs of the African sharptooth catfish, Clarias gariepinus, were studied to broaden existing understanding of the adaptive stratagems that have evolved for air-breathing in fish. The gills were well-developed and the air-breathing organs (ABOs) comprised labyrinthine organs (LOs), suprabranchial chamber membranes (SBCMs) and gill fans (GFns). Respectively, the gills and the LOs had the highest mass-specific respiratory surface areas of 133.7 and 141.9 mm2 per gram and among the ABOs, with a harmonic mean thickness of the blood-barrier (BGB) of 0.39 µm, the LOs had the thinnest BGB followed by the GFns (0.48 µm) and the SBCMs (0.49 µm): the water-blood barrier of the gills was relatively much thicker (7.93 µm). Vindicating why C. gariepinus is an obligate air-breather, the total mass-specific morphometric (anatomical) diffusing capacity of the ABOs for O2 per unit body weight (W) (Dto2/W) comprised 90.5% of the mean total value for all the respiratory organs. Compared with the East African catfish, Clarias mossambicus, the Dto2/W of the ABOs of C. gariepinus was 5.7 times greater. The difference between the two species of fish may be explained by the physicochemical differences of the aquatic habitats they occupy: the former occupies a seasonal river which dries up during the summer months leaving shallow pools of water in which the O2 concentrations are very low and CO2 very high while the later populates a highly eutrophic dam where the O2 levels greatly fluctuate seasonally.


Assuntos
Peixes-Gato/anatomia & histologia , Sistema Respiratório/anatomia & histologia , Animais , Peixes-Gato/fisiologia , Ecossistema , Brânquias/anatomia & histologia
16.
J Morphol ; 279(12): 1716-1724, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30427064

RESUMO

Fish gill surface area varies across species and with respect to ecological lifestyles. The majority of previous studies only qualitatively describe gill surface area in relation to ecology and focus primarily on teleosts. Here, we quantitatively examined the relationship of gill surface area with respect to specific ecological lifestyle traits in elasmobranchs, which offer an independent evaluation of observed patterns in teleosts. As gill surface area increases ontogenetically with body mass, examination of how gill surface area varies with ecological lifestyle traits must be assessed in the context of its allometry (scaling). Thus, we examined how the relationship of gill surface area and body mass across 11 shark species from the literature and one species for which we made measurements, the Gray Smoothhound Mustelus californicus, varied with three ecological lifestyle traits: activity level, habitat, and maximum body size. Relative gill surface area (gill surface area at a specified body mass; here we used 5,000g, termed the 'standardized intercept') ranged from 4,724.98 to 35,694.39 cm2 (mean and standard error: 17,796.65 ± 2,948.61 cm2 ) and varied across species and the ecological lifestyle traits examined. Specifically, larger-bodied, active, oceanic species had greater relative gill surface area than smaller-bodied, less active, coastal species. In contrast, the rate at which gill surface area scaled with body mass (slope) was generally consistent across species (0.85 ± 0.02) and did not differ statistically with activity level, habitat, or maximum body size. Our results suggest that ecology may influence relative gill surface area, rather than the rate at which gill surface area scales with body mass. Future comparisons of gill surface area and ecological lifestyle traits using the quantitative techniques applied in this study can provide further insight into patterns dictating the relationship between gill surface area, metabolism, and ecological lifestyle traits.


Assuntos
Fenômenos Ecológicos e Ambientais , Brânquias/anatomia & histologia , Tubarões/anatomia & histologia , Animais , Tamanho Corporal , Análise de Regressão , Especificidade da Espécie
17.
J Morphol ; 279(11): 1548-1558, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30407645

RESUMO

Facultative air-breathing fish can exchange respiratory gases using an air-breathing organ (ABO), such as the oral cavity of the integument, during environmental hypoxia. The goby Gobionellus oceanicus inhabits areas subject to environmental hypoxia; however, its ABO is unknown. To investigate the respiratory potential of G. oceanicus, the gill and integument surface area, diffusion capacity, and their diffusion barrier thickness were measured. Our results show that although gill surface area is smaller than observed in other facultative air-breathing fish, but it has all features necessary to perform aquatic gas exchange. Additionally the integument of the palate has a short diffusion barrier thickness and a large calculated O2 -diffusion capacity suggesting that it functions as the ABO.


Assuntos
Tegumento Comum/anatomia & histologia , Tegumento Comum/fisiologia , Perciformes/anatomia & histologia , Perciformes/fisiologia , Respiração , Nadadeiras de Animais/anatomia & histologia , Animais , Brânquias/anatomia & histologia , Brânquias/fisiologia , Hipóxia
18.
J Morphol ; 279(11): 1615-1628, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30368877

RESUMO

Hypophthalmichthys molitrix, silver carp, is an invasive Asian carp that has become increasingly widespread and ecologically destructive within the upper Mississippi River Basin. Its complex trophic anatomy may help explain the apparent efficiency with which they consume phytoplankton, outcompeting native filter feeders. This cypriniform species is characterized by trophic synapomorphies that include a palatal organ, loss of upper pharyngeal jaws, and a hypertrophied lower pharyngeal jaw. However, in silver carp these structures have become greatly modified and diverge from the more basal condition that characterizes species such as goldfish. The trophic apparatus of silver carp is composed of discrete structures that are functionally coupled: filtering plates, paired epibranchial organs (EBO), a modified palatal organ composed of large muscular folds that interdigitate with the filtering plates, and hypertrophied lower pharyngeal jaws and teeth. The filtering plates fill a significant portion of the buccal cavity, especially since the distal parts of these filtering plates make up a key component of the EBOs. EBOs, food aggregating structures found in many teleosts, are thought to have independently evolved at least six times. Ranging in complexity from small slits on the dorsal wall of the pharyngeal cavity to exceedingly intricate spiraling structures, EBOs are morphologically diverse among filter-feeding fishes. Despite this morphological diversity and broad taxonomic distribution, little is known regarding the functional anatomy of the EBO. Moreover, the EBO in silver carp is distinct from the organs previously described in other species, being created by four independent pharyngeal involutions (instead of the more typical one or two) that form spiral-shaped pharyngeal tubes surrounded by circumferential muscle. On each side of the head greatly hypertrophied hyomandibulae and opercles are connected to the anterior cartilaginous caps of the bilateral EBOs via enlarged muscles. Given that these fish are pump filter feeders we hypothesize that the opercula may compress and expand the EBOs during pumping causing food to be moved posteriorly toward the pharyngeal jaws.


Assuntos
Estruturas Animais/anatomia & histologia , Carpas/anatomia & histologia , Estruturas Animais/citologia , Estruturas Animais/ultraestrutura , Animais , Brânquias/anatomia & histologia , Músculos/anatomia & histologia , Músculos/diagnóstico por imagem , Faringe/anatomia & histologia , Microtomografia por Raio-X
19.
J Fish Biol ; 93(6): 1141-1150, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30306569

RESUMO

In the present work we describe the larval development of Brycon amazonicus, with emphasis on structures linked to swimming, respiration and feeding. We monitored from larval hatching (13 h post-fertilization) to juvenile stage. Formation of the oral cavity and differentiation of gill arches began within 4 h post-hatching (hph) and within 11 hph the primordium of the pectoral fin appeared. At 25 hph, the head was in a rectilinear position with a terminal mouth, when the onset of tooth formation appeared. At 35 hph, gill arches were covered by the operculum and branchiostegal membrane and cusps of teeth pierced the epithelium of the premaxilla and anterior dentary region. Sharp teeth were observed in the maxilla at 171 hph and the pelvic fin primordium appeared at 243 hph, with taste buds on the tongue and the roof of the buccopharyngeal cavity. At 579 hph, all structures related to swimming and food capture were formed. Exogenous feeding of the larvae started at 29 hph, before the endogenous reserves were used up and the development of efficient swimming ability, reflecting the species' need to increasingly specialize on prey capture.


Assuntos
Comportamento Animal , Caraciformes/crescimento & desenvolvimento , Animais , Caraciformes/anatomia & histologia , Caraciformes/fisiologia , Desenvolvimento Embrionário , Comportamento Alimentar , Brânquias/anatomia & histologia , Brânquias/fisiologia , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Larva/fisiologia , Boca/anatomia & histologia , Boca/fisiologia , Natação
20.
PLoS One ; 13(8): e0201913, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30125292

RESUMO

The dalatiid genus Isistius Gill (1864) has three valid species currently recognized in the literature: Isistius brasiliensis Quoy & Gaimard (1824), I. plutodus Garrick & Springer (1964), and I. labialis Meng, Zhu & Li (1985). The most common species, I. brasiliensis, has a wide geographic distribution and is found in subtemperate and tropical seas circumglobally. A comparative analysis of specimens from different localities throughout its range, however, had never been undertaken. In the present paper, the morphological variation of this species along its entire distribution has been thoroughly analyzed, corroborating that it represents a single widespread species and that I. labialis is its junior synonym. The other congeneric species, I. plutodus, is known from only a few specimens and is also distributed worldwide. A detailed comparative analysis of available material of I. plutodus was conducted verifying its validity as a single widespread species. The present study analyzed in detail the external morphology (coloration, dentition, dermal denticles), internal morphology (skeleton, musculature), lateral-line canals, and morphometric and meristic characters of species of Isistius in order to better define the genus and its included valid species.


Assuntos
Brânquias/anatomia & histologia , Tubarões/anatomia & histologia , Animais , Masculino , Tubarões/classificação
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