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1.
Braz. J. Biol. ; 83: 1-5, 2023. mapas, tab
Artigo em Inglês | VETINDEX, VETINDEX | ID: vti-765542

RESUMO

This study estimated the length–weight relationships of 16 fish species occurring close to the shores of sandy beaches along the lower Negro River basin, Brazilian Amazon. The specimens were captured for one day each month, in October to November 2016, early in the morning and early evening, using trawl net (20 m length and 3.5 m height, 5 mm mesh between opposite knots). Measurements were taken for standard length (SL 0.1 cm precision) and total weight (TW 0.01 g precision). The parameters a and b of the equation WT = a.LTb were estimated. The a values ranged from 0.0018 to 0.0226 and b values ranged from 2.5271 to 3.3244. This study also provides new data on of maximum lengths for six species, Amazonsprattus scintilla, Brycon pesu, Moenkhausia megalops, Pachyurus paucirastrus, Reganella depressa and Trachydoras microstomus, and new reports of the LWRs parameters of 15 fish species.(AU)


Este estudo estimou as relações comprimento-peso de 16 espécies de peixes que ocorrem às margens de praias arenosas ao longo da bacia do baixo Rio Negro, Amazônia brasileira. As espécies foram capturadas durante um dia de cada mês, de outubro a novembro de 2016, no início da manhã e no início da noite, usando rede de cerco (20 m de comprimento e 3,5 m de altura, 5 malha mm entre nós opostos). As medidas foram feitas para comprimento padrão (SL - precisão de 0,1 cm) e peso total (TW - precisão de 0,01 g). Os parâmetros a e b da equação WT = a.LTb foram estimados. Os valores de a variaram de 0,0018 a 0,0226 e os valores de b variaram de 2,5271 a 3,3244. Este estudo também fornece novos dados sobre comprimentos máximos para seis espécies, Amazonsprattus scintilla, Brycon pesu, Moenkhausia megalops, Pachyurus paucirastrus, Reganella depressa e Trachydoras microstomus, e novos reportes dos parâmetros da LWRs de 15 espécies de peixes.(AU)


Assuntos
Animais , Peixes/anatomia & histologia , Peixes/crescimento & desenvolvimento
2.
Sci Data ; 9(1): 287, 2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35680897

RESUMO

Preserving maritime ecosystems is a major concern for governments and administrations. Additionally, improving fishing industry processes, as well as that of fish markets, to have a more precise evaluation of the captures, will lead to a better control on the fish stocks. Many automated fish species classification and size estimation proposals have appeared in recent years, however, they require data to train and evaluate their performance. Furthermore, this data needs to be organized and labelled. This paper presents a dataset of images of fish trays from a local wholesale fish market. It includes pixel-wise (mask) labelled specimens, along with species information, and different size measurements. A total of 1,291 labelled images were collected, including 7,339 specimens of 59 different species (in 60 different class labels). This dataset can be of interest to evaluate the performance of novel fish instance segmentation and/or size estimation methods, which are key for systems aimed at the automated control of stocks exploitation, and therefore have a beneficial impact on fish populations in the long run.


Assuntos
Peixes , Animais , Tamanho Corporal , Ecossistema , Pesqueiros , Peixes/anatomia & histologia , Peixes/classificação , Processamento de Imagem Assistida por Computador
3.
Elife ; 112022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35674421

RESUMO

Placoderms, as the earliest branching jawed vertebrates, are crucial to understanding how the characters of crown gnathostomes comprising Chondrichthyes and Osteichthyes evolved from their stem relatives. Despite the growing knowledge of the anatomy and diversity of placoderms over the past decade, the dermal scales of placoderms are predominantly known from isolated material, either morphologically or histologically, resulting in their squamation being poorly understood. Here we provide a comprehensive description of the squamation and scale morphology of a primitive taxon of Antiarcha (a clade at the root of jawed vertebrates), Parayunnanolepis xitunensis, based on the virtual restoration of an articulated specimen by using X-ray computed tomography. Thirteen morphotypes of scales are classified to exhibit how the morphology changes with their position on the body in primitive antiarchs, based on which nine areas of the post-thoracic body are distinguished to show their scale variations in the dorsal, flank, ventral, and caudal lobe regions. In this study, the histological structure of yunnanolepidoid scales is described for the first time based on disarticulated scales from the type locality and horizon of P. xitunensis. The results demonstrate that yunnanolepidoid scales are remarkably different from their dermal plates as well as euantiarch scales in lack of a well-developed middle layer. Together, our study reveals that the high regionalization of squamation and the bipartite histological structure of scales might be plesiomorphic for antiarchs, and jawed vertebrates in general.


Many vertebrates have an outer skeleton covering their body. Some, like crocodiles, have large bony plates of armor, while others, like fish, have small slippery scales. The type, shape, and arrangement of these structures can tell scientists a lot about how different species evolved. Most modern fish are completely covered in scales, but this has not always been the case. Over 400 millions of years ago in the Earth's oceans lived a major group of armored fish called antiarch placoderms which had a combination of bony plates, scales and naked skin. These ancient fish are particularly interesting to scientists because they were one of the first jawed vertebrates to evolve. However, much of what is known about this group has come from isolated materials, which has made it difficult to study the organization and shape of their scales. To overcome this, Wang and Zhu used a specialized x-ray imaging procedure to create a three-dimensional model of one of the best-preserved antiarch placoderm species, Parayunnanolepis xitunensis. The model showed that the fish had thirteen types of scales, found in nine distinct regions on its body. To better understand the structure of these scales, Wang and Zhu looked at the fossils of other extinct jawed fish which where were found in the region where P. xitunensis once lived. The scales of these ancient fish were very different from their bony plates, and from the scales of modern fish. Understanding the skin armor of ancient fish could help to explain how the scales of modern vertebrates evolved. The next step is to look in more detail at the scales of other placoderms to see how they changed over time.


Assuntos
Evolução Biológica , Fósseis , Animais , Peixes/anatomia & histologia , Arcada Osseodentária/anatomia & histologia , Filogenia , Vertebrados/anatomia & histologia
4.
Nat Commun ; 13(1): 2390, 2022 05 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
5.
Nature ; 606(7912): 109-112, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35614222

RESUMO

Palaeospondylus gunni, from the Middle Devonian period, is one of the most enigmatic fossil vertebrates, and its phylogenetic position has remained unclear since its discovery in Scotland in 1890 (ref. 1). The fossil's strange set of morphological features has made comparisons with known vertebrate morphotype diversity difficult. Here we use synchrotron radiation X-ray micro-computed tomography to show that Palaeospondylus was a sarcopterygian, and most probably a stem-tetrapod. The skeleton of Palaeospondylus consisted solely of endoskeletal elements in which hypertrophied chondrocyte cell lacunae, osteoids and a small fraction of perichondral bones developed. Despite the complete lack of teeth and dermal bones, the neurocranium of Palaeospondylus resembles those of stem-tetrapod Eusthenopteron2 and Panderichthys3, and phylogenetic analyses place Palaeospondylus in between them. Because the unique features of Palaeospondylus, such as the cartilaginous skeleton and the absence of paired appendages, are present in the larva of crown tetrapods, our study highlights an unanticipated heterochronic evolution at the root of tetrapods.


Assuntos
Fósseis , Filogenia , Vertebrados , Animais , Peixes/anatomia & histologia , Peixes/classificação , Crânio/anatomia & histologia , Vertebrados/anatomia & histologia , Vertebrados/classificação , Microtomografia por Raio-X
6.
Bioinspir Biomim ; 17(4)2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35366647

RESUMO

Several fishes swim by undulating a thin and elongated median fin while the body is mostly kept straight, allowing them to perform forward and directional maneuvers. We used a robotic vessel with similar fin propulsion to determine the thrust scaling and efficiency. Using precise force and swimming kinematics measurements with the robotic vessel, the thrust generated by the undulating fin was found to scale with the square of the relative velocity between the free streaming flow and the wave speed. A hydrodynamic efficiency is presented based on propulsive force measurements and modelling of the power required to oscillate the fin laterally. It was found that the propulsive efficiency has a broadly high performance versus swimming speed, with a maximum efficiency of 75%. An expression to calculate the swimming speed over wave speed was found to depend on two parameters:Ap/Ae(ratio between body frontal area to fin swept area) andCD/Cx(ratio of body drag to fin thrust coefficient). The models used to calculate propulsive force and free-swimming speed were compared with experimental results. The broader impacts of these results are discussed in relation to morphology and the function of undulating fin swimmers. In particular, we suggest that the ratio of fin and body height found in natural swimmers could be due to a trade-off between swimming efficiency and swimming speed.


Assuntos
Robótica , Natação , Animais , Fenômenos Biomecânicos , Peixes/anatomia & histologia , Hidrodinâmica
7.
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
8.
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
9.
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
10.
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
11.
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
12.
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
13.
Braz. J. Biol. ; 82: 1-6, 2022. mapas, tab, ilus
Artigo em Inglês | VETINDEX, VETINDEX | ID: vti-33340

RESUMO

The "piaussu", Megaleporinus macrocephalus is an anostomatid fish species native to the basin of the Paraguay River, in the Pantanal biome of western Brazil. However, this species has now been recorded in a number of other drainages, including those of the upper Paraná, Uruguay, Jacuí, Doce, Mucuri, and Paraíba do Sulrivers. This study presents two new records of the occurrence of M. macrocephalus, in the basins of the Itapecuru and Mearim rivers in the state of Maranhão, in the Brazilian Northeast. The piaussu is a large-bodied fish of commercial interest that is widely raised on fish farms, and its occurrence in the Itapecuru and Mearim rivers is likely the result of individuals escaping from fish tanks when they overflow during the rainy season. Morphological analyses and sequences of the Cytochrome Oxidase Subunit I (COI) gene confirmed the taxonomic identification of the specimens as M. macrocephalus. The COI sequences were 99.66% similar to those of M. macrocephalus deposited in the BOLDSystems database. These records extend the known distribution of M. macrocephalus to the basins of the Itapecuru and Mearim rivers in the Brazilian Northeast, highlighting a new case of introduction of exotic fish species into Brazilian river basins.(AU)


Megaleporinus macrocephalus é uma espécie de peixe anostomatídeo nativa da bacia do rio Paraguai, no bioma Pantanal do oeste do Brasil. No entanto, essa espécie já foi registrada em várias outras drenagens, incluindo as dos rios Alto Paraná, Uruguai, Jacuí, Doce, Mucuri e Paraíba do Sul. Este estudo apresenta dois novos registros da ocorrência de M. macrocephalus, nas bacias dos rios Itapecuru e Mearim, no estado do Maranhão, no nordeste brasileiro. O piaussu é um peixe de grande porte, de interesse comercial, amplamente criado em pisciculturas, e sua ocorrência nos rios Itapecuru e Mearim é provavelmente o resultado de indivíduos que escapam dos tanques quando transbordam durante a estação chuvosa. Análises morfológicas e sequências do gene da subunidade I do citocromo oxidase (COI) confirmaram a identificação taxonômica dos espécimes como M. macrocephalus. As sequências de COI foram 99,66% semelhantes às de M. macrocephalus depositadas no banco de dados BOLDSystems. Esses registros estendem a conhecida distribuição de M. macrocephalus às bacias dos rios Itapecuru e Mearim, no nordeste brasileiro, destacando um novo caso de introdução de espécies exóticas de peixes nas bacias hidrográficas brasileiras.(AU)


Assuntos
Animais , Peixes/anatomia & histologia , Peixes/genética
14.
Braz. J. Biol. ; 82: 1-7, 2022. ilus, tab, graf
Artigo em Inglês | VETINDEX, VETINDEX | ID: vti-18689

RESUMO

The present study was conducted for the taxonomic, morphometric and limnological assessment of the commercially important ichthyofauna of Sakhakot Stream, Malakand, Pakistan. The study area was divided into three sites along the water course namely Dargai Stream, Sakhakot Stream and Shergarh Stream. Fish samples were collected randomly during January to August 2017 with the help of fish gears. A taxonomic key was designed for the collected fish specimens. Ten fish species were identified belonging to 3 orders and 4 families. Family Cyprinidae was the dominant family with seven representative species while families Siluridae, Nemacheilidae and Mastacembelidae were represented by one species each. Lower mean total length and standard length was recorded in Puntius conchonius (Hamilton, 1822) as 9.2 ± 0.6 cm and 7.3 ± 0.6 cm respectively, while highest mean total length and standard length was recorded in Mastacembelus armatus (Lacepede, 1800) as 28.1 ± 1.7 cm and 15.9 ± 2.4 cm respectively. Mean pH of the water ranged from 6.1 at Shergarh Stream in August to 8.7 at Sakhakot Stream in January. Average temperature range was recorded from 10.9 °C in January at Dargai Stream to 18.7 °C in August at Shergarh Stream. No statistically significant difference was found for temperature (p = 0.96) and pH (p = 0.14) in the three water streams. The present study will provide a baseline for the rearing and enhancement of wild stock of the commercially important ichthyofauna in the field of aquaculture and fisheries.(AU)


O presente estudo foi realizado para a avaliação taxonômica, morfométrica e limnológica da ictiofauna comercialmente importante do Riacho Sakhakot, Malakand, Paquistão. A área de estudo foi dividida em três locais ao longo do curso de água, nomeadamente Riacho Dargai, Riacho Sakhakot e Riacho Shergarh. As amostras de peixes foram coletadas aleatoriamente durante janeiro e agosto de 2017, com a ajuda de artes de peixes. Uma chave taxonômica foi projetada para os espécimes de peixes coletados. Foram identificadas dez espécies de peixes pertencentes a 3 ordens e 4 famílias. A família Cyprinidae foi a família dominante, com sete espécies representativas, enquanto as famílias Siluridae, Nemacheilidae e Mastacembelidae foram representadas por uma espécie cada. O comprimento total médio mais baixo e o comprimento padrão foram registrados em Puntius conchonius (Hamilton, 1822) como 9.2 ± 0.6 cm e 7.3 ± 0.6 cm, respectivamente, enquanto o comprimento total médio e o comprimento padrão mais altos foram registrados em Mastacembelus armatus (Lacepede, 1800) como 28.1 ± 1.7 cm e 15.9 ± 2.4 cm, respectivamente. O pH médio da água variou de 6.1 no Riacho Shergarh em agosto a 8.7 no Riacho Sakhakot em janeiro. A faixa de temperatura média foi registrada de 10.9 °C em janeiro no Riacho Dargai a 18.7 °C em agosto no Riacho Shergarh. Não foi encontrada diferença estatisticamente significativa para temperatura (p = 0,96) e pH (p = 0,14) nos três cursos de água. O presente estudo fornecerá uma linha de base para a criação e aprimoramento do estoque selvagem da ictiofauna comercialmente importante no campo da aquicultura e pesca.(AU)


Assuntos
Animais , Peixes/anatomia & histologia , Peixes/crescimento & desenvolvimento , Cyprinidae/crescimento & desenvolvimento , Peixes-Gato , Classificação/métodos
15.
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
16.
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
17.
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
18.
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
19.
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
20.
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
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