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1.
Science ; 383(6687): 1041, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38452074

RESUMO

The fish's genomes change so slowly that species separated since the dinosaurs can produce fertile hybrids today.


Assuntos
Evolução Biológica , Quimera , Peixes , Animais , Peixes/classificação , Peixes/genética , Genoma , Reparo do DNA/genética
2.
Nature ; 626(7997): 119-127, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38200310

RESUMO

The evolution of reproductive barriers is the first step in the formation of new species and can help us understand the diversification of life on Earth. These reproductive barriers often take the form of hybrid incompatibilities, in which alleles derived from two different species no longer interact properly in hybrids1-3. Theory predicts that hybrid incompatibilities may be more likely to arise at rapidly evolving genes4-6 and that incompatibilities involving multiple genes should be common7,8, but there has been sparse empirical data to evaluate these predictions. Here we describe a mitonuclear incompatibility involving three genes whose protein products are in physical contact within respiratory complex I of naturally hybridizing swordtail fish species. Individuals homozygous for mismatched protein combinations do not complete embryonic development or die as juveniles, whereas those heterozygous for the incompatibility have reduced complex I function and unbalanced representation of parental alleles in the mitochondrial proteome. We find that the effects of different genetic interactions on survival are non-additive, highlighting subtle complexity in the genetic architecture of hybrid incompatibilities. Finally, we document the evolutionary history of the genes involved, showing signals of accelerated evolution and evidence that an incompatibility has been transferred between species via hybridization.


Assuntos
Núcleo Celular , Complexo I de Transporte de Elétrons , Peixes , Genes Letais , Especiação Genética , Hibridização Genética , Proteínas Mitocondriais , Animais , Alelos , Complexo I de Transporte de Elétrons/genética , Peixes/classificação , Peixes/embriologia , Peixes/genética , Peixes/crescimento & desenvolvimento , Homozigoto , Genes Letais/genética , Especificidade da Espécie , Desenvolvimento Embrionário/genética , Proteínas Mitocondriais/genética , Núcleo Celular/genética , Heterozigoto , Evolução Molecular
3.
Braz J Biol ; 83: e274100, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37820206

RESUMO

We evaluated the influence of flooding and receding comparison and spatial variation on the composition and structure of fish assemblages in blackwater and clearwater rivers of the Aracá-Demeni sub-basin in the middle Negro River, Amazonas state, Brazil. The collections were carried out during the falling-water period (November 2018) and the rising-water period (April 2019) using gillnets with meshes ranging from 30 to 120mm stretched mesh size. Ecological estimates of richness, equitability, the Shannon-Wiener diversity index, and the Berger-Parker index showed no significant differences between the periods. The composition of the ichthyofauna showed variations between the falling-water and rising-water periods. Beta diversity in the Aracá-Demeni sub-basin is almost completely caused by species substitution, with spatial turnover accounting for most of the estimate. The identification of these patterns and of the responsible factors are fundamental for the definition of conservation strategies, especially in an ecosystem whose dynamics can be influenced by climate change through changes in the intensity of the flood pulse and connectivity.


Assuntos
Biodiversidade , Ecossistema , Peixes , Rios , Animais , Peixes/classificação , Estresse Fisiológico , Brasil , Inundações
4.
Nature ; 621(7978): 324-329, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37648851

RESUMO

Marine heatwaves have been linked to negative ecological effects in recent decades1,2. If marine heatwaves regularly induce community reorganization and biomass collapses in fishes, the consequences could be catastrophic for ecosystems, fisheries and human communities3,4. However, the extent to which marine heatwaves have negative impacts on fish biomass or community composition, or even whether their effects can be distinguished from natural and sampling variability, remains unclear. We investigated the effects of 248 sea-bottom heatwaves from 1993 to 2019 on marine fishes by analysing 82,322 hauls (samples) from long-term scientific surveys of continental shelf ecosystems in North America and Europe spanning the subtropics to the Arctic. Here we show that the effects of marine heatwaves on fish biomass were often minimal and could not be distinguished from natural and sampling variability. Furthermore, marine heatwaves were not consistently associated with tropicalization (gain of warm-affiliated species) or deborealization (loss of cold-affiliated species) in these ecosystems. Although steep declines in biomass occasionally occurred after marine heatwaves, these were the exception, not the rule. Against the highly variable backdrop of ocean ecosystems, marine heatwaves have not driven biomass change or community turnover in fish communities that support many of the world's largest and most productive fisheries.


Assuntos
Biomassa , Calor Extremo , Peixes , Animais , Europa (Continente) , Pesqueiros/estatística & dados numéricos , Peixes/classificação , Peixes/fisiologia , Calor Extremo/efeitos adversos , América do Norte , Biodiversidade
5.
Philos Trans R Soc Lond B Biol Sci ; 378(1884): 20220139, 2023 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-37427477

RESUMO

Among ray-finned fishes that provide parental care, many spawn in constructed nests, ranging from bowls, burrows and ridges to nests made of algae or bubbles. Because a nest by definition is a construction that enhances the nest-builder's fitness by helping it meet the needs of the developing offspring, nest-building behaviour is naturally selected, as is a preference for spawning with mates that provide well-built nests. However, nest-building behaviour can also be sexually selected, when nest traits increase mating success, protect against sperm competition or nest take-overs by conspecifics. Here, we offer a systematic review, with examples of how competition for sites and location of fish nests relates to sexual selection. We examine direct and indirect benefits of mate choice linked to nest traits, and different types of nests, from a sexual selection perspective. Nest-related behaviours are often under both natural and sexual selection, and we disentangle examples where that is the case, with special attention to females. We highlight some taxa in which nest building is likely to be sexually selected, but lack of research has left them uninvestigated. Some of them are established aquarium species, making them particularly amenable for future research. Finally, we compare with arthropods, amphibians and birds. This article is part of the theme issue 'The evolutionary ecology of nests: a cross-taxon approach'.


Assuntos
Peixes , Comportamento de Nidação , Peixes/classificação , Peixes/crescimento & desenvolvimento , Peixes/fisiologia , Ecossistema , Masculino , Feminino , Animais , Preferência de Acasalamento Animal , Reprodução , Estágios do Ciclo de Vida
6.
Nature ; 618(7964): 322-327, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37198484

RESUMO

Individual growth is a fundamental life history trait1-4, yet its macroevolutionary trajectories have rarely been investigated for entire animal assemblages. Here we analyse the evolution of growth in a highly diverse vertebrate assemblage-coral reef fishes. We combine state-of-the-art extreme gradient boosted regression trees with phylogenetic comparative methods to detect the timing, number, location and magnitude of shifts in the adaptive regime of somatic growth. We also explored the evolution of the allometric relationship between body size and growth. Our results show that the evolution of fast growth trajectories in reef fishes has been considerably more common than the evolution of slow growth trajectories. Many reef fish lineages shifted towards faster growth and smaller body size evolutionary optima in the Eocene (56-33.9 million years ago), pointing to a major expansion of life history strategies in this Epoch. Of all lineages examined, the small-bodied, high-turnover cryptobenthic fishes shifted most towards extremely high growth optima, even after accounting for body size allometry. These results suggest that the high global temperatures of the Eocene5 and subsequent habitat reconfigurations6 might have been critical for the rise and retention of the highly productive, high-turnover fish faunas that characterize modern coral reef ecosystems.


Assuntos
Evolução Biológica , Recifes de Corais , Peixes , Animais , Tamanho Corporal , Peixes/anatomia & histologia , Peixes/classificação , Peixes/crescimento & desenvolvimento , Filogenia , Fatores de Tempo , Adaptação Biológica
7.
Rev. Inst. Adolfo Lutz (Online) ; 82: e39255, maio 2023. tab
Artigo em Português | LILACS, VETINDEX, Sec. Est. Saúde SP | ID: biblio-1523899

RESUMO

O objetivo deste artigo é determinar quais são as espécies de peixes mais comumente substituídas, relatadas em revisões sobre falsificações por troca de espécies, em artigos científicos publicados entre 2002 e 2022, assim como expor quais são os fatores que levam à ocorrência de casos de falsificação, quais os danos sociais que tal prática ilegal pode gerar e em que tipo de estabelecimentos as falsificações normalmente são detectadas. Assim, por meio de uma revisão sistemática de literatura, foi verificado que as espécies de peixes mais comumente falsificadas foram Anoplopoma fimbria, Gadus morhua, Solea solea, Thunnus albacares, Scomberomorus commerson, Lates calcarifer e Rastrelliger brachysoma. As motivações por trás das falsificações intencionais foram predominantemente econômicas, tendo sido observados impactos negativos das falsificações na economia, na saúde pública e no meio ambiente. A maioria das falsificações foi encontrada no final da cadeia produtiva, em locais como varejos, restaurantes e peixarias. Dessa forma, ao saber como as falsificações acontecem e suas razões, torna-se possível saber como minimizar a sua ocorrência.


The aim of this article is to identify the most frequently mislabeled fish species, based on reports and reviews of species mislabeling-related falsifications, in scientific articles published between 2002 and 2022. It also aims to explore the factors contributing these counterfeiting incidents, the social harms associated with this illegal practice and the types of establishments where counterfeits are typically detected. Through a systematic literature review, it was verified that the most commonly mislabeled fish species were Anoplopoma fimbria, Gadus morhua, Solea solea, Thunnus albacares, Scomberomorus commerson, Lates calcarifer and Rastrelliger brachysoma. The primary motivations behind intentional counterfeiting were economic in nature, and negative impacts of counterfeiting on the economy, public health and the environment were widely recognized. Most counterfeits were found at the end of the production chain, in places such as retail stores, restaurants and fishmongers' businesses. By understanding the mechanisms and motivations behind counterfeiting, we can effectively minimize its prevalence.


Assuntos
Animais , Peixes/classificação , Fraude/estatística & dados numéricos , Crimes contra a Saúde Pública
8.
Nature ; 615(7954): 858-865, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36949201

RESUMO

Human society is dependent on nature1,2, but whether our ecological foundations are at risk remains unknown in the absence of systematic monitoring of species' populations3. Knowledge of species fluctuations is particularly inadequate in the marine realm4. Here we assess the population trends of 1,057 common shallow reef species from multiple phyla at 1,636 sites around Australia over the past decade. Most populations decreased over this period, including many tropical fishes, temperate invertebrates (particularly echinoderms) and southwestern Australian macroalgae, whereas coral populations remained relatively stable. Population declines typically followed heatwave years, when local water temperatures were more than 0.5 °C above temperatures in 2008. Following heatwaves5,6, species abundances generally tended to decline near warm range edges, and increase near cool range edges. More than 30% of shallow invertebrate species in cool latitudes exhibited high extinction risk, with rapidly declining populations trapped by deep ocean barriers, preventing poleward retreat as temperatures rise. Greater conservation effort is needed to safeguard temperate marine ecosystems, which are disproportionately threatened and include species with deep evolutionary roots. Fundamental among such efforts, and broader societal needs to efficiently adapt to interacting anthropogenic and natural pressures, is greatly expanded monitoring of species' population trends7,8.


Assuntos
Antozoários , Recifes de Corais , Calor Extremo , Peixes , Aquecimento Global , Invertebrados , Oceanos e Mares , Água do Mar , Alga Marinha , Animais , Austrália , Peixes/classificação , Invertebrados/classificação , Aquecimento Global/estatística & dados numéricos , Alga Marinha/classificação , Dinâmica Populacional , Densidade Demográfica , Água do Mar/análise , Extinção Biológica , Conservação dos Recursos Naturais/tendências , Equinodermos/classificação
9.
Science ; 379(6632): 572-575, 2023 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-36758078

RESUMO

Accurate species phylogenies are a prerequisite for all evolutionary research. Teleosts are the largest and most diversified group of extant vertebrates, but relationships among their three oldest extant lineages remain unresolved. On the basis of seven high-quality new genome assemblies in Elopomorpha (tarpons, eels), we revisited the topology of the deepest branches of the teleost phylogeny using independent gene sequence and chromosomal rearrangement phylogenomic approaches. These analyses converged to a single scenario that unambiguously places the Elopomorpha and Osteoglossomorpha (arapaima, elephantnose fish) in a monophyletic sister group to all other teleosts, i.e., the Clupeocephala lineage (zebrafish, medaka). This finding resolves more than 50 years of controversy on the evolutionary relationships of these lineages and highlights the power of combining different levels of genome-wide information to solve complex phylogenies.


Assuntos
Evolução Biológica , Peixes , Animais , Enguias/classificação , Enguias/genética , Peixes/classificação , Peixes/genética , Genoma , Filogenia , Peixe-Zebra/classificação , Peixe-Zebra/genética
11.
Braz. j. biol ; 83: 1-10, 2023. map, tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468827

RESUMO

The colonization pattern of fish assemblages in streams is often studied in the context of environmental filters. On the other hand, when fish assemblages are subjected to anthropogenic effects, variables associated with environmental quality assume more importance. Therefore, this work evaluated the richness and composition of fish from streams sampled at different urbanization levels, aiming to determine any direct effects on the structure of fish assemblages. To accomplish this, samples were collected from 2003 to 2011 at 31 sites distributed among 3 microbasins in the Rio Ivinhema Basin, Alto Rio Paraná. Based on environmental variables, physicochemical of the water and analysis of the use and occupation of the soil, the microbasins were classified into different urbanization levels (low, medium and high). A total of 4,320 individuals were sampled, out of which 57 fish species were recorded. Sampled sites with medium urbanization level presented higher richness compared to sampled sites with high urbanization level which presented lower richness. Species richness in these sites was explained mainly by water temperature and water velocity. Results confirmed that urbanization does directly affect environmental integrity, which, in turn, can lead to the homogenization of stream assemblages.


Estudos sobre assembleias de peixes em riachos enfatizam o papel dos filtros ambientais associados ao padrão de colonização das assembleias, por outro lado, quando a assembleia está sujeita aos efeitos antropogênicos, as variáveis ambientais associadas à qualidade ambiental assumem maior importância. Dessa forma, o objetivo deste estudo foi analisar a riqueza e a composição de peixes de riachos amostrados em diferentes níveis de urbanização, buscando evidenciar se o efeito reflete diretamente na estrutura das assembleias. As amostragens foram realizadas em 31 locais distribuídos em três microbacias na bacia Rio Ivinhema, Alto Rio Paraná, no período de 2003 a 2011. Com base nas variáveis ambientais, físico-químicos da água e análise do uso e ocupação do solo as microbacias foram classificadas em diferentes níveis de urbanização (baixo, médio e alto). Foram amostrados um total 4.320 indivíduos, dos quais foram registradas 57 espécies de peixes. Os locais amostrados com influência média da urbanização apresentaram maior riqueza de espécies, entretanto, os locais amostrados com alta influência da urbanização apresentaram menor riqueza de espécies. Dessa forma, constatamos que a urbanização influencia diretamente na integridade ambiental, que pode levar a homogeneização das assembleias de riachos.


Assuntos
Animais , Análise do Solo , Bacias Fluviais/análise , Peixes/classificação , Peixes/crescimento & desenvolvimento , Poluição Ambiental/análise , Urbanização , Usos do Solo , Água/análise , Água/química
12.
Braz. j. biol ; 83: 1-18, 2023. map, ilus, tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468988

RESUMO

This study was conducted to estimate the diversity and the occurrence of commercially important finfish species collected by twenty fish sampling site of Sindh and Baluchistan coasts of the Arabian Sea in Pakistan from January to December 2019. Additionally, physicochemical characteristics of seawater were analyzed from these selected sites and found to be within suitable ranges required for fish growth and survive. A total of 81287 fish individuals were collected and identified as 49 species belonging to 26 families in our study. The most diversified family was Sparidae (13 species) followed by Carangidae and Lutjanidae (4 species), Mullidae, Serranidae, Ariidae (3 species), and Sciaenidae (2 species). The remaining 20 families were represented by only one species. The values of Shannon diversity index calculated for the four selected habitats revealed that high fish diversity was reported at Sonmiani Coast (H’=1.81), while less at Ormara Coast (H’=0.23). Likewise, Evenness index (E) was high at Sonmiani Coast (E=0.50) and less fish diversity was reported at Ormara Coast (E=0.06). Reducing risks to threatened marine species in coastal habitats also requires conservation actions at multiple scales. Thus, it was concluded that our study could be valuable in providing the more information’s regarding to the diversity of finfish species and their occurrence along the Pakistan Coast. Further, to better understand the effects, regular monitoring and conservation measures should be taken to mitigate the influence of anthropogenic activities and protect finfish diversity from further decline.


Este estudo foi conduzido para estimar a diversidade e a ocorrência de espécies de peixes comercialmente importantes coletadas por vinte locais de amostragem de peixes nas costas de Sindh e Baluchistão do mar da Arábia, no Paquistão, de janeiro a dezembro de 2019. Além disso, as características físico-químicas da água do mar foram analisadas a partir desses peixes locais selecionados e considerados dentro dos intervalos adequados necessários para o crescimento e sobrevivência dos peixes. Um total de 8.1287 indivíduos de peixes foi coletado e identificado como 49 espécies pertencentes a 26 famílias em nosso estudo. A família mais diversificada foi Sparidae (13 espécies), seguida por Carangidae e Lutjanidae (4 espécies), Mullidae, Serranidae, Ariidae (3 espécies) e Sciaenidae (2 espécies). As 20 famílias restantes foram representadas por apenas uma espécie. Os valores do índice de diversidade de Shannon calculados para os quatro habitats selecionados revelaram que uma alta diversidade de peixes foi relatada na costa Sonmiani (H’ = 1,81), enquanto menos na costa Ormara (H’ = 0,23). Da mesma forma, o índice de regularidade (E) foi alto na costa de Sonmiani (E = 0,50) e menos diversidade de peixes foi relatada na costa de Ormara (E = 0,06). A redução dos riscos para as espécies marinhas ameaçadas em habitats costeiros também requer ações de conservação em várias escalas. Assim, concluiu-se que nosso estudo pode ser valioso para fornecer mais informações sobre a diversidade de espécies de peixes finos e sua ocorrência ao longo da costa do Paquistão. Além disso, para compreender melhor os efeitos, medidas regulares de monitoramento e conservação devem ser tomadas para mitigar a influência das atividades antropogênicas e proteger a diversidade de peixes finos de um declínio maior.


Assuntos
Animais , Biodiversidade , Fenômenos Químicos , Peixes/classificação , Peixes/crescimento & desenvolvimento , Água do Mar/química
13.
Nature ; 609(7929): 969-974, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36171377

RESUMO

Modern representatives of chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods) have contrasting skeletal anatomies and developmental trajectories1-4 that underscore the distant evolutionary split5-7 of the two clades. Recent work on upper Silurian and Devonian jawed vertebrates7-10 has revealed similar skeletal conditions that blur the conventional distinctions between osteichthyans, chondrichthyans and their jawed gnathostome ancestors. Here we describe the remains (dermal plates, scales and fin spines) of a chondrichthyan, Fanjingshania renovata gen. et sp. nov., from the lower Silurian of China that pre-date the earliest articulated fossils of jawed vertebrates10-12. Fanjingshania possesses dermal shoulder girdle plates and a complement of fin spines that have a striking anatomical similarity to those recorded in a subset of stem chondrichthyans5,7,13 (climatiid 'acanthodians'14). Uniquely among chondrichthyans, however, it demonstrates osteichthyan-like resorptive shedding of scale odontodes (dermal teeth) and an absence of odontogenic tissues in its spines. Our results identify independent acquisition of these conditions in the chondrichthyan stem group, adding Fanjingshania to an increasing number of taxa7,15 nested within conventionally defined acanthodians16. The discovery of Fanjingshania provides the strongest support yet for a proposed7 early Silurian radiation of jawed vertebrates before their widespread appearance5 in the fossil record in the Lower Devonian series.


Assuntos
Peixes , Fósseis , Filogenia , Animais , China , Peixes/anatomia & histologia , Peixes/classificação , Arcada Osseodentária/anatomia & histologia , Dente
14.
Nature ; 609(7929): 954-958, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36171378

RESUMO

Molecular studies suggest that the origin of jawed vertebrates was no later than the Late Ordovician period (around 450 million years ago (Ma))1,2. Together with disarticulated micro-remains of putative chondrichthyans from the Ordovician and early Silurian period3-8, these analyses suggest an evolutionary proliferation of jawed vertebrates before, and immediately after, the end-Ordovician mass extinction. However, until now, the earliest complete fossils of jawed fishes for which a detailed reconstruction of their morphology was possible came from late Silurian assemblages (about 425 Ma)9-13. The dearth of articulated, whole-body fossils from before the late Silurian has long rendered the earliest history of jawed vertebrates obscure. Here we report a newly discovered Konservat-Lagerstätte, which is marked by the presence of diverse, well-preserved jawed fishes with complete bodies, from the early Silurian (Telychian age, around 436 Ma) of Chongqing, South China. The dominant species, a 'placoderm' or jawed stem gnathostome, which we name Xiushanosteus mirabilis gen. et sp. nov., combines characters from major placoderm subgroups14-17 and foreshadows the transformation of the skull roof pattern from the placoderm to the osteichthyan condition10. The chondrichthyan Shenacanthus vermiformis gen. et sp. nov. exhibits extensive thoracic armour plates that were previously unknown in this lineage, and include a large median dorsal plate as in placoderms14-16, combined with a conventional chondrichthyan bauplan18,19. Together, these species reveal a previously unseen diversification of jawed vertebrates in the early Silurian, and provide detailed insights into the whole-body morphology of the jawed vertebrates of this period.


Assuntos
Fósseis , Arcada Osseodentária , Vertebrados , Animais , China , Peixes/anatomia & histologia , Peixes/classificação , Arcada Osseodentária/anatomia & histologia , Filogenia , Crânio/anatomia & histologia , Vertebrados/anatomia & histologia , Vertebrados/classificação
15.
J Fish Biol ; 101(6): 1474-1500, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36111840

RESUMO

Although there have been many studies on the taxonomy of lanternfishes, morphological similarities during larval and juvenile stages make it difficult to identify species and understand their early life histories. During an ichthyoplankton survey in the Northwest Pacific (East Sea, East China Sea) between 2017 and 2020, a research vessel from the National Institute of Fisheries Science collected larvae and juveniles that belonged to the family Myctophidae using a bongo net. To accurately identify species, mtDNA sequences encoding cytochrome c oxidase subunit I and 16S ribosomal RNA were obtained and compared with those of adult voucher specimens. These comparisons led to the identification of four previously unknown larval lanternfish species (Diaphus chrysorhynchus, Diaphus suborbitalis, Diaphus watasei and Lampanyctus fernae), which are described here for the first time. The authors also describe the cryptic diversity of Benthosema pterotum and provide identification keys for 10 species of larval lanternfish, in accordance with their developmental stages.


Assuntos
DNA Mitocondrial , Peixes , Animais , China , DNA Mitocondrial/genética , Peixes/classificação , Peixes/genética , RNA Ribossômico 16S/genética , Biodiversidade , Oceano Pacífico
16.
Nature ; 608(7923): 563-568, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35859171

RESUMO

A fundamental gap in the study of the origin of limbed vertebrates lies in understanding the morphological and functional diversity of their closest relatives. Whereas analyses of the elpistostegalians Panderichthys rhombolepis, Tiktaalik roseae and Elpistostege watsoni have revealed a sequence of changes in locomotor, feeding and respiratory structures during the transition1-9, an isolated bone, a putative humerus, has controversially hinted at a wider range in form and function than now recognized10-14. Here we report the discovery of a new elpistostegalian from the Late Devonian period of the Canadian Arctic that shows surprising disparity in the group. The specimen includes partial upper and lower jaws, pharyngeal elements, a pectoral fin and scalation. This new genus is phylogenetically proximate to T. roseae and E. watsoni but evinces notable differences from both taxa and, indeed, other described tetrapodomorphs. Lacking processes, joint orientations and muscle scars indicative of appendage-based support on a hard substrate13, its pectoral fin shows specializations for swimming that are unlike those known from other sarcopterygians. This unexpected morphological and functional diversity represents a previously hidden ecological expansion, a secondary return to open water, near the origin of limbed vertebrates.


Assuntos
Evolução Biológica , Peixes , Fósseis , Nadadeiras de Animais/anatomia & histologia , Escamas de Animais/anatomia & histologia , Animais , Regiões Árticas , Canadá , Peixes/anatomia & histologia , Peixes/classificação , História Antiga , Mandíbula/anatomia & histologia , Faringe/anatomia & histologia , Filogenia , Natação
18.
PLoS One ; 17(7): e0271121, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35802740

RESUMO

The suborder Gobioidei is among the most diverse groups of vertebrates, comprising about 2310 species. In the fossil record gobioids date back to the early Eocene (c. 50 m.y. ago), and a considerable increase in numbers of described species is evident since the middle Miocene (c. 16 m.y. ago). About 40 skeleton-based gobioid species and > 100 otolith-based species have been described until to date. However, assignment of a fossil gobioid species to specific families has often remained tentative, even if well preserved complete specimens are available. The reasons are that synapomorphies that can be recognized in a fossil skeleton are rare (or absent) and that no phylogenetic framework applicable to gobioid fossils exists. Here we aim to overcome this problem by developing a phylogenetic total evidence framework that is suitable to place a fossil skeleton-based gobioid at family level. Using both literature and newly collected data we assembled a morphological character matrix (48 characters) for 29 extant species, representing all extant gobioid families, and ten fossil gobioid species, and we compiled a multi-gene concatenated alignment (supermatrix; 6271 bp) of published molecular sequence data for the extant species. Bayesian and Maximum Parsimony analyses revealed that our selection of extant species was sufficient to achieve a molecular 'backbone' that fully conforms to previous molecular work. Our data revealed that inclusion of all fossil species simultaneously produced very poorly resolved trees, even for some extant taxa. In contrast, addition of a single fossil species to the total evidence data set of the extant species provided new insight in its possible placement at family level, especially in a Bayesian framework. Five out of the ten fossil species were recovered in the same family as had been suggested in previous works based on comparative morphology. The remaining five fossil species had hitherto been left as family incertae sedis. Now, based on our phylogenetic framework, new and mostly well supported hypotheses to which clades they could belong can be presented. We conclude that the total evidence framework presented here will be beneficial for all future work dealing with the phylogenetic placement of a fossil skeleton-based gobioid and thus will help to improve our understanding of the evolutionary history of these fascinating fishes. Moreover, our data highlight that increased sampling of fossil taxa in a total-evidence context is not universally beneficial, as might be expected, but strongly depends on the study group and peculiarities of the morphological data.


Assuntos
Peixes , Fósseis , Filogenia , Animais , Teorema de Bayes , Evolução Biológica , Peixes/anatomia & histologia , Peixes/classificação , Membrana dos Otólitos/ultraestrutura
19.
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
20.
PLoS One ; 17(2): e0263196, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35113953

RESUMO

Urban riverine systems serve as conduits for the transport of plastic waste from the terrestrial dumpsites to marine repositories. This study presented data on the occurrence of microplastics in water, sediment, Bagrid Catfish (Chrysichthys nigrodigitatus) and Black-chinned Tilapia (Sarotherodon melanotheron) from the Densu River, an urban riverine system in Ghana. Microplastics were extracted from the samples collected from both the lentic and lotic sections of the river. The results indicated widespread pollution of the Densu River with microplastics in all the compartments studied. The average numbers of microplastic particles deposited in the Dam (2.0 ± 0.58) and Delta (2.50 ± 0.48) sections of the river were not affected by the differences in their hydrology. However, the stagnant water system of the Dam promoted the floating of larger-sized microplastics while the flowing waters of the Delta did not show any selectivity in the deposition of microplastics between sediment and the water column. The number of microplastics ingestions by the Bagrid Catfish (2.88 ± 2.11) was similar to the Black-chinned Tilapia (2.38 ± 1.66) but both species ingested lower numbers of microplastics than reported for marine fish species in coastal Ghana.


Assuntos
Monitoramento Ambiental/métodos , Peixes/classificação , Peixes/metabolismo , Microplásticos/análise , Rios/química , Poluentes Químicos da Água/análise , Animais , Gana , Prevalência
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