RESUMEN
BACKGROUND: Interspecific hybrids of rohu (Labeo rohita) and catla (Labeo catla) are common, especially in India due to constrained breeding. These hybrids must segregate from their wild parents as part of conservational strategies. This study intended to screen the hybrids from wild rohu and catla parents using both morphometric and molecular approaches. METHODS & RESULTS: The carp samples were collected from Jharkhand and West Bengal, India. The correlation and regression analysis of morphometric features are considered superficial but could be protracted statistically by clustering analysis and further consolidated by nucleotide variations of one mitochondrial and one nuclear gene to differentiate hybrids from their parents. Out of 21 morphometric features, 6 were used for clustering analysis that exhibited discrete separation among rohu, catla, and their hybrids when the data points were plotted in a low-dimensional 2-D plane using the first 2 principal components. Out of 40 selected single nucleotide polymorphism (SNP) positions of the COX1 gene, hybrid showed 100% similarity with catla. Concerning SNP similarity of the 18S rRNA nuclear gene, the hybrid showed 100% similarity with rohu but not with catla; exhibiting its probable parental inheritance. CONCLUSIONS: Along with morphometric analysis, the SNP comparison study together points towards strong evidence of interspecific hybridization between rohu and catla, as these hybrids share both morphological and molecular differences with either parent. However, this study will help screen the hybrids from their wild parents, as a strategy for conservational management.
Asunto(s)
Carpas , Hibridación Genética , Polimorfismo de Nucleótido Simple , Animales , Carpas/genética , Carpas/anatomía & histología , Hibridación Genética/genética , Polimorfismo de Nucleótido Simple/genética , India , ARN Ribosómico 18S/genética , Filogenia , Cyprinidae/genética , Cyprinidae/anatomía & histología , Quimera/genética , Análisis por ConglomeradosRESUMEN
To evaluate scale morphological variability (shape, size, topological macro- and microstructures, ornamentation patterns) of cyprinid fishes, nine species of the genus Garra were selected and their scales from five different body regions were studied by using light and scanning electron microscopy. The scales of the examined species were thin with a central or antero-centrally positioned focus, with no cteni in the posterior part. In addition to these typical characteristics, some morphological variation was observed in the overall shape (irregular round, true oval, round-triangular, irregular pentagonal, hexagonal, irregular hexagonal, pentagonal, ovoid), and the focus shape. These variations were mainly dependent on the fish lengths and the flank region. Morphological analysis clustered the examined species into two distinct groups. Group I consisted of G. amirhosseini and G. gymnothorax, while Group II has three subgroups, which include G. persica and G. mondica (subgroup I), G. meymehensis, G. rossica, G. nudiventris, G. hormuzensis (subgroup II), and G. rufa (subgroup III). The grouping of the studied Garra species based on the current scale morphological characters and the molecular data was only consistent for G. rossica and G. nudiventris. In addition, in the phylogenetic tree, G. persica, G. mondica, G. amirhosseini, and G. hormuzensis formed a distinct clade. However, these species did not represent close relationships in the dendrogram obtained from the scale morphology. A possible explanation why the grouping of the studied Garra species based on their scale morphological characters does not match their phylogenetic relationships is that most of the scale morphological traits vary depending on the fish size and the location of the scales on the flank. Therefore, except for some traits, that is, central or antero-centrally positioned focus, having no cteni, a specific sectioned form so called "tetra-sectioned" type, the other examined variables are not useful enough to be used in the taxonomic study of the examined cyprinid fishes. Therefore, scale morphological characters should be used carefully for taxonomic purposes. RESEARCH HIGHLIGHTS: Shape, size, topological macro- and microstructures, and ornamentation patterns of nine species of the genus Garra were studied by using light and scanning electron microscopy. The scales were thin with a central or antero-centrally positioned focus, with no cteni in the posterior part. Morphological variation was observed in the overall shape (irregular round, true oval, round-triangular, irregular pentagonal, hexagonal, irregular hexagonal, pentagonal, and ovoid), and the focus shape. The grouping of Garra species based on the current scale morphological characters and the molecular data was only consistent for G. rossica and G. nudiventris.
Asunto(s)
Escamas de Animales , Cyprinidae , Microscopía Electrónica de Rastreo , Microscopía , Filogenia , Animales , Cyprinidae/anatomía & histología , Cyprinidae/clasificación , Escamas de Animales/anatomía & histología , Escamas de Animales/ultraestructuraRESUMEN
The present drainage network of Bulgaria is the result of a complex Neogene and Quaternary evolution. Karst, which has developed on 23% of the territory, further complicates the hydrological pattern. Fresh waters of Bulgaria drain into the Black Sea and the Aegean Sea basins and can be roughly divided into the Danube (Middle and Lower Danube), non-Danube Black Sea, East Aegean, and West Aegean hydrological regions. Phoxinus, a small leuciscid fish, has a mosaic distribution in all four of these regions, inhabiting small mountainous and semi-mountainous streams. Based on morphology, it was identified as three species, Phoxinus phoxinus in the Danube, Phoxinus strandjae in the non-Danube, and Phoxinus strymonicus in West Aegean region. Later, molecular data revealed Phoxinus csikii and Phoxinus lumaireul in the Middle Danube and P. csikii in the Lower Danube. Phoxinus has been the focus of many studies, showing a high molecular and morphological diversity, which is not entirely consistent with previous morphology-only-based taxonomic concepts. In this study, molecular (a mitochondrial marker and a nuclear marker) and morphological data from both historical and recently sampled collections were analysed to assess the applicability of the integrative approach in Phoxinus. The results showed a significant influence of the complex paleo- and recent hydrology on the currently observed genetic structure of the considered populations and species. Furthermore, the study also demonstrated a strong influence of phenotypic plasticity on the morphological analysis of Phoxinus and the lack of a clear differentiation between P. csikii and P. strandjae. A barcoded specimen was designated as neotype to fix the species named P. strandjae in the current taxonomic concept. Finally, a significant discordance between genetically delimited clades and phenotypic groups did not allow a proper delineation of the species distributed in Bulgaria, demonstrating that more molecular markers are needed for further taxonomic study of the Phoxinus complex.
Asunto(s)
Fenotipo , Filogenia , Animales , Bulgaria , Cyprinidae/genética , Cyprinidae/clasificación , Cyprinidae/anatomía & histologíaRESUMEN
The hemicultrine fishes are a group of small-sized cyprinids, widely distributed but endemic to East Asian rivers and lakes. Till now, the taxonomic boundaries and relationships within this group remain poorly explored. In the present study, we study the phylogeny of this group, providing suggestions for classification of the hemicultrine group. Using two mitochondrial and three nuclear genes, and samples representing all genera, our results showed that the group consists of seven major lineages, of which four (Hemiculterella, Hainania, Pseudolaubuca, and Anabarilius) were monophyletic and three (Hemiculter, Toxabramis, and Pseudohemiculter) were not. Based on the phylogenetic tree, we redefined the genera. We revive the genus Siniichthys, which has three species, Siniichthys bleekeri, Siniichthys lucidus, and S. varpachovskii, that were previously treated as members of the genus Hemiculter but showed distant relationships to the genus Hemiculter in our phylogenetic tree. With the new results, a diagnostic key for clades of the hemicultrine group is provided. Furthermore, we provide more detailed information on diagnostic features of the recently described species Hemiculter yungaoi (Vasil'eva et al., 2022). This work will facilitate future systematic studies, pave the way for evolutionary studies, and provide valuable information for the urgent conservation of hemicultrine fishes.
Asunto(s)
Cyprinidae , Filogenia , Animales , Núcleo Celular/genética , Cyprinidae/genética , Cyprinidae/clasificación , Cyprinidae/anatomía & histologíaRESUMEN
Fish typically adapt to their environment through evolutionary traits, and this adaptive strategy plays a critical role in promoting species diversity. Onychostoma macrolepis is a rare and endangered wild species that exhibits a life history of overwintering in caves and breeding in mountain streams. We analyzed the morphological characteristics, histological structure, and expression of circadian clock genes in O. macrolepis to elucidate its adaptive strategies to environmental changes in this study. The results showed that the relative values of O. macrolepis eye diameter, body height, and caudal peduncle height enlarged significantly during the breeding period. The outer layer of the heart was dense; the ventricular myocardial wall was thickened; the fat was accumulated in the liver cells; the red and white pulp structures of the spleen, renal tubules, and glomeruli were increased; and the goblet cells of the intestine were decreased in the breeding period. In addition, the spermatogenic cyst contained mature sperm, and the ovaries were filled with eggs at various stages of development. Throughout the overwintering period, the melano-macrophage center is located between the spleen and kidney, and the melano-macrophage center in the cytoplasm has the ability to synthesize melanin, and is arranged in clusters to form cell clusters or white pulp scattered in it. Circadian clock genes were identified in all organs, exhibiting significant differences between the before/after overwintering period and the breeding period. These findings indicate that the environment plays an important role in shaping the behavior of O. macrolepis, helping the animals to build self-defense mechanisms during cyclical habitat changes. Studying the morphological, histological structure and circadian clock gene expression of O. macrolepis during the overwintering and breeding periods is beneficial for understanding its unique hibernation behavior in caves. Additionally, it provides an excellent biological sample for investigating the environmental adaptability of atypical cavefish species.
Asunto(s)
Adaptación Fisiológica , Relojes Circadianos , Cyprinidae , Relojes Circadianos/genética , Cyprinidae/anatomía & histología , Cyprinidae/genética , Cyprinidae/fisiología , Cruzamiento , Conducta Sexual Animal/fisiología , Adaptación Fisiológica/fisiología , Animales , Masculino , Femenino , Estaciones del Año , Hígado/metabolismo , Bazo , Riñón , Proteínas de Peces/genética , Expresión Génica/fisiologíaRESUMEN
Members of the genus Cyprinion (Cypriniformes: Cyprinidae) are found in the Indus River basin west to the Arabian Peninsula and the Tigris-Euphrates River drainages (Persian Gulf basin). The taxonomic status of Cyprinion including Cyprinion muscatense is poorly understood when compared to other cyprinid genera. C. muscatense has been considered as a member of the Cyprinion watsoni-microphthalmum group and a valid species endemic to the Arabian Peninsula. Here, we redescribe C. muscatense based on an integrative morphological and molecular approach and freshly sampled material from several localities in the Oman Mountains ecoregion. The results showed that C. muscatense is distinguished from the other Cyprinion species in the Arabian Peninsula by having a short, thin, and slightly serrated last unbranched dorsal fin ray; the lower number of circumpeduncular scales; lateral line scales; and also scales between the lateral line and the dorsal-fin origin. Subterminal mouth, presence of one pair of small barbels at the mouth corner, 3-4 unbranched and 9½-10½ dorsal-fin branched rays, 12-14 pectoral-fin rays, 7-8 pelvic-fin rays, 2-3 unbranched and 6½-7½ branched anal-fin rays, and 37-40 lateral line scales are other morphological characteristics of C. muscatense. C. muscatense is also well distinguished by molecular characters among its congeners. The first molecular phylogenetic analysis of the genus, covering all currently recognized Cyprinion species except for C. watsoni, is also presented. C. muscatense is resolved as the sister species to another endemic fish of the Arabian Peninsula Cyprinion mhalense, with a Kimura-2-Parameter model distance of 5.3%.
Asunto(s)
Cyprinidae , Filogenia , Animales , Cyprinidae/genética , Cyprinidae/clasificación , Cyprinidae/anatomía & histología , Omán , ADN Mitocondrial/genéticaRESUMEN
A new species, Sinocyclocheilus xingyiensis, is described based on specimens collected from a karst cave in Guizhou Province, China. The authors used an integrated taxonomic approach, including morphological and molecular data, to identify the new species as a member of the Sinocyclocheilu angularis group, and it can be distinguished from all other members of this group by a combination of the following features: two pairs of long barbels and long pectoral fins, 42-46 lateral-line scales, 7 (13-14) on outer (inner) side of the first gill arch and 35 (14-15 + 4 + 16 - 17) vertebrae. Phylogenetic analyses based on the cytochrome b (cyt b) gene fragment suggest that S. xingyiensis is a sister lineage to Sinocyclocheilus flexuosdorsalis. The genetic distance (Kimura 2-parameter) between the S. xingyiensis and S. angularis groups of Sinocyclocheilus species based on cyt b gene fragment ranged from 1.2% to 15.4%.
Asunto(s)
Cyprinidae , Cipriniformes , Animales , Cipriniformes/genética , Cipriniformes/anatomía & histología , Ríos , Filogenia , Citocromos b/genética , Cyprinidae/genética , Cyprinidae/anatomía & histología , ChinaRESUMEN
The complex architecture of fish scale has been investigated for several decades to show an existing link between scale morphology/microstructure and systematic/evolutionary relationships of fishes. In the present study, the surface architecture structure associated with the scales of a hill stream cyprinid fish Garra shamal restricted to the Hajar Mountains of the Arabian Peninsula was examined by optical light and scanning electron microscopy; (i) to describe the whole morphology, architectural design and hidden microstructures of scales in an endemic fish of the Arabian Peninsula, G. shamal, (ii) to investigate the phenotypic plasticity of scales in six selected regions of the fish body, (iii) to show an ontogenetic pattern of scale morphology in different size classes, and (iv) to study morphometric parameters for scales, and determine the most valuable indices for differentiating the scales of different body regions and the different size groups of studied species. For this purpose, scales were removed from six body regions of three size classes. The scale of G. shamal, as an ossified platelet and hard structure covering the outer part of fish in different body parts and size groups, demonstrated numerous hidden morphological and structural characteristics, and sculptural design, for example, type, shape, and size in general term, and circuli (thickness, arrangement, and relative spacing of circuli around the focus), radii (number, shape, its origin from focus), lepidonts (the texture, shape, size, orientation, and type of its attachment), and granules (shape, size, number, and configurations) in a specific term, that can contribute efficiently in fish identification and classification at the genus and species levels. Position of focus, presence of radii in all four fields of scales (anterior, posterior, and laterals) and thus tetra-sectioned type, presence of specific tubercle arrangement on the posterior region, and some scale indices can be used as a taxonomic tool in Garra identification. Moreover, scales in G. shamal demonstrated plasticity in different fish size classes, and the origin of scales on the fish body, revealing a kind of ontogenetic variation, and the importance of key scales (scales below the dorsal fin) in the lepidological studies. The quantitative and qualitative traits described here based on the optical light microscopy and electron scanning microscopy can be implemented along with other morphological and molecular characteristics to have a better taxonomic resolution of the genus Garra. RESEARCH HIGHLIGHTS: The optical light microscopy (LM) and scanning electron microscopy (SEM) techniques enhanced our knowledge of scale morphology in a cyprinid fish restricted to the Arabian Peninsula. The scale of G. shamal, in different body parts and size groups, demonstrated numerous hidden morphological and structural characteristics, and sculptural design that can contribute efficiently in fish identification and classification at the genus and species levels. Tetra-sectioned cycloid type, position of focus, presence of specific tubercle arrangement on the posterior region, and some scale indices can be used as a taxonomic tool for identification of the genus Garra. The scales showed plasticity in different fish size classes, and the origin of scales on the fish body, revealing a kind of ontogenetic variation.
Asunto(s)
Cyprinidae , Animales , Microscopía Electrónica de Rastreo , Cyprinidae/anatomía & histología , Ríos , Evolución BiológicaRESUMEN
In South and South East Asia three genera of fish species i.e. Tor, Neolissochilus and Naziritor are commonly known as Mahseer with at least 47 species. Among these 23 belongs to genus Tor, 22 to Neolissochilus and one to Naziritor i.e. Naziritor zhobensis. Recently another species added to genus Naziritor is Naziritor chelynoides in India. Among Tor species Tor putitora (Hamilton) is the most widely distributed Mahseer in Pakistan and other countries of the Indian subcontinent. However, based alone on morphological characters some authors identify the Pakistani counterparts as Tor macrolepis (Heckel), (a species presumed to be found exclusively in the Indus River system) distinct from Tor putitora (a species found in Ganga Brahmaputra River system). In order to resolve this taxonomic ambiguity, present study carried out meristic and morphometric measurements of Mahseer collected from a total of 11 water bodies of Pakistan. Ratios between the morphometric characters were calculated and statistically analyzed using t-test and correlation coefficient. Two species identified as Tor putitora and Naziritor zhobensis were the sole Mahseer inhabitants of Indus system in Pakistan. Tor putitora occurred at all surveyed sites while Nazirtor zhobensis had a distribution range from river Zhob to tributaries of river Gomal the right bank tributaries of River Indus. The study corroborates that there are no unequivocal morphological synapomorphies in any existing populations of both species. The study further demonstrates that head length, a character frequently used in Mahseer taxonomy, is not a good measure for species identification. Finally the present study establishes that Naziritor zhobensis still exists in the water bodies of Pakistan and that golden Mahseer occurring in Indus riverine system of Pakistan is Tor putitora.
No sul e sudeste da Ásia, três gêneros de espécies de peixes, ou seja, Tor, Neolissochilus e Naziritor, são comumente conhecidos como Mahseer com pelo menos 47 espécies. Entre estas, 23 pertencem ao gênero Tor, 22 a Neolissochilus e um a Naziritor, ou seja, Naziritor zhobensis. Recentemente, outra espécie adicionada ao gênero Naziritor é Naziritor chelynoides na Índia. Entre as espécies de Tor, Tor putitora (Hamilton) é o Mahseer mais amplamente distribuído no Paquistão e em outros países do subcontinente indiano. No entanto, com base apenas em caracteres morfológicos, alguns autores identificam as contrapartes paquistanesas como Tor macrolepis (Heckel) (uma espécie que se presume ser encontrada exclusivamente no sistema do rio Indo), distinta de Tor putitora (uma espécie encontrada no sistema do rio Ganga Brahmaputra). A fim de resolver essas ambiguidades taxonômicas, o presente estudo realizou medidas merísticas e morfométricas de Mahseer coletadas em um total de 11 corpos dágua do Paquistão. As razões entre os caracteres morfométricos foram calculadas e analisadas estatisticamente usando o teste t e o coeficiente de correlação. Duas espécies identificadas como Tor putitora e Naziritor zhobensis foram os únicos habitantes Mahseer do sistema fluvial Indo no Paquistão. Tor putitora ocorreu em todos os locais pesquisados, enquanto Nazirtor zhobensis tinha uma faixa de distribuição do rio Zhob aos afluentes do rio Gomal, afluentes da margem direita do rio Indo. O estudo corrobora que não há sinapomorfias morfológicas inequívocas em nenhuma das populações existentes de ambas as espécies. O estudo demonstra ainda que o comprimento da cabeça, um caractere frequentemente usado na taxonomia de Mahseer, não é boa medida para identificação das espécies. Finalmente, o presente estudo estabelece que Naziritor zhobensis ainda existe nos corpos d'água do Paquistão e que o Mahseer dourado ocorrendo no sistema fluvial Indo do Paquistão é Tor putitora.
Asunto(s)
Animales , Cyprinidae/anatomía & histología , Cyprinidae/clasificaciónRESUMEN
The two species hypothesis for S. cephaloides and S. cii, both occurring in the southern Marmara Sea basin, is tested. Our results suggested that there are no morphological and molecular characters to support this hypothesis, and we treat Squalius cephaloides as a junior synonym of S. cii.
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Cyprinidae , Cipriniformes , Animales , Cyprinidae/anatomía & histologíaRESUMEN
The small cyprinid genus Prolabeops Schultz, 1941 is restricted to the Nyong and Sanaga River systems in Cameroon. In the past, the genus had been suggested to be either a member of the Labeoninae, Torinae or the Smiliogastrinae mainly on the basis of morphological similarities, and it is nowadays considered as incertae sedis within the Cypriniformes. This study provides the first attempt to reveal the phylogenetic position of Prolabeops using molecular data. For this purpose, the authors sequenced a large fraction of the mitochondrial genome (c. 13,600 bp), including all mitochondrial protein coding genes, of two Prolabeops melanhypopterus specimens and an additional four Enteromius specimens. The large-scale phylogenetic analysis was based on an alignment including all mitochondrial protein coding genes of 902 specimens representing c. 899 cypriniform species. Prolabeops was clearly recovered within the African Smiliogastrinae, forming a weakly supported clade together with Enteromius jae, Enteromius hulstaerti and Barboides gracilis. The study data underline the urgent need of a thorough taxonomic revision of the small African barbs collectively placed in the genus Enteromius.
Asunto(s)
Cyprinidae , Cipriniformes , Genoma Mitocondrial , Animales , Filogenia , Cipriniformes/genética , Cyprinidae/anatomía & histología , Proteínas Mitocondriales/genéticaRESUMEN
Sicyopterus garra Hora, 1925 from the insular streams of South Andaman Islands was synonymized with Sicyopterus microcephalus described from Java, South East Asia and has retained this taxonomic status since then. Recent collections of Sicyopterus from the type locality of S. garra and the examination of syntypes of this species revealed significant morphological and genetic differences from S. microcephalus and the other Sicyopterus species with papillae on upper lip. S. garra is thus a valid species and not a synonym of S. microcephalus. S. garra differs from S. microcephalus in having fewer lateral scales 53-59 vs. 57-68, fewer zigzag series (12-14 vs. 13-16), a longer caudal peduncle length (16-21 vs. 13-17), and by having a high percentage of divergence in COI gene (5.5%-5.8%).
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Cyprinidae , Perciformes , Animales , Cyprinidae/anatomía & histología , Perciformes/anatomía & histología , India , IslasRESUMEN
The blind troglobite cavefish Sinocyclocheilus rhinocerous lives in oligotrophic, phreatic subterranean waters and possesses a unique cranial morphology including a pronounced supra-occipital horn. We used a combined approach of laboratory observations and Computational Fluid Dynamics modeling to characterize the swimming behavior and other hydrodynamic aspects, i.e., drag coefficients and lateral line sensing distance of S. rhinocerous. Motion capture and tracking based on an Artificial Neural Network, complemented by a Particle Image Velocimetry system to map out water velocity fields, were utilized to analyze the motion of a live specimen in a laboratory aquarium. Computational Fluid Dynamics simulations on flow fields and pressure fields, based on digital models of S. rhinocerous, were also performed. These simulations were compared to analogous simulations employing models of the sympatric, large-eyed troglophile cavefish S. angustiporus. Features of the cavefish swimming behavior deduced from the both live-specimen experiments and simulations included average swimming velocities and three dimensional trajectories, estimates for drag coefficients and potential lateral line sensing distances, and mapping of the flow field around the fish. As expected, typical S. rhinocerous swimming speeds were relatively slow. The lateral line sensing distance was approximately 0.25 body lengths, which may explain the observation that specimen introduced to a new environment tend to swim parallel and near to the walls. Three-dimensional simulations demonstrate that just upstream from the region under the supra-occipital horn the equipotential of the water pressure and velocity fields are nearly vertical. Results support the hypothesis that the conspicuous cranial horn of S. rhinocerous may lead to greater stimulus of the lateral line compared to fish that do not possess such morphology.
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Characidae , Cyprinidae , Animales , Fenómenos Biomecánicos , China , Cyprinidae/anatomía & histología , Hidrodinámica , Natación , AguaRESUMEN
Specimens of Devario from a tributary to the Salween River in Myanmar initially identified as Devario browni but with a different colour pattern, were subjected to a comparative morphological analysis with syntypes and other specimens of D. browni from near its putative type locality. The Salween sample was recognised as representing a distinct species, here named Devario ahlanderi. No significant morphometric differences were found between D. ahlanderi and D. browni. The type series of Devario ahlanderi differed from D. browni and most other species of Devario in the presence of 14 vs 12 circumpeduncular scale rows. Devario ahlanderi, D. browni, and D. fangae shared subadult colour pattern. Adult D. ahlanderi differed from adult D. browni in the trunk colour pattern, consisting of rows of dark blotches or short vertical bars. In D. browni, the flank colour pattern consisted of horizontal dark stripes, the middle of which (the P stripe) frequently diverged anteriorly, enclosing a small light blotch. Specimens previously reported as D. browni from the upper Salween River basin in Yunnan differed slightly in colour pattern, and may represent a distinct species. Devario ahlanderi shared spotted colour pattern with that of one ontogenetic state in D. kysonensis, except that a row of spots marking the P-1 stripe in D. kysonensis was absent in D. ahlanderi. The minimum genetic distance between D. ahlanderi and congeneric species varied from 2.1 to 5% in the mt-coI gene.
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Cyprinidae , Cipriniformes , Animales , Cyprinidae/anatomía & histología , Cyprinidae/genética , Mianmar , RíosRESUMEN
The present study was aimed at comparing the brain size of mahseer (Tor putitora) in relation to their body weight and standard length, to investigate the potential impact of rearing environment on brain development in fish. The weight of the brain and three of its subdivisions cerebellum (CB), optic tectum (OT), and telencephalon (TC) were measured for both wild and hatchery-reared fish. The data was analysed using multiple analysis of covariance (MANCOVA), analysis of covariance (ANCOVA), and discriminate function analysis (DFA). We found the fish reared under hatchery conditions exhibit smaller brain size related to body weight, when compared to the wild ones. A significant (p<0.5) difference was observed in the length of CB and OT concerning the standard body length while no significant difference was found in TC of the fish from both the origins. The results of the current study highlight a logical assumption that neural deficiency affects the behaviour of fish, that's why the captive-reared fish show maladaptive response and face fitness decline when released to the natural environment for wild stock enhancement. The current study concluded that hatchery-reared fish exhibit variations in gross brain morphology as compared to their wild counterpart.
O presente estudo teve como objetivo comparar o tamanho do cérebro de mahseer (Tor putitora) em relação ao seu peso corporal e comprimento padrão, para investigar o impacto potencial do ambiente de criação no desenvolvimento do cérebro em peixes. O peso do cérebro e três de suas subdivisões cerebelo (CB), tectum óptico (OT) e telencéfalo (TC) foram medidos para peixes selvagens e criados em incubadoras. Os dados foram analisados usando análise múltipla de covariância (MANCOVA), análise de covariância (ANCOVA) e análise de função discriminante (DFA). Descobrimos que os peixes criados em condições de incubação apresentam menor tamanho do cérebro em relação ao peso corporal quando comparados aos selvagens. Uma diferença significativa (p <0,5) foi observada no comprimento do CB e OT em relação ao comprimento corporal padrão, enquanto nenhuma diferença significativa foi encontrada no CT dos peixes de ambas as origens. Os resultados do estudo atual destacam uma suposição lógica de que a deficiência neural afeta o comportamento dos peixes. É por isso que os peixes criados em cativeiro mostram uma resposta mal adaptativa e enfrentam declínio de aptidão quando liberados no ambiente natural para o aprimoramento do estoque selvagem. O estudo atual concluiu que os peixes criados em incubadoras exibem variações na morfologia cerebral bruta em comparação com suas contrapartes selvagens.
Asunto(s)
Animales , Conducta Animal , Cyprinidae/anatomía & histología , Cyprinidae/crecimiento & desarrollo , Cerebro/crecimiento & desarrolloRESUMEN
Hypoxia is one of the most significant threats to biodiversity in aquatic systems. The ability of high-latitude fish to tolerate hypoxia with histological and physiological responses is mostly unknown. We address this knowledge gap by investigating the effects of exposures to different oxygen levels using Phoxinus lagowskii (a high-latitude, cold-water fish) as a model. Fish were exposed to different oxygen levels (0.5 mg/L and 3 mg/L) for 24 h. The loss of equilibrium (LOE), an indicator of acute hypoxia tolerance, was 0.21 ± 0.01 mg/L, revealing the ability of fish to tolerate low-oxygen conditions. We sought to determine if, in P. lagowskii, the histology of gills and liver, blood indicators, enzyme activities of carbohydrate and lipid metabolism, and antioxidants changed to relieve stress in response to acute hypoxia. Notably, changes in vigorous jumping behavior under low oxygen revealed the exceptional hypoxia acclimation response compared with other low-latitude fish. A decrease in blood parameters, including RBC, WBC, and Hb, as well as an increase in MCV was observed compared to the controls. The increased total area in lamella and decreased ILCM volume in P. lagowskii gills were detected in the present study. Our results also showed the size of vacuoles in the livers of the hypoxic fish shrunk. Interestingly, an increase in the enzyme activity of lipid metabolism but not glucose metabolism was observed in the groups exposed to hypoxia at 6 h and 24 h. After combining histology and physiology results, our findings provide evidence that lipid metabolism plays a crucial role in enhancing hypoxia acclimation in P. lagowskii. Additionally, SOD activity significantly increased during hypoxia, suggesting the presence of an antioxidant response of P. lagowskii during hypoxia. High expression levels of lipogenesis and lipolysis-related genes were detected in the 6 h 3 mg/L and 24 h 3 mg/L hypoxia group. Enhanced expression of lipid-metabolism genes (ALS4, PGC-1, and FASN) was detected during hypoxia exposure. Together, these data suggest that P. lagowskii's ability to tolerate hypoxic events is likely mediated by a comprehensive strategy.
Asunto(s)
Aclimatación , Cyprinidae , Oxígeno , Animales , Conducta Animal , Cyprinidae/anatomía & histología , Cyprinidae/sangre , Cyprinidae/genética , Cyprinidae/metabolismo , Geografía , Branquias/patología , Glucosa/metabolismo , Pruebas Hematológicas , Metabolismo de los Lípidos , Hígado/metabolismo , Hígado/patología , Hígado/ultraestructura , Oxidorreductasas/metabolismoRESUMEN
Two fluviolacustrine lineages (SI1 Barbus and SI2 Barbus) of the Barbus genus have been recently detected in the Apulia-Campania ichthyogeographic district (southern Italy). The aim of this study was to determine the taxonomic status of these lineages by comparing them with the two already-established Italian fluviolacustrine species Barbus plebejus and Barbus tyberinus through a more in-depth molecular and morphological investigation. Genetic analyses were performed on both mitochondrial (cytochrome b) and nuclear (growth hormone paralog 2) DNA markers, and morphological analyses were carried out on specific age classes and purebred populations. Molecular analyses detected four evolutionary lineages at the mitochondrial level, whereas the nuclear data set highlighted the strict evolutionary relation between B. plebejus sensu stricto and the new lineages, converged in the B. plebejus complex clade. The morphological analyses allowed us to discriminate SI1 Barbus and SI2 Barbus from both B. plebejus and B. tyberinus. The new taxa could be discriminated by the greatest maximum body height and the longest pre-orbital distance, respectively. Both the new lineages have longer ventral and pectoral fins than B. plebejus and B. tyberinus, a larger caudal fin than B. tyberinus and a lower number of scales along the lateral line than B. plebejus. Both molecular and morphological results suggested the two southern Italian lineages could be considered as distinct endemic species: the formal description of the new species Barbus samniticus sp. nov. (i.e., SI1 Barbus) and the revalidation of Barbus fucini Costa, 1853 (i.e., SI2 Barbus) were thus proposed, and, for both species, molecular and morphological diagnosis were provided.
Asunto(s)
Biodiversidad , Cyprinidae/clasificación , Filogenia , Animales , Evolución Biológica , Cyprinidae/anatomía & histología , Cyprinidae/genética , Citocromos b/genética , Proteínas de Peces/genética , Marcadores Genéticos/genética , Italia , Especificidad de la EspecieRESUMEN
Morphological variation is fundamentally related to various aspects of fish ecology, including foraging, locomotion, and habitat utilisation. Twenty-six species of closely related cyprinid fish (n = 502) were analysed for patterns of morphological variations by using geometric morphometric methods. Ecological data of feeding and habitat preferences were determined by the observations in fields and laboratory together with the gathering of bibliographic information. The findings of major variation displayed in all parts of the fish body and correlated with ecological parameters. Variations of head shape especially form and position of mouthpart involved with feeding behaviours, whereas the variations of body depth and length which affected swimming patterns reflected responsiveness of water currents and habitat uses. Adaptation of head shape and body elongation was remarkably related to the feeding regime, swimming manoeuvrability and habitat utilisation of the species. Some convergent variation was observed between the tribes Smiliogastrini and Poropuntiini. Therefore, we propose that the morphological diversity of cyprinine fish is mainly affected by ecological gradients, while phylogenetic effects on morphology are minor.
Asunto(s)
Cyprinidae/anatomía & histología , Cyprinidae/clasificación , Ecosistema , Ríos , Adaptación Fisiológica , Animales , Cyprinidae/fisiología , Conducta Alimentaria/fisiología , Natación/fisiología , TailandiaRESUMEN
In the current study, the histological structure of the gallbladder of Alburnus tarichi (Güldenstädt, 1814) was investigated. Hematoxylin and eosin were used to stain the histological sections for routine examinations, in addition to using periodic acid Schiff (PAS) for the neutral mucins, aldehyde fuchsin (AF) for the sulphated mucins, and Alcian blue (AB; pH: 2.5) for the acidic mucins. In addition, proliferating cell nuclear antigen (PCNA) immune-staining was performed for the detection of dividing cells among the epithelium. The gallbladder of A. tarichi was composed of mucosa, muscularis, and serosa or adventitia layers. The mucosa covering the wavy pleomorphic folds was made up of tall columnar epithelium and a lamina propria. The apical surface of the epithelial cells was lined by continuous short microvilli. On the epithelium, the luminal surface was remarkably stained with PAS, AF, and AB. Slight to moderate staining was observed on the epithelial cells in the apical zone with PAS. The cytoplasm of epithelial cells were stained in a slight manner with AF. No goblet cells were observed among the epithelium. According to the PCNA immune-staining, some epithelial cells were observed to proliferate. The lamina propria consisted of loose connective tissue that contained fibrocytes, collagen and elastic fibers, capillaries, and small blood vessels. The muscularis layer displayed muscle fibers that were circular, smooth, and surrounded by collagen fibers. The subserosal and serosal or adventitial layers had typical morphology to those of other fish and vertebrates.
En este estudio, se investigó la estructura histológica de la vesícula biliar de Alburnus tarichi (Güldenstädt, 1814). Las secciones histológicas se tiñeron con Hematoxilina-Eosina para los exámenes de rutina, además de usar el ácido periódico de Schiff (PAS) para las mucinas neutras, aldehído fucsina (FA) para las mucinas sulfatadas y azul alcián (AB; pH: 2,5) para las mucinas ácidas. Además, se realizó una tinción inmune de antígeno nuclear de células proliferativas (PCNA) para la detección de células en división entre el epitelio. La vesícula biliar de A. tarichi estaba compuesta de capas, mucosa, muscular y serosa o adventicia. La mucosa que cubría los pliegues pleomórficos ondulados estaba formada por un epitelio columnar alto y una lámina propia. Se observó una superficie apical de las células epiteliales revestida por microvellosidades cortas y continuas. En el epitelio se observó una tinción importante de la superficie luminal teñida con PAS, FA y AB. Se observó una tinción leve a moderada en las células epiteliales en la zona apical con PAS. El citoplasma de las células epiteliales se tiñó ligeramente con FA. No se observaron células caliciformes entre el epitelio. Según la tinción de PCNA, se observó que proliferaban algunas células epiteliales. La lámina propia consistía en tejido conectivo laxo que contenía fibrocitos, colágeno y fibras elásticas, capilares y pequeños vasos sanguíneos. La capa muscular mostraba fibras musculares circulares, lisas y rodeadas de fibras de colágeno. Las capas subserosas y serosas o adventicias tenían una morfología típica a la de otros peces y vertebrados.
Asunto(s)
Animales , Cyprinidae/anatomía & histología , Vesícula Biliar/anatomía & histología , Antígeno Nuclear de Célula en ProliferaciónRESUMEN
Over the last 100 years, fishes native to the Southwestern United States have faced a myriad of biotic and abiotic pressures which has resulted in most being federally listed as endangered or threatened. Most notably, water diversions and the introduction of non-native fishes have been the primary culprits in causing the downfall of native fish populations. We describe how recent studies of morphology, physiology, and behavior yield insights into the failed (occasionally successful) management of this vanishing biota. We describe how understanding locomotor morphologies, physiologies, and behaviors unique to Southwestern native fishes can be used to create habitats that favor native fishes. Additionally, through realizing differences in morphologies and behaviors between native and non-native fishes, we describe how understanding predator-prey interactions might render greater survivorship of native fishes when stocked into the wild from repatriation programs. Understanding fundamental form-function relationships is imperative for managers to make educated decisions on how to best recover species of concern in the Southwestern United States and worldwide.