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1.
Sci Total Environ ; 802: 149720, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34464804

RESUMO

Barrier removal and fish pass construction are increasingly used as tools to restore river connectivity and improve habitat quality, but the effectiveness of subcatchment-scale connectivity restoration on recovery of fish communities is poorly understood. We used a before-after-downstream-upstream methodology to determine the effects of subcatchment-scale connectivity restoration on fishes in a fragmented tributary of the River Wear, Northeast England, between 2013 and 2019. Following restoration (three barriers removed, five barriers fitted with fish passes, two barriers unaltered), riffle habitat increased, fine sediment decreased, and most fish species benefitted. Total fish abundance, comprising seven native species, increased 3 years after the restoration and remained elevated to the end of the study. Mean brown trout (Salmo trutta) density increased from 20.9 ±â€¯6.3 to 33.8 ±â€¯16.8 per 100m2 from 2013 to 2019, with Young-of-Year trout increasing from 10.6 ±â€¯4.6 to 19.8 ±â€¯11.8 per 100m2. Connectivity restoration reduced the mean age of trout, suggesting a change to an increased migratory component of the population. Density of bullhead (Cottus perifretum), a species with poor dispersal ability, increased from 4.6 ±â€¯2.7 to 32.6 ±â€¯17.9 per 100m2 over 2013 to 2019. Stone loach (Barbatula barbatula), also a less mobile species but tolerant to fine sediment, decreased in abundance where barriers were removed. Atlantic salmon (Salmo salar) were absent over the study timescale, despite being common in the Wear, and despite suitable habitat and water quality in the restored subcatchment, suggesting a hysteresis effect. Our findings indicate that, where good water quality exists, restoring river connectivity and hydromorphology at a subcatchment scale is beneficial for most native resident and migratory fishes. However, the ecological benefits of connectivity restoration, especially in rivers with many barriers, may take several years to develop. We encourage well-controlled long-term studies reporting the outcomes of large-scale connectivity restoration.


Assuntos
Cipriniformes , Perciformes , Animais , Ecossistema , Peixes , Rios , Truta
2.
J Fish Biol ; 99(5): 1677-1695, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34498257

RESUMO

The Kanehira bitterling, Acheilognathus rhombeus, is a freshwater fish, discontinuously distributed in western Japan and the Korean Peninsula. Unusually among bitterling it is an autumn-spawning species and shows developmental diapause. Consequently, the characterization of its evolutionary history is significant not only in the context of the fish assemblage of East Asia, but also for understanding life-history evolution. This study aimed to investigate the phylogeography of A. rhombeus and its sister species Acheilognathus barbatulus, distributed in China, using a mitochondrial analysis of the ND1 gene from 311 samples collected from 50 localities in Japan and continental Asia. Phylogenetic analysis revealed that A. barbatulus is included in A. rhombeus and genetically closer to Japanese A. rhombeus than to Korean A. rhombeus. Divergence of Korean A. rhombeus and A. barbatulus from Japanese A. rhombeus was estimated to be from the late Pliocene (3.44 Mya) and the early Pleistocene (1.98 Mya), respectively. Each event closely coincided with the time of the Japan Sea opening. Japanese A. rhombeus comprised seven lineages: three in Honshu and four in Kyushu. One lineage in central Kyushu was genetically closer to the Honshu lineages than to other lineages in northern Kyushu. Divergence of Japanese lineages was estimated to be from the early to middle Pleistocene (0.55-0.93 Mya), during a period of geological and paleoclimatic change, including volcanic activity. Population expansion in the late Pleistocene (<0.10 Ma) was suggested in many of the lineages, which accords with other freshwater fishes. Biogeographically the ancestral A. rhombeus/A. barbatulus was likely to have repeatedly colonized Japan from the continent through land bridges in the late Pliocene and the early Pleistocene. However, the close genetic relationship between Japanese A. rhombeus and A. barbatulus suggests another possibility, with the second colonization occurring in reverse, from Japan to China. The small genetic distance between them indicates that the colonization occurred later than colonization events of other freshwater fishes, including other bitterling species.


Assuntos
Cipriniformes , DNA Mitocondrial , Animais , DNA Mitocondrial/genética , Mitocôndrias , Filogenia , Filogeografia
3.
J Exp Zool A Ecol Integr Physiol ; 335(7): 587-594, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34224637

RESUMO

Hybrid sterility is an inevitable phenomenon in the speciation process to avoid indiscriminate increases in species, but it is not always unconditional. We used computer assisted sperm analysis (CASA) to analyze sperm motility of Cobitis hankugensis, Iksookimia longicorpa, and their unisexual natural hybrids. In parental species, the sperm concentrations of C. hankugensis and I. longicorpa were 11.6 ± 4.8 × 109 and 16.5 ± 6.8 × 109 , respectively. For sperm motility, the total motility was higher in the parental species (C. hankugensis, 91.3%; I. longicorpa, 87.5%) than other hybrids. After 1 min, the motility duration was reduced to 14% in C. hankugensis and 3.3% in I. longicorpa. This result could indicate that the duration of sperm motility of C. hankugensis is longer than that of I. longicorpa up to 1 min after spermatozoa activation. All of the hybrids had a low concentration and it was distinct from their parent species. Total motility and other velocity parameters also showed significantly lower values except for the HHL (one from the C. hankugensis genome with two from the I. longicorpa genome) type motility measurement (13.6%). These results suggest that the hybrids derived from C. hankugensis and I. longicorpa, are not completely infertile, contrary to histological observations.


Assuntos
Cipriniformes , Animais , Cipriniformes/genética , Masculino , Motilidade Espermática
4.
Sci Rep ; 11(1): 13962, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234240

RESUMO

Fish has poor utilization capacity for glucose metabolism. The possible reasons are related to the core regulatory elements of glucose metabolism: transport proteins. Studies on the species and functions of Sglt1 in aquatic animals are scarce, therefore further studies are needed. In this study, the full length of blunt snout bream (Megalobrama amblycephala) sglt1 (Masglt1) was 2965 bp including 5'-UTR region of 168 bp and a 3'-UTR region of 820 bp. Masglt1 have a highest sequence homology in Cypriniformes fish. MaSglt1 protein was identified as a transmembrane protein with 14 α-helix structures locating plasma membrane by the methods of predicted tertiary structure and immunohistochemical staining. MaSglt1 protein has a hollow channel forms which could be specifically coupled with two Na+ ions to recognize glucose and carry out transmembrane transport. High sglt1 mRNA was found in the intestine and kidney. The mRNA levels of intestinal sglt1 had a positive correlation with dietary starch levels at 3 h after feeding, and the mRNA was significantly higher than that at 24 h, however, the mRNA levels of renal sglt1 presented results opposite to those of intestinal sglt1. The mRNA levels of renal sglt1 had a positive correlation with dietary starch levels at 24 h after feeding, and the expression was significantly higher than that at 3 h. These results confirmed that Masglt11 was mainly found in the intestine and kidney and was located in the cell membrane, playing a role in glucose homeostasis.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Cipriniformes/genética , Cipriniformes/metabolismo , Transportador 1 de Glucose-Sódio/genética , Transportador 1 de Glucose-Sódio/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Biologia Computacional/métodos , Cipriniformes/classificação , Expressão Gênica , Imuno-Histoquímica , Modelos Moleculares , Filogenia , Conformação Proteica , Transportador 1 de Glucose-Sódio/química , Relação Estrutura-Atividade
5.
Zootaxa ; 4974(1): 135150, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34186866

RESUMO

Oxynoemacheilus nasreddini, new species, from Lake Aksehir, Eber, Egirdir, and Ilgin basins in Central Anatolia is distinguished from other species of Oxynoemacheilus in Central Anatolia by having irregularly shaped blotches on flank; 24 dark-brown bands on caudal fin; a slender body, and an emarginate caudal fin in which the shortest middle caudal-fin ray is 7691% of the longest ray of the upper caudal-fin lobe. Molecular data suggest that the new species is closely related to O. mediterraneus from the Aksu and Köprüçay drainages. Although the two species are separated by only a minimum K2P distance of 1.2% in the mtDNA COI barcode region, they are well distinguished morphologically. The situation is complicated by loaches from Lake Egirdir basin that are identified as O. nasreddini by their morphological character states but are only distinguished from O. mediterraneus by a minimum K2P distance of 0.2% in the mtDNA COI barcode region.


Assuntos
Cipriniformes/anatomia & histologia , Cipriniformes/classificação , Rios , Animais , DNA Mitocondrial , Lagos , Turquia
6.
Zootaxa ; 4975(2): 369378, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34186562

RESUMO

Oxynoemacheilus isauricus, new species, from the Lakes Beysehir and Sugla basins in Central Anatolia is distinguished from all other species of the O. angorae group by having a very slender caudal peduncle (its depth 2.22.6 times in its length). The new species is further distinguished by having a short head (head length 2124% SL), and a midlateral series of irregularly shaped blotches on the flank. Oxynoemacheilus isauricus is also distinguished by a minimum K2P sequence divergence of 7.5% and 8.0% in the mtDNA-COI barcode region from O. eregliensis and O. atili, its closest relatives.


Assuntos
Cipriniformes/classificação , Animais , Cipriniformes/anatomia & histologia , DNA Mitocondrial/genética , Lagos , Turquia
7.
Aquat Toxicol ; 237: 105898, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34157443

RESUMO

Total dissolved gas (TDG) supersaturation caused by the operation of hydropower stations can threaten the survival and swimming performance of fish species. Different modes of hydropower flood discharges (regular vs. intermittent) from the Dagangshan hydropower station in China were studied in July and September 2017 to study the impact of TDG supersaturation on two native fish species in the downstream Dadu River. The average TDG supersaturation value was 114.3% in July under the regular discharge mode. In September, the supersaturation of TDG fluctuated in response to the intermittent discharge mode with an average TDG of 119.3%. Apparent gas bubble trauma was found on young-of-the-year (YOY) Prenant's schizothoracin and elongate loach in cages at different water depths during the flood discharge period. The mortality rate of YOY Prenant's schizothoracin and elongate loach in cages with water depths of 0-1 m were 16.25% and 2.5%, respectively, in July. The fluctuating TDG levels with higher peaks in September caused higher fish mortality rates. The final mortality rates of YOY Prenant's schizothoracin and elongate loach in cages with water depths of 0-1 m were 75% and 33.75%, respectively. Fish in the cages at a 0-3 m water depth survived better than those in the cages at a 0-1 m water depth. The critical swimming speeds (Ucrit) of YOY Prenant's schizothoracin and elongate loach without exposure to TDG supersaturation were 11.64 and 16.76 BL s-1, respectively. Ucrit decreased significantly after experiencing the flood discharge period and recovered to the normal level after experiencing the corresponding interval period.


Assuntos
Cipriniformes , Poluentes Químicos da Água , Animais , Inundações , Gases/análise , Movimentos da Água , Poluentes Químicos da Água/toxicidade
8.
Zool Res ; 42(4): 423-427, 2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34114755

RESUMO

A new species of the genus Troglonectes is described from Guangxi Zhuang Autonomous Region, China. Troglonectes hechiensis sp. nov. can be easily distinguished from its congeners based on the following characters: eyes normal; whole body covered by scales except head, throat, and abdomen; lateral line incomplete; caudal fin concave; and color pattern present on body.


Assuntos
Cipriniformes/classificação , Animais , China , Cipriniformes/anatomia & histologia , Cipriniformes/genética , Ecossistema , Filogenia , Rios , Especificidade da Espécie
9.
Parasitol Res ; 120(6): 1993-2001, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34021801

RESUMO

A new genus, Megancestus n. gen., is proposed to accommodate the caryophyllidean tapeworm Biacetabulum carpiodi Mackiewicz, 1969 from carpsuckers and quillback (Carpiodes spp.) in North America. This species is not closely related to other species of Biacetabulum Hunter, 1927 and is transferred to a newly erected genus. This new genus is typified by the possession of a small body (total length of 3.1-7.5 mm) with a scolex that bears a pair of large acetabulum-like loculi, two pairs of shallow lateral loculi, and a slightly convex apical disc, testes arranged in one or two layers, oval, thick-walled cirrus-sac, well-developed external seminal vesicle, separate gonopores, H-shaped ovary, few median vitelline follicles, and the uterus extending by a single loop anterior to the cirrus-sac. Megancestus differs from all Nearctic caryophyllidean genera (family Capingentidae), including Biacetabulum, by vitelline follicles dorsal to the ovary that connect the preovarian and postovarian vitelline fields. The most closely related Hunterella Mackiewicz et McCrae, 1962 differs by shape of the scolex (tholate, i.e., devoid of any loculi), dumbbell-shaped ovary and the uterus not extending anterior to the cirrus-sac. Megancestus carpiodi (Mackiewicz, 1969) n. comb. is the only species of the genus and it is a stenoxenous parasite, which has been found only in the river carpsucker (Carpiodes carpio-type host), quillback (Carpiodes cyprinus) and highfin carpsucker (Carpiodes velifer) (Catostomidae: Ictiobinae) in the lower and middle Mississippi basin.


Assuntos
Cestoides/classificação , Infecções por Cestoides/veterinária , Cipriniformes/parasitologia , Doenças dos Peixes/parasitologia , Animais , Cestoides/anatomia & histologia , Infecções por Cestoides/parasitologia , Feminino , Doenças dos Peixes/epidemiologia , América do Norte/epidemiologia , Filogenia , Especificidade da Espécie
10.
Zoology (Jena) ; 146: 125924, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33962259

RESUMO

In the American Southwest, the fishes within the genus Gila evolved in an environment with seasonal rainstorms that caused stochastic flooding. Some species within this genus, such as bonytail (Gila elegans), possess locomotor morphologies that are similar to those seen in high-performance swimmers such as tuna and lamnid sharks. These shared features include a shallow caudal peduncle, lunate tail, and mechanisms to transmit force from the anterior musculature to the tail fin. We compared the skeletal anatomy of the caudal region of bonytail to roundtail chub (Gila robusta) and humpback chub (Gila cypha) to determine which vertebral elements have been modified to create a shallow peduncle. We also tested the tensile strength of the red (slow oxidative) axial muscle by performing a standard stress test. If the muscle can withstand a large load, this suggests it may play a tendon-like role in transmitting force from the anterior muscle to the hypural plate of the tail. Lastly, we measured the collagen content of the red axial muscle (visualized using serial sections and Masson's trichrome stain) to determine if increased tensile strength is associated with increased collagen content. We found bonytail caudal peduncles are characterized by acute vertebral spines and have red axial muscle that can resist tearing under tension. Roundtail chub peduncles are characterized by relatively more obtuse angles and the red muscle tears easily under tension. Humpback chub possess an intermediate morphology, with relatively obtuse vertebral spine angles and the red muscle can resist tearing under tension. Bonytail have increased collagen content in posterior red axial muscle compared to the anterior musculature also suggesting a tendon-like role of the posterior red muscle. In combination with previous studies of swimming performance, our findings suggest that the axial musculature of bonytail may play a role in transmitting force directly to the shallow peduncle in a manner similar to that of the great lateral tendon of scombrids.


Assuntos
Cipriniformes/anatomia & histologia , Cipriniformes/fisiologia , Músculo Esquelético/fisiologia , Cauda/anatomia & histologia , Animais , Fenômenos Biomecânicos , Cauda/fisiologia
11.
Cytogenet Genome Res ; 161(3-4): 178-186, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33971659

RESUMO

In dojo loach (Misgurnus anguillicaudatus), although most wild types are gonochoristic diploids that are genetically differentiated into 2 groups, A and B, clonal lineages appear in certain localities. Clonal loaches have been considered to have hybrid origins between the 2 groups by a series of genetic studies. In this study, using FISH with a newly developed probe (ManDra-A), we identified 26 (1 pair of metacentric and 12 pairs of telocentric chromosomes) of 50 diploid chromosomes in contemporary wild-type group A loach. In contrast, ManDra-A signals were not detected on metacentric chromosomes derived from the ancestral group A of clonal loach. The FISH results clearly showed the presence of certain differentiations in metacentric chromosomes between ancestral and contemporary group A loach. Two-color FISH with ManDra-A and group B-specific ManDra (renamed ManDra-B) probes reconfirmed the hybrid origin of clones by identifying chromosomes from both groups A and B in metaphases. Our results showed the hybrid origin of clonally reproducing fish and the possibility that chromosomal differentiation between ancestral and contemporary fish can affect gametogenesis. In meiotic spermatocytes of sex-reversed clones, ManDra-A, and not ManDra-B, signals were detected in 12 out of 50 bivalents. Thus, the results further support the previous conclusion that clonal gametogenesis was assured by pairing between sister chromosomes duplicated from each ancestral chromosome from group A or B. Our study deepens the knowledge about the association between clonality and hybridity in unisexual vertebrates.


Assuntos
Cromossomos/genética , Cipriniformes/genética , Sondas de DNA/genética , Genoma/genética , Hibridização in Situ Fluorescente/métodos , Animais , Pareamento Cromossômico/genética , Células Clonais/metabolismo , Cipriniformes/classificação , Diploide , Feminino , Hibridização Genética/genética , Masculino , Meiose/genética , Microscopia de Fluorescência , Triploidia
12.
Parasitology ; 148(9): 1040-1056, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33975665

RESUMO

Monozoic tapeworms (Caryophyllidea) are dominant components of parasite communities of suckers (Catostomidae) in North America, with Biacetabulum Hunter, 1927 representing one of the more species-rich genera. Molecular (28S rDNA) and morphological (including scanning electron microscopy and histology) evaluation of newly collected tapeworms from different fish hosts revealed the existence of four similar (and three closely related) species of Biacetabulum. These four species differ from their congeners by having a long body (up to 48 mm long) with a very long, slender neck (its length represents ≥30% of total body length), a large, globular scolex with a prominent central acetabulum-like loculus on the dorsal and ventral sides, two pairs of shallow lateral loculi and a distinct, slightly convex apical disc, and a cirrus-sac that is situated between the anterior arms of the ovarian wings. Taken together, the morphological and molecular data and the host associations of these species provide evidence of their host specificity. Biacetabulum isaureae n. sp. occurs in notch clip redhorse, Moxostoma collapsum, in South Carolina (USA), B. longicollum n. sp. in silver redhorse, Moxostoma anisurum (type host), and golden redhorse, M. erythrurum, in Manitoba (Canada) and West Virginia (USA), B. overstreeti n. sp. in a spotted sucker, Minytrema melanops, in Mississippi, and B. hypentelii n. sp. in northern hogsucker, Hypentelium nigricans, in Tennessee (USA). The new species differ from each other in the number of postovarian vitelline follicles, the posterior extent of preovarian vitelline follicles and relative size of the cirrus sac.


Assuntos
Evolução Biológica , Cestoides/genética , Cipriniformes/parasitologia , Especiação Genética , Interações Hospedeiro-Parasita , Animais , Canadá , Infecções por Cestoides/parasitologia , Infecções por Cestoides/veterinária , Doenças dos Peixes/parasitologia , Estados Unidos
13.
Zootaxa ; 4952(1): zootaxa.4952.1.8, 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33903383

RESUMO

Oxynoemacheilus phasicus, new species, is described from the Rioni and Enguri River drainages in Georgia. It is distinguished from other Oxynoemacheilus species in the O. brandtii group by a mottled or marbled flank pattern in adults, a slightly emarginate caudal fin, and a deep caudal peduncle. Molecular data suggest that the new species is characterized by a minimum K2P distance of 7.5% from O. brandtii from the Kura drainage in the mtDNA COI barcode region. Oxynoemacheilus brandtii and O. elsae are re-diagnosed. A very slender Oxynoemacheilus from the Aras drainage clusters as sister to O. elsae in our molecular analysis and not with O. brandtii from the Kura River. However, it is identified as O. brandtii as it is indistinguishable from this species in morphological characters.


Assuntos
Cipriniformes , Animais , Mar Negro , Cipriniformes/classificação , Cipriniformes/genética , DNA Mitocondrial , Rios
14.
Zool Res ; 42(3): 310-334, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-33929106

RESUMO

The loach tribe Yunnanilini from China is reviewed here using morphological characters and complete mitochondrial genomes of select species. Molecular data suggest that the tribe Yunnanilini is not monophyletic and can be divided into three clades. Species of the Yunnanilus nigromaculatus group form an independent genus and are placed in Eonemachilus. In the phylogenetic tree, Y. jinxiensis clusters with Paranemachilus genilepis, and Y. pulcherrimus clusters with Micronemacheilus cruciatus, indicating that Y. jinxiensis and Y. pulcherrimus belong to Paranemachilus and Micronemacheilus, respectively. Based on morphological data, Y. bailianensis and Y. longibarbatus are placed in Heminoemacheilus, while Y. jinxiensis and Y. pulcherrimus, are placed in Paranemachilus and Micronemacheilus, respectively. Yunnanilus niulanensis and Y. qujinensis are treated as junior synonyms of Eonemachilus caohaiensis. Eonemachilus, Micronemacheilus, and Yunnanilus are show short separation between anterior and posterior nostrils. The genera can be distinguished from each other by mouth structure, lateral line and cephalic lateral-line canals, and papillae on median part of both lips. The anterior and posterior nostrils of Heminoemacheilus and Paranemachilus are closely set. Paranemachilus and Micronemacheilus are distinguished by cheeks covered with scales and lips with papillae, respectively. Our phylogenetic tree and morphological characters support Traccatichthys as a valid genus, which can be distinguished from Micronemacheilus by anterior and posterior nostrils closely set (vs. clearly separated). Four species are placed in Traccatichthys.


Assuntos
Cipriniformes/anatomia & histologia , Cipriniformes/genética , Genoma Mitocondrial , Animais , China , Cipriniformes/classificação , Filogenia , Especificidade da Espécie
15.
Zootaxa ; 4964(1): zootaxa.4964.1.6, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33903531

RESUMO

Oxynoemacheilus sarus, new species, is described from the lower Ceyhan and Seyhan drainages in southern Anatolia. It is distinguished from other Oxynoemacheilus species in Cilicia (including the Göksu, Seyhan and Ceyhan drainages) by possession of a series of irregularly shaped midlateral blotches, 3-5 dark-brown bands on the caudal fin, a complete lateral line, a forked caudal fin (shortest middle caudal-fin ray is 56-70% of longest ray of the upper caudal-fin lobe), the caudal peduncle depth 1.4-1.8 times in its length, and a suborbital groove in male individuals. The new species occurs in sympatry with superficially similar O. seyhanicola and O. evreni, and is distinguished by colour pattern as well as morphometric and molecular characters. Molecular data suggest that the closest relatives to the new species in our dataset are O. euphraticus and O. shehabi, which is characterised by a minimum K2P distance of 3.6% and 3.8%, respectively, in the COI mtDNA barcode region.


Assuntos
Cipriniformes , Animais , Cipriniformes/classificação , Cipriniformes/genética , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Proteínas de Peixes/genética , Masculino , Pigmentação , Rios , Especificidade da Espécie , Simpatria , Turquia
16.
Mol Ecol Resour ; 21(6): 1922-1935, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33893720

RESUMO

Butterfly hillstream loach (Beaufortia kweichowensis), a benthic fish in the torrential mountain streams, possesses a totally flat ventrum, flattened craniofacial and body skeletons, and enlarged paired fins covered by substantially small keratinous structures. However, little is known about the genetic basis of these specialized morphological adaptations. Here we present a 448.52-Mb genome assembly with contig N50 length of 5.53 Mb by integrating Illumina short-read sequencing, Nanopore long-read sequencing and HiC-based chromatin map. Demographic history reconstruction of the butterfly hillstream loach reveals that the population dynamics is correlated with the different stages of uplifting of the Tibetan Plateau. Comparative genomic analysis finds evidence of six keratin genes in butterfly hillstream loach evolving under positive selection. Within these genes, two keratin genes exhibit species-specific and divergent amino acid changes, suggesting a role in the formation of the unculi. Additionally, a series of positively selected genes, rapid evolving genes, specific variant genes and expanded gene families are found, including genes related to Hedgehog, Notch and BMP pathways, which may be involved in craniofacial development. These findings may have important implications for understanding the genetic basis of phenotypic adaptation to torrential mountain stream life.


Assuntos
Adaptação Fisiológica , Cipriniformes , Genoma , Adaptação Fisiológica/genética , Animais , China , Cipriniformes/genética , Proteínas de Peixes/genética , Queratinas/genética , Rios
17.
Zoolog Sci ; 38(2): 162-169, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33812355

RESUMO

Pesticide use is known to have a negative impact on the habitat use of birds. The decomposition of residual pesticides causes a drastic decrease in the biomass of wildlife food sources, indirectly affecting the ecosystem. In this study, we investigated the effects of pesticide use on the distributions of grey herons (Ardea cinerea) and great egrets (Ardea alba) in rice fields in the Republic of Korea. From early May to mid-June in 2015 and 2016, we recorded the abundance of these birds and their prey (loaches, other fish, tadpoles, and benthic invertebrates) and investigated their dependence on rice agricultural practices (eco-friendly vs conventional) and field types (harrowed, plowed, or transplanted). We found that both grey herons and great egrets preferentially used transplanted fields. Grey herons were observed more in conventional rice fields, while great egrets were observed more in eco-friendly rice fields. This may be driven by the distribution of their preferred prey types; we observed a higher density of tadpoles (the prey type favored by grey herons) in conventional fields and a higher density of loaches (the preferred prey of great egrets) in eco-friendly fields. Pesticides drive these patterns both directly and indirectly; pesticide use in conventional rice fields directly suppresses the abundance of loaches, which frees the tadpole population from predation pressures and indirectly boosts their abundance in conventional rice fields. Our findings suggest that the distributions of grey herons and great egrets vary depending on food availability and are directly and indirectly influenced by pesticide use.


Assuntos
Aves/fisiologia , Cipriniformes/fisiologia , Oryza , Praguicidas/toxicidade , Agricultura , Animais , Ecossistema , Comportamento Alimentar , República da Coreia
18.
Sci Rep ; 11(1): 9065, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33907285

RESUMO

Although the pace of senescence varies considerably, the physiological systems that contribute to different patterns of senescence are not well understood, especially in long-lived vertebrates. Long-lived bony fish (i.e., Class Osteichthyes) are a particularly useful model for studies of senescence because they can readily be aged and exhibit some of the longest lifespans among vertebrates. In this study we examined the potential relationship between age and multiple physiological systems including: stress levels, immune function, and telomere length in individuals ranging in age from 2 to 99 years old in bigmouth buffalo (Ictiobus cyprinellus), the oldest known freshwater teleost fish. Contrary to expectation, we did not find any evidence for age-related declines in these physiological systems. Instead, older fish appeared to be less stressed and had greater immunity than younger fish, suggesting age-related improvements rather than declines in these systems. There was no significant effect of age on telomeres, but individuals that may be more stressed had shorter telomeres. Taken together, these findings suggest that bigmouth buffalo exhibit negligible senescence in multiple physiological systems despite living for nearly a century.


Assuntos
Cipriniformes/fisiologia , Longevidade , Encurtamento do Telômero , Telômero , Animais , Água Doce
19.
Syst Parasitol ; 98(3): 307-319, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33871763

RESUMO

A new gyrodactylid species, Gyrodactylus ajime n. sp., is described from the skin and fins of an endemic and commercially important loach Niwaella delicata (Niwa) (Cypriniformes: Cobitoidea: Cobitidae), from the upper reach of the River Yura in Ashiu, Kyoto Prefecture, Japan with scanning electron microscopy observations and molecular data. This species can be distinguished from congenerics by characteristics of the sickle of the marginal hook: the sickle proper is composed of two straight sections and a curved section; its short point extends beyond the limit of the toe and is directed downwards; and the upper corner of heel angular is slightly raised. There are 31 species and subspecies of native loaches (Cobitoidea) known from Japan, of which 25 are red-listed nationally, and two are commercially important. I reviewed all reports of monogeneans from Japanese loaches, and found that only five fish species have been recorded as hosts of these parasites. This suggests that the parasite fauna of these fishes is poorly described. It is urgent to thoroughly describe the monogenean parasites of loaches in Japan as some of the parasite species may be threatened with co-extinction because their hosts are threatened, and to understand any negative impacts on commercially important fish species.


Assuntos
Cipriniformes , Doenças dos Peixes , Trematódeos , Nadadeiras de Animais/parasitologia , Animais , Cipriniformes/parasitologia , Doenças dos Peixes/parasitologia , Japão , Microscopia Eletrônica de Varredura , Pele/parasitologia , Especificidade da Espécie , Trematódeos/classificação , Trematódeos/ultraestrutura
20.
J Fish Biol ; 99(3): 807-817, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33900620

RESUMO

Triplophysa ferganaensis sp. nov. is described from the Shakhimardan stream, a small tributary of the Syr Darya, which does not reach the river in Fergana Valley. It can be distinguished from other valid Triplophysa loaches based on the following combination of characters: body smooth and scaleless, lateral line complete, posterior chamber of air bladder degenerated, inner gill rakers 10-11 on the first-gill arch, outer gill rakers absent, vertebrae 4 + 35-36, 8 + 8 branched caudal-fin rays, caudal peduncle depth 2.1-2.7 times its length, two supratemporal pores, dorsal-fin origin closer to the caudal-fin base than to the snout tip, caudal fin emarginated and pelvic-fin tip reaching the anus. The new species can also be distinguished from its congeners based on the molecular analyses of mitochondrial cytochrome oxidase subunit I (coI) gene sequences. The phylogenetic position of this new species indicates that it is a sister taxon of Triplophysa tenuis.


Assuntos
Cipriniformes , Animais , Ásia , Cipriniformes/genética , Brânquias , Filogenia , Rios
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