Academic literature on the topic 'Catfishes Anatomy'

Giant cells are the histopathological units of granulomatous tissue which can be induced by the presence of endogenous or exogenous materials. Besides in other animals it has been reported in several fish species. A histopathological study of systemic granuloma in reared catfish Parasilurous asotus was reported in Taiwan. The ultrastructure of the giant cells of the granulomatous tissue of the same species of catfish was studied. The giant cells with a central amorphrous core, a transitional zone and a peripheral cellular zone (Fig. 1) is present in this report.

Dumbo catfish (Clarias gariepinus) and Gabus (Channa striata) have additional organ respiratory system structures in the gills, called labyrinth. This organ is a tool for fish to take oxygen directly from the air so that it can live in low oxygen habitats. Both fish have differences at the Order level. Catfish is an order of Siluriformes as Gabus is an order of Perciformes. The purpose of this study was to distinguish the anatomy and histology of the gill structure and labyrinth in both fish. The macroanatomy observation was conveyed by dissection to determine the gill topography in the two fish species. Histology preparations were carried out using the paraffin method and using Hematoxylin-Eosin (HE) staining that showed in the labyrinth organ there were many blood vessels to bind oxygen then distributed to all parts of the fish's body.

The genus Pseudoplatystoma Bleeker consists of three species long recognized as: P. fasciatum (Linnaeus), P. tigrinum (Valenciennes), and P. corruscans (Spix & Agassiz), and five species recently recognized or described here: P. punctifer (Castelnau), P. reticulatum Eigenmann & Eigenmann, P. orinocoense n. sp., P. metaense n. sp., and P. magdaleniatum n. sp. The eight species form a monophyletic group with two clades that are supported by anatomical features (i.e., skeletal anatomy and myology). One clade (P. tigrinum and P. metaense) is restricted to the Orinoco and Amazon basins, and the other clade, comprised of the remaining six species, is found in the Guyanas, Orinoco, Amazon, and Paraná basins. The species are diagnosed on the basis of body shape, color pattern (e.g., bars, loops, and spots), skeletal anatomy, and vertebral numbers. Pseudoplatystoma punctifer and P. tigrinum) are sympatric in the Amazon Basin, P. metaense and P. orinocoense in the Orinoco Basin, and P. corruscans and P. reticulatum, are sympatric in the Paraná. Pseudoplatystoma magdaleniatum (Magdalena basin) and P. fasciatum (Guyanas) each occur as the only species of Pseudoplatystoma in their respective individual ranges. Pseudoplatystoma reticulatum may be sympatric with the two other species in the Amazon Basin, but we have no records of them being captured together in the mainstream or tributaries. All eight species are used as food in both commercial and subsistence fishing, and there is a moderate–sized ornamental fish market for the young and juveniles. A key to adults of the eight species is included.

Herpesviruses comprise an extensive family of enveloped DNA-containing animal viruses. Although they infect a wide range of vertebrate hosts and their linear double-stranded genomes vary substantially in size and other properties, the nucleocapsid appears to be a conservative element of viral design. The capsid shell is icosahedrally symmetric (T=16), and in the case of alphaherpesviruses is 125 nm in diameter and 15nm thick. Recently, we have studied the molecular anatomy of herpes simplex virus1 (HSV-1), whose capsid contains four major proteins, by combining cryo-electron microscopy and 3-dimensional reconstruction with biochemical depletion experiments and antibody-labelling. In order to probe structural perturbations attributable to evolutionary differences, we have extended these studies to channel catfish virus. CCV exhibits the gross morphology of a herpesvirus, although no evident relationship to other herpesviruses was found in an analysis of proteins predicted from its complete DNA sequence.

The big-oui hybrid catfish (female C. macrocephalus x male C. gariepinus) was successfully achieved using artificial hybridization. This hybrid combines the superior taste of the C. macrocephalus with the faster growth rate and higher resistance to environmental conditions of the C. gariepinus and is now the biggest fresh-water aquaculture product in Thailand. In this thesis the results of experiments involving hybridization and genetic manipulation were used to investigate the nature of the hybridization event. This information was used to develop broodstock for Clarias catfish breeding programme. Allozyme studies resolved 18 protein loci encoding different enzyme systems in C. batrachus, C. macrocephalus, C. gariepinus and the big-oui hybrid. GPI-2*, MDH-2* and LDH-l* show clearly variation between the hybrid and the parental species and were used for species diagnostic loci. Comparisons of fertilisation and survival of the big-oui hybrid, reciprocal cross hybrid, F2 hybrid, back cross hybrid and their parental species were carried out. The only cross involving the F 1 big-oui hybrid still gave viable embryos and fry was between female F 1 hybrid and male C. gariepinus. The F2 hybrid never developed to hatch. Karyotyping studies showed a modal chromosome number of 2n=54 in C. macrocephalus; 2n=56 in C. gariepinus; 2n=55 in the big-oui hybrid, the reciprocal hybrid and the back cross hybrid. Using male C. gariepinus from two other stocks ('Malawee' and 'Wageningen') were carried out to produce the big-oui hybrid. Cold shock at 2°C administered for 15 mins duration and 4 mins after fertilisation was the most effective in inducing 100% triploidy in big-oui hybrid while heat and pressure shock were less effective. Growth performance of diploid and triploid hybrids was not significantly different. The triploid hybrid were shown to be functionally and endocrinologically sterile. Gynogenetic diploids were produced by fertilizing C. macrocephalus eggs with C. gariepinus sperm that had been genetically inactivated with ultraviolet (UV) light, and then cold shocking the eggs after fertilisation. The UV dose of 200 Il W cm -2 for 2 mins using a sperm concentration of 2.5 x 108 mrl was optimal in genetically inactivating sperm without seriously compromising motility. Cold shock at 2°C, started at 4 mins after fertilisation and 15 mins duration gave the maximum number of meiotic gynogenetic offspring. The parental contribution in the gynogenetic offspring was check by using the species diagnostic allozyme loci and showed no evidence of male contribution. Gynogenetic offspring were grown on to investigate the sex ratio. All gynogenetic offspring were female suggesting female homogamety in this species. The possible implications of the above results of hybridization and genetic manipulation studies in Clarias catfish culture are discussed.

Estudou-se o sistema porta hepático do bagre africano Clarias gariepinus Burchell, 1822, sob o ponto de vista da anatomia macroscópica e microscópica, utilizando-se várias técnicas anatômicas, que envolveram anestesia, injeção de substâncias recomendadas ao estudo do sistema vascular (látex, nanquim, cloreto de polivinil e substância radiopaca), dissecação, corrosão ou radiografia, conforme a exigência de cada técnica, como meio de compreensão da anatomia vascular do fígado deste peixe. Foram utilizados 16 exemplares do sexo feminino, com comprimento total entre 45 e 53,5 centímetros e massa corpórea entre 575 e 1068 gramas. Para a execução dessas técnicas, os peixes foram devidamente anestesiados com benzocaína, garantindo a narcose profunda e evitando qualquer tipo de sofrimento a eles. Os resultados obtidos com essas técnicas mostram que o fígado de Clarias gariepinus ocupa a cavidade abdominal cranial e apresenta uma lobação bem definida, sendo constituído por dois grandes lobos, denominados direito e esquerdo, conectados cranialmente por uma ponte dorsal à transição entre o esôfago e o estômago. O lobo esquerdo apresenta-se ligeiramente maior que o contralateral. Em suas extremidades caudais, os lobos esquerdo e direito formam um ápice pontiagudo, de formato triangular, que continua tenuemente através de um istmo eminentemente vascular que liga esses ápices a dois outros lobos, chamados acessórios direito e esquerdo, bem menores que os demais, e que ficam seqüestrados em um recesso peritoneal, lateral à cavidade abdominal. Os resultados indicam ainda que o sistema porta hepático de Clarias gariepinus está representado por duas veias portas principais denominadas direita e esquerda, levemente assimétricas em diâmetro, que drenam o sangue das vísceras abdominais (baço, estômago, vesícula biliar, intestino e gônadas) através dos tributários viscerais desse sistema. Ainda, devido a uma situação peculiar dos lobos acessórios, definem-se mais duas veias portas secundárias ligadas às principais e designadas igualmente por acessórias, uma esquerda e outra direita. Ambas as vv. portas principais se ramificam, atingindo o hilo da face visceral, enquanto que as vv. acessórias penetram por uma região restrita do lobo. Através de ramos interlobares, ambas as vv. portas principais se anastomosam no parênquima hepático. A v. porta esquerda, com discreto aumento de diâmetro, forma-se pela terminação da v. intestinal, concomitante à desembocadura da v. gastrointestinal e da v. porta acessória esquerda. A v. porta direita se define pela terminação da v. intestinal cranial, simultaneamente à chegada da v. porta acessória ipsilateral, drenando sangue do intestino médio, estômago e vesícula biliar. Nessa espécie, também estão caracterizados dois sítios de comunicação entre o sistema porta hepático e o sistema porta renal através de anastomoses em cada v. porta. Sob as condições em que o trabalho foi desenvolvido e considerando-se a metodologia proposta e a análise dos resultados, conclui-se que todos os métodos foram adequados ao estudo do aparelho circulatório de Clarias gariepinus, sendo recomendados para experimentos futuros sobre o mesmo assunto em outras espécies piscícolas; porém, dentre as três metodologias utilizadas para análises macroscópicas, a injeção de cloreto de polivinil seguida de corrosão das peças e subseqüente obtenção de moldes vasculares mostrou-se mais eficiente na marcação e identificação dos vasos que compõem o sistema porta hepático deste peixe. Conclui-se também que, devido à presença dos lobos acessórios, a lobação hepática é peculiar nesta espécie, em virtude da posição ocupada por estes lobos, assim como a circulação porta, em função das duas veias porta acessórias, e ainda a anastomose entre as duas veias porta principais, característica que deve ser considerada em trabalhos que envolvam cirurgia hepática no bagre africano
The hepatic portal system of the African catfish Clarias gariepinus Burchell, 1822, was studied considering the macroscopic and microscopic anatomy, by means of several anatomic techniques, including anesthesia, injection of substances recommended to the study of the vascular system (latex, Indian ink, polyvinyl chloride and radiopaque substance), dissection, corrosion or radiography, according to the requirement of each technique, as a way of understanding the hepatic circulatory pathway in the African catfish. Sixteen female specimen were used, being the entire length between 45 and 53.5 centimeters and the corporal mass between 575 and 1068 grams. To perform these techniques, the fishes were adequately anesthetized with benzocaine, assuring the deep narcosis and preventing them from any suffering. The results obtained through such techniques show that the liver of Clarias gariepinus occupies the cranial abdominal cavity and shows a clear lobation, the liver consisting of two large lobes, called right and left, cranially connected by a bridge dorsal to the transition between the esophagus and the stomach. The left lobe is slightly larger than the contralateral lobe. At their caudal ends, the left and the right lobes form a sharp triangle-like apex that tenuously passes through a strip eminently vascular that links these apexes with two other lobes, called right and left accessories, much smaller than the others, these lobes being wrapped in a peritoneal recess, situated at the side of the abdominal cavity. The results still show that the hepatic portal system of Clarias gariepinus is represented by two main portal veins named right and left, slightly asymmetric in diameter, that empty the blood out of the abdominal viscera (spleen, stomach, gall bladder, intestine and gonads) through the visceral tributaries of this system. Furthermore, due to a peculiar situation of the accessory lobes, two other secondary portal veins were defined; they are connected to the main veins and are equally called right and left accessories. Both the main portal veins branch, reaching the hilum of the visceral face, whereas the accessory veins go into a restricted region of the lobe. Through interlobar branches, both the main portal veins anastomose in the hepatic parenchyma. The left portal vein, with a slight increase in diameter, is formed by the terminatio of the intestinal vein, accompanying the discharge of the gastrointestinal vein and the accessory left portal vein. The right portal vein is defined by the terminatio of the cranial intestinal vein, simultaneously with the accessory ipsilateral portal vein, emptying the blood out of the medial intestine, stomach and gall bladder. In this species it is also possible to distinguish two connecting sites between the hepatic portal system and the renal portal system by means of anastomoses in each portal vein. Under the conditions in which the experiment was carried out and considering the methodology suggested and the analysis of the results, it is concluded that all the methods were suitable for the study of the circulatory system of Clarias gariepinus, being recommended for future tests on the same subject in other fish species; however, among the three methodologies used in the macroscopic analyses, the injection of polyvinyl chloride followed by the corrosion of pieces and subsequent getting of vascular moulds was believed to be more efficient at the marking and identification of the vessels that compose the hepatic portal system of this fish. It was also concluded that, due to the presence of the accessory lobes, the hepatic lobation is peculiar in this species because of the position occupied by these lobes, as well as the portal circulation, caused by the two accessory portal veins, in addition to the anastomose between the two main portal veins, a characteristic that must be thought of in studies of hepatic surgery in the African catfish