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Caballerocotyla lenti n. sp., a capsalid monogenean from Auxis thazard (Scombridae) from off the southeastern coast of Brazil
Mogrovejo, Cristina D;Santos, Cláudia P;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000700023
Abstract: caballerocotyla lenti n. sp. (monogenea: capsalidae), recovered from the gills of auxis thazard (lacépède) captured off the coast of rio de janeiro, brazil, is described using light and scanning electron microscopy. the new species is characterized by: a tegument with 2-5 rows of dorso-marginal, unicuspid spines; 53-54 round testes; a constricted pharynx with numerous papillae on its border; and a haptor with a plicate marginal border, a central polygonal area and seven complete septa. c. manteri (price, 1951) and c. gouri chauhan, 1953 sensu murugesh (1995) are figured and commented upon.
Caballerocotyla lenti n. sp., a capsalid monogenean from Auxis thazard (Scombridae) from off the southeastern coast of Brazil  [cached]
Mogrovejo Cristina D,Santos Cláudia P
Memórias do Instituto Oswaldo Cruz , 2002,
Abstract: Caballerocotyla lenti n. sp. (Monogenea: Capsalidae), recovered from the gills of Auxis thazard (Lacépède) captured off the coast of Rio de Janeiro, Brazil, is described using light and scanning electron microscopy. The new species is characterized by: a tegument with 2-5 rows of dorso-marginal, unicuspid spines; 53-54 round testes; a constricted pharynx with numerous papillae on its border; and a haptor with a plicate marginal border, a central polygonal area and seven complete septa. C. manteri (Price, 1951) and C. gouri Chauhan, 1953 sensu Murugesh (1995) are figured and commented upon.
Age and growth changes and population dynamics of the black pomfret (Parastromateus niger) and the frigate tuna (Auxis thazard thazard), in the Taiwan Strait
Tao,Yu; Mingru,Chen; Jianguo,Du; Zhenbin,Lu; Shengyun,Yang;
Latin american journal of aquatic research , 2012, DOI: 103856/vol40-issue3-fulltext-13
Abstract: the age and growth and population dynamics of the black pomfret, parastromateus niger and the frigate tuna, auxis thazard thazard were studied from specimens collected monthly in the taiwan strait from april 2005 to march 2006. with five age groups of each, the dominant black pomfret was one year, while frigate tuna was two years. the total mortality coefficient (z) and the fishing mortality (f) of the black pomfret were at high levels, the exploitation ratio (e) was over 0.5, and the number of captured juvenile fishes showed that the stock of black pomfret in this area was overexploited and improper fishing gear was utilized. compared with previous studies, the maximum and mean fork length, body weight and age of the two fishes declined gradually, the populations were younger in age and smaller in size. the growth coefficient k increased and age at the inflexion point of weight tr was younger than before. the smaller change of the fork length at first maturity of the two fishes has indicated a more vulnerable fishery ecosystem in this area. therefore, in addition to the traditional fishery management approach, such as taking the minimum length into consideration, ecosystem approach to fisheries management (eaf) should be taken to improve the practical fishing management, including conserving the small pelagic fishery population in order to achieve the sustainable fishing of the stocks.
Age and growth changes and population dynamics of the black pomfret (Parastromateus niger) and the frigate tuna (Auxis thazard thazard), in the Taiwan Strait Cambios en la edad y el crecimiento y dinámica poblacional de la palometa negra (Parastromateus niger) y del atún fragata (Auxis thazard thazard), en el estrecho de Taiwán
Yu Tao,Chen Mingru,Du Jianguo,Lu Zhenbin
Latin american journal of aquatic research , 2012,
Abstract: The age and growth and population dynamics of the black pomfret, Parastromateus niger and the frigate tuna, Auxis thazard thazard were studied from specimens collected monthly in the Taiwan Strait from April 2005 to March 2006. With five age groups of each, the dominant black pomfret was one year, while frigate tuna was two years. The total mortality coefficient (Z) and the fishing mortality (F) of the black pomfret were at high levels, the exploitation ratio (E) was over 0.5, and the number of captured juvenile fishes showed that the stock of black pomfret in this area was overexploited and improper fishing gear was utilized. Compared with previous studies, the maximum and mean fork length, body weight and age of the two fishes declined gradually, the populations were younger in age and smaller in size. The growth coefficient k increased and age at the inflexion point of weight t r was younger than before. The smaller change of the fork length at first maturity of the two fishes has indicated a more vulnerable fishery ecosystem in this area. Therefore, in addition to the traditional fishery management approach, such as taking the minimum length into consideration, ecosystem approach to fisheries management (EAF) should be taken to improve the practical fishing management, including conserving the small pelagic fishery population in order to achieve the sustainable fishing of the stocks. La edad y crecimiento de la palometa negra, Parastromateus niger y del atún fragata o melva, Auxis thazard thazard se estudiaron a partir de especímenes capturados mensualmente en el estrecho de Taiwan, entre abril 2005 y marzo 2006. Se determinaron cinco grupos de edad, siendo dominante en la palometa negra los ejemplares de un ano, mientras que en el atún fragata los de dos anos. El coeficiente de mortalidad total (Z) y la mortalidad por pesca (F) de la palometa negra se encontraron en niveles altos. La tasa de explotación E resultó sobre 0,5 y el número de peces juveniles capturados demuestra que la población está sobreexplotada en la región y los equipos de pesca utilizados resultan inadecuados. En comparación con estudios previos, la longitud horquilla máxima y media, el peso corporal y la edad en ambas especies ha disminuido en forma gradual, presentando las poblaciones peces de menor edad y tamano. El coeficiente de crecimiento k aumentó y la edad en el punto de inflexión en peso t r se obtuvo en ejemplares más jóvenes que en anos previos. El pequeno cambio de la longitud horquilla determinado en la primer madurez en las dos especies indica que en esta zona, el e
COEXISTENCIA DE LAS DOS ESPECIES DE CACHORRETA (PISCES: AUXIS) EN LA REGIóN DE SANTA MARTA, COLOMBIA
Acero P.,Arturo; Polanco F.,Andrea; Garzón-Ferreira,Jaime;
Boletín de Investigaciones Marinas y Costeras - INVEMAR , 2006,
Abstract: the marine environment of the santa marta region (colombian caribbean) is unique in many ways. the coexistence there of both species of auxis is herewith reported and discussed. auxis thazard, the frigate tuna or frigate mackerel, has been reported several times from santa marta; however, the occurrence of a. rochei, the bullet tuna or bullet mackerel, is reported for the first time. some inter and intraspecific differences are discussed; fishery aspects are commented as well.
Myxosporean hyperparasites of gill monogeneans are basal to the Multivalvulida
Mark A Freeman, Andrew P Shinn
Parasites & Vectors , 2011, DOI: 10.1186/1756-3305-4-220
Abstract: The present study aimed to collect new hyperparasite material from Malaysia for morphological and molecular descriptions. In addition, PCR screening of host fish was undertaken to determine whether they are also hosts for the myxosporean.Heavy myxosporean infections were observed in monogeneans from two out of 14 fish and were detected from a further five fish using specific PCRs and pooled monogenean DNA. Positive DNA isolates were sequenced and were from a single species of myxosporean. Myxospore morphology was consistent with Myxidium with histozoic development in the parenchymal tissues of the monogenean. Simultaneous infections in the fish could not be confirmed microscopically; however, identical myxosporean DNA could be amplified from kidney, spleen and intestinal tract tissues using the specific PCR. Small subunit (SSU) rDNA for the myxosporean was amplified and was found to be most similar (92%) to that of another hyperparasitic myxosporean from a gill monogenean from Japan and to numerous multivalvulidan myxosporeans from the genus Kudoa (89-91%). Phylogenetic analyses placed the hyperparasite sequence basally to clades containing Kudoa, Unicapsula and Sphaerospora.The myxosporean infecting the gill monogenean, Diplectanocotyla gracilis, from the Indo-Pacific tarpon, Megalops cyprinoides, is described as a new species, Myxidium incomptavermi, based on a histozoic development in the monogenean host and its phylogenetic placement.We have demonstrated for the first time that a myxosporean hyperparasite of gill monogeneans is detectable in the fish host. However, myxospores could not be isolated from the fish and confirmation was by PCR alone. The relationship between the myxosporean infection in gill monogeneans and the presence of parasitic DNA in fish is not yet fully understood. Nonetheless, myxospores with a Myxidium-like morphology, two of which we have shown to be phylogenetically related, have now been reported to develop in three different gill monoge
Notes on helminth parasites of tuna fishes (Scombridae) in Brazil Notas sobre los helmintos parásitos del atún (Scombridae) en Brasil  [cached]
Márcia Cristina Nascimento-Justo,Anna Kohn
Revista mexicana de biodiversidad , 2012,
Abstract: Four species of Scombridae from the coast of Rio de Janeiro, southwest Atlantic Ocean were found to be parasitized with species of Didymozoidae (Digenea): Thunnus atlanticus (Lesson) a new host record for Nephrodidymotrema ahi Yamaguti, 1970, Didymocystis neothunni (Yamaguti, 1970), and Didymozoon longicolle (Yamaguti, 1970); Thunnus obesus (Lowe) parasitized by Didymozoon longicolle and reported as a new host for Nephrodidymotrema ahi; Thunnus albacares (Bonaterre) parasitized by Nephrodidymotrema ahi, and Katsuwonus pelamis (Linnaeus) by Didymozoon longicolle. Measurements, figures, and parameters of infection are presented. Cuatro especies de Scombridae de la costa de Río de Janeiro, suroeste del océano Atlántico, se reportan parasitados con diferentes especies de Didymozoidae (Digenea): Thunnus atlanticus (Lesson) un registro de nuevo huésped para Nephrodidymotrema ahi Yamaguti, 1970, Didymocystis neothunni (Yamaguti, 1970) y para Didymozoon longicolle (Yamaguti, 1970); Thunnus obesus (Lowe) parasitado por Didymozoon longicolle, se indica como nuevo huésped para Nephrodidymotrema ahi; Thunnus albacares (Bonaterre) parasitados por Nephrodidymotrema ahi y Katsuwonus pelamis (Linnaeus) por Didymozoon longicolle. Se presentan las mediciones, las figuras y los parámetros de la infección.
Acoel Flatworms Are Not Platyhelminthes: Evidence from Phylogenomics  [PDF]
Hervé Philippe, Henner Brinkmann, Pedro Martinez, Marta Riutort, Jaume Bagu?à
PLOS ONE , 2007, DOI: 10.1371/journal.pone.0000717
Abstract: Acoel flatworms are small marine worms traditionally considered to belong to the phylum Platyhelminthes. However, molecular phylogenetic analyses suggest that acoels are not members of Platyhelminthes, but are rather extant members of the earliest diverging Bilateria. This result has been called into question, under suspicions of a long branch attraction (LBA) artefact. Here we re-examine this problem through a phylogenomic approach using 68 different protein-coding genes from the acoel Convoluta pulchra and 51 metazoan species belonging to 15 different phyla. We employ a mixture model, named CAT, previously found to overcome LBA artefacts where classical models fail. Our results unequivocally show that acoels are not part of the classically defined Platyhelminthes, making the latter polyphyletic. Moreover, they indicate a deuterostome affinity for acoels, potentially as a sister group to all deuterostomes, to Xenoturbellida, to Ambulacraria, or even to chordates. However, the weak support found for most deuterostome nodes, together with the very fast evolutionary rate of the acoel Convoluta pulchra, call for more data from slowly evolving acoels (or from its sister-group, the Nemertodermatida) to solve this challenging phylogenetic problem.
Dynamics of Population of Five Parasitic Monogeneans of Oreochromis niloticus Linne, 1757 in the Dam of Loumbila and Possible Interest in Intensive Pisciculture  [PDF]
M. Boungou,G.B. Kabre,A. Marques,L. Sawadogo
Pakistan Journal of Biological Sciences , 2008,
Abstract: The study of the gill fishes of 176 Oreochromis niloticus (L.) was undertaken in the dam of Loumbila (Burkina Faso), in order to obtain the first information on the dynamics of population of the Monogeneans parasites in a population of wild hosts. These data are essential in the search for means to avoid the enormous losses that often occur in intensive pisciculture. This analysis revealed the presence of five species of Monogeneans (Cichlidogyrus tilapiae, Cichlidogyrus halli, Cichlidogyrus thurstonae, Cichlidogyrus rognoni and Scutogyrus longicornis). On the levels of the recorded infestations, these species taken individually probably do not control the population of Oreochromis niloticus. In the dam of Loumbila, the fluctuations of parasitic abundances are neither seasonal nor cyclic. The size either does not have an influence on parasitism. However, the sex effect was noted with C. halli, the females thus were more infested than the males. O. niloticus is parasitized all the year, because the recruitment of these organisms, although relatively weak, is continuous; this logically results in their accumulation in this fish.
Ultrastructure and cytochemistry of the tegument of Atriaster heterodus (Platyhelminthes: Monogenea)
Santos, Cláudia Portes;Lanfredi, Reinalda Marisa;
Memórias do Instituto Oswaldo Cruz , 2000, DOI: 10.1590/S0074-02762000000600028
Abstract: the tegument of the polyopisthocotylean monogenean atriaster heterodus lebedev & parukhin, 1969 was studied using transmission electron microscopy. the outer syncytial layer of the tegument is connected to the internal cell bodies by cytoplasmic extensions which interweave between the muscular fibres. the free surface of the syncytium has projections of the external membrane which are similar to microvilli. the undulating basal membrane, with numerous narrow elongate projections, is associated with the basal lamina situated between the syncytial and muscular layers. the cell bodies and syncytial layer of the tegument exhibit two types of vesicles, one with fibrous contents and one with electron-dense contents; these were analysed using two cytochemical tests, the e-pta and alcian blue methods, used for the first time on monogeneans.
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