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Registros recuperados: 15 | |
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Díaz, M.V.; Pájaro, M.. |
The study of larvae nutritional condition allows to assess the physiologic state that reflects the environmental situation they were exposed to. It represents a useful instrument to determine favourable nursery areas, provides tools for the management of a population subject to fishing and furnishes information to establish appropriate closed areas and periods. The material analyzed derived from three cruises carried out to assess Argentine anchovy Northern stock during the 2003, 2004 and 2006 reproductive peak (SW Atlantic Ocean, Argentine Sea). The objective of this work was to study the nutritional status of Argentine anchovy first feeding larvae caught in the coastal and mid-shelf of the Río de la Plata River maritime front in relation to the... |
Tipo: Journal Contribution |
Palavras-chave: Fish larvae; Nursery grounds; Spawning populations; Morphometry; Length-weight relationships; Abundance. |
Ano: 2013 |
URL: http://hdl.handle.net/1834/5496 |
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Díaz, M.V.; Saia, J.; Soroet, S.; Pájaro, M.; Negri, R.M.. |
A study on the seasonal variation of Engraulis anchoita larvae nutritional condition was performed. The material employed was collected at the Estación Permanente de Estudios Ambientales (EPEA) during the 2008-2011 period (Buenos Aires prov., Argentina). In order to determine the morphological differences among individuals, the six morphometric variables measured for each larvae were analyzed using the Principal Component Analysis (PCA). Water temperature and salinity and density of the different ichthyoplankton components were also registered. The PCA revealed a larger larvae body width in Spring, which would indicate an improvement of nutritional condition during that season. Mean abundance of eggs and larvae, higher in spring, was significantly lower... |
Tipo: Journal Contribution |
Palavras-chave: Fish larvae Animal nutrition Morphometry Food availability Ichthyoplankton Engraulis anchoita PSW; Argentina; Buenos Aires marine environment. |
Ano: 2012 |
URL: http://hdl.handle.net/1834/4904 |
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Montoya, N.G.; Akselman, R.; Pájaro, M.; Perrotta, R.G.; Carreto, J.I.. |
Spring blooms of the toxic dinoflagellate Alexandrium tamarense in the Argentine sea produce shellfish toxicity through the parallytic shellfish poison (PSP)accumulation. The trace PSP content in the mackerel Scomber japonicus liver was previously demonstrated in the Buenos Aires province coastal region (Carreto et al, 1993a),and a certain capability to accumulate the toxins was suggested.However, it was up to spring 1993 when a great number of PSP intoxicated mackerels where detected for the first time in a wideshelf area off the Buenos Aires province. This area, known as 'El Rincón' (39°00'-40°30'S), has become a growing importance mackerel fishing ground during the last few years. A high PSP concentration was determined in those mackerels, being the... |
Tipo: Journal Contribution |
Palavras-chave: Toxicity; Algal blooms; Biological poisons; Stomach; Toxicity; Stomach; Algal blooms; Http://aims.fao.org/aos/agrovoc/c_7826; Http://aims.fao.org/aos/agrovoc/c_7422; Http://aims.fao.org/aos/agrovoc/c_32367. |
Ano: 1997 |
URL: http://hdl.handle.net/1834/1939 |
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Pájaro, M.. |
Cannibalism is not an abnormal behaviour and it can be observed in a wide number of animals. In Pisces, cannibalism may be the result of endogenous intraspecific factors (nutritional state, size, age, state of development) or exogenous intraspecific factors (food, density, light). Nevertheless, external fertilization and the high fecundity of teleost fish tend to increase egg cannibalism, in particular among filter feeding fishes such as anchovies. In the present work, two important Argentine anchovy Engraulis anchoita stocks were studied. The first is to the north of 41°S, and spawns during spring on the coastal and shelf waters of Buenos Aires Province,Argentina, and Uruguay. The second one inhabits the Patagonian region, from 41°S to 47°S. It spawns... |
Tipo: Theses and Dissertations |
Palavras-chave: Feeding behaviour; Cannibalism; Natural mortality; Fish larvae; Fish eggs; Spawning seasons; Stocks; Food preferences; Reproduction; Stocks; Food preferences; Feeding behaviour; Cannibalism; Fish larvae; Reproduction; Http://aims.fao.org/aos/agrovoc/c_28772; Http://aims.fao.org/aos/agrovoc/c_3024; Http://aims.fao.org/aos/agrovoc/c_10778; Http://aims.fao.org/aos/agrovoc/c_9580; Http://aims.fao.org/aos/agrovoc/c_2924; Http://aims.fao.org/aos/agrovoc/c_6507. |
Ano: 1998 |
URL: http://hdl.handle.net/1834/1476 |
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Leonarduzzi, E.; Di Marco, E.J.; Pájaro, M.. |
The daily spawning females fraction (S) of Argentine anchovy (Engraulis anchoita) in relation to the year, length, proportion of females, temperature and salinity variables was studied using generalized linear models. Samples were collected during eleven research surveys carried out in the main spawning seasons and areas during 1993-2008 (Southwest Atlantic Ocean, Argentine Sea). The aim of this work was to identify the factors that affect the spawning activity. No temporary differences were observed and an S 0.12 average value was estimated. The poor explanatory percentage of the models analyzed did not allow to clearly detect the variables that could affect S. Length and temperature were the only variables that related positively, which suggests that... |
Tipo: Journal Contribution |
Palavras-chave: Pelagic fish; Reproduction; Biomass; Spawning; Mathematical models. |
Ano: 2013 |
URL: http://hdl.handle.net/1834/5492 |
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Pájaro, M.; Macchi, G.J.; Ehrlich, M.D.. |
Batch fecundity and spawning frequency of Argentine hake inhabiting Patagonian waters south of 41° S were estimated using monthly samples collected during the December 2000-March 2001 reproductive season and at the end of the March 2002 spawning period. Batch fecundity was fitted to a power function of total length and a linear function of ovary-free female weight with values ranging between 100,000 (32 cm total length) and 2,300,000 (87 cm total length) hydrated oocytes. Batch and relative fecundity showed variations during the spawning season with a marked decrease towards the end of the reproductive period (March). The spawning frequency, which ranged between 0.10 and 0.15, was estimated from the proportion of females with day-1 postovulatory follicles... |
Tipo: Journal Contribution |
Palavras-chave: Spawning seasons; Ovaries; Hake fisheries; Ovaries; Http://aims.fao.org/aos/agrovoc/c_5456. |
Ano: 2006 |
URL: http://hdl.handle.net/1834/1566 |
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Pájaro, M.; Hansen, J.E.; Leonarduzzi, E.. |
Engraulis anchoita northern stock reproductive biomass (SSB) during the 1993-2008 period was estimated applying the Daily Egg Production Method (DEPM) and accuracy of estimates assessed using a bootstrap technique (SW Atlantic Ocean, Argentine Sea). The basic data were collected in different research surveys carried out in late Spring, at the peak of the spawning season. The aim of this work was to build reliable confidence intervals around the estimates of the mean reproductive biomass applying a non-parametric bootstrap method. Resampling methods are becoming increasingly popular as statistical tools as they are robust and do not require the assumption of any particular distribution of the basic data. This is especially relevant when assessing the DEPM... |
Tipo: Journal Contribution |
Palavras-chave: Spawning; Stocks; Fecundity; Biomass; Statistical analysis. |
Ano: 2013 |
URL: http://hdl.handle.net/1834/5494 |
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Registros recuperados: 15 | |
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