Navegando por Assunto "Fecundidade"

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Acesso aberto (Open Access)
Dinâmica populacional do camarão cascudo Macrobrachium amazonicum (Heller, 1862) da Ilha de Combú – Belém-PA
(Universidade Federal do Pará, 2006-04-28) SILVA, Márcia Cristina Nylander; ROSA FILHO, José Souto; http://lattes.cnpq.br/3223362071251898; FRÉDOU, Flávia Lucena; http://lattes.cnpq.br/4779271407117528
Shrimps of genus Macrobrachium, family Palaemonidae, are largely utilized for aquaculture and also are explored by commercial fisheries. Amongst the species of this genus, M. amazonicum is largely consumed, shows valued meat and is largely distributed. Considering the social-economic importance of this resource in the State of Pará, this study has the objective of describing the population dynamics and assesses the stock of barky shrimp M. amazonicum in island of the Combú (Pará). Data was collect from March 2002 to February 2003 (except august) where approximately 500 grams of shrimp were monthly obtained. In laboratory, individuals were measured (total length and length of carapace) and weighted (total weight). For determining the fecundity, after removed the eggs mass, were transferred to a water solution were they were counted under a microscopy. For the determination of the population parameters, it was utilized the Program FISAT (Fish Stock Assessment Tools). Females showed smaller maximum length when compared to males, although their average mensal lengths through all year were superior to those of males. It was registered a significant positive sexual proportion to females in July, September, January and February and for the length classes 2.5-2.9 cm and 6.5 to 9.4 cm. The fecundity showed a positive linear relation with the total length and the number of eggs varied from 40 to 3375 eggs/female. It was registered 3 cohorts for the species which were born in December-January/02, September-October/02 and April-May/03. Considering the different methodologies, growth parameters were similar between them and K for males was superior when compared to females and varied from 0.7 to 1.35 cm/month. For females K varied from 0.66 to 0.91 cm/month. L∞ (for most methodologies) was also superior for males (12.37 to 17.66 cm) when compared to females (12.66 to 14.14 cm). Estimated values of total mortality Z for the capture curve had been bigger in the higher for males (values from 3.15 to 6.13) than for females (values from 3.86 to 6.89) the same occurred for method of Beverton and Holt, males (values between 5.43 to 9.31). The length at first capture (Lc) was superior for females (5.88 cm) than for males (4.25 cm). The EMSY (explotation rate for the maximum sustainable yield) for males and females is below the E (exploitation rate) indicating that M. amazonicum of island of the Combú is over-exploited.
Acesso aberto (Open Access)
Efeito dos ambientes estuário e reservatório na fecundidade de Macrobrachium amazonicum (Decapoda: Palaemonidae) (Heller, 1862)
(Universidade Federal do Pará, 2019-02-27) SILVA, Breno Richard Monteiro; FERREIRA, Maria Auxiliadora Pantoja; http://lattes.cnpq.br/1832728101486131
Studies reveal that the Amazon region is suffering a strong anthropogenic and climatic influence which interferes in the environmental conditions. In crustaceans, climate change can influence growth and reproduction, and as life history patterns is influenced by environmental factors, the fertility is an important factor to estimate the reproductive potential and natural population stock. The specie Macrobrachium amazonicum has a wide geographical distribution and ecological and morphological plasticity. Based on the hypothesis that the physical and chemical conditions different of the environment influence on populations of M. amazonicum, we have the following question: What are the main environmental factors that will influence M. Amazonicum fecundity between populations of different places? Thus, the aim of present study is to determine the influence of physical and chemical factors on the relative fecundity of populations of M. amazonicum in estuary and reservoir. In the period of study, temperature, pH, salinity, turbidity and dissolved oxygen concentration in the water were obtained in situ. Precipitation was obtained from INMET, 2018 with establishment of four seasonal periods: dry, transitional dry-rainy, rainy, transitional rainy-dry. A total of 255ovigerous females, 181 from the estuary environment and 75 from the reservoir were collected for analysis of biometrics, number and size of eggs throughout the year. Embryonated eggs were measured according to the developmental stages. In the relationship effect of the environmental variables on the ovigerous females, turbidity and precipitation were the main factor on estuary. The mass-length relationship of females was represented by the following equations, Mt = 0.017xCt2.630 (R² = 0.880) for the estuary and Mt = 0.021xCt2.441 (R² = 0.810) for the reservoir, where ovigerous females in the estuary were larger and larger mass in comparison to the reservoir. In the relationship between fecundity and biometry of the animal, from both sites, there was a high positive correlation, between the length (r = 0.788) and the weight (r = 0.843) of the ovigerous females, as well as the relation with the morphometry of the eggs. The estuarine environment presented females with the highest amount of eggs in the dry-rainy and rainy periods in relation to the females from the reservoir that presented the highest fecundity in the rainy-dry and dry season. In our results observed four stages of development considering the presence and the appearance of the eye, and the eggs of the females reservoir, although in smaller numbers, presented larger sizes in relation to the estuary. The correlation observed if the physical and chemical factors influence the fecundity of M. amazonicum from the estuary was confirmed, with precipitation and turbidity being the factors that contributed the best reproductive performance of the species in the estuary. When it comes to the reservoir, we believe that there is a combination of all the environmental factors involved promoting the tolerance of the animal to maintain its life cycle.
Acesso aberto (Open Access)
Polimorfismos no gene da osteopontina e suas associações com a fertilidade de búfalos na Amazônia
(Universidade Federal do Pará, 2012-09-24) ROLIM FILHO, Sebastião Tavares; RIBEIRO, Haroldo Francisco Lobato; http://lattes.cnpq.br/1614582293203770
Because the osteopontin gene can influence the fertility of water buffaloes, the aim of this work was to identify polymorphisms in this gene and associate them with fertility parameters of animals kept under extensive grazing. We used 306 male buffaloes older than 18 months, bred on two farms, one in the state of Amapá and the other in the state of Pará. We identified three SNP for the region amplified by the primer OS4 (5`UTR) and four SNP polymorphisms for the region amplified by the primer OS9 (exon 5 to exon 6). The polymorphisms were in positions 1478, 1513 and 1611 in the region amplified by OS4 and positions 6690, 6737, 6925 and 6952 in the region amplified by OS9. We calculated correlations with the traits scrotal circumference and volume and sperm motility, concentration and pathology. There were SNPs for all the traits studied at 5% significance: for circumference, SNP 6690; for volume, SNP 6737; for concentration, SNP 6690; for motility, SNP 6690; and for pathology, SNP 6690. Therefore, SNP 6690 was related to four traits. The AA genotype of SNP 6690 presented the highest averages for scrotal circumference, sperm concentration and motility and the lowest total number of pathologies. However, for the scrotal volume trait, the animals with the largest volume were correlated with the presence of the GG genotype of SNP 6737. This indicates that the osteopontin gene is important because it can have a substantial influence on the reproductive traits of male buffaloes.
Acesso aberto (Open Access)
Reproductive ecology of the catfish, Hassar affinis (ACTINOPTERYGII: DORADIDAE), in three lakes of the Pindaré- Mearim lake system, Maranhão
(Universidade Federal do Pará, 2017-09) CANTANHÊDE, Lorrane Gabrielle; CARVALHO, Irayana Fernanda da Silva; NUNES, Karla Bittencourt; ALMEIDA, Zafira da Silva de; SANTOS, Nayara Barbosa
Reproductive biology affords fundamental features for the establishment of protective measures for fish. The aim of the present work therefore was to determine the reproductive features of the catfish, Hassar affinis, known locally as bico-deflor, in three lakes of the Pindaré-Mearim Lake System, in the state of Maranhão, with the aim of subsidising the closed season. Monthly collections were carried out between July 2014 and July 2015, when 206 individuals were sampled from Lake Aquiri (LA), 247 from Lake Cajari (LC), and 126 from Lake Viana (LV). In the laboratory, each individual was weighed and measured; a ventral longitudinal incision was then made in order to observe the gonads macroscopically. They were then fixed in Bouin’s solution for microscopic analysis and in Gilson’s solution for an analysis of fecundity. Positive allometry was recorded at the three study sites. The sex ratio for the total period was 3.29F:1M (LA), 2.43F:1M (LC) and 2.15F:1M (LV). Mean length at first sexual maturity was estimated at 10.60 cm (LA), 10.84 cm (LC) and 11.12 cm (LV). The period from March to May was defined as the breeding season for this species in the three lakes. Mean absolute fecundity was 21,634 oocytes (LA), 16,357 oocytes (LC) and 25,898 oocytes (LV). The information obtained through this study indicates that, in addition to being important spawning areas, the three lakes are interconnected in relation to the migratory dynamics of H. affinis, so it is necessary to arrive at a model that would satisfactorily cover the three lakes, considering that the dam has a negative effect on Lake Viana.