Navegando por Assunto "Larvas de peixe"

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Acesso aberto (Open Access)
Composição e distribuição espaço-temporal das larvas de peixes do estuário do Rio Quatipuru - Nordeste Paraense
(Universidade Federal do Pará, 2011-10-25) SILVA, Potira Fernandes e; MELO, Nuno Filipe Alves Correia de; http://lattes.cnpq.br/4989238044542736; QUEIROZ, Helder Lima de; http://lattes.cnpq.br/3131281054700225
In Quatipuru Estuary, located in Northeast Pará two campaigns were carried out in dry season (November/2009) and rainy season (May/2010) with spatial and nictemeral collections. Larvae were collected using a plankton net, conical, with 60 cm mouth opening, 1.80 m long and 500 m mesh opening. The samples were screened and identified as to their stage of larval development and species level, some typed. The family Clupeidae was the most abundant in drags spatial-temporal in dry season and Scianidae (Cynoscion acoupa) characterized the rainy season. In dry season, were observed low density, highest value 8.50 ind./m³ (Clupeidae sp.3) and the lowest value 0.06 ind./m³ (Engraulididae sp.2). In the Quatipuru Estuary 65% of the larvae at the stage of pre-flexion, flexion 25% and 10% post-flexion. In rainy season were observed 64% in pre-flexion, flexion 14% and 22% in post-flexion. In cluster analysis (mode Q) distinguished two main groups according to the seasonal site, so R did not distinguish between major groups and the association of species. According Principal Component Analysis (PCA) the first two axes explained 82% of data variance, a trend can be observed according to the distribution of species richness. In nictemeral drag, the Clupeidae family was mean larval density in dry season (Clupeidae sp.1), and Scianidae family best characterized in rainy season (Cynoscion acoupa). Also very low density, the higher value of 2.96 ind./m³ during the rainy season and the lowest 0.01 ind./m³ in the dry season. During the dry season were 57% in the stage of preflexion, 26% flexion and 17% in post-flexion, since the rainy season 11% in pre-flexion, 38% flexion and 51% in post-flexion. The Q mode cluster analysis also distinguishes two groups according to seasonality (dry/rainy), the R mode also did not distinguish between major groups regarding the association of its kind. In PCA. the shaft 01 is responsible for 70% directly related to the richness and density of organisms, a tendency was observed of distribution according to species occurrence in the horizontal direction.
Acesso aberto (Open Access)
Efeito da salinidade e da frequência alimentar durante a larvicultura dos ornamentais amazônicos acará bandeira Pterophyllum scalare (SCHULTZE, 1823) e acará severo Heros severus (HECKEL, 1840)
(Universidade Federal do Pará, 2016-07-21) EIRAS, Bruno José Corecha Fernandes; VERAS, Galileu Crovatto; http://lattes.cnpq.br/4497651649653210; COSTA, Rauquírio André Albuquerque Marinho da; http://lattes.cnpq.br/4504677939464624
With the study aimed to evaluate the effect of salinity and feeding frequency on growth, uniformity and survival of the angelfish Pterophyllum scalare and banded cichlid post-larvae. Were conducted two experiments in a completely randomized in a factorial 5 x 2, with five different sodium chloride concentrations (0; 2; 4; 6 and 8 g L-1) and two feed frequency (2 and 4 times per day). It was observed the water salinity and feeding frequency influenced significantly (p < 0,05) in torso length and body height in the angelfish larviculture. The eye diameter, was affected (p < 0,05) only by salinity, while the final standard length, standard length gain, head length, torso length, post-anal length, head height, body height, final weight, weight gain, specific growth rate and allometric condition factor differed significantly (p < 0,05) only for the feeding frequency. In the banded cichlid larviculture, there was a significant difference (p < 0,05) in the head length, post-anal length, head height and allometric condition factor by salinity and feeding frequency. The water salinity influenced significantly (p < 0,05) the final standard length, standard length gain, torso length, eye diameter, body height, survival hate and uniformity in weight. The feeding frequency influenced significantly (p < 0,05) the final weight, weight gain and specific growth rate. It was concluded that angelfish post-larvae can be grown with salinity up to 4 g L-1 without problems for the development and survival. On the other hand, the banded cichlid post-larvae had better survival hate in water without salt add. The feeding frequency of four times a day with artemia nauplii is the most recommended for the both species.
Acesso aberto (Open Access)
Fotoperíodo e frequência alimentar na larvicultura do peixe beta
(FEPMVZ Editora, 2016-08) SALES, Abner Dias; VERAS, Galileu Crovatto; BRABO, Marcos Ferreira; ABRUNHOSA, Fernando Araujo; ALVES, Adriana Xavier; DIAS, Bruno César Brito; CAMPELO, Daniel Abreu Vasconcelos; FERREIRA, M.S.S.
The aim of this study was to evaluate the growth, uniformity and survival of Betta splendens larvae, submitted to different photoperiods and feeding frequency. Four hundred and eighty individuals (4.53mg ± 0.32 and 5.51 ± 0.58mm) were randomly distributed into 48 plastic containers (1L) at a density of 10 larvae/L. A completely randomized design was used, with four replications in a factorial 6 x 2, six photoperiods (0L:24D, 6L:18D, 12L:12D, 16L:8D, 20L:4D, 24L:0D) and two feeding frequencies (two or four times a day). The larvae were fed performed with Artemia nauplii at averaging 800/ larvae/ day, for 15 days. Beta larvae subjected to photoperiod 12L:12D and 16L:8E showed the greatest weight gain (P<0.10), while those fed four times daily had greater length growth and uniformity (P<0.10). However, individuals fed four times daily had lower survival when subjected to photoperiod 16L:8E, 20L:4L and 24E:0D (P<0.10). On the other hand, larvae subjected to a photoperiod of 12L:12D, 16L:8L and 20L:4E showed higher survival rate when fed twice a day (P<0.10). Therefore, with the intention of better growth, uniformity and survival of Betta splendens larvae, it is recommended that the hatchery in this species be done under a photoperiod of 12L: 12D with supply of Artemia nauplii twice daily.
Acesso aberto (Open Access)
Impacts of urban life on water quality and fish larvae communities in two creeks of the Brazilian Amazon
(2016-03) SOUZA, Claíde Lorena Reis de; COSTA, Vanessa Bandeira da; PEREIRA, Simone de Fátima Pinheiro; SILVA, Debora Cristina Melo da; SARPEDONTI, Valérie
This study investigated the impact of anthropogenic activities in Belém City, Brazilian Amazon, by comparing water quality and fish larvae communities in two creeks that flow into the Guamá River. One creek crossed a poor and crowded suburb of Belém while the other was located in an island section that was declared an Environmental Protected Area in 1997. Two sampling points were set in each creek and monitored over eight hours once every three months over a one-year period. Strong variations of water quality were registered all year long and at all tides in Belém's mainland creek, along with, among other things, a very high number of thermotolerant coliforms. Few larvae were found. The water was considered unsuitable for human use and activities as well as for aquatic life. The island creek presented early signs of bacterial and nutrient contaminations during the rainy season, probably partly related to non-point source pollution. In both creeks, larvae communities were almost exclusively composed of clupeiforms. All larval development stages were encountered. Higher densities and proportion of newly hatched larvae were registered during the dry season and associated with the presence of nitrate. The results of the study show that adequate sewage and drainage systems must be developed in the city and suggest that it would be useful to conduct an integrated ambient monitoring study in Combú Creek.