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.
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