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The present study describes the ovarian development stages of wild Farfantepenaeus paulensis (Pe¤ rez-Farfante) through the combined observation of histological and visual characteristics. Twenty-¢ve females (61.872.4 g) were captured in 35^40-m deep waters o¡ southern Brazil (271S). The females were grouped according to the size and shape of their ovary and then killed. The colour of the fresh ovary was compared with a chromatic scale catalogue. Analysis of the histological sections of each ovary determined the morphological characteristics, size and frequency of the di¡erent oocyte types. Based on these characteristics, four distinct stages of ovarian maturation are proposed: stage I (immature), characterized by the presence of small basophilic oocytes (52.1719.9 mm) and ovary colour ranging from translucent to creamy; stage II (developing), with yolky oocytes (YOs) (144.2726.1 mm) and a light green colour; stage III (mature), presenting largeYOs but with cortical rods (235.0730.2 mm) and an olivebrown colour; and stage IV (spent), with atretic oocytes and the same ovary colour pattern as stage I. The gonadosomatic index ranged from 1.6 (stage IV) to 13.7% (stage III) and was closely related to the different ovarian maturation stages. The observation of visual features coupled with histological characteristics was found to represent a reliable procedure to evaluate the ovarian maturation of F. paulensis.

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The effect of the addition of Bacillus probiotic during larvae and postlarvae culture of the white shrimp Litopenaeus vannamei was examined in three separate experiments: (I) Nauplius 4-5 to Zoea 3 , which were exposed to probiotic in the water (P w ), only in the microalgae (P m ), in the water and microalgae (P wm ) and a control with no probiotic (C); (II) Mysis 1 to Mysis 3 , which were exposed to probiotic in the water (P w ), only in Artemia (P a ), in the water and Artemia (P wa ) and a control (C); (III) PL 1 to PL 10 , which were exposed to similar treatments for mysis experiment. The use of probiotic Bacillus spp. resulted in an increase in the survival and growth of zoea and mysis phases, especially when the probiotic was added only in the water. For postlarvae, the use of the probiotic had no influence on the zootechnical parameters, however, there was a reduction in the count of presumptive Vibrio both for water and shrimp.