Macrobrachium brasiliense is a cosmopolitan shrimp species found in the channel of large rivers, streams, lakes, igapós and upland igarapés and can present diversity in the use of food resources. This study aimed to evaluate the feeding habits according to sex, molt stage, seasonal and spatial variation, and size class. Organisms were collected every three months from May 2011 to March 2012 at three sampling sites in the Curral de Arame Stream, including the upstream, middle, and downstream sections. Animals were sampled with 50x50cm sieves (1 mm mesh size) on the margin, and with "D" dip nets 40 cm wide (500 µm mesh size) at the bottom. Of each animal we examined the sex, molt stage, carapace length, and stomach content. Data were analyzed through the frequency of occurrence and compared by a chi-square test. Four-hundred-thirty shrimps were collected, of which 26.05% male and 73.95% female; of the total males, 69.64% showed content in the stomach, and females, 72.96%. Among food items stood out: Non-identified Organic Matter (90%), Insects (89.68%), Sand (87.10%), Algae (49.03%), Oligochaeta (29.68%), Fungi (26.77%) and Plant fragment (14.52%). No significant difference was detected in the diet between males and females, but there was a seasonal difference related to the molt stage, and differences along the space and per size classes, and it was concluded that the species has omnivorous habits.

Emerita brasiliensis Schmitt, 1935 is a common mole crab called "tatuíra" in Brazil, with distribution from Espírito-Santo State (Brazil) to Buenos Aires Province (Argentina). Specimens were collected bimonthly from May/1992 through March/1993 with 4mm siffers mesh, in the intertidal region at Vermelha do Norte Beach, Ubatuba, São Paulo, Brazil. The animals were sexed and measured with a precision caliper of 0.1 mm (Cl = carapace length). Males presented cl amplitude from 3.4-17.3mm (13.2±2.1mm), and females from 13.8-26.3mm (20.5±1.8mm), showing a well-defined sexual dimorfism for this variable. The population presented a smaller incidence of males in relation to females (0.54:1.00), however in May/1992 an inverse pattern occurred (1.84:1.00). Ovigerous females were present in all samples with exception of May and September/1992 with greater frequencies in July/1992 and January/1993. It is probable that female maturity occurs is reached with 17mm CL, the smallest size in wich ovigerous females were found.