Ichthyoplankton composition form ARGO cruise 396, Southern Brazilian Shelf, in 1996@en

The ichthyoplankton component of the ARGO project was developed by the Laboratório de Ecologia do Ictioplâncton of the Department of Oceanography of the Federal University of Rio Grande. The objective was to gain further knowledge about the life cycle of fish in the shelf break and oceanic region adjacent to the South Brazil Continental Shelf. Six oceanographic cruises were carried out during the years 1996 and 1998 in the oceanic region and slope between 26º54'S and 34º30'S on the research vessel Atlantico Sul. The ichthyoplankton samples were obtained with oblique trawls made between the surface and 200 m above the bottom with a 0.6m diameter, 300 µm-mesh net coupled with a digital flowmeter. In the first cruise (ARGO_396) stratified trawls were made with a Kahlsico MultiNet containing 3 nets of 300 µm mesh opening and mouth area of 0.75 m2. Stratified vertical arrays were conducted in the last three cruises (ARGO_397, ARGO_198, ARGO_298) using a 0.6m conical-cylindrical, 140µm-mesh net with a closing mechanism. The samples were fixed and preserved in formaldehyde solution, buffered with sodium tetraborate, diluted in sea water with a final approximate concentration of 4%. The filtered volume was calculated and used to standardize the abundance of fish eggs and larvae per 100 m3 of filtered water (Muelbert et al., 1999; Franco et al., 2006).