The Convergência Subtropical (CONVERSUT) cruise series was conducted by the Departamento de Hidrografia e Navegação (DHN) from the Brazilian Navy on board the Oceanographic Ship (NOc.) Almirante Saldanha. The project objective was to determine the western boundary of the South Atlantic Subtropical Convergence in different times of the year (Hubold, 1980a, 1980b, Cordeiro & Montu, 1991). The first cruise of the series (CONVERSUT_1) was carried out between August and November 1977, between Ilha do Mel (25°S) and Mar del Plata (Argentina, 40°S), resulting in 24 transects perpendicular to the coast and 200 oceanographic stations spaced about 30 nautical miles (~ 55 km) apart. Sampling ranged from the coastal region to the oceanic region, approximately 300 nautical miles away from the coast (Hubold, 1980a). Samples from the second cruise (CONVERSUT_2) were conducted between southern Santa Catarina Island (28°S) and southern region of Mar del Plata (Argentina, 48°30'S) from April to June 1978. Twenty-one transects were performed resulting in 180 oceanographic stations, covering an area that stretched up to 250 nautical miles (463 km) toward the ocean (Hubold, 1980b). The 153 stations on the third cruise of the series (CONVERSUT_3) were the result of 24 transects between Ilha do Mel (25°S) and Mar del Plata (Argentina, 40°S) during the period between January and April 1981 (Cordeiro & Montu, 1991). Two sampling strategies were employed in the first two cruises, oblique and vertical trawls at each station, while in the third cruise only oblique trawls were performed. A conical plankton net (Hensen type) with 0.80 m of mouth diameter, 2.6 m of total length and 250 µm of mesh was used (Hubold, 1980a; Cordeiro & Montu, 1991). For technical reasons, in the second cruise, a Hensen-type network with 0.60 m diameter was used in the oblique trawls (Hubold, 1980b; Hubold, 1982). The oblique and vertical trawls were driven from 200 m depth to the surface, or from within 1-5 m from the bottom in shallow areas. The average velocity during the descent of the net in oblique trawls was 0.5 ms-1, reaching 2 ms-1 on the rise, while in vertical trawls velocity was 1 ms-1 (Hubold, 1982). Flowmeters were coupled in all nets to determine the volume of filtered water in each trawl. Samples were fixed and preserved in buffered formaldehyde solution diluted in sea water with a final approximate concentration of 4% (Hubold & Ehrlich, 1981). The filtered volume was calculated and used to standardize the abundance of fish eggs and larvae per 100 m3 of filtered water.