Plâncton amostrado na região sudeste do Brasil, em coletas integradas verticalmente e estratificadas, foi utilizado no estudo do comportamento alimentar das larvas de sardinha-verdadeira (Sardinella brasiliensis). As coletas de ictioplâncton foram realizadas com rede tipo Bongo de 60 cm de diâmetro durante os períodos de desova de 1991/92 e 1992/93. Microzooplâncton foi amostrado na região costeira ao largo de Ubatuba em dezembro de 1995, usando uma rede de fechamento. O estudo da alimentação foi baseado em um total de 901 larvas capturadas. A análise do conteúdo do trato digestório das larvas de sardinha-verdadeira indicaram um padrão de alimentação diurno. Os náuplios de copépode dominaram a dieta de larvas em préflexão e flexão e foram o segundo item em abundância em larvas em pósflexão, que preferencialmente se alimentaram de copepoditos e adultos de Oncaea spp. Em média, a incidência alimentar das 901 larvas foi de 37,6%, porém aumentou para 58,5% para larvas coletadas no período diurno. Setenta por cento das partículas ingeridas foram encontradas no trato médio e a digestão das partículas aumentou naturalmente desde o trato inicial até o trato final. A distribuição vertical do microzooplâncton revelou que os náuplios de copépode estiveram presentes em densidades de 10-20 ind. L-1, principalmente na camada superior de mistura (0-20 m da superfície), entretanto altas densidades de copepoditos e adultos de Oncaea, Oithona e Paracalanus foram encontradas dentro e através da termoclina. Os resultados obtidos indicaram que a larva de sardinha-verdadeira pode adaptar a sua dieta com sucesso, alimentando-se das partículas mais abundantes da camada de mistura na área estudada.

Results from depth integrated and vertically stratified plankton samples collected in the southeastern Brazilian Bight were used to study the feeding behavior of Brazilian sardine (Sardinella brasiliensis) larvae. Sampling of the ichthyoplankton was carried out with 60 cm Bongo nets in the Bight during the spawning seasons of 1991/92 and 1992/93. The sampling of microzooplankton was carried out in the coastal region off Ubatuba, using the closing-type plankton net, in December 1995. The feeding study was based on a total of 901 captured larvae. Gut content analysis of the sardine larvae showed a diurnal pattern of food intake. Copepod nauplii dominated the diet of the preflexion and flexion larvae, but they were the second in abundance for the postflexion larvae which fed preferentially on copepodites and adults of Oncaea spp. Averaged feeding incidence of the 901 larvae was 37.6%, but it increased to 58.5% for day-caught larvae. Seventy percent of the food particles were found in the mid-gut and food eaten showed a natural increase in digestion from fore-gut to hind-gut. Vertical distribution of microzooplankton revealed that copepod nauplii were present in densities of 10-20 ind. L-1, mainly in the upper mixed layer (0-20 m depth), but higher densities of copepodite and adult of Oncaea, Oithona and Paracalamis were found within and beneath the thermocline. These results show that Brazilian sardine larvae can successfully adapt their diet, feeding on the most abundant food particles in the upper mixed layer of the survey area.

Baseado nos dados coletados durante nove cruzeiros oceanográficos realizados na região sudeste, as áreas de desova da sardinha-verdadeira (Sardinella brasiliensis) foram apresentadas c discutidas em relação às condições oceanográficas. As áreas de desova intensiva foram localizadas na parte sul da área de investigação, onde a ressurgência costeira foi menos freqüente. A intensidade de desova demonstrou uma variação anual relativamente grande. A produção total de ovos da sardinha- verdadeira variou de 99 bilhões de ovos durante o cruzeiro de janeiro de 1988 para 4669 bilhões de ovos em janeiro de 1981. O pico de desova ocorre na camada de mistura de superfície uma hora após a meia noite e os ovos eclodem em 19 horas com a temperatura de água 24 °e.

Based on sampling over the period 1976-1993 in the southeast Brazilian Bight, the distribution of spawning of the Brazilian sardine (Sardinella brasi/iensis) is described in relation to environmental conditions. The area of intense spawning occurs in the southern part of the bight where coastal upwelling was less /Tequent. Spawning intensity showed high interannllal variation and the egg abundance in the survey area ranged /Tom 99 billion eggs in the January 1988 cruise to 4669 billion eggs in the January 1981 cruise. Peak spawning takes place one hour after midnight and eggs hatch . out within 19 hours with a water temperature of 24 °e.

No presente trabalho estudaram-se a distribuição e a abundância de larvas de peixes da família Carangidae da costa sudeste do Brasil, entre Cabo Frio (23ºS) e Cabo de Santa Marta Grande (29ºS). As amostras foram coletadas com rede Bongô (malhagens de 0,505 mm e 0,333mm) em arrastos oblíquos, durante dez cruzeiros oceanográficos com o N/Oc. "Prof.W.Besnard", do Instituto Oceanográfico da USP e com N/Oc. "Cruz dei Sur", da PDP-SUDEPE. Foram identificados cinco táxons ao nível de espécie (Trachurus lathami, Chloroscombrus chrysurus, Decapterus punctatus, Selene setapinnis e Selene vomer), além de quatro ao nível de gênero (Oligoplites, Caranx, Serioia e Trachinotus). A espécie mais abundante foi T lathami (58,44% do total de larvas da família Carangidae), seguida por C. chrysurus (15,22%) e D. punctatus (12,17%). T. lathami e D. punctatus apresentaram distribuição ampla por toda a região nerítica, enquanto que C. chrysurus restringiu-se apenas às regiões mais próximas da costa. As larvas de carangídeos foram encontradas durante todas as épocas do ano, mas na primavera e no verão observou-se a maior abundância, o que caracteriza maior intensidade de desova durante estas estações. Esse período de pico de desova relaciona-se, aparentemente, à variação da estrutura hidrográfica da região.

Distribution and abundance of the carangid larvae collected during ten survey cruises in the southeastern Brazilian Bight were analyzed. Trachurus lathami was the most abundant species in the surveyed area with 58.54 % of total carangids taken, followed by Chloroscombrus chrysurus with 15.22 % and Decapteruspunctatus with 12.17 %. Larvae of T lathami and D. punctatus were found all over the continental shelf while the distribution of C. chrysurus larvae was limited to the coastal region. Most of the species occurred all year-around but remarkably during spring and summer. This intensive spawning period of most carangid species seems to be related to the seasonal variation of the hydrographie structure of the southeastern coast of Brazil.

Neste trabalho são analisados os padrões sazonais de desova da sardinha-verdadeira, Sardinella brasiliensis, e da anchoita, Engraulis anchoita, baseado em dados coletados em águas costeiras de Ubatuba (SP), entre 1985 e 1988. Ambas as espécies habitam a costa sudeste do Brasil A primeira efetua desova durante a noite (21:00 - 23:00 h) na região costeira durante o fim da primavera e o verão, enquanto que a segunda desova durante todo o ano, principalmente na região costeira durante o verão e na região nerítica durante o inverno. A desova da anchoita foi observada ao longo de todo o dia, porém com mais intensidade à noite. No verão, ocorre uma forte estratificação vertical das massas d'água. A desova da sardinha-verdadeira ocorre na camada superficial de mistura, enquanto que a da anchoita ocorre abaixo da termoclina, nas águas frias da "Água Central do Atlântico Sul" (ACAS), que ocupam as camadas do fundo durante o verão. Entretanto, ovos e larvas de ambas as espécies foram encontrados tanto na camada superior, de água tropical, como na camada inferior, de água fria, embora predominantemente acima da termoclina.

The Brazilian sardine (Sardinella brasiliensis) and anchoita (Engrautis anchoita) inhabit the southeastern Brazilian Bight. The former spawns at night (21:00-03:00) in coastal region during late-spring and summer, meanwhile, the latter spawns all year-around, mainly in coastal region during summer and in neritic region during winter. The spawning time of E. anchoita was observed all day long, but more intensively at night. During summer there occurs a strong vertical stratification of water masses. The spawning of S. brasiliensis occurs in surface mixed layer, while that of E. anchoita occurs beneath the thermocline inside the cool South Atlantic Central Water which occupies the bottom layer during late spring and summer. However, the sardine and anchovy egss and larvae were found inside both the upper tropical and lower cold water masses, but predominantly above thermocline in this region

Larvas de peixes foram coletadas com rede de nêuston e rede bongô, na costa sudeste do Brasil, durante quatro cruzeiros oceanográficos (Jan/1980; Jan/1981; Out/1981; Mar/1982). São estudados os padrões de distribuição diária de larvas e problemas de amostragem. Numa comparação entre coletas de superfície e coletas oblíquas, observam-se diferenças em composição, tanto em termos de espécies como de tamanho de larvas. Pode ser observada uma clara tendência de estratificação por composição de tamanho para Sardinella brasiliensis em que espécimes juvenis (> 19 mm) ocorreram preferencialmente na camada superficial. Estes juvenis também apresentaram maior capacidade de fuga da boca da rede durante o período diurno. A maioria dos táxons de ocorrência neustônica foi também capturada em camadas mais profundas, mas alguns grupos como Mugilidae, Mullidae e Gerreidae predomiram na camada superficial. A densidade do ictionêuston é mais elevada na nossa região do que a observada no Atlântico noroeste, e o numero de larvas de peixes da coleta diuna com rede de nêuston excedeu o da coleta noturna.

Fish larvae were collected by neuston and bongo nets, in the Southeastern Brazil, during four océanographie cruises (January 1980; January 1981; October 1981; and March 1982). The results are compared and analyzed in order to study the patterns of diel vertical distributions of fish larvae and to detect sampling problems. Larvae collected with neuston net were quite different in types and size composition, when compared with those collected with bongo net in oblique tows. Clear tendency of stratification in size composition at the uppermost layer can be observed on juveniles ( > 19 mm) of Sardinella brasiliensis which also showed day time avoidance. Most of the neustonic taxa were also caught in the deeper layers, although some groups, e.g. Mugilidae, Mullidae, and Gerreidae, were more abundant at the surface. Density of ichthyoneuston is much higher than those observed in the Northwest Atlantic and number of fish larvae collected during the day by neuston net exceeded that of night samples.

Thyrsitops lepidopoides larvae were caught with Bongo nets in the upper 200 m of the ocean from the coast of southern Brazil during 1975-1978. Based on a serie of 271 specimens ranging from 2.5 to 24.0 mm body lenght, morphological and osteological development of the larvae and juveniles is described. Small larvae (2.5-12.0 mm NL) can be distinguished from all known gempylid larvae by the presence of a distinct melanophore at the base of the dorsal and anal fins. The larvae have well developed dorsal and ventral spines. It is the only gempylid with six preopercular spines and non-serrated dorsal and ventral spines during the larval stage.

Size compositions and total landings of skipjack tuna caught in the southeastern Brazilian waters by bait-boats are used as the basis of the assessment of the population for 1980-1983 period, employing the length cohort analysis and virtual population analysis. From monthly size frequency data it is suggested that there is constant immigration and emigration of different modal groups in the fishing area with an interval of two to three months. The exploitation rate was very low for length class between 35-45 cm FL, then increased gradually. The weighted mean exploitation rates were 0.060 and 0.448, respectively for length classes smaller and larger than 55 cmFL. The estimate of the average number of fish attaining a size of 43 cm FL (recruit) was 11.0 x 10(6) fish for assumed values of M - 0.7 and K = 0.307. Increasing the fishing mortality rate by 30% and 50%, an estimated increment in yield is 8% and 12%, respectively. From virtual population analysis, we obtained the biomass estimate of skipjack population older than two years-old to be 70.3 thousand tonnes for assumed value of M = 0.7 and the estimated MSY was 24.6 thousand tonnes.

Based on data from two ichthyoplankton surveys carried out off the eastern Brazilian coast in June and November-December 1978, the larval distribution of skipjack is discussed. Skipjack larvae were more abundant in the November-December cruise (southern hemisphere spring). They occurred mainly at stations near the margin of the continental shelf or over seamounts. Out of 240 specimens of scombrid larvae collected in this area, skipjack larvae comprised only 10.4% (25 specimens), whereas the most abundant larvae were Thunnus spp. with 68.8% (165 specimens).

A surplus-yield model of Schaefer (1954; 1957) was used to study a maximum sustainable yield of the Brazilian sardine. Applying the prices of sardine and operation cost, an economical yield of sardine was discussed. The maximum sustainable yield of sardine was estimated on 173 thousands metric tons and the optimum fishing effort was 28,292 sets of net. With the operation cost of Cr$ 71,040.00 per cruise, the price of sardine has to be higher than Cr$ 10,00/kg.

Eggs and larvae of the cutlassfish, Trichiurus lepturus, were collected during the survey cruises of the project FINEP to determinate spawning areas and season. Six cruises were made from 1975 to 1977 in southern Brazil (23º S -29º S). Spawning occurred throughout the year, but intensively in the cruise, May 1976 (autumn). The heavy spawning area was offshore region of Ilha Grande and of Ilha de Sta. Catarina. Mean temperature of the spawning area was 24.09 ºC, ranging from 21.15 to 26.29 ºC and mean salinity was 35.31 ‰, ranging from 35.04 to 35.52 ‰. Catch data of cutlassfish fishery showed a gradual increase last several years in the two states: São Paulo and Santa Catarina.

Abundances of Zooplankton volumes, fish eggs and larvae were determined for 812 oceanographic stations on six survey cruises to the southern Brazilian continental shelf. Contour charts of Zooplankton volumes are presented. A marked seasonality on Zooplankton volumes and number of fish eggs and larvae was observed. The highest values were obtained during late spring and summer seasons and the lowest in the autumn. The mean values of Zooplankton volumes, eggs and larvae for different depth zones and subareas were presented. Major part of fish larvae were classified into 55 families. The most abundant group were those of family Engraulidae, Myctophidae and Gonostomatidae. The larvae of Clupeidae were abundant in the late-spring and summer cruises.

Relaciona-se neste trabalho a ocorrência de 11 famílias e 26 gêneros de diferentes espécies de larvas e jovens de peixes coletados na Ilha Anchieta, Ubatuba (Lat. 23º32'S - Long. 45º05'W), durante os anos de 1973 e 1974. Foram analisados todos os peixes coletados, procurando-se estabelecer o período das desovas através da ocorrência dos diferentes estágios de desenvolvimento em que se encontravam, relacionando-os com as condições ambientais. A espécie mais abundante foi Eucinostomus sp., que ocorreu principalmente no verão. Umbrina coroides apareceu quase que durante o ano todo, Menticirrhus littoralis durante o inverno, enquanto que M. americanus ocorreu durante o verão. No outono, houve a ocorrência de Coleotropis sp. e a espécie mais abundante durante o inverno foi Anchoa lyolepis. Outras espécies que ocorreram em abundância durante o verão foram Albula vulpes, Sardinella brasiliensis, Harengula jaguana, Trachinotus carolinus e T. falcatus. Apresenta-se também a descrição morfológica de larvas e jovens de castanha (Umbrina coroides).

Occurrences of fish larvae and juveniles taken by beach seine at the Ilha Anchieta (Lat. 23º32'S; Long. 45º05'W) during the period from August 1973 to July 1974, were studied. The predominant species was Eucinostomus sp. (Gerreidae) which occurred more abundantly during summer season. Other species which occurred during hot summer season were: Albula vulpes (Linnaeus, 1758) (Albulidae), Sardinella brasiliensis (Steindachner, 1879), Harengula Jaguana Poey, 1865 (Clupeidae), Trachinotus carolinus (Linnaeus, 1766), Trachinotus falcatus (Linnaeus, 1758) (Carangidae), and Menticirrhus americanus (Linnaeus, 1758) (Sciaenidae). Menticirrhus littoralis (Holbrook, 1856), occurred all the year-round. Anchoa lyolepis (Evermann & Marsh, 1902) (Engraulidae) occurred more abundantly during winter and Coleotropis sp. (Atherinidae) during autumn. Morphological description of larvae and juveniles of Umbrina coroides Cuvier, 1830 was given.