Informações sobre o hábito alimentar e a atividade alimentar diária de populações de peixes são variáveis de fundamental importância para entender seu papel em um ecossistema aquático. Investigações sobre esses aspectos foram realizadas em jovens da corvina (Micropogonias furnieri), da tortinha (Isopisthus parvipinnis) e da oveva (Larimus breviceps) e em jovens e adultos de maria luiza (Paralonchurus brasiliensis), cujas amostras foram obtidas em um ciclo de 24 horas (4 a 5 de setembro de 1987), na plataforma continental do sudeste do Brasil. A corvina e a maria luiza se alimentaram, principalmente, de poliquetas e camarões carídeos e não apresentaram um padrão claro de atividade alimentar. A tortinha e a oveva apresentaram dieta semelhante, composta de crustáceos e peixes teleósteos; ambas tiveram como presas principais os camarões pelágicos sergestídeos e os camarões bentônicos carídeos, e a oveva, além dessas duas presas, misidáceos. A tortinha apresentou, principalmente, hábito alimentar diurno, mas se alimentou de algumas presas em períodos de escuro. A oveva apresentou hábito alimentar noturno, com registros dos maiores valores de repleção estomacal entre o anoitecer e o período de escuro.

Food habits and daily feeding activity of fish populations are important ecological variables for understanding their role in the ecosystem. Diel changes in feeding activity and dietary composition of juvenile whitemouth croaker Micropogonias furnieri, shortfin corvina Isopisthus parvipinnis, shorthead drum Larimus breviceps and of juvenile and adult banded croaker Paralonchurus brasiliensis were investigated from samples taken over a 24 hours period from 4 to 5 September 1987 on the continental shelf off South-eastern Brazil. Whitemouth croaker and banded croaker had a benthic diet based on polychaetes and some caridean shrimps and showed no diel feeding pattern. Shortfin corvina and shorthead drum fed on crustaceans and teleostean fish, the former species primarily on pelagic sergestid shrimps and benthic caridean shrimps, and the latter mainly on pelagic sergestid shrimps, mysidacean and benthic caridean shrimps. Shortfin corvina is primarily a diurnal feeder, but preyed on some items only at night. Shorthead drum is a night feeder, with minimum stomach fullness values between dawn and daytime, and maximum values between dusk and night time.

1) Sardinella bvasilieneis apresenta desova individual do tipo total; entretanto as fêmeas desovantes nao maturam todas ao mesmo tempo, ocorrendo maturação e desovas sucessivas de grupos de indivíduos (cardumes), o que determina um período de desova prolongado; 2) Durante o período de desova de 1964-65 foram constatados valores para os índices de maturidade e gonadal, e para o fator de condição, mais eleva dos que durante 1963-64, o que sugere melhores condições alimentares durante tal período; 3) Os pesos médios por classe de comprimento, para as fêmeas, também foram mais elevados durante 1964-65, bem como o comprimento médio, a fecundidade média por fêmea e o potencial reprodutivo relativo; 4) Os valores dos índices.considerados foram distintos dentro de um mes mo período, entre as varias fases, mas também variaram significativamente para uma mesma fase, entre os dois períodos, indicando não poderem ser utilizados como fator isolado para a caracterização do grau de desenvolvimento dos ovarios; 5) As relações entre fecundidade e comprimento total, peso total, peso das gonadas e peso do corpo mostraram-se significativamente diferentes entre os dois períodos; 6) O tamanho dos óvulos, para uma mesma fase, variou de um período para o outro, sendo mais elevado durante 1964-65; 7) Os resultados mostram que, apesar dos índices e relações terem um significado biológico, referem-se a organismos vivos submetidos à ação do meio ambiente variável, e não podem ser encarados como fixos; sua utilização deve ser associada a observações puramente biológicas, servindo apenas como "auxiliares" na determinação ou avaliação de um processo biológico qualquer.

This paper is a contribution to the knowledgment of some aspects of the reproduction of Sardinella brasiliensis (Steindachner, 1879) from the area between 23º40'S and 24º20'S, Brazil. The individual spawning, fecundity, maturation and gonadal indexes, condition factor and spawning power, have been evaluated for the spawning periods of 1963-64 and 1964-65 and the results were statistically analysed. Fecundity/ total length, total weight, ovarian weight and body weight relations were determined for each period and the results statisticaly compared, showing significant differences between the periods under observation.

This paper deals with some aspects of faunistic diversification and refers to part of the distribution area of a sciaenid fish Micropogon furnieri (Desmarest, 1822) Jordan & Evermann 1884, widely distributed. Such species is characteristic of the tropical area and occurs along the Brazilian coast with highest abundance south of Cabo Frio. The analysis of variations of six meristic characters and eight body proportions and of some reproduction and growth features has shown that along the coast between latitudes 23ºS and 33ºS diversifi cation occurs within the species; such diversification implies in the existence of two populations, one occupying the area between 23ºS and 29ºS (area I) and the other between 29ºS and 33ºS (area II). The eco logical differences between the two mentioned areas according to our point of view is the reason for the species diversification in the whole area under observation. The differences recorded as the characteristics studied were suf ficient enough to illustrate the existence of two populations reproductively isolated suggesting that some gene exchange, if any, between both populations occurs in a very low rate. Our results show that abundance estimates of M. furnieri in this area must be made for each population as a whole until further studies on genetic characters are developed which may confirm the existence of gene exchange and if so, the gene flow rate. As the present study does not cover the total area of occurrence of Micropogon furnieri no hypothesis is extended to the general pattern of diversification (eventual presence of sub-species) and no systematic "status" and names are given to the populations identified.

Micropogon furnieri (Desmarest, 1822) Jordan, 1884 is one of the species of fish of commercial importance occurring along the southern coast of Brazil. It has been the subject of several studies and some aspects of its life cicle, behavior and abundance are already known. This is a contribution to the knowledge of some aspects of the reproduction of the species. The type of spawning is discussed and fecundity has been evaluated and shown to be dependent on body length, not on body weight.

O presente trabalho constitui parte de um projeto a longo prazo que visa o estudo ecológico da fauna íctica da baía de Santos (23º58'S a 24º02'S 45º19'W a 46º24"W). Foi iniciado pelo levantamento da ictiofauna da região (etapa I) sendo que esta série tem a finalidade de possibilitar uma identificação rápida dos exemplares durante trabalhos de campo. Iniciamos essa série pelos Sciaenidae, por ser esta a família que possui o maior número de espécies representadas na região. Foram organizadas chaves para os gêneros e espécies, descrições sucintas das espécies, notas ecológicas sôbre as espécies em nossas águas, desenho e fotografia. Dos quinze gêneros de Sciaenidae marinhos que ocorrem no Brasil, nove gêneros foram registrados na baía de Santos; êsses nove gêneros encontram-se representados no Brasil por 21 espécies, tendo sido verificada a ocorrência de 12, na baía.

Considering the great extension and the diversity of environmental conditions of the Brazilian coast, the study of the fauna of well-delimited regions seems to be advisable, as is the case of the region under study, namely the Bay of Santos, São Paulo, Brazil (from 23º58'S to 24º02'S; from 45º19'W to 46º24'W). This paper comprises part of a long-term program aiming at the ecological study of the ichthyological fauna of the Bay of Santos, which was initiated by the ichthyofauna of the region (1st part). The present series begins with the Scianidae since this is the family with a greater number of species represented in the region. As many as 21 species of 15 Sciaenidae genus recorded for the Brazilian waters, 9 occur in the Bay of Santos, represented by 12 species. Keys are given for the genus and species and also a brief description of the species, ecological notes for those recorded in Brazilian waters, drawings and photos.

The aim of this paper is to evaluate the apparent abundance of the croaker (Micropogon furnieri) along the central and southern coast of Brazil (from 23º50'S to 35ºS). The data on catch and effort of the fish taken in the same area and at the same time, with different gear, are analysed from January 1959 to December 1962. The different gears used were reduced to the same level of efficiency, and the apparent abundance was estimated according to the fishing area (area I - from 23º50'S to 26ºS, and area II - from 26ºS to 35ºS), by quarters and by year. The results allow us to draw the following conclusions: 1 - There is a tendency of increase of the apparent abundance from the beginning to the end of each year and of decrease in following years, in both areas. The decrease is greater in area II. 2 - The levels of apparent abundance, in both areas, was very different. The level in area II is higher. 3 - Variations in the availability during the year, were observed. Data suggest that they are determined in area I by extrinsic factors, and in area II by intrinsic factors. 4 - Different responses of the stock, in both areas, to fishing intensity was verified, supporting the hypothesis of occurrence of two different croaker stocks. The stock of area I probably has reached a state of equilibrium with the fishery while in area II the stock has not yet reached this stage.

The correlation between the latitude where denser concentrations of the croaker (Micropogon furnieri) occurred and the month of the year were established in this paper. The unit effort production (kg/hour haul) was used as the concentration index and the hauls made within 30' were grouped in the immediate superior latitude. The croaker migrates along the Brazilian coast between 28º S and 33º S, according to the expression: y = 30.6 + 1.85 cos 30 (x - 2), where: y = latitude (ºS) x = 1, 2 .... 12 (months of the year)

This paper presents an analysis of the fecundity and spawning of the sea trout, "pescada-foguete" (Macrodon ancylodon), of the Brazilian coast south of 29ºS, based mostly on egg count estimates of 21 specimens. The following conclusions were drawn: 1 - The eggs in the pre-spawning fish present a multimodal distribution of diameters, suggesting that they are spent successively within each spawning. 2 - The long spawning period, November-May, may be due to the partial spawning suggested above. 3 - In spent fish the ovaries contain mostly (97.5%) ovocytes less than 140 micra in diameter, plus a small quantity (2.5%) of eggs being resorbed. 4 - Correlations were drawn between fecundity (F)/total length (L) and fecundity (F)/weight (W), and are presented in equations (a) and (b) above. 5 - The value of L for F = 0 was determined and the value obtained (23.6 cm) is close to that verified for the beginning of the first maturity.

This paper presents results obtained in analysis of the data on catch and effort, for croaker (Micropogon furnieri) caught along the southern coast of Brazil, between 23º50'S and 35ºS, in a band of approximately 30 nautical miles, and landed at Santos from January 1959 to December 1962. The unweighted and weighted indexes of density and the concentration index were computed according to gear and to fishing area (I - from 23º50'S to 26ºS, and II - from 26ºS to 35ºS) and the data were grouped by quarters. The results suggest the following conclusions: 1) The croaker catch, to some extent, has been done without directive thus the fishing fleet has operated in the areas with density lower than average. 2) The level of unit-effort production differ largely between areas, suggesting the presence of two separate croaker populations. 3) The decrease in production per unit-effort year after year in the two areas, suggests a decrease in the relative abundance along the studied fishing area.

Studies on wild oyster populations in the Santos region were started in March 1960, and in September of the same year work was begun on experimental culture. Several natural beds were found, the majority in the Bertioga Canal. Both the observations of wild populations and the experiments showed that the Canal is the most favorable location for oyster development. It was possible in the experimental work to show that both growth and survival rates are much higher there than they are in waters of higher salinity. Also the yield of meat per unit weight is higher in the Canal; about 1.5 g per centimeter of total length at the commercial size of approximately 8 cm. Two extended periods of fixation were found in the Canal, one in summer and the other from the end of winter through spring, although in the bay the fixation was practically year round. These results indicate good possibilities for a commercial oyster-culture industry. However, a bacteriological analysis of oysters from Canal beds showed coliform bacteria, so that provisions for purification should be made in any plans for development of oyster culture.