RCAAP Repository

The possibility of the use of electropherogrames of plasma proteins in polyacrylamide slab gel in the study of populations of marine cat-fishes was examined. A total of 176 samples of plasma from four species. Sciadeichtys luniscutis. Arius spixii, Genidens genidens and Netuma barbas was used. Inter-specific as well as intra-specific differences were found and the locus E of the plasma of all the four species showed a typical dialelic variation. The locus is recommended as one of alternatives which deserve due consideration in the planing of studies of populations of these species by means of biochemical methods.

Monthly variations in the chemical composition of the mussel (Perna perna) cultivated and the environment factors were studied in the Guamache Bay (Margarita Island, Venezuela). The study was carried out on mussels of 65-70 mm shell lenght and on a size that was monthly increased in 5 mm from 40-45 mm to 100-105 mm. The weight of meat ranged from 8,05 to 10,87 g, the weight of shell from 8,88 to 11,00 g and weight of the intervalve water from 2,64 to 6,83 g. In both experiences the water fluctuated between 72,2 and 86,7% ashes from 2,25 to 3,58% and proteins between 9,10 and 16,05% . The influence of the meteorological conditions on temperature and salinity was analized. The percentage of oxygen saturation was always over 80%. The primary nutrients registered low values only the ammonia mean, reached 2,43 µg-at/L Chlorophyll "a" fluctuated between 0,25 and 4,50 µg/L. The results showed that the variations in the chemical composition of mussels was independent of the size and they would be caused by the environment conditions.

Menella coeruieoalba is a dolphin widely distributed in temperate and tropical waters. This species is recorded for our marine fauna on the basis of a 2.35 m long specimen found at 20 km North of the East rocky jetty on the access channel into Lagoa dos Patos, RS, (MORG 064) and also from a sightning in front of Santa Catarina coast. Its vertebral formula is: C 7 + D 14 + L 21 + Ca 34 = 76, with 23 Chevron bones. The number of alveoli is 48-48 / 43-42, its presents 14 pairs of ribs, 8 of them double-headed. The skull measurements of this specimen are compared with other three from the Southern Hemisphere. Through colour slides obtained in front of Rio de Janeiro coasts, Steno bredanensis was recorded. This dolphin also presents a wide distribution similar to the previous species. During the first cruise of the R/V "Atlântico Sul" two pods of the spotted dolphin, Stenella cfr. plagiodon were sighted and photographed. This species can be easily identified on the basis of the clear brown tegument with numerous white rounded spots, in adults. One of the skull (MCNRS 026) studied may belong to this species.

Studies on cetaceans at Argentina, Uruguay and Brazil can be divided in three periods. During the first one (1861-1963), studies of the Argentines Burmeister, Gallardo, Lahille and Marelli were done on dolphin and porpoise osteology, occasionally on whales, these wire followed by those of Miranda Ribeiro and Carvalho in Brazil. The second period (1969-1976) begins with the studies of the North Américan Gilmore (1969) in Patagonia. From this year on, numerous forcing expeditions came to Argentina and Uruguay, to study the right whale, Eubalaena australis behavior in Patagonia and the La Plata river dolphin. Pontoporia blainvillei biology at Punta del Diablo, Uruguay. These expeditions have contributed to a better knowledge of whales and dolphins, not only in South if not also, abroad. During thin period studies on bekzvior, bioacustics, population dynamics and bio-ecological studies ; began. Simultaneously it is observed that Latin Americm researches, specially those of Uruguay and Brazil, become interested ind doing cetological research on systematic aspects. The third period (1976- ) it is characterized by an increased effort on this field and also by a better exchange of information between the three S. W. Atlantic countries. In Brazil, during the last two years, a gret interest on the minke whale conservation problem has developed, not only at the public opinion, but also at the government level.

Sexual maturity and other reproductive features of Tivela mactroides collected from Playa Guiria, Carúpano, Sucre State, Venezuela, were studied on the basis of smears and histological sections of gonads. There was continuous sexual cycle, but the development of the visceral mass, in females was less from January to March, 1975. A five steps maturity sexual scale was used to examine the histological sections, indicating that the dominant phase consist of a partial spawning. In total sexes and in intervals (10.1 - 30.0 mm) the ratio does not vary from the proportion 1:1, although the males outnumber the females; the number of females is significantly higher in the larger ones (30,1-45.00 mm).

With the purpose of obtaining data which could be useful for complementing investigations on estuarine biological oceanography, the authors carried out a survey on the distribution and volume of catch produced by fish-traps used by traditional fishermen in the lagoon region of Cananéia-Iguape (São Paulo, Brasil), mainly for catching mullet. As many as 170 fish-traps were initially spotted and mapped in the whole region, some of which are concentrated in particular areas that seem to be points of more freauent passage of mullet and other fishes, according to the experience and observations of regional fishermen. In consequence of the dam recently built on the Valo Grande - an artificial canal conich formerly linked the RibeiraRiver to the lagoon system of Cananéia-Iguape - it is expected that the sea-water circulation within the lagoon will be intensified, with a consequent increase in the salinity rates of its waters, which in turn will probably affect the ecological balance of time. The authors suggest that a continuous monitoring of the volume and composition of the commercial catch produced by the fish-traps operating in the lagoon-region could eventually offer useful data for detecting the alterations of distribution of the several different fish species that are found in the lagoon, in consequence of the foreseen changes in the salinity rates of its waters.

The coastal lagoon system of El Carmen-Machona-Redonda, located in the coastal plateau South of the Gulf of Mexico, in the State of Tabasco was studied from August 1977 to July 1978. Tempetature, chlorinity and dissolved oxygen were recorded every two months during the study period. The maximum depth of the system is 3.0 m, decreasing toward the edges and the oyster banks: the average depth is 1.0 - 1.30 m. Only a very small amount of freshwater reaches the system; the chlorinity content is additionally increased on account of the very recent opening of an artificial sea mouth. The highest average temperature (30.1ºC) was recorded in august 1977, and the lowest (25.5ºC) was recorded in december of the same year, thus showing m small annual variation. The average chlorinity value of 4.12‰ between the highest and the lowest average monthly values (19.19-15.47‰) makes it a rather homogeneous system throughout the year. Dissolved oxygen average values varied from 4,52 ml/L in February 1978, to 5.92 ml/L in July of the same year. Thus the system represent a typical, tropical marine lagunar system, with small freshwater influence.

This work deals with the bionomy of the population of Homalaspis plana (Milne Edwards, 1834) sampled in Coronel, Chile. Homalaspis plana share his biotope with: Paraxanthus barbiger (Poeppig, 1836) and Gaudichaudia gaudichaudi (Milne Edwards, 1834). A marked sexual dimorphism is apparent, the males are larger and heavier than the females; moreover, the volumes of the chelae of the first are also larger. The percentaje of the female population was significantly larger than the males population. The spawning extends from June to December. Each class of the ovigerous females, gives a different contribution, the maxima is done by the 5,74 cm class with 29,21%. The minimum size of ovigerous females is 49,3 mm L.C

No summary/description provided

Monthly quantitative sampling of the beach benthic macro fauna was made from June 1972 through December 1974. Determinations of the distribution index, length |dry weight correlation and vertical distribution pattern was also made.

In this paper, by means of a histoecological approach, the convenience of incorporating the stereological analysis of the maturing oocitary stocks in the study of the femenine gonads sexual cycles - mainly in species producing a large number of gametes - is shown. So the numerical and volumetric characteristics of each one of the oocitary stratums are determined, which allows the characterization of the sexual maturation stages by a diversity index.

The paper deals with some base trophic factors in relation to two herbivores, namely oysters and mullets, which derive their energy directly from the first trophic level of an estuarine ecosystem. The analysis of the gut contents of both organisms has shown that they feed mostly on micro-organisms, especially planktonic and benthic diatoms, and a significant percentage of detritus materials, including inorganic particles, is always present. Their dietary components are very much related to seasonal abundance of food production of the estuary. Current yields of oysters and mullets are far too low and food source is not a limiting factor for their production on large scale. Tidal flows, particularly in relation to salinity, have profound effect on culture grounds. Mortality is largely due to predation.

The larval primary settlement and the changes originated during the metamorphosis of some species of Chilean bivalves, are comparatively studied, being described, the larval and post - larval stages from the veliconcha to late plantigrade. By observing in ropes "anchovetera" nets and plankton samples, in the mitiliculture of Codihué (41º 46'S; 73º 24'W), it was verified for Mytilus chilensis Hupé, 1854 and Aulacomya ater (Molina, 1782), primary settlement on the filamentous algae of genera Enteromorpha with an average size of 33º µ high, minimum average of definitive settlement, byssus positional changes, etc. Information concerning average and number of larval and post - larval attachment to different deep and inmersión period and morphological characters of larval and post - larval of: Bankia martensi Stempell, 1898 (Teredinidae), Pholas chiloensis (Molina, 1782) (Pholadidae) y Chlamys patriae Doello Jurado, 1918 (Pectinidae), are also given.

The improved study of the Eastern South Pacific undertaken in the last years enables us to have a better view of the marine communities' biogeography. The author, elaborating on several ideas of previous studies, proposes four subdivisions or districts in that region: 1) tropical of the Panamic-Pacific province up to 3º 30'S; 2) intermediate, from approximately 3º 30' to 7º S, where tropical and southern waters influence the presence of organisms; 3) temperate, of the Peruvian Coastal Current or Humboldt Current; and 4) tropical, in the waters off this last Current Joining the Peruvian Oceanic Current. The author, consulting extensive literature, examines the presence of molluscs and fishes, in order to select a characterization of each biogeographical district. Some of the proposals are, for instance, Littorina peruviana, Ocypode guadichaudii and Engraulis ringens for the temperate district; Littorina paytensis, Olivella broggi and Scorpaena afuerae for the intermediate one; the thunids and Exocoetus volitans for the tropical oceanic waters; and Anadara tuberculosa, Littorina varia, Pomadasys panamensis and Sciades troschelli for the tropical waters north of 3º 30'.

A short review on estuarine ichthyoplankton identification, description and growth is given. The need for qualitative, quantitative, horizontal and temporal distributions related to environmental factors, period and kind of spawning and fecundity of different species are discussed. Resulu of studies on Micropogonias fumieri, Brevoortia pectinata, Lycengraulis olidus, Achirus garmani and other suggest me necessity to sample fish larvae and juveniles at mid water, bottom and at the margin of the estuary. Further more, it would be of interest to extent and periodically survey the study area to the adjacent coastal waters, and the fresh water part of the Lagoon as well as the channels and tributaries.

A case of fish mortality, the occurrence of 32 species of bony fishes and one species of diatomae, Asterionella japonica at Itanhaem, SP, are discussed.

No summary/description provided

No summary/description provided

Este estudo apresenta variações, durante a estocagem em gelo, dos teores de umidade, proteína, cinza e trimetilamina na carne de camarões Penaeus (M.) brasiliensis Latreille, capturado na costa centro-sul do Brasil. As mudanças estão relacionadas com o período de estocagem, relaçao sexo-tamanho e grau de maturaçao das fêmeas, sendo observadas interações significativas para umidade e proteina. Os teores de umidade e trimetilamina aumentam e os de proteína e cinza decrescem, durante a extensão do período de estocagem. O acréscimo de trimetilamina foi equivalente para macho e femea; no entanto, o mesmo aparenta ser maior para os especimes machos, porque os mesmos atingem o estágio de produção de trimetilamina antes que as femeas, provavelmente devido ao seu menor porte e, consequentemente, maior superfície de exposição a ação do gelo e bactérias. A influência do tamanho dos camarões na produção de trimetilamina durante a estocagem em gelo já havia sido observada por Fieger & Friloux (1954) e Govidan (1962), nos EUA e Índia, respectivamente, porem esta e a primeira evidencia de que os acréscimos de trimetilamina não diferem significativamente entre machos, de menor porte, e fêmeas, imaturas e em maturação.

Measurements of primary productivity and excretion of DOM in natural phytoplankton populations were carried out in surface waters from Lat. 17º14'S -Long. 039º13'W to Lat. 28º36'S -Long. 048º49'W. The relative rates of excretion varied between two and thirty percent from the total assimilated in the transparent bottle. In relative terms the excretion increased towards the pelagic zones, but in absolute results it followed the production values. Based on the predominat water masses and on the excretion values a classification of the stations under study is suggested.