Reproductive biology of male franciscanas (Pontoporia blainvillei) (Mammalia: Cetacea) from Rio Grande do Sul, southern Brazil

The reproductive biology of male franciscanas (Pontoporia blainvillei), based on 121 individuals collected in Rio Grande do Sul State, southern Brazil, was studied. Estimates on age, length, and weight at attainment of sexual maturity are presented. Data on the reproductive seasonality and on the relationship between some testicular characteristics and age, size, and maturity status are provided. Sexual maturity was assessed by histological examination of the testes. Seasonality was determined by changes in relative and total testis weight, and in seminiferous tubule diameters. Testis weight, testicular index of maturity, and seminiferous tubule diameters were reliable indicators of sexual maturity, whereas testis length, age, length, and weight of the dolphin were not. Sexual maturity was estimated to be attained at 3.6 years (CI 95% =2.7–4.5) with the DeMaster method and 3.0 years with the logistic equation. Length and weight at attainment of sexual maturity were 128.2 cm (CI 95%=125.3–131.1 cm) and 26.4 kg (CI 95% =24.7–28.1 kg), respectively. It could not be verified that there was any seasonal change in the testis weight and in the seminiferous tubule diameters in mature males. It is suggested that at least some mature males may remain reproductively active throughout the year. The extremely low relative testis weight indicates that sperm competition does not occur in the species. On the other hand, the absence of secondary sexual characteristics, the reversed sexual size dimorphism, and the small number of scars from intrassexual combats in males reinforce the hypothesis that male combats for female reproductive access may be rare for franciscana. It is hypothesized that P. blainvillei form temporary pairs (one male copulating with only one female) during the reproductive period.

Pesca de atum no indico: seu desenvolvimento recente e consequências para os Países da Subregião Sul Ocidental

In this study the author provided a synthesis of the most relevant aspects of fisheries in Mozambique and Indo-Pacific Region, discussed at the “Seminario sobre avaliaçāo de mananciais de atum na regiāo indo-pacifiqa-jacarta” held in Jakarta from 20 to 22 August 1984. Tens of documents belonging to the Department of Documentation and Information of the Fisheries Research Institute of Maputo and containing valuable information on the tuna fishing in Indo-Pacífic Region were studied in preparation of this seminar.

Pesca experimental de corrico na zona sul da costa de Mocambique

Based on the proven existence of large pelagic fish resources in the southern coast of Mozambique, an experimental fishing trolling program has been designed to study the possibility of resources exploitation through the introduction of trolling technique on artisanal vessels (Project FAO/TCP/MOZ/5653). Although operational problems occurred, the program carried out during the year 1957, provided a collection of data and knowledge. It allowed the preparation of present paper, which could serve as an indicator for a possible implementation of this fishing method in the Mozambican artisanal sector. Sharing this study, the author expects to give a further contribution to the development of a greater pelagic fishery in the waters of Mozambique.

Relatorio do cruzeiro realizado no Banco de Sofala pelo arrastao Muleve em Julho-Agosto/1979

In July-August 1979 a first survey of Sofala Bank was carried out with shallow water prawn resources as the main objective. Some preliminary conclusions on the circulation in the Sofala Bank and the influence of the Zambezi River in this area were drawn. Analysis of catch rates and distribution of the different prawn species resulted in the division of Sofala Bank in 6 areas. Particular importance is given to the species Penaeus indicus and Metapenaeus monoceros which constitute 70-90% of catches in depths less than 25 m. The greatest concentrations of P. indicus are found very close to the shore, principally in an area north of Quelimane and another south of Angoche. At the time of the survey 40% of females of this species were in late maturing stages. The species M. monoceros is most abundant in depths greater than 15 m, with concentrations south of Zambezi River and in small areas near Pebane and Angoche.

Relatório do cruzeiro realizado no Banco de Sofala pelo navio "Pantikapey" de 7/23 - Junho de 1981: camarāo de superficíe

This report of the cruise along the Sofala Bank (Mozambique) describes the catch composition and catch distributions of the shallow water shrimp. Biological data are given for Penaeus indicus and Metapenaeus monoceros which represent 77% of the total catch.

Relatório do cruzeiro realizado no Banco de Sofala pelo navio "Pantikapey" de 7-23/Junho/1981: peixes demersais e fauna acompanhante de camarāo

Catch composition and bathymetric distribution of demersal fish caught along the coast of Mozambique between parallels 16 degree 20' and 19 degree 30' S at depths of 11 to 180 metres are given. The shrimp by-catch was also studied.

Relatório do cruzeiro realizado no Banco de Sofala pelo navio "Pantikapey" de 7-23/Junho/1981: peixes pelágicos e fauna acompanhante de Carapau e Cavala

This report of the research cruise (7 to 23 June 1981) surveying pelagic marine resources of the Sofala Bank (Mozambique) describes the size composition, distribution, length-weight relationships and sex-ratio of the fish captured. Decapterus russellii, D. macrosoma, Selar crumenophthalmus and Rastrelliger kanagurta represented 21.7% of the total catch. The by-catch was also studied.

Relatório do cruzeiro realizado no Banco de Sofala pelo navio "Pantikapey" de 21 de Julho a 7 de Agosto de 1981: peixes pelágicos e fauna acompanhante de Carapau e Cavala

This report of the research cruise (21 July to 7 August, 1981) surveying pelagic marine resources of the Sofala Bank (Mozambique) describes size composition distribution, length-weight relationships and sex-ratio of the fish captured. Decapterus russellii, D. macrosoma, Selar crumenophthalmus and Rastrelliger kanagurta represented 21.7% of the total catch. The by-catch was also studied.

Relatório do cruzeiro realizado no Banco de Sofala no barco "Meleia" em Agosto de 1981: camarāo de águas pouco profundas

The geographic and bathymetric distribution of the shrimps Penaeus indicus, Metapenaeus monoceros, P. japonicus and P. monodon along the coast of Mozambique are given. Biological data of the main species P. indicus and M. monoceros are presented.

Relatório do cruzeiro realizado no Banco de Sofala no barco "Meleia" em Agosto de 1981: fauna acompanhante de camarāo

This cruise report describes the Sofala Bank (Mozambique) crustacean stocks and the fish by-catch. A survey was made of the stock assessment of demersal fish with commercial interest, fishing grounds, biology and distribution of the most abundant demersal fishes and the specific composition of trawl catch areas.

Relatório do cruzeiro realizado no Banco de Sofala pelo navio Pantikapey em Julho-Agosto de [1981]: peixes demersais

Thanks to an agreement between the Institute of Fisheries Research of Mozambique and the Soviet part Azcherniro and Ingribpomrazvedka, surveys in the waters of Mozambique were conducted from June to August 1981 on the ship Pantikapei. The survey made along the Sofala Bank and Boa Paz (16°00-21°00'S) was at a depths of 11 and 90 meters. Demersal and pelagic fisheries experiments were conducted using acoustic devices. This paper described the results obtained on demersal fishery resources.

Relatório do cruzeiro realizado no Banco de Sofala pelo navio SRTM "Sebastopolsky ribak" de Setembro a Outubro de 1982: camarāo de águas pouco profundas

In September-October 1982, the Soviet ship "Sebastopolsky Rybak" conducted a cruise on the Sofala Bank in the area between 16°20'S and parallel 19°40'S. Two surveys were made, one from South to North (depth 10-110 meters) and vice versa. The type of coverage used was systematic. The Sofala Bank was divided into seven sub-areas. During this cruise sub-areas 3 and 4 were covered. Sub-area 5 has not been fully covered.

Relatório do cruzeiro realizado no Banco de Sofala pelo navio SRTM "Sebastopolsky rybak" de Novembro a Dezembro de 1982: camarāo de águas pouco profundas

From November 18th to December 17th 1982, the SRTM "Sebastopolsky Rybak" carried out research cruises on the Sofala Bank in the area between 16°20'S and parallel 19°40'S. The authors analyze data collected on biological characteristics, sexual maturity and localization of Penaeus indicus, Metapenaeus monoceros, Penaeus japonicus, Penaeus monodon and Penaeus latisulcatus.