José Roberto Verani

Dinâmica da alimentação natural de Callinectes danae Smith (Decapoda, Portunidae) na Lagoa da Conceição, Florianôpolis, Santa Catarina, Brasil

From March/91 to February/92 monthly collcction surveys were carried out to obtain basic information about the dynamics of feeding and trophic spectrum of C. danae Smith, 1869. A total of 456 males and 527 females were caught. The diet of the species was not sex related. The trophic spectrum of C. danae is composed by a high number of items. The 35 items were assembled in 14 categories and the feeding index was applied. Mollusca, Polychaeta and Crustacea were observed to be basic elements in the species diet, Osteichthyes and MOND appear as secondary resource whereas vegetal material were found to be of less importance.

Quali-quantitative analysis of sea-bob-shrimp's ichthyofauna bycatch, at Armação do Itapocoroy, Penha, Santa Catarina

The ichthyofauna bycatch in sea-bob-shrimps fishery was monthly studied from August 1996 to July 2003, in the artisanal fishing grounds at Armacao do Itapocoroy, Penha. It had been used two net-of-drag with doors, mesh of 3.0 cm in the sleeve and body and of 2.0 cm in the sacker, pushed for whaleboat with average speed of 2.0 km/h. Mean values of bottom water temperature and salinity remained uniform in a seasonal fluctuation, showing no significant differences among the studied years. A total of 60 species were collected, in which 22 were considered common species along the sampled period. Sciaenidae, Carangidae and Clupeidae families presented the highest number of specimens, accounting to 92% of catches, being Stellifer spp., Paralonchurus brasiliensis and Isopisthus parvipinnis, the dominant species, occurring regularly along the years. Seasonal fluctuations were observed in the abundance and diversity of ichthyofauna, with significant differences observed among the sampled years and biomass, as well as numerical abundance. The monitoring of trawling fishery targeting sea-bob-shrimp may contribute in a way to maintain the exploited stocks and guarantee the subsistence of traditional communities along Santa Catarinas coast.

Population structure and reproductive biology of Cichla kelberi (Perciformes, Cichlidae) in Lobo Reservoir, Brazil

The structure of Cichla kelberi population was characterized regarding the sex ratio, total length composition and some reproductive characteristics. The specimens were collected in two periods, from November 2002 to November 2003 and from December 2004 to May 2006. The sex ratio was significantly different than 1:1. The total length varied from 3.4 to 40.1 cm, with individuals in the shortest length classes occurring throughout the year, but with greater incidence in the warmer periods. Females and males reached similar lengths and there was no difference between the sexes regarding the length-weight relationship. The estimated values of condition factor were near the central value of 1.0 and decreased during the cooler months, coinciding with periods of lower reproductive activity. Individuals with mature or semi-spent gonads occurred from November to April, indicating that Cichla kelberi reproduces for a long period of time. The spawning is partitioned, with an average absolute fecundity of 6072 oocytes (from 5220 to 6908 oocytes). The high relative condition factor values, long reproductive period, large output of fingerlings and high fecundity are biological conditions that indicate the species is well adapted in this reservoir.

ESTUDO POPULACIONAL DO CAMARÃO-ROSA Penaeus paulensis PEREZ FARFANTE (NATANTIA, PENAEIDAE) NA LAGOA DA CONCEIÇÃO, SANTA CATARINA, BRASIL

In the time period between May/92 to April/93, 2693 (1243 males and 1450 females) specimens of Penaeus paulensis Perez Farfante, 1967 were collected. The shrimps were captured by night using a hand net in areas between 30 to 150 cm deep. The abundance of P. paulensis is regulated mainly by the temperature, the summer being the season of greater profusion. The major recruiting period takes place in the Spring with shrimps measuring between 1,0 to 3,0 cm and approximately 2,0 months old. The population reaches the pre-adult in the Fall-Winter period with average length between 8,8 cm (females) and 9,3 cm (males). The migration to the ocean occurs during the Winter. The artisanal fishing in the Conceicao Lake is predatory, acting upon the young and pre-adult shrimps, which may jeopardize the marine reproducer stock.

Reproductive traits of the yellow-mandi catfish Pime/odus maculatus Lacepede (Osteichthyes, Siluriformes) in captive breeding

Pimelodus maculatus Lacepede, 1803 is an important fish of the Sao Francisco river basin, where it is economically significant in both professional and sports fisheries. The fish, maintained in captivity, was subjected to hypophysation with crude caip pituitary extract. Approximately 70% of the females treated spawned viable eggs. The eggs were opaque, demersal, yellow and free. Egg stripping was performed at 213 hour-degrees (duration = 8.3 h) after the second dose injection, at water temperature of 25-26oC. Hatching occurred at 394 hour-degrees (duration = 16.3 h) after egg fertilization, at water temperature of 24-25oC. Egg fertilization rate was 64.8%. The relationship between absolute fecundity (AF), initial fertility (IF) and final fertility (FF) and body weight are expressed, respectively, by AF = - 331 + 181717 Wt (r2 = 0.62), IF = - 16839+ 158123 Wt (r2 = 0.65), and FF = -9874 + 100365 Wt (r2 = 0.63).

Biologia reprodutiva de Oligosarcus jenynsii (Günther) (Characiformes, Characidae) da Lagoa das Custódias, Tramandaí, Rio Grande do Sul, Brasil

The Custodias lagoon has a great importance in the Tramandai system, because it works as reproduction area, feeding and nursery grounds to several fish species. The aim of this work is the study of aspects related to the reproduction of Oligosarcus jenynsii (Gunther, 1864) as such as reproductive period, sexual ratio, fecundity and size of the first gonadal maturation. The specimens were sampled monthly from October/1994 to October/1995. For each sex, maturation curves were established, based on the monthly variation of the gonadossomatic index mean values, as well as, the relative frequencies of the sexual maturity stages. Breeding seasons took place during the winter and spring. The sex ratio was significanthly different from 1:1, with more females than male in almost all month. The species had a average fecundity of 9.694 ovocytes. The estimated size of first sexual maturation was 114 mm for male and 131 mm for females.

Aspectos bioecológicos do camarão-rosa Penaeus Brasiliensis latreille (natantia, penaeidae) da Lagoa da Conceiçao, Florianópolis, Santa Catarina, Brasil

In the time period between May/92 to Abril/93, 602 (267 males and 335 females) specimens oi P. brasiliensis Latreille, 1817 were collected. The shrimps were captured by night using a hand net in areas between 30 to 150 cm deep. The amplitude of length ranged from 1,3 to 13,7 cm, the highest frequencies of capture were registered during the Fali between the classes of 7,0 and 10,0 cm. The males present isometric growth and the females negative allometric one. The size of the pre-adult ranged from 8,8 cm for the females and 9,2 cm for the males. The recruiting occurs chiefly in the Summer with intense growth during the Fall-Winter period, reaching a climax with the migration of pre-adults to the ocean in midwinter.

Reproductive Ecology of Prochilodus brevis an Endemic Fish from the Semiarid Region of Brazil

The commercially important migratory fish Prochilodus brevis is from the Neotropical region, and understanding the reproductive ecology of this potamodromous fish is essential for its conservation and management. This study investigated the length-mass relationship, sex ratio, length at first gonadal maturity, gonadal development stages, gonadosomatic index, condition factor, and reproductive period of P. brevis. Temporal distribution of rainfall, temperature, dissolved oxygen concentration, pH, and electrical conductivity of the water were related to the reproductive period of this fish. Rainfall seems to be the main environmental factor which modulates changes in limnological parameters and the timing of the spawning period of this fish. P. brevis migrates into lower reaches of the river to feed during the dry season and returns to the upper reaches during the rainy season to spawn. Inadequate facilities for migration create obstacles for spawning success of this ecologically important fish.

Reproductive strategies of two sympatric swimming crabs Callinectes danae and Callinectes ornatus (Crustacea: Portunidae) in an estuarine system, south-eastern Brazil

The present study analysed the reproductive biology of Callinectes danae and Callinectes ornatus, which are captured as by-catch from pink-shrimp trawling in Guanabara Bay. The size atgonadal maturity was 79.9 mm and 67.4 mm respectively, for C. danae and C. ornatus. The pattern of reproduction was continuous for both species; however, the gonadosomatic index analyses showed seasonal and alternating reproductive peaks in the bay. While C. danae showed reproductive peaks in the autumn and in the winter, C. ornatus showed an apparent reproductive peak in the summer and probably another in the spring. The sex-ratio of C. danae was significantly skewed in favour of females (3.0:1). However, in C. ornatus, males predominated (1.2:1). This reproductive pattern indicated that possibly the females of C. danae return to the estuary after spawning where trawling takes place, while ovigerous females of C. ornatus migrate to adjacent coastal areas around the bay.

Aspectos biológicos e pesqueiros de Paralonchurus brasiliensis Steindachner, (Pisces, Sciaenidae), na Armação do Itapocoroy, Penha, Santa Catarina, Brasil

Due to abundance of P. brasiliensis (Steindachner, 1875) in ictiofauna of the sea-bob-shrimp´s bycatch, it presents low commercial value and frequently being discarded. This work aims to present basic information on biology and fisheries of P. brasiliensis in the Armacao do Itapocoroy, Penha, Santa Catarina. The collections were carried out monthly during the period of August 1996 to July 2003, in three traditional areas of performance of artisan fisheries. The species presented positive alometric growth, with a sexual ratio of 1:2,1 between males and females, and the size of first maturation in 14,8 cm and 15,0 cm. P. brasiliensis presented a great trophy specter composed by 27 items, being that, from the spring a gradual increment in the food ingestion occurred until the summer, followed of abrupt fall in the autumn and small recovery in the winter. Despite of the seasonal fluctuations during the seven years, this species occupied the second position in number and biomass among the integrant of ictiofauna bycatch.