THE INFLUENCE OF THE 1992-1993 EL NINO ON THE REPRODUCTIVE BIOLOGY OF Scomber japonicus peruanus (JORDAN & HUBB, 1925)

The influence of the 1992-1993 El Nino events on the reproductive behavior of the Scomber japonicus peruanus (Chub mackerel) was studied from samples collected monthly, along the Peruvian coast (3 degrees 23`S-14 degrees 00`S), from January 1990 to December 1993. The monthly variation of the gonadosomatic index and the frequency of the periods of gonad maturation evidenced that the spawning of the species occurred all year long, being more intense in summer. The values of the gonadosomatic index were higher during the occurrence of the 1992-1993 El Nino, while the body weight and gonad weight decreased. Regarding the condition factor, its values decreased in females over 35 cm in fork length.

Growth parameters and mortality rate of the Scomber japonicus peruanus (Jordan & Hubb, 1925) along the Peruvian coast, South Pacific

The growth parameters and the mortality rates of the Scomber japonicus peruanus (Chub mackerel) were studied based on monthly data of frequency of fork length classes obtained from commercial landings off the Peruvian coast from 1996 to 1998. The asymptotic body length and growth rate values obtained by the ELEFAN I (Electronic Length Frequency Analysis) ranged from 40.20 cm to 42.20 cm and from 0.38 to 0.39, respectively. The oscillation amplitude was 0.60; the Winter point values varied from 0.50 to 0.60 and the performance index from 2.79 to 2.84. The total mortality rate of the Chub mackerel obtained by the linearized catch curve oscillated between 1.68 and 3.35. The rate of fishing mortality varied from 1.16 to 2.78 and the exploitation rate from 0.68 to 0.84. The annual rate of natural mortality estimated by the Pauly`s method ranged from 0.52 to 0.53. The results obtained allow us to conclude that the longevity of the Chub mackerel was slightly over seven years.

Ecological distribution of the shrimp Litopenaeus schmitti (Burkenroad, 1936) (Decapoda, Penaeoidea) in Ubatuba Bay, Sao Paulo, Brazil

The penaeidean Litopenaeus schmitti, popularly known as white shrimp, is a species of great economic importance, being a target of fishing fleets in the southeast region of Brazil. It is distributed through the western Atlantic, from Cuba to Brazil, until Rio Grande do Sul. Adults are found from shallow depths up to 30 m and have been found to depths of 47 m in the state of Rio de Janeiro, while juveniles are located in bays and estuaries. The studied species is seasonally distributed in the region of Ubatuba. The objectives of this study are to analyze the abundance and ecological distribution of L. schmitti and to assess if and when juveniles use the Indaia estuary during their life cycle. Furthermore, the hypothesis was tested that the main period of recruitment in the bay coincides with the period of closure of fisheries defined by the Instruction of IBAMA. To that end, samples were taken monthly from July 2005 through June 2007, both in Ubatuba Bay and in the estuary formed by the Rio Indaia. At each sampling station, salinity, temperature (bottom), depth, organic matter content (%), and grain size of sediments were measured. We found that the largest catches in the estuary were in late spring and early summer. In Ubatuba Bay, peak catches occurred during winter and early spring, whereas in the second year, already in May, there was a high peak capture. The variation in the number of individuals was correlated with some environmental factors both in the estuary and in the inlet (p < 0.05). In the estuary, abundance was positively correlated with temperature (p = 0.008) and organic matter (p = 0.025) and negatively with depth (p = 0.009). Regarding the Ubatuba Bay, only temperature (p = 0.034) and depth (p = 0.013) were significantly associated with the distribution of the shrimp, both being negative relations. The shrimp L. schmitti uses both the estuarine as well the shore environment, particularly the Ubatuba estuary and its adjacent bay, to complete its life cycle. The proposed period of fisheries closure (between March to May in the state of Sao Paulo) for this and other shrimps coincides with individuals capable of reproduction entering the inlet and thus are being protected.

delta-Superderivations of Semisimple Finite-Dimensional Jordan Superalgebras

In the paper, a complete description of the delta-derivations and the delta-superderivations of semisimple finite-dimensional Jordan superalgebras over an algebraically closed field of characteristic p not equal 2 is given. In particular, new examples of nontrivial (1/2)-derivations and odd (1/2)-superderivations are given that are not operators of right multiplication by an element of the superalgebra.

Subjetividade construída: uma leitura sobre os trabalhos de Barbara Bloom

Esse artigo utiliza como referência a noção de “total design” desenvolvida por Hall Foster em 2002 e, através dela, busca se aproximar de dois trabalhos desenvolvidos pela artista Barbara Bloom (1951, Califórnia- EUA): The Reign of Narcissism (1989) e Mood Ring Home (2002). Consideramos o corpo de obras de Barbara Bloom como uma importante contribuição para o debate sobre papel que o design (em seu sentido ampliado) assume perante os mecanismos de produção e disseminação de formas culturais e de novas subjetividades no mundo contemporâneo.