Age and growth were analysed on the basis of 372 vertebrae from specimens of the crocodile shark Pseudocarcharias kamoharai (66·0-122·0 cm, total length, LT ) collected in the south-western Atlantic Ocean. Centrum edge analysis suggested the first four months of the year as the period of band completion, leading to acceptance of free-living bands as annual. A pre-birth ring is formed in embryos >31·0 cm LT , whereas the birthmark is deposited in newborns of 46·1 ± 1·1 cm LT (mean ± s.d.). Growth was parameterized using seven models and the AIC was used for selection of the most plausible model. The von Bertalanffy growth model received the greatest support from the data, providing the following growth parameters for combined sexes: L∞ = 129·2 cm, k = 0·137 year(-1) and t0 = -3·9 years. No significant differences were detected in growth by sex, but significant differences in age composition by sex were found in the sample. Overall age ranged from 2 to >13 years in females and from 1 to 8 years in males. Males achieved first maturity at 3·1 years and females at 5·1 years, with pregnancy appearing at 4·8 years. Similar to other lamnoid species, P. kamoharai is relatively fast growing.
Between 2003 and 2005, vertebrae of 151 Xingu River Potamotrygon leopoldi (Potamotrygonidae) (75 males and 76 females) were analysed to derive a growth curve for this species. The disc width (W ) was significantly different between sexes, with females measuring 149-700 mm W and males 109-500 mm W . The average percentage error for vertebrae readings of the whole sample was 2·7%. The marginal increment ratio (R ) showed an increasing trend with the highest value in November, decreasing from December on. The majority of vertebrae displaying R zero, occurred in September, but the annual periodicity of ring deposition throughout the year was not conclusive. Tetracycline (TCN) injected specimens were held in captivity for 13 months and displayed a fluorescent mark in vertebrae confirming a yearly periodicity of band pair formation with the translucent ring deposited in September-October. The Akaike information criterion (AIC) showed that, among the seven models considered, the best fit was obtained for the von Bertalanffy modified with W (where W = W at birth) for both sexes. Growth parameters for females were: W = 149 mm; W = 763·06 mm; k = 0·12 year , whereas for males: W = 109 mm; W = 536·4 and k = 0·22 year . Maximal ages were 7·2 years in males and 14·3 years in females. The species shows sexual dimorphism expressed in the growth pattern, size at maturity, longevity and asymptotic sizes. Concern for sustainability is raised due to the construction of the Belo Monte Hydroelectric Power Plant (2015 and 2016) in the State of Pará causing changes to the habitat of this species, which is endemic to the Xingu River and two of its tributaries.
The state of Maranhão has a vast coastline that promotes the development of coastal recreational fishery, an activity that has attracted more and more fans in recent years. In this context, the objective of this work was to demonstrate the importance of sport fishing as an auxiliary source in monitoring the diversity of fish on the beaches of the metropolitan region of São Luís, Maranhão, through the monitoring of sport fishing tournaments, held in December 2018 on the beach do Olho d‟água and in July 2019, at Araçagi beach. The captured fish were stored in isothermal boxes containing ice and transported to the laboratory for taxonomic identification. 252 specimens were captured, belonging to 19 species, and distributed in 10 families. The family Sciaenidae was the most representative with 3 species. The predominant species were Conodon nobilis and Genyatremus luteus from the Haemulidae family, which together represented 39% of the specimens captured on the Olho d‟água beach and 24% on the Araçagi beach. The individuals of C. nobilis had an average weight of 29.4 ± 12.7 g and an average length of 12.3 ± 2.0 cm, with a curve of weight x length ratio represented by the equation PT = 0.034 CT2.6637 and R2 = 0, 67, with b = 2.67. While in G. luteus, the individuals had an average weight of 96.5 ± 82.2 g and an average length of 15.8 ± 4.4 cm, with a curve of the weight x length ratio represented by the equation: PT = 0.0145CT3.0999 and R2 = 0.81, with b = 3.09. The diversity of fish in beach fisheries can contribute to studies of fishery biology to support the development of management strategies and conservation of fish stocks.
This paper intents to bring into the technology field a debate regarding gender perspective. We analyze the professional qualifications and trajectories of three women who have distinct experiences and functions working with digital fabrication at two Brazilian universities' laboratories. The semi-structured interviews were executed remotely along with data collection over the internet. In the analysis is debated the protagonism of these professionals inside the laboratories, the role they play in the dissemination of this technology and on the reproduction of technological knowledge among women around different regions of Brazil.
Digital fabrication technologies have been developing rapidly; the number of shapes that can be created in different design sectors by this technology has grown exponentially and in the jewelry field it's not different. Jewelry is an old and constantly evolving craft and the digital manufacturing was first incorporated into it as a form of prototyping and problem solving, but today there are many creative uses for it. This article presents data on some productive practices, prioritizing information on learning, knowledge domain and access to digital fabrication technologies. We discuss the ways which the technology is appropriated in a specific socio-productive context of design jewelry production located in Northeastern Brazil. The study identifies the techniques and technologies effectively appropriated by the surveyed audience and discusses the conditions of these appropriations.
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