Moreira A.A.,University of Sao Paulo |
Moreira A.A.,Mogi Das Cruzes University |
Tomas A.R.G.,Fisheries Institute |
Hilsdorf A.W.S.,Mogi Das Cruzes University
Journal of Experimental Marine Biology and Ecology | Year: 2011
Octopus vulgaris is a cephalopod species in several oceans and commonly caught by artisanal and industrial fisheries. In Brazil, O. vulgaris populations are mainly distributed along the southern coast and have been subjected to intensive fishing during recent years. Despite the importance of this marine resource, no genetic study has been carried out to examine genetic differences among populations along the coast of Brazil. In this study, 343 individuals collected by commercial vessels were genotyped at six microsatellite loci to investigate the genetic differences in O. vulgaris populations along the southern coast of Brazil. Genetic structure and levels of differentiation among sampling sites were estimated via a genotype assignment test and F-statistics. Our results indicate that the O. vulgaris stock consists of four genetic populations with an overall significant analogous FST (ΦCT=0.10710, P<0.05) value. The genetic diversity was high with an observed heterozygosity of Ho=0.987. The negative values of FIS found for most of the loci examined suggested a possible bottleneck process. These findings are important for further steps toward more sustainable octopus fisheries, so that this marine resource can be preserved for long-term utilization. © 2011 Elsevier B.V.
Savage found that pondweeds in the presence of light stimulate spawning in Xenopus laevis ... This finding prompts me to report my own experience with this amphibian under more natural conditions ... At the Provincial Fisheries Institute, Lydenberg, fishponds ... are filled with water and fertilized with fowl manure in spring for the breeding of fish. Within 2 or 3 days after fertilization such ponds usually contain large numbers of Xenopus, which immediately start spawning, so that by the time plankton has developed the pond is teeming with larvae ... that they are attracted by fertilized water and spawn before an algal bloom develops suggests that the primary stimulus for spawning ... could be the fertilizer. Mr. Beebe has had a wide experience of jungle-life in many lands, and hence his latest experiences in Brazil have the greater value ... Abundance of species and a relative fewness of individuals, he remarks, are pronounced characteristics of any tropical fauna ... He quickly discovered that more was to be obtained by watching particular trees ... [D]uring the space of a week of intermittent watching he obtained no fewer than seventy-six new species ... Just before leaving a brilliant idea struck Mr. Beebe ... he suddenly bethought him to fill a bag with four square feet of jungle earth, and this was examined ... while on board ship on the voyage home ... Among the captures thus made were representatives of two genera of ants new to science. There can be no doubt that important discoveries ... would accrue if this example of Mr Beebe's were generally followed in the future.
Bernadochi L.C.,Fisheries Institute |
Alves J.L.,Cocanha Beach Fishermen and Mariculturist Association MAPEC |
Marques H.L.A.,Fisheries Institute
Aquaculture Research | Year: 2016
In Southeastern Brazil, there is good cultivation potential for the pearl oyster Pinctada imbricata, which is often found on mussel ropes or seed collectors across the north coast of Sao Paulo State. Despite this, very few studies have focused on the biology of this species in Brazil. This research aimed to partially address this lack of information by evaluating the optimal season and preferred depth range (surface, first and second metres of depth) for the settlement of juvenile P. imbricata on artificial collectors. Two replicate artificial collectors made from braided fishing nets and comprising of horizontally and vertically suspended lines were deployed at Cocanha Beach, Brazil, and left in situ for a period of 5 months. At the end of the deployment period, the density of juveniles was significantly greater on the surface than the first and second metres of depth. It was also found that the period from November to March was more favourable for the placement of collectors and settlement of juveniles. Furthermore the results of the study confirm that is feasible to capture juvenile P. imbricata using artificial collectors to provide a continuous supply of commercial cultures. © 2016 John Wiley & Sons Ltd.
Furlan N.,Fisheries Institute |
Esteves K.E.,Institute Pesca |
Quinaglia G.A.,Companhia Ambiental do Estado de Sao Paulo CETESB
Environmental Biology of Fishes | Year: 2013
The rivers and streams of the large urban centers in Southeast Brazil are increasingly being degraded, demanding expanded conservation efforts. This study was conducted in the Grande River, one of the main tributaries of the Billings Complex, a reservoir that is a strategic fresh water resource for the São Paulo metropolitan region. Water quality, habitat features and fish fauna were investigated at seven sites along the longitudinal gradient with the aim of identifying the distribution patterns and relative contributions of the environmental factors. The water samples and environmental characteristics were recorded, and fish were collected during the rainy (January to March) and dry seasons (July and August) of 2009. The water quality varied along the river, with higher values of conductivity, fecal coliforms and total phosphorus in the lower reach, indicating a strong influence of the urban area. Twenty-two fish species were recorded, two of which are considered endangered. A canonical correspondence analysis (CCA) indicated marked differences in species composition between the river's upper and lower reaches, which was mainly attributed to vegetation cover and the presence of different meso-habitats, such as riffles and pools. Trychomycterus spp. and Astyanax paranae were associated with the upper reaches, while Astyanax fasciatus and Astyanax bockmanni, Cyphocharax modestus, Hoplias malabaricus and Hypostomus ancistroides occurred in the lower reaches. Despite the disturbance in water quality and riparian vegetation in the lower river section, no detectable changes in community structure were observed. However, the presence of some tolerant species, such as Astyanax fasciatus, Hoplosternum littorale and Hypostomus ancistroides, may indicate that the community is experiencing initial stages of disturbance. © 2012 Springer Science+Business Media B.V.
dos Santos F.B.,Fisheries Institute |
Esteves K.E.,Fisheries Institute APTA
Environmental Management | Year: 2015
A multimetric, fish-based Index of Biotic Integrity (IBI) was developed and tested to assess the ecological status of streams with different riparian conditions in the Piracicaba River Basin. Nine streams with three categories of riparian zone preservation were selected: native forest (NF) with preserved forest, secondary forest (SF) with forest in an advanced state of regeneration and surrounded by sugarcane plantations, and sugarcane (SC) without riparian vegetation and surrounded by SC crops. A continuous scoring system was employed, and candidate metrics were tested for range, responsiveness, and redundancy, resulting in the selection of eight metrics to compose the index. The final IBI score was positively correlated with an Environmental Index both in the dry (Spearman’s rho = 0.76; P = 0.01) and rainy seasons (Spearman’s rho = 0.66; P = 0.04), suggesting that this IBI is a suitable tool for the assessment of the biological conditions of these streams. The highest IBI values were observed in the rainy season at the NF and SF sites, with significant differences between the NF and SC sites (Kruskal–Wallis test: P = 0.03). The results indicated some variability in the biological integrity at SF and SC sites, suggesting a relationship with the intensity of the management of this crop. Patterns were consistent with other studies that have shown the effects of agriculture on the environmental quality of streams, which indicate the importance of the riparian zone to the maintenance of ecosystem integrity and supports the use of the IBI for biological monitoring in similar regions. © 2015, Springer Science+Business Media New York.