4,082 research outputs found
Population structure, effort and dye yielding of the snail Plicopurpura pansa (Gould, 1853) in the Mexican Pacific [Estructura de la población, esfuerzo y rendimeinto de tinte del caracol Plicopurpura pansa (Gould, 1853) en el Pacífico mexicano]
No full textThe purple snail (Plicopurpura pansa) is a conspicuous rocky-shore species in the tidal zone of the American tropical Pacific. It is considered a potential resource because of the dye it produces. In the 1980s the snail underwent exploitation in the Pacific coast of Mexico. Samples in 12 rocky shores of the Baja California Sur, Jalisco and Oaxaca states, and the Socorro Island were made, finding a sexual ratio near to 1:1, densities ranging from 0.47 to 1.24 snails m-2 and a relation between dye yield and specimens' length. By interviews with the Mixteco people in Oaxaca and milking of the snails over cotton skeins, dye yield was calculated as 2.5 liters of dye per week/fisherman or 2.2 skeins per week/fisherman
Lawesson J.E., 1995 -Studies of woody flora and vegetation in Senegal.
No full textLebigre Jean-Michel. Lawesson J.E., 1995 -Studies of woody flora and vegetation in Senegal.. In: Cahiers d'outre-mer. N° 201 - 51e année, Janvier-mars 1998. pp. 109-110
Population structure, effort and dye yielding of the snail Plicopurpura pansa (Gould, 1853) in the Mexican Pacific [Estructura de la población, esfuerzo y rendimeinto de tinte del caracol Plicopurpura pansa (Gould, 1853) en el Pacífico mexicano]
No full textThe purple snail (Plicopurpura pansa) is a conspicuous rocky-shore species in the tidal zone of the American tropical Pacific. It is considered a potential resource because of the dye it produces. In the 1980s the snail underwent exploitation in the Pacific coast of Mexico. Samples in 12 rocky shores of the Baja California Sur, Jalisco and Oaxaca states, and the Socorro Island were made, finding a sexual ratio near to 1:1, densities ranging from 0.47 to 1.24 snails m-2 and a relation between dye yield and specimens' length. By interviews with the Mixteco people in Oaxaca and milking of the snails over cotton skeins, dye yield was calculated as 2.5 liters of dye per week/fisherman or 2.2 skeins per week/fisherman
Lawesson J.E., 1995 -Studies of woody flora and vegetation in Senegal.
No full textLebigre Jean-Michel. Lawesson J.E., 1995 -Studies of woody flora and vegetation in Senegal.. In: Cahiers d'outre-mer. N° 201 - 51e année, Janvier-mars 1998. pp. 109-110
Effect of repetitive dye extraction over yield and survival rate of the purple snail Plicopurpura Pansa(Gould, 1853)
No full textThe purple snail is an important economic species because of the dye obtained from it in western Mexico. This dye has been used since ancient times to color ceremonial dresses purple. Other snails produce dye, but Plicopurpura pansa dye extraction was done without killing the snail. Repetitive dye extraction is possible. The best time between each milking, dye yield versus milking frequency, and effect on survival was determined by repetitive milking snail groups several times (7, 14, 21, and 28 days). Mortality in the most frequently milked groups and dye yield reduction occurred (every 7 and 14 days). When milking frequency occurred every 21 days, the best dye yield and 100% survival rate was observed. These results suggest wild populations can be exploited using optimum extraction schedules, leaving at least 21 days between each dye extraction
Strategies for sustainable dye harvest of the purple conch Plicopurpura pansa (Gould, 1853) from west central Mexico
No full textThe purple conch, Plicopurpura pansa, occurs on rocky shores of the tropical eastern Pacific of North and Central America, ranging from Magdalena Bay, Baja California to Colombia. When disturbed, it exudes a secretion that photo-oxidizes to an intense purple hue. This product has been used as a dye for ceremonial dresses. Unlike the case in other dye-producing molluscs, it is not necessary to sacrifice individuals to obtain the dye, allowing repetitive "milking" of the same animal without causing mortality. Evaluation of population parameters, rates of dye produced as a function of age at first milking, and milking frequency allowed us to simulate different exploitation scenarios and to evaluate strategies to determine the most profitable exploitation intensity and optimum milking frequencies. Laboratory experiments and field data showed that mortality occurs when the interval between milking is lower than 21 days. The most profitable exploitation strategies suggest that up to 310 L of dye in 50 km of shoreline length can be harvested during the three-month milking season. This volume of dye is sufficient to stain up to 260 skeins of cotton thread. Simulations showed that the stocks can withstand sustainable exploitation along their distribution range, allowing commercial exploitation of the dye produced by stocks of purple conch in other areas apart from those where it currently takes place, benefiting other groups of fishers elsewhere and ensuring the conservation of this tradition
Strategies for sustainable dye harvest of the purple conch Plicopurpura pansa (Gould, 1853) from west central Mexico
No full textThe purple conch, Plicopurpura pansa, occurs on rocky shores of the tropical eastern Pacific of North and Central America, ranging from Magdalena Bay, Baja California to Colombia. When disturbed, it exudes a secretion that photo-oxidizes to an intense purple hue. This product has been used as a dye for ceremonial dresses. Unlike the case in other dye-producing molluscs, it is not necessary to sacrifice individuals to obtain the dye, allowing repetitive "milking" of the same animal without causing mortality. Evaluation of population parameters, rates of dye produced as a function of age at first milking, and milking frequency allowed us to simulate different exploitation scenarios and to evaluate strategies to determine the most profitable exploitation intensity and optimum milking frequencies. Laboratory experiments and field data showed that mortality occurs when the interval between milking is lower than 21 days. The most profitable exploitation strategies suggest that up to 310 L of dye in 50 km of shoreline length can be harvested during the three-month milking season. This volume of dye is sufficient to stain up to 260 skeins of cotton thread. Simulations showed that the stocks can withstand sustainable exploitation along their distribution range, allowing commercial exploitation of the dye produced by stocks of purple conch in other areas apart from those where it currently takes place, benefiting other groups of fishers elsewhere and ensuring the conservation of this tradition
Effect of repetitive dye extraction over yield and survival rate of the purple snail Plicopurpura Pansa(Gould, 1853)
No full textThe purple snail is an important economic species because of the dye obtained from it in western Mexico. This dye has been used since ancient times to color ceremonial dresses purple. Other snails produce dye, but Plicopurpura pansa dye extraction was done without killing the snail. Repetitive dye extraction is possible. The best time between each milking, dye yield versus milking frequency, and effect on survival was determined by repetitive milking snail groups several times (7, 14, 21, and 28 days). Mortality in the most frequently milked groups and dye yield reduction occurred (every 7 and 14 days). When milking frequency occurred every 21 days, the best dye yield and 100% survival rate was observed. These results suggest wild populations can be exploited using optimum extraction schedules, leaving at least 21 days between each dye extraction
Population structure and accompanying biota of the snail Turbo (Callopoma) funiculosus (Gastropoda: Turbinidae), on Socorro Island, Revillagigedo Archipelago, Mexico
No full textThe porcelain snail, Turbo funiculosus, is a potential fishery resource that almost has not been studied or used commercially. In March of 1992, we sampled T. funiculosus in Bah�a Binners and Bah�a Blanca, Socorro Island, Revillagigedo Archipelago, using 25 m2 quadrants. We found that total length varies between 3.0 and 85 mm, proportional weight between 3.0 and 228 g, and density between 6.21 and 9.87 ind/m2. The largest organisms (over 50 mm) contain 30.6 % of soft parts. Porcelain snail populations remain unexploited on Revillagedo Archipelago and could be a potential resource under an adequate management strategy
Bagnis, B. ; Mazellier, P. ; Bennett, J. et Christian, E. — Poissons de Polynésie, avec la collaboration de A. Cea Egana, J. Dubois et J.E. Bandall. Papeete, Les Éditions du Pacifique et Paris, Albin Michel, 1974
No full textBourlière François. Bagnis, B. ; Mazellier, P. ; Bennett, J. et Christian, E. — Poissons de Polynésie, avec la collaboration de A. Cea Egana, J. Dubois et J.E. Bandall. Papeete, Les Éditions du Pacifique et Paris, Albin Michel, 1974. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 28, n°3, 1974. p. 477
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