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Copyright of Caldasia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

According to classical sources Barcelona was known as an oyster (Ostrea edulis Linnaeus 1758) harvesting point from Roman times onwards. Still, as of this writing, archaeomalacological studies from historical periods in the city are nearly absent. In this paper we present the analysis of archaeomalacological remains recovered from different rescue excavations on the outer side of the Roman walls of Barcelona, in particular between towers 27 and 28, along present day Sotstinent Navarro Street. The excavated area essentially corresponds with a space that in medieval times was occupied by buildings that were attached to the defensive wall, where domestic remains were found. Our results suggest that consumption was primarily focused on the edible oyster, showing a continuation of the ancient tradition into later phases. A few thorny oysters (Spondylus gaederopus Linnaeus 1758) and other bivalves (Glycymeris spp.) which might not have been necessarily consumed, were also trieved. Marine gastropods are scarce, with the exception of some murex snails. This is the first time that an archaeomalacological study addresses marine mollusc consumption in Barcelona during historical times. [ABSTRACT FROM AUTHOR]

This work presents the results of the archaeomalacological study of an archaeological intervention carried out in the Parque de las Acacias of Algeciras (Cádiz province, Spain) during 2015, which allowed exhuming part of one of the salting factories in the industrial area of the Roman city of Iulia Traducta, with different contexts dated between advanced moments of the 2nd and the 5th c. A.D. well dated stratigraphically, and with an extensive ceramic and numismatic record. Among the various taxa of marine bivalves and gastropods, the high presence of "corrucos" (Acanthocardia tuberculata) stands out, a type of large bivalve that has a unique extraction system, characterized by a perforation in one of the leaflets. Oysters (Ostrea edulis) with evidence of artificial breeding and limpets abound, and a possible buccinum on a shell with an intentionally fractured apex (Charonia lampas) has been documented. The main interest of this work lies in checking the evolution of the exploitation of malacological resources in a production area specialized in the maritime economy for a long period, and the confirmation of the use of these marine resources in the manufacture of canned seafood, since they have been documented as discarded remains in depositional strata in these fish-salting plants, adding to the already known findings of the nearby cetariae of San Nicolás st. at Algeciras. [ABSTRACT FROM AUTHOR]

The oysters are sessile and filter-feeding bivalves, commonly used as biomonitors of toxic compounds. The ranges of concentrations of copper and zinc of the soft tissues of Crassostrea gigas from two cultivation farms located in northern Sinaloa (El Colorado, Ahome and La Pitaya, Guasave). During the rainy and dry season in 2005 were 0.73-204.38 and 102.38-622.62 μg/g (dry weight), respectively. The concentration of metals was different between seasons and farms due to diverse contributions at each site. In both farms the order of accumulation of metals was Zn>Cu, presenting the highest values in rainy season. According to the international sanitary standards, the levels of Cu in oysters of both farms surpassed the permissible levels, so that the consumption of oysters coming from the two farms represent a risk for human health. The present work becomes relevant for the information obtained compared to that reported over time for such metals in the sites of studied cultivation. [ABSTRACT FROM AUTHOR]

In order to study the growth of nine Tithonia diversifolia materials, collected in central-eastern Cuba, an experiment was conducted using a completely randomized design, with ten replicates and under rainfed conditions. The indicators height of the plant (cm), number of leaves and branches, diameter of the stem (mm) and monitoring of pests and diseases were determined. All were taken every fortnight, for 12 weeks. The multivariate analysis showed that in the rainy season 89.41% of the variability was explained, and in the dry 95.58%. The variables of greatest preponderance in the rain were height, number of leaves and branches, and diameter of the stem, in the dry the height of the plant was emphasized, number of branches and diameter of the stem in the first component and in the other number of leaves all in positive relation. During the rain, materials 1, 5, 6 and 7 presented slow recovery after the cut and started with positive values from the fourth sampling. While 3, 8 and 9 do so markedly from the third sampling, the rest more paused. In dry, the structure indicator reached the highest values with materials 8 and 9 followed by 3, 4 and 5, and the minor ones 1 and 6. For the leaf indicator, the same behavior was observed. All materials reached negative values after the fifth sampling. It is concluded that the materials that exhibit more stable growth both in the rainy season and in dry season are 3, 8 and 9, and lower 1 and 6. It is recommended to develop other works with them in order to evaluate their growth curve. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Disease control problems have major constraints in aquaculture production, and the use of probiotics in larviculture is a valid alternative to antibiotics. This study analyzed the effect of probiotic bacteria on survival and final size of Cortez oyster larvae Crassostrea corteziensis. Two different probiotic concentrations were evaluated, 1x104 and 1x105CFU/ml of Lactic acid bacteria (strain NS61) isolated from Nodipecten subnodosus, and bacilli isolated from the white leg shrimp, Litopenaeus vannamei (Pseudomonas aeruginosa, strain YC58) and C. corteziensis (Burkholderia cepacia, strain Y021). Bacteria were added directly into culture tanks, starting the bioassays from veliger to pediveliger stages as follows: (1) Control, without probiotics; (2) lactic acid bacteria (Lb); (3) bacilli mix (Mb) in a proportion 1:1. Results showed a higher larval survival with Lb and Mb at a dose of 1x104CFU/ml compared to the control group. Larvae exposed to Mb at 1x105CFU/ml showed higher survival than Lb and control. Larval final size was not significantly increased with the tested probiotics, but larvae treated with Lb at 1x105CFU/ml showed less survival rate than those treated at 1x104CFU/ml. This study showed the beneficial effect of these probiotics, added individually or mixed in C. corteziensis larvae culture. Rev. Biol. Trop. 59 (1): 183-191. Epub 2011 March 01. [ABSTRACT FROM AUTHOR]

The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II) in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson's solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7µm thick) and stained with Harris hematoxylin and Eosin (HE). Additionally, 30 oysters were sampled, at each point, for a condition index analysis. The water temperature ranged from 23.5°C to 30°C and the salinity from 15 to 25 ups at Point I (Maraú) and from 25 to 35 at Point II (Tanque Island). The oyster's height ranged from 30 to 92mm at Point I and from 27 to 102mm at Point II, with an average of 49.0mm±9.1 (n=230) and 49.9mm±9.9 (n=237), respectively. Among the sampled oysters at Point I, 59.1% were females, 31.3% males, 1.3% hermaphrodites and 8.2% of the oysters of undetermined sex. At Point II, 66.2% were females, 30.4% males, 0.8% hermaphrodites and 2.5% (n=237) of undetermined sex. The gonadic stage analysis indicated that the reproduction period of the C. rhizophorae in the Maraú Peninsula was continuous all year, without any regressive phase. The condition index (R) ranged from 8.0% to 17.7%. The peak periods of R coincided with the expressive oyster's percentage in the maturation and liberation gametic stages. The results of these findings will contribute information for the oyster spat collection and to the process installation of the oyster culture in Camamu Bay. Rev. Biol. Trop. 59 (1): 137-149. Epub 2011 March 01. [ABSTRACT FROM AUTHOR]

Para evaluar la variabilidad genética de los ostiones suministrados por el Centro Reproductor de Especies Marinas del Estado de Sonora, se analizaron loci alozímicos en Crassostrea gigas triploide (n = 78) y la F1 de un nuevo lote de ostión nativo Crassostrea corteziensis (n = 78). En la muestra de C. gigas se analizaron 10 sistemas enzimáticos que revelaron 16 loci, de los cuales 12 fueron polimórficos. Para C. corteziensis, 9 sistemas enzimáticos revelaron 13 loci, de los cuales 8 fueron polmórficos. Los promedios de la heterocigosis esperada y observada para C. gigas fueron de 0.350 y 0.309, respectivamente, sin diferencias significativas entre ellos. Estos niveles son similares a los reportados para organismos silvestres diploides pero menores a los reportados para organismos triploides. Los promedios de la heterocigosis esperada y observada para C. corteziensis fueron de 0.294 y 0.065, con diferencias significativas (P = 0.001). El análisis de las frecuencias fenotípicas de los 12 loci polimórficos en C.gigas demostró que sólo 3 loci (AKP*, EST-2 y PEP-1*) estuvieron en equilibrio de Hardy- Weinberg, con una endogamia promedio de 0.133. Para C. corteziensis, los 8 loci polimórficos estuvieron fuera del equilibrio de Hardy-Weinberg y reflejaron una alta endogamia de 0.777 debido a una gran deficiencia de heterocigotos en todos los loci, sugiriendo que el pie de cría fuente está genéticamente erosionado. Si la variabilidad genética no se considera en la selección del pie de cría, el cultivo de ostión en el noroeste de México será inestable. Se recomienda un programa de selección de un linaje diploide de C.gigas que posea una buena variabilidad genética y un buen nivel de heterocigosis, además de seleccionar las poblaciones silvestres de C. corteziensis con el menor índice de endogamia con el fin de obtener un pie de cría genéticamente saludable. [ABSTRACT FROM AUTHOR]

The presence of boring polychaetes of the family Spionidae in the lagoon of Barra de Navidad, Jalisco, constitutes a risk for any oyster commercial farm since they might reduce the quality of the final product. From February to May 2006, 2000 Crassostrea gigas oysters (initial length and weight of 11.25 ± 1.55 mm and 0.2023 ± 0.07 g, respectively) were reared in the lagoon. The percentage of infestation and total number of spionids (intensity) extracted from the valves were measured weekly. In addition, oyster growth and water quality were recorded and their relation with the number of polychaete was analyzed. The infestation started at the seventh culture week (March), and the initial percentage of infestation was high (60%) and increased up to 100 % from the tenth week. The intensity increased gradually up to a mean number of 8.7 polychaetes per host shell in the last week. There was a statistically significant relationship (p<0.05) between the intensity and the dissolved oxygen (r=0.7453), and between the intensity and the total length of the oyster (r=0.9206). The results show that mudworm initial settling is rapid. Possible causes for the mudworm presence in the culture site are discussed. [ABSTRACT FROM AUTHOR]

Specimens of Crassostrea angulata were exposed to sublethal copper concentrations (200 and 600 μg L-1 Cu2+) during 2 to 30 days. The accumulation of copper and histopathological effects on the gills, digestive gland and heart were studied. The highest copper concentrations were found in the gills, with values over 2 mg g-1 dry weight for organisms exposed to the highest concentration at the end of the exposure period (day 30). In the digestive gland, the concentration was 1 mg g-1 dry weight (highest exposure on day 30). The rate of bioconcentration (BCr, defined as the concentration in the tissue at an exposure concentration at time t minus the mean concentration of the control throughout the experiment, divided by the exposure time) decreased in both tissues. The values ranged from 392 to 57 μg g-1 day-1 for gills and from 133 to 18 μg g-1 d-1 for the digestive gland. In the gills, specimens exposed to 200 μg L-1 Cu2+ showed disorganization and apical alterations of the cilia cells and hyperplasia, lamellar fusion and lamellar loss in organisms exposed to 600 μg L-1 Cu2+. In the digestive gland, specimens exposed to 200 μg L-1 Cu2+ showed hemocytic infiltration in the underlying connective tissue and numerous brown cells compared to the control specimens. On the other hand, thinning of the epithelium of the digestive tubules, occlusion in the lumen of some primary tubules and dilation of the digestive ducts occurred in organisms exposed to 600 μg L-1 Cu2+. The heart of oysters exposed to copper showed thinning of the epithelium of the auricles and ventricle and an increase in brown cells on the walls of the auricles, as well as connective tissue destruction in the auricles and ventricle [ABSTRACT FROM AUTHOR]

Discusses a study that investigated the growth and mortality of the rock oyster, Crassostrea iridescens, at San Ignacio, Sinaloa, Mexico. Comparison of the survival rate in the natural beds and in controlled production system; Assessment of the annual natural mortality rate of the oyster; Length-weight relationship of rock oysters.