Cultivo de la lluenta (Callista chione)

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Larval growth and development of the smooth clam Callista chione (Mollusca: Bivalvia) under laboratory conditions

This study describes the first data on larval development and growth of the smooth clam Callista chione under two different temperature regimes (19 and 23 ºC). The mean diameter of the oocytes was 89.5 ± 0.7 micrometers. After seven days, the mean length of D-shaped larvae was 132.9 ± 7.8 micrometers at 19 ºC and 148.38 ± 12.74 micrometers at 23 ºC. Metamorphosis took place between days 32 and 39. Differences in length associated with different culture temperatures were statistically significant on days 11, 13, and 20. At 23 ºC, larvae reached a length of 175.15 micrometers within 11 days, whilst during the same period they reached 137.88 micrometers at 19 ºC (a difference in growth of 39%); however, survival rate was higher at 19 ºC (8%) than at 23 ºC (2%)

Boodstock conditioning and gonadal development of the smooth clam Callista chione (Linnaeus, 1758) (Mollusca: Bivalvia) on the Catalan coast (NE Spain)

In order to select the most suitable broodstock conditions for Callista chione a conditioning experiment was performed and the gametogenic cycle of a natural population on the coast of Arenys de Mar (Catalonia, NE Spain) was studied. The influence of food availability and sand bed presence on energy balance and gonadal development was analyzed and the proliferation of intracellular bacteria in gills was monitored. The gametogenic cycle started between August and September. In November most of the gonads were ripe and spawning began in December. The higher abundance of spawning clams was between January and April (with sea surface temperature 13-15ºC). Three experimental conditions were tested in September at a constant temperature of 14ºC: T1 (0.10% of organic weight of microalgae as a proportion of the live weight of the clams per day and a sand bed); T2 (0.05% and a sand bed); T3 (0.10% without a sand bed). Gonadal maturity was a priority for this species and was reached at the end of all trials. Food availability and sand bed presence benefit survival and gonadal development and the best results were obtained in clams from trial T1. Nevertheless, broodstock conditions seemed to trigger the proliferation of intracellular bacteria in gills, and as the experiment advanced, prevalence and intensity of infection increased for all trials reaching values of 100% and between 9-40 intracellular bacteria/pair of gill plica, respectively.Versión del edito

Growth and development of Callista chione (Linnaesu, 1758) larvae ina a hatchery system

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Delaying surgery for patients with a previous SARS-CoV-2 infection

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Head and neck cancer surgery during the COVID-19 pandemic: An international, multicenter, observational cohort study

Background: The aims of this study were to provide data on the safety of head and neck cancer surgery currently being undertaken during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This international, observational cohort study comprised 1137 consecutive patients with head and neck cancer undergoing primary surgery with curative intent in 26 countries. Factors associated with severe pulmonary complications in COVID-19–positive patients and infections in the surgical team were determined by univariate analysis. Results: Among the 1137 patients, the commonest sites were the oral cavity (38%) and the thyroid (21%). For oropharynx and larynx tumors, nonsurgical therapy was favored in most cases. There was evidence of surgical de-escalation of neck management and reconstruction. Overall 30-day mortality was 1.2%. Twenty-nine patients (3%) tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within 30 days of surgery; 13 of these patients (44.8%) developed severe respiratory complications, and 3.51 (10.3%) died. There were significant correlations with an advanced tumor stage and admission to critical care. Members of the surgical team tested positive within 30 days of surgery in 40 cases (3%). There were significant associations with operations in which the patients also tested positive for SARS-CoV-2 within 30 days, with a high community incidence of SARS-CoV-2, with screened patients, with oral tumor sites, and with tracheostomy. Conclusions: Head and neck cancer surgery in the COVID-19 era appears safe even when surgery is prolonged and complex. The overlap in COVID-19 between patients and members of the surgical team raises the suspicion of failures in cross-infection measures or the use of personal protective equipment. Lay Summary: Head and neck surgery is safe for patients during the coronavirus disease 2019 pandemic even when it is lengthy and complex. This is significant because concerns over patient safety raised in many guidelines appear not to be reflected by outcomes, even for those who have other serious illnesses or require complex reconstructions. Patients subjected to suboptimal or nonstandard treatments should be carefully followed up to optimize their cancer outcomes. The overlap between patients and surgeons testing positive for severe acute respiratory syndrome coronavirus 2 is notable and emphasizes the need for fastidious cross-infection controls and effective personal protective equipment