An integrated rearing system for Cantareus aspersus under environmental conditions in an experimental orchard is proposed. In this study, the natural behaviour, circadian rhythms and suitable rearing conditions of the edible snail were optimised to produce homogeneous growth and low variability. The growth was standardised, and growth pattern fit was assessed with various models. One thousand fry were cultured in the orchard, and a random sample of 100 snails were measured weekly for 23 weeks. The rearing system had the following characteristics: snails and earthworms were included in the experimental rearing orchard; a homogeneous group of juvenile snails of the same age and size and high rearing density (500 snails/m2) was used; snails were fed with layers mash ad libitum; and mixed and fringes vegetation was planted in the orchard. A commercial size of 60% of snails was achieved in 21 weeks and 95% in 23 weeks. The different models showed a good fit, and the quadratic model obtained the best fit. This experimental snail orchard proposal can be extended to other areas, although it must be corrected according to different environmental conditions and fit to other species of interest. This experimental model could constitute a viable alternative to traditional models of animal experimentation with mammals, and given its high adaptability, it could be applied in different fields of science.

RESUMENLos periodos de estivación e hibernación del caracol son periodos críticos de en la producción helicícola y su conocimiento contribuye decisivamente a la organización productiva y los resultados económicos de las granjas. El objetivo de este estudio fue determinar la evolución del peso vivo y la viabilidad del caracol terrestre (Cantareus aspersus), en condiciones semicontroladas durante el periodo de reposo. La experiencia tuvo una duración de 32 semanas, desde septiembre de 2013 hasta mayo del 2014. Los resultados obtenidos muestran una disminución del peso vivo del 13,57 % y una perdida de la viabilidad en torno al 20 %. Este estudio abre nuevas líneas de investigación orientadas al conocimiento de la fase de hibernación de los caracoles que manejados adecuadamente permite establecer distintas estrategias reproductivas y de manejo en la producción industrial del caracol terrestre C. aspersus. Viability of land snail (Cantareus aspersus) during resting period SUMMARYA estivation and hibernation periods of the snail are critical in the farms performance, the knowledge about this contributes to productive organization and performances. The aim of this study was to determinate the evolution for life weight and feasibility of land snail in semicontrolled conditions during a resting period of 32 weeks (September 2013 to May 2014). The results showed a decreasing of life weight in 13.57 % and a losing of feasibility around 20 %. This study opens new research lines oriented to the knowledge of snail hibernation period, which with an adequate management is possible to develop.

Meier and Zupan proved that an orientable surface [Formula: see text] in [Formula: see text] admits a tri-plane diagram with zero crossings if and only if [Formula: see text] is unknotted, so that the crossing number of [Formula: see text] is zero. We determine the minimal crossing numbers of nonorientable unknotted surfaces in [Formula: see text], proving that [Formula: see text], where [Formula: see text] denotes the connected sum of [Formula: see text] unknotted projective planes with normal Euler number [Formula: see text] and [Formula: see text] unknotted projective planes with normal Euler number [Formula: see text]. In addition, we convert Yoshikawa’s table of knotted surface ch-diagrams to tri-plane diagrams, finding the minimal bridge number for each surface in the table and providing upper bounds for the crossing numbers.