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- Preliminary results on light conditions manipulation in Octopus vulgaris (Cuvier, 1797) paralarval rearingPublication . Garrido, Diego; Reis, Diana; Orol, Diego; Gonçalves, Rui A.; Martín, M.; Sykes, António V.; Rodríguez, Covadonga; Felipe, Beatriz; Zheng, Xiaodong; Lagos, Luis; Almansa, EduardoHigh paralarvae mortality is a major bottleneck currently hindering the control over the lifecycle of common octopus (Octopus vulgaris Cuvier, 1797). It is believed that this problem might be related to either zoo-technical and/or nutritional aspects. The present paper is focused on the study of different zoo-technical aspects related to light conditions on the rearing of paralarvae, including the effects of polarization in prey ingestion, the use of a blue filter to simulate natural conditions, and the use of focused light to avoid reflections of the rearing tank’s walls. In the first experiment, O. vulgaris paralarvae ingestion of Artemia sp. and copepods (Tisbe sp.) was assessed under either normal or polarized light. In the second experiment, the effect of a blue filter with natural light or focused artificial light on growth and mortality was assessed over 15 days of rearing. Ingestion rate was not influenced by light polarization. Nonetheless, a significantly higher ingestion of Artemia sp. with respect to copepods was observed. The blue filter promoted the use of natural light conditions in Octopus paralarval culture, while focused light reduced the collision of the paralarvae against the walls. However, no significant differences were found in paralarval growth nor survival.
- Characterization of deformed hatchlings of Octopus vulgaris obtained under captivity from a small femalePublication . Jiménez-Prada, Pablo; Scherbakova, Anastasia; Riera, Rodrigo; Felipe, Beatriz C.; Sykes, António V.; Gonçalves, Rui A.; Andrade, José Pedro; Perales-Raya, Catalina; Rodríguez, Covadonga; Almansa, EduardoThe common octopus (Octopus vulgaris), a promising species for aquaculture, spawns easily under cap-tivity from mature females (usually above 1 kg wet weight). Octopus juveniles and adults are collectedfrom nature to obtain eggs and paralarvae for aquaculture development trials. In July 2011, a very smallfemale (150 g wet weight but with an age estimation of 300 days-old) spawned almost 77,000 paralar-vae. Malformations of paralarvae were noticed in the first spawning days, namely the absence of arms.Despite not being lethal, these abnormalities might be derived from the physiological condition of thebreeding specimen (the female’s lower weight to the estimated amount of living days), which might beeventually related to nutritional unbalances or genetic parameters that were transferred to the eggs.