Dwellers in dens on sandy bottoms: Ecological and behavioural traits of Octopus vulgaris

• DOI: 10.3989/scimar.04071.28f
• Publication Date: 2014-07-30T11:36:39Z
• Authors: Ángel Guerra; Jorge Hernández-U...; Manuel E. Garci; Marta Sestelo; Marcos Regueira; Ángel F. González; Miguel Cabanellas...; Matías Calvo-Manazza; Beatriz Morales-Nin
• Keywords: octopus (software)

Four visual censuses targeting Octopus vulgaris living in dens on sandy bottoms were carried out from June to October 2013 the National Park of Atlantic Galician Islands (NW Spain). Censuses undertaken by scuba diving between 5 and 21 m depth daytime. The total area swept was 13.75 ha. There no significant differences octopus presence during open closed fishing seasons. Depth had a negative relationship with occupancy. average number per 1000 m2 3.84±0.84 3.89 October. den 260 m2. Den estimations varied 1586 2057. largest (76.5%) found 10 depth. distribution clumped. No size classes (small, medium large) diameter. Associate observed. diameter shell types around middens. Many could be “permanent”. Drilling bivalve behaviour is discussed. surveyed 1100 individuals, mainly small specimens. Substrate, type food abundance availability (especially razors Ensis arcuatus) seem main factors influencing density distribution. does not appear limiting factor this case. Temperature, availability, predators pressure are Rodas inlet may preferential habitat for O. individuals ranging 200 2000 g, but especially specimens ( ≤ g).