Age of spent Octopus vulgaris and stress mark analysis using beaks of wild individuals

Abstract

Age estimation of the cephalopod Octopus vulgaris by using beaks has improved in recent years, but maximum age and longevity in the wild have not been confirmed due to the low availability of senescent wild octopuses. In this study, a beak analysis of lateral wall surfaces (LWS) from 20 spent specimens confirmed the one-year lifecycle of the species in Central East Atlantic waters. Stress marks (checks) were clearly located in the daily increment sequence of rostrum sagittal sections (RSS). The highest daily variations in sea surface temperature (ΔT) that occurred during the last months of their lifetimes coincided with the locations of the marks on the beak, enabling confirmation of O. vulgaris beaks as life recorders for the first time. It also supports the daily deposition of RSS beak increments in the wild. Individuals were grouped into two main zones, at 20ºN and 18ºN respectively. Both groups showed different thermal check patterns, in accordance with the oceanographic differences. Two other checks (not coinciding with high values of ΔT) were observed in RSS at averages of 15 and 28 days before death, respectively, which were interpreted as responding to senescent-related events.

Cephalopod beak sections used to trace mercury levels throughout the life of cephalopods: The giant warty squid Moroteuthopsis longimana as a case study

“…Cephalopod beaks grow throughout the life of the individuals without replacement. The rostrum is the first region to be formed with the lateral wall, crest and hood growing continuously by the addition of new beak material (Perales-Raya et al, 2010, 2014a, 2014bQueirós et al, 2018). Mercury bioaccumulates in organisms, increasing from early life-stages to adults (Jakimska et al, 2011).…”

Interactive Governance for Small-Scale Fisheries

“…high individual variability in increases in length or weight), a short lifespan, and a high sensitivity to environmental infl uences (Alford and Jackson 1993 ;Sobrino et al 2002 ;Otero et al 2008 ;Pierce et al 2010 ;Sonderblohm et al 2014 ). Age estimates for the eastern Atlantic demonstrate that octopuses live for 1-2 years (Domain et al 2000 ;Perales-Raya et al 2014 ) and annual abundance of the resource depends on the level of survival of the pelagic paralarvae, which in turn is strongly related to environmental conditions, such as upwelling intensity, temperature and the input of fresh water (Otero et al 2008 ;Sonderblohm et al 2014 ). Aside from the high fl uctuations in abundance due to environmental factors, the fact that octopuses are terminal breeders and have nonoverlapping generations also has implications for fi sheries.…”

Stock identification of neon flying squid (<em>Ommastrephes bartramii</em>) in the North Pacific Ocean on the basis of beak and statolith morphology

“…They are also used in studies of species identification (Clarke 1978, Dommergues et al 2000, Lombarte et al2006, age estimation (Villanueva 1992, Sánchez 1995, Arkhipkin and Shcherbich 2012, growth pattern (Yatsu 2000, Yatsu et al 1997) and trace elements (such as strontium) (Durholtz et al 1997, Ikeda et al 1996, Yatsu et al 1998b) to determine life history and relevant environmental conditions. As the main feeding organ, the beak can be easily preserved, and is non-corroding, so it has been used in the studies of chemical structure (Miserez et al 2010), aging and growth (Yatsu et al 1997, Raya and Hernández-González 1998, Yatsu and Mori 2000, Raya et al 2010, Castanhari and Tomás 2012, Perales-Raya et al 2014, species identification (Smale et al 1993), biomass estimation (Lu and Ickeringill 2002), trophic dynamics Hobson 2005, Cherel et al 2009) and paralarval ontogeny (Uchikawa et al 2009). …”