Age and growth estimation of Southern Ocean squid Moroteuthopsis longimana: can we use beaks collected from predators’ stomachs?
| Autor: | José P. Queirós, Aurora Bartolomé, Uwe Piatkowski, José C. Xavier, Catalina Perales-Raya |
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| Přispěvatelé: | Perales-Raya, Catalina |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
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| Popis: | Los datos puros del artículo pueden consultarse en el siguiente enlace: https://doi.org/10.5281/zenodo.7351679. Squid play a major role in the Southern Ocean food web. However, their age and growth remain poorly studied. Here, using upper and lower beaks of Moroteuthopsis longimana collected from the diet of Dissostichus mawsoni from Pacific and Atlantic sectors of the Southern Ocean, we studied: (1) Feasibility of using beaks collected from predators’ stomachs to study the age of Southern Ocean oceanic squid; and (2) Age estimation and growth patterns of M. longimana. The rostrum sagittal section (RSS) of both beaks had micro-increments, with the lower beak being the best to observe and count a readable sequence of increments to estimate the age. Assuming a daily deposition of increments, our results suggest that M. longimana can live up to 820 days and may hatch throughout the year. Studied individuals presented a consistent growth rate from hatching to death but with, at least, one period of faster growth. A novel pattern of regular cycles, composed of 7–10 lighter increments followed by a darker one, was found in the medium-anterior region of the RSS. Differences were found in the growth rate and size reached at the same age between individuals from the Pacific and Atlantic sectors, which might be related with different environmental conditions between both capture sites. This study shows that lower beaks from predators’ stomachs can be used to study the age of Southern Ocean squids and that M. longimana hatches in all seasons, being available year round to predators that feed of this species. Open access funding provided by FCT|FCCN (b-on). This work was supported by the strategic program of Marine and Environmental Sciences Centre (MARE), financed by the FCT (UIDB/704292/2020). JPQ was supported by a FCT/MCTES through national funds (PIDDAC) and Portuguese Polar Program (PROPOLAR) and by FCT PhD scholarship co-financed by FSE (SFRH/BD/144320/2019). |
| Databáze: | OpenAIRE |
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