Potentially handicapped but otherwise functional: Malformations in prey capture tools show no impacts on octopus life

Larval mortality is a keystone ecological factor for many benthic octopus since it mostly occurs before their settlement in the sea bottom as benthic juveniles. The literature had revealed that records of adult animals with morphological abnormalities (teratologies) are fewer in species with complex life cycle than in those with direct development. This is a direct consequence of the morphological, physiological, and development challenges that the transition from the larval to the adult morphology represents. During a routine fishing sample, we found an immature female horned octopus with additional buccal structures in two suckers of its ventral arms, likely rendering these suckers as inefficient. Based on the literature about the natural history of octopus, we provide evidence that these abnormalities were present at the moment of hatch. We evaluated the impact of the teratologies by comparing the shape of the buccal beaks and the trophic niche of the individual with five normal conspecifics. Although the beaks showed a different shape than normal individuals, the trophic niche was similar. Surprisingly, the teratological condition of the individual likely had no severe impacts on its life, even though it likely represents a handicap for its survival during its planktonic life. We also comment on other previous records from the literature of teratological adult octopus to highlight the amazing adaptive capacity of octopus to deal with challenging morphologies.We are thankful for SAP crew (project Ref. ARP029/18/00003, Departament d'Agricultura, Ramaderia, Pesca i Alimentació, Generalitat de Catalunya) for granting the access to the samples. Elena Guerrero (ICM‐CSIC) performed the curation of the morphological vouchers under the CBR‐ICM. We thank Keith Browne (National University of Ireland Galway) for proofreading the text. We thank three anonymous reviewers for their helpful comments. F.Á.F.‐Á. was supported by an Irish Research Council—Government of Ireland Postdoctoral Fellowship Award (Ref. GOIPD/2019/460). MF was contracted within the framework of the project CLIFISH (CTM2015‐66400‐C3‐3‐R, MINECO/FEDER), funded by the Spanish Ministry of Economy and Competitiveness and by the European Regional Development Fund. JN was funded by the Spanish National Program Ramón y Cajal (RYC‐2015‐17809). RV has been supported by the Spanish Ministry of Science, Innovation and Universities (OCTOSET project, RTI2018‐097908‐B‐I00, MCIU/AEI/ FEDER, EU). This is a contribution to the Initiative AFOC (shape analysis of cephalopods' beaks; ICM‐CSIC).peer-reviewe