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Knowledge of recruitment to a fishery is particularly important in short-lived species, like most cephalopods, in which there is a complete turnover of individual every 1 or 2 years. In this study, age, body length, statolith length and growth rates of loliginid paralarvae (Alloteuthis media, A. subulata and Loligo vulgaris) were determined to evaluate the form of the growth curve and differences between species and hatching seasons. A total of 222 paralarvae collected in zooplankton samples along the Galician coast (NW Spain) were used to determine relationships between dorsal mantle length (DML), statolith length (SL) and the number of increments (NI)) deposited in the statolith. The paralarvae of L. vulgaris were between 1 and 35 days old, while both Alloteuthis species ranged in age from 1 to 54 days. Generalised additive models (GAMs) revealed non-linear growth in DML, with L. vulgaris exhibiting higher DML-at-age than Alloteuthis species. The best parametric model fit for these data was obtained using exponential regressions. The SL–NI relationship also differed between species, with L. vulgaris having larger statolith length at age. The paralarvae of L. vulgaris and A. media had two well-differentiated hatching peaks, one in late spring-early summer (beginning of the upwelling season) and another peak in late autumn (end of the upwelling season). Alloteuthis subulata had an earlier hatching peak in spring than in the other two loliginid species—and the second peak in autumn was barely visible, possibly because this species occurs further north in areas not sampled in autumn

We present the description of defensive behavior in wild Octopus vulgaris against conger eel (Conger conger) attacks based on three video sequences recorded by recreational SCUBA divers in the eastern Atlantic off the coast of Galicia (NW Spain) and in the Cantabrian Sea (NW Spain). These records document common traits in defensive behavior: (1) the octopuses enveloped the conger eel's head to obscure its view; (2) they covered the eel's gills in an attempt to suffocate it; (3) they released ink; (4) the octopuses lost some appendages because of the fight. In the third video, the octopus did not exhibit the defensive behavior described in the first two videos due to an inability to utilize its arms in defense, and the conger eel's success in capturing octopuses is discussed. Additionally, both the cost that the octopus could face by losing some arms during the fight and whether the experience it acquires can be an advantage for future encounters are analyzed. The defensive behavior exhibited by octopuses in this study highlights their ability to survive in a hostile environment and serves as an example of the extensive repertoire of anti-predator strategies employed by these cephalopods

This paper compiles the data regarding the first occurrence of Oithona davisae and O. atlantica in NW Spain, which is supported by morphological and molecular analysis. Additionally, we investigated the seasonal dynamics of the invasive O. davisae, revealing that its abundance is conditioned by upwelling-downwelling patterns in the Rías Baixas of Galicia. Temperature was the most correlated factor, with higher abundances in upwelling relaxation-downwelling events. More studies in long-term zooplankton dynamics and molecular analysis are needed to determine if O. davisae is displacing other native species of the same genus, such as O. atlantica, in Galician waters.

The common octopus, Octopus vulgaris Cuvier, 1797, is a meroplanktonic species with planktonic hatchlings and bentic juveniles and adults, which is found throughout the northeast and eastern central Atlantic Ocean, including central Atlantic islands and the Mediterranean Sea. [...]

This chapter describes past and present publication trends in octopus research following a systematic mapping approach. Publication rates in popular research topics such as life history and ecology are decreasing, while others are increasing and taking the spotlight. Interest in behaviour has seen a considerable uptick in recent years. Also, rapid advances, emerging tools, and widespread access to DNA sequence information have stimulated an increased focus on topics relating to genomics & evolution. Research related to diversity & bBiogeography is also increasing, especially in the context of the concurrent biodiversity and climate crises. Although global change represents the least studied topic to date, interest has increased tremendously over the past 5 years, with more than double the publication rate observed for behaviour (the topic with the second largest publication rate). Our analysis also provides a geographical perspective; the food and argriculture organization region with the most octopus-related studies is the Mediterranean, followed by the Northeast and Western-Central Atlantic Ocean. Regarding species of interest, Octopus vulgaris stands out as the overwhelming front-runner representing more than half of all records and over five times more than the second most studied species, Octopus maya. We also provide a discussion on future directions for key subjects, including behaviour and cognition, iEcology and citizen science, bio-robotics, deep-sea research, climate change, and culture and welfare, among others, with the hope of providing an agenda for future research

Our knowledge of the diet of wild octopus paralarvae, Octopus vulgaris, is restricted to the first 2 weeks of its planktonic phase when they are selective hunters found near the coastline. These small paralarvae, bearing only three suckers per arm, are transported by oceanic currents from the coast towards offshore waters, where they complete the planktonic phase over 2 months. Here, we have investigated the trophic ecology of O. vulgaris paralarvae in two contrasting upwelling sub-regions of the Iberian Canary current (ICC) eastern boundary upwelling system and have evaluated dietary change as paralarvae develop (inferred by counting the number of suckers per arm, ranging from three to 15) along the coastal-oceanic gradient during their planktonic phase. Using high-throughput amplicon sequencing, we have characterised the diet of 100 paralarvae collected along the Northwest Iberian Peninsula (n = 65, three to five suckers per arm) and off the west coast of Morocco (n = 35, three to 15 suckers per arm), identifying up to 87 different prey species. The diet of paralarvae varied along the ICC, with crabs (53.4%), siphonophores (12.2%), copepods (12.3%), cnidarians (8.4%) and pteropods (3.7%) accounting for 90% of the variability detected off NW Iberian Peninsula, whereas off W Morocco, crabs (46.2%), copepods (23.1%), cnidarians (12.9%), krill (9.3%) and fishes (4.2%) explained 95.6% of the variability observed using frequency of observance (FOO%) data. Ontogenetic changes in the diet based on groups of paralarvae with similar numbers per arm were evidenced by the decreasing contribution of coastal meroplankton and an increase in oceanic holoplankton, including siphonophores, copepods, pteropods and krill. Trophic niche breadth values ranged from 0.06 to 0.67, with averaged values ranging from 0.23 to 0.33 (generalist = 1 and specialist = 0), suggesting that O. vulgaris paralarvae are selective predators through their ontogenetic transition between coastal and oceanic

The European hake, one of the most commercially valuable species in ICES fishing areas, is considered an important neglected source of zoonotic risk by nematode parasites belonging to the genus Anisakis. Merluccius merluccius is, by far, the most important host of Anisakis spp. at the European fishing grounds, in terms of demographic infection values, and carries the highest parasite burden. These high parasite population densities within an individual fish host offer a chance to explore new sources of variations for the genetic structure of Anisakis spp. populations. A total of 873 Anisakis spp. third-stage larvae, originally sampled from viscera and muscular sections of hake collected at ten fishing grounds, were primarily identified using ITS rDNA region as molecular marker. After that, we used mtDNA cox2 gene to reveal the high haplotype diversity and the lack of genetic structure for A. simplex. Dominant haplotypes were shared among the different fishing areas and fish sections analyzed. Results indicate a clear connection of A. simplex from European hake along the Northern North Sea to the Portuguese coast, constituting a single genetic population but revealing a certain level of genetic sub-structuring on the Northwest coast of Scotland. This study also provides useful information to advance the understanding of parasite speciation to different fish host tissues or microenvironments

[Statement of the problem] Evidence of Anisakidae larvae in a high and rising number of fish species of commercial interest around the world has remarkably increased. The importance of fish infection by Anisakidae lies in their repercussion on seafood safety and quality, increasing awareness about anisakids as a re-emergent risk in fish-eating consumers. Parasite Biobank was implemented at the UTB-CSIC in 2013. Until now, it managed more than 100000 parasite samples (mainly Anisakidae) from almost 25000 extractions. Furthermore, during that period a BoB (EpiData, software Bio-o-Bank Vitro®) was generated, with all the traced information for any extraction and sample. Those data showed to be an invaluable asset for evaluating and monitoring the Anisakidae presence in fisheries and aquaculture systems, but also for other significant objectives, such as developing risk management tools. From 2018 to 2022, as part of several collaborative projects between CSIC and the Spanish Seafood industry, a technological support task was designed to develop new strategies for anisakid risk management. Fish industry operators made the inspection and banked the results. As data was the banked “golden” items, we developed a quality control process to ensure their quality and traceability, [Proposed solution] Data collection: Detection method is a key step. Operators evaluated the presence of zoonotic Anisakidae following the UV-Press inspection method, as described in ISO 23036-1:2021. Operators were trained at the UTB, which also provided mentoring, advising and technical assistance regarding the inspection process as well as the data traceability within the Biobank platform tool. Verification plan: In order to ensure that the inspection method was properly implemented according to ISO 23036-1:2021 standard, pressed portions of fish, randomly selected and previously inspected by operators, were sent to UTB (i.e. verifier), where they were re-examined by highly specialised laboratory staff., [Validation] As UTB act as verifier and their results were stablish as the “gold standard”, we designed an internal quality control to validate our own performance on the ISO 23036-1:2021., [Conclusion] Data quality is a measure of the condition of data based on factors such as accuracy, completeness, consistency and reliability. We (UTB-CSIC) developed a normalized protocol to routinely assess on these parameters of quality for banked data provided by registers (fish inspectors) during collection processes.

Fish are an important part of a healthy, well-balanced diet. They provide a good source of protein and vitamins and are a primary dietary source of heart-healthy omega-3 fatty acids. While eating fish has nutritional benefits, it also has potential risks. Fish can take in harmful biohazards from naturally exploited ecosystems and the food they eat. Regarding parasite hazards, there is plenty of scientific evidence related to the raised natural impact of marine parasites on the 3S stands for Fisheries: Security, Safety, and Sustainability. Many parasites, which occur in exploited ecosystems, could potentially overcome a hierarchical series of barriers to cause spillover effects on wild fish productivity and sustainability, and/or seafood consumer´s health. The conclusion behind an intensive decade of fish parasite monitoring at ICES fishing areas tell us about quality product rejection with significant economic losses along the fish-production value chain, serious parasite risk exposure for fish-eating consumers, unsustainable fishing practices on heavily-parasitized stocks still being considered, and an increased confused concern at the fish industry on how managing these challenges. The idea that parasite biodiversity may constitutes a threat to efficient ICES fish production value chains provokes a very real sound perspective of parasites being integrated within the fish holobiont paradigm, and as a part of the socioecological management system in any particular fishery. We provide data to argue that a parasite hazard warning system based on the 3S model (from net to plate), integrated in an adaptive co-management of fisheries, could be the best choice highlighted by the cost-effectiveness to prevent such socioecological potentially damaging impact of parasites to ICES fisheries. Overall, we propose a design for major parasite threats integrated in the One Health approach needed in ecosystem management practices

Cephalopods are a key component of the marine food webs. Nevertheless, the deep-sea cephalopods are still poorly studied worldwide. The distribution and composition of the mesopelagic cephalopod’s community in different deep scattering layers from the Canary Islands (North-eastern Atlantic) are described here. The results of a mesopelagic fishing survey (CETOBAPH) at the western slopes of three islands of the Canary archipelago (El Hierro, La Palma and Tenerife) are reported. A total of 3,717 specimens of 17 families were caught at different acoustic scattering layers previously detected in depth. The pelagic families Pyroteuthidae, Enoploteuthidae, Onychoteuthidae and Cranchiidae comprised 91% of the total cephalopod catch. Species belonging to these families were responsible for the differences found in the cephalopod community assembly between the shallow sound scattering layers, situated at night in the epipelagic zone and deep sound scattering layers in the mesopelagic zone. No differences were observed in the cephalopod community composition among the three sampled islands. The species richness among islands were similar with 32, 30 and 31 species collected for El Hierro, La Palma and Tenerife, respectively. These results suggest the existence of vertical but no horizontal segregation of small cephalopod species at the mesoscale level in the Canary Islands

We have used a certified Community Trade Mark (FPR Standard) to rank the exposure to the risk by the presence of anisakids in 1702 individuals of eight cephalopod species (Dosidicus gigas, Illex argentinus, Illex illecebrosus, Doriteuthis gahi, Octopus vulgaris, Sepia officinalis, Sepia pharaonis and Urotheuthis duvaucellii) from six different fishing grounds. Individuals vere examined to detect zoonotic nematodes by the UV-Press method, which has been proved as highly efficient for anisakids detection. Morphometric data, results of visual inspection for parasites, as well as the parasitation data were also obtained and results introduced in the Biobank platform of the IIM-CSIC. Demographic values of infection were also calculated. The method for determining the risk for anisakids was the scoring system approach, for the parasite predictive assessment of fish lots, and adapted to frozen samples and to cephalopods. Results were translated to the FPR Standard, which allows the classification of the cephalopod lots into five categories: poor, fair, good, very good and excellent. I. argentinus, I. illecebrosus, D. gahi and O. vulgaris gave a positive result for anisakid parasitation, althoug it was only visceral in D. gahi. Muscular parasitation was only detected in both Illex species and in O. vulgaris from NE Atlantic, but it has a very low prevalence. These cephalopod species reached the category of VERY GOOD in the FPR Standard. The other examined species reached the category of EXCELLENT, as no muscular parasitation was detected. Data showed that the risk due to zoonotic nematodes could be consider negligible in cephalopods

Prey identification in wild cephalopod paralarvae may be difficult by visual methods due to the ingestion of liquidised contents, while next-generation sequencing (NGS) can provide a better resolution. Molecular techniques such as NGS could be a good complementary approach to identify prey from family to species from the stomach content. This study shows for the first time the trophic interactions of Loligo vulgaris paralarvae in the western Iberian Peninsula. DNA from the dissected digestive system of 31 paralarvae was amplified with universal primers for mitochondrial cytochrome c oxidase subunit I gene (COI) and sequenced with the MiSeq platform. Overall, 130 Amplicon Sequencing Variants (ASV) were identified as prey (158,457 reads), being crustaceans the main prey accounting for 88.09% of the total reads, mainly represented by calanoids 73.22%, euphausiids 5.73%, and decapods 2.75%. Distance based linear model (DistLM) showed that the variables that most influenced the diet patterns were the spatial variables accounting for 46.92% of the total variation. In the southwest Galicia, the dominant prey were calanoids and euphausiids, while in the northern Galician coast the most important prey were siphonophores and myopsids. The prey of Portuguese paralarva could only be classified at phylum and class category identifying DNA of arthropods and hydrozoans. The results obtained in this study suggested that L. vulgaris paralarvae are generalist predators during their paralarval stage

Several old and recent collections of oceanic cephalopods collected during research surveys in Atlantic waters, were put together to improve our knowledge on the distribution of cephalopod species and the pelagic realm biodiversity in the Atlantic Ocean. Sampling area covers the Irving, Tyro and Atlantis seamounts south of the Azores Archipelago and the Gorringe Bank, Seine, Ampere and Josephine seamounts in the Madeira-Tore region, the oceanic waters between the Portuguese southern continental shelf and these seamounts and waters surrounding Cape Verde Islands. Samples from 1994 were taken with the German RV Poseidon under the research project Eurosquid II. Samples from 2015 and 2016 were taken by the Portuguese RV Noruega under the research project Biometore. Additional samples were taken with German research vessels in oceanic waters surrounding the Azores and the Cape Verde Archipelagos. Cephalopods of these collections were collected with a Pelagic Trawl and Isaacs-Kidd Midwater Trawl (IKMT) to sample mesopelagic and epipelagic adults and juveniles, and Bongo nets to sample paralarvae in the upper 200 m. The early life stages of many cephalopod species are virtually unknown, which makes the taxonomic identification of cephalopods captured by plankton nets very difficult. Furthermore, the identification of early stages of many well-known species is problematic due to strong morphologic similarities between related taxa within each family. Therefore, molecular techniques were used to identify some paralarval specimens in the alcohol preserved samples. Cephalopod distribution is analysed in relation to topographic features in the open ocean, such as seamounts and islands

Although cephalopod fisheries are of world-wide importance, in Europe catching cephalopods is managed only in small-scale fisheries, at national level, and few stocks are formally assessed. Because cephalopod are not quota species under the EU’s Common Fisheries Policy, there is currently no requirement for assessment or management at European level. Given increasing interest in targeting cephalopods in Europe, there is a risk that they will be fished unsustainably. Although there have been recent review papers on progress in stock assessment and fishery forecasting for commercially fished cephalopods there has been no recent review of cephalopod fishery management. We aim to fill this gap, with a particular focus on European cephalopod fisheries.We review potential barriers to sustainable fishing and reasons why management of cephalopod fisheries differs from that for finfish fisheries, e.g. due to the high inherent volatility and the possibly cyclic nature of year-to-year variation in cephalopod abundance, reflecting their short lifespan, rapid growth and high sensitivity to environmental conditions. We review fishery management approaches in important cephalopod fisheries worldwide (e.g. in the USA, Japan, Falklands, South Africa, Australia and Russia) and current management of small-scale cephalopod fisheries in Europe. We identify knowledge gaps and limitations to current monitoring programmes and stock assessments and discuss the options available for cephalopod fishery management in Europe, considering the suitability or otherwise of catch and effort limits, use of closed areas and seasons, restrictions on sizes caught and types of fishing gear, and the ole of market-based sustainability pathways

Trophic interactions in cephalopod paralarvae are difficult to evaluate due to the ingestion of liquified prey contents that are not recognizable by visual methods; however, molecular techniques such as next generation sequencing (NGS) can provide better resolution. In this study, we used NGS techniques to determine the diet of Loligo vulgaris paralarvae collected along the West Iberian Peninsula coast. Trophic analyses were conducted on 31 paralarvae ranging from 1.61-6.01 mm in dorsal mantle length, with an estimated age between 2 and 28 d. The digestive system of each paralarvae was dissected and a 300 bp section of the mitochondrial cytochrome c oxidase subunit I gene was sequenced with the MiSeq platform. After quality selection, 3201878 reads were obtained and 130 amplicon sequencing variants were identified as prey (158457 reads). Crustaceans accounted for 88.09% of the total reads, mainly represented by calanoids (73.22%), euphausiids (5.73%) and decapods (2.75%). Distance-based linear modelling showed that diet patterns depended mainly on spatial variables, accounting for 46.92% of the total variation, with calanoids and euphausiids comprising the dominant prey in the diet of paralarvae from SW Galicia, while siphonophores and myopsids constituted the most important prey on the Northern Galician coast

[EN] The main aim of this work was to learn more about the paralarval phase of loliginid squids, probably the most difficult phase to study, which are of high interest for stock predictions, growth models or as a model for ontogenetic patterns. Two main difficulties are constraining this field, namely the scarcity of squid paralarvae in the plankton and the lack of reliable morphological characters to accurately identify the paralarvae. Previous studies showed an unexpected diversity of loliginid paralarvae in the plankton of NW Iberian Peninsula, traditionally considered to be exclusively inhabited by Loligo vulgaris. Accordingly, the hidden diversity of loliginid paralarvae was unraveled to establish baseline studies for future species-specific management strategies. Visual identification of early life stages in squids can be problematic because ethanol-preserved paralarvae might lose the chromatophore patterns that help to identify each species. Therefore, molecular approaches are the only reliable tool to identify different species, when morphological characters are lost or not yet developed. For this study, the mitochondrial cytochrome c oxidase subunit 1 (COI), also known as the barcoding gene, was used to unequivocally identify the different loliginid paralarvae. In Galician waters, three different species were identified: Loligo vulgaris (n=99), Alloteuthis media (n=118) and Alloteuthis subulata (n=15) showing a different spatial distribution pattern. While in the south-west of Galicia the most abundant species was A. media, in the north was A. subulata. Loligo vulgaris maintained its abundance similar in both locations. These differences between Alloteuthis species, might result from interspecific competitive interactions, in order to minimize resource competition by shifting the habitat, both horizontally and vertically. Understanding the demographic structure of these three loliginid species along the Galician coast, involves estimating growth patterns fo, [ES] El principal objetivo de este trabajo fue mejorar el conocimiento de la ecología de los loligínidos, centrando los estudios en la etapa planctónica que es la más desconocida y esencial para evaluación de stocks, desarrollar modelos de crecimiento o estudiar desarrollo ontogenético, entre otros. Sin embargo, el estudio de la etapa larvaria de cefalópodos es muy complejo debido a la escasez de paralarvas y a la falta de caracteres morfológicos que permitan identificarlas inequívocamente. Estudios previos mostraron que, en el Noroeste de la Península Ibérica, Loligo vulgaris no era el único loligínido presente en el plancton, sino que cohabitan con paralarvas de su misma familia. Por lo tanto, el primer objetivo consistía en desentrañar cuales son estas especies, para poder estudiarlas por separado y establecer las bases para desarrollar futuras herramientas de gestión. La identificación visual de los calamares en sus primeras etapas de vida puede ser bastante difícil debido a que las paralarvas que se conservan en etanol tienden a perder los patrones de cromatóforos que caracterizan a cada especie. Por lo tanto, las técnicas moleculares son las únicas herramientas seguras para identificar las diferentes especies que habitan en un área. Para este fin, se empleó uno de los genes mitocondriales más frecuentes en genómica, que es la subunidad 1 del citocromo c oxidasa (COI). En la costa gallega, se identificaron genéticamente tres especies: Loligo vulgaris (n=99), Alloteuthis media (n=118) y Alloteuthis subulata (n=15) mostrando diferencias en su distribución espacial. Mientras que la especie más abundante en el suroeste de Galicia fue A. media, en el norte de Galicia fue A. subulata. L. vulgaris mantuvo una frecuencia similar en las dos localizaciones muestreadas. Estas diferencias entre ambas especies de Alloteuthis, pueden ser debidas a competencia interespecífica y una manera de evitarla es ocupar distintos nichos dentro del mismo hábitat. Para entender la estruc

The use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960’s, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed