ABSTRACT Aim The Canary Current Large Marine Ecosystem (CCLME) is one of the four major marine upwelling systems worldwide. Cephalopods in this region exhibit high diversity and abundance, but the distributional patterns of most species are largely unknown. The present study updated the latitudinal and bathymetric distributions cephalopods species in the CCLME. Location Northwest Atlantic coast of Africa. Taxon Ninety species of Cephalopoda. Methods We use data from specimens collected in 10 bottom trawl surveys (2004–2012) along the coast, developed in the continental shelf and slope (20–2000 m). Only data from specimens identified to species level were considered. For bathymetric analysis data and literature widest depth range for each species were used. If our data fall outside of literature range, the depth range of the species was extended. A presence/absence matrix of species was determined to study their latitudinal distribution. In addition, species were also categorised as coastal or oceanic based on their relationship with the continental shelf and/or slope, regardless of their benthic or pelagic habits. Results The continental shelf is dominated by species from the Sepiidae, Loliginidae and Octopodidae. In contrast, species from the Octopodidae and Cranchiidae are predominant in slope waters. The dominant species on both the shelf and slope belonged to the families Octopodidae, Ommastrephidae and Sepiolidae. The bathymetric distribution of 13 cephalopod species was extended. The latitudinal distribution of Eledone cirrhosa , Ommastrephes cylindraceus , Ommastrephes caroli and Onykia robsoni, was extended. Clear differences in species composition were found between northern and southern of Cape Blanc. Main Conclusions This work provides a complete analysis of the latitudinal and bathymetric distributions of Cephalopoda species currently recorded in the CCLME, with special attention given to the differences in Cephalopoda composition between northern and southern Cape Blanc in Mauritania. No similar studies on cephalopods exist in the full area.

The Falkland Shelf is a highly productive ecosystem in the Southwest Atlantic Ocean. It is characterized by upwelling oceanographic dynamics and displays a wasp-waist structure, with few intermediate trophic-level species and many top predators that migrate on the shelf for feeding. One of these resident intermediate trophic-level species, the Patagonian longfin-squid Doryteuthis gahi, is abundant and plays an important role in the ecosystem. We used two methods to estimate the trophic structure of the Falkland Shelf food web, focusing on the trophic niche of D. gahi and its impacts on other species and functional groups to highlight the importance of D. gahi in the ecosystem. First, stable isotope measurements served to calculate trophic levels based on an established nitrogen baseline. Second, an Ecopath model was built to corroborate trophic levels derived from stable isotopes and inform about trophic interactions of D. gahi with other functional groups. The results of both methods placed D. gahi in the centre of the ecosystem with a trophic level of similar to 3. The Ecopath model predicted high impacts and therefore a high keystoneness for both seasonal cohorts of D. gahi. Our results show that the Falkland Shelf is not only controlled by species feeding at the top and the bottom of the trophic chain. The importance of species feeding at the third trophic level (e.g. D. gahi and Patagonotothen ramsayi) and observed architecture of energy flows confirm the ecosystem's wasp-waist structure with middle-out control mechanisms at play.

Quantitative data on cephalopods collected in ten multidisciplinary surveys (20–2000 m) between 2004 and 2012, together with original oceanographic and satellite data, were analyzed using multivariate techniques. Statistical analyses were based on presence–absence matrices by species and hydrological variable indices. The results show that cephalopods are distributed in two main zoogeographical groups separated by latitude: “Temperate water” and “Tropical water” clusters. They extended by temperate and tropical regions, separated by a geographical boundary, Cape Blanc, particularly strong in the case of coastal species between these groups. For the total fauna, we have identified a third particular cephalopods’ cluster, the “Upwelling” cluster (22°–17°N), characterized by a higher diversity and dominance of oceanic cephalopods. This is proposed as a new zoogeographical region that would coincide with the area of greatest productivity, intensity and permanence throughout the year of the canary current upwelling, confined between the north of Cape Blanc and the south of Mauritania. The results confirm the strong relationship between the three zoogeographical regions (temperate, tropical, and upwelling) and certain water bodies that characterize the regional hydrology. This paper deepens into the zoogeography of the cephalopods from Northwest Africa (Central-Eastern Atlantic), providing a new, more detailed insight into the region and its boundaries in relation to the oceanography.

The Patagonian longfin squid Doryteuthis gahi has an annual life cycle with two seasonal cohorts (autumn and spring spawners). Previous studies estimated the trophic level of adult squid by stable isotope analysis of their muscle or gladius tissues, but few studies compared different sizes and spawning cohorts. In this study, mixed models were used to compare carbon (δ13C) and nitrogen (δ15N) stable isotope signatures of muscle and gladius tissues of the autumn and spring spawning cohorts and squid of different sizes. A published isoscape model provided δ15N baselines to calculate the trophic level of D. gahi. Sampled herbivorous prey such as Euphausiacea, planktonic juveniles Munida gregaria and salps Ihlea supported the trophic level estimates. The autumn spawning cohort had higher δ13C values than the spring spawning cohort. δ15N values increased with increasing dorsal mantle length, suggesting an ontogenetic change towards larger prey. Muscle tissue was enriched in 15N but slightly depleted in 13C compared to gladius tissue. Adult squid had an estimated trophic level of ∼3.2, with no significant differences between spawning cohorts. Stable isotope values followed a seasonal trend, with lower δ15N values and lower δ13C value between July and September. Large individuals of the spring spawning cohort were found to have the least niche overlap with other groups of D. gahi. Our study of the trophic levels and ecology of D. gahi can provide important information on its role in the food chain and can build the basis of studies on interaction with other species, and the impact of environmental changes on their populations. This information can inform the development of management strategies aimed at preserving the balance of the ecosystem and ensuring its sustainable use.

The United Nations (UN) Decade of Ocean Science highlights a need to improve the way in which scientific results effectively inform action and policies regarding the ocean. Our research contributes to achieving this goal by identifying practical actions, barriers, stakeholder contributions and resources required to increase the sustainability of activities carried out in the context of artisanal fisheries to meet UN Sustainable Development Goals (SDG) and International Year of Artisanal Fisheries and Aquaculture (IYAFA) Global Action Plan (GAP) Pillar targets. We conducted a novel ‘social value chain analysis’ via a participatory workshop to elicit perspectives of value chain actors and fisheries stakeholders associated with two Spanish artisanal common octopus (Octopus vulgaris) fisheries (western Asturias—Marine Stewardship Council [MSC] certified, and Galicia—non-MSC certified) about their priorities regarding sustainable octopus production and commercialization. Our adapted Rapfish sustainability framework emphasised the importance of economic, environmental, ethical, institutional, social, and technological indicators to different actors across the value chain. We mapped participants’ shared sustainability priorities (e.g. integrated fisheries management, knowledge-based management, product traceability) to six Rapfish indicators, seven IYAFA Pillars and twelve SDGs to reveal how our results can inform ocean policy and actions. This identified how certification incentives and other cooperative approaches can facilitate environmental, economic and social sustainability (e.g. value-added products, price premiums for producers, gender inclusive organisations); support IYAFA priority outcomes (raised awareness, strengthened science-policy interface, empowered stakeholders, partnerships); and help to achieve UN SDG targets (e.g. SDG 14.b, SDG 17.17). The results can inform actors, stakeholders and policymakers about how different actors contribute to efforts to achieve the SDGs and how to manage priorities for sustainable actions within artisanal fisheries and their value chains. We recommend inclusive and equitable participatory knowledge transfer and governance platforms as part of the UN Decade of Ocean Science and beyond where participants can create theories of change towards sustainability involving the development of multi-sectoral ocean policies framed at the level of the value chain and supported by appropriate governance structures.

The Mayan octopus (Octopus maya) and the American octopus (O. americanus) are the two species that support the octopus fishery on the Campeche Bank. The large-scale fleet catches both species. However, landings are recorded as American octopus in the official statistics, and this causes a problem for the management of the fishery. The large-scale octopus fishery on the Campeche Bank was studied using a model based on data from interviews with skippers. A total of 180 valid interviews were conducted in the base ports of Progreso and Yucalpeten (Yucatan), representing 51.1% of the skippers in the fleet in 2019. This information was used for the first time to estimate catch per unit effort (CPUE) and total catches for each octopus species. The mean CPUE ranged between 50 and 500 kg day-1, with minimums of 10 kg day-1. The mean estimated potential catches ranged from 5069 to 3456 t per year for O. maya and from 4113 to 2805 t per year for O. americanus. The relationship between official landings and estimated catches showed a significant correlation (rxy=0.898). The total estimated catches were on average 20% lower than the official landings of O. americanus. The origin of this discrepancy is discussed.

Abstract An extensive review of cephalopod fauna in the Central and North Atlantic coast of Africa was performed based on material collected during 10 research cruises in these waters. In the Canary Current Large Marine Ecosystem (CCLME) area, a total of 378,377 cephalopod specimens was collected from 1247 bottom trawl stations. Of those specimens, 300 were sampled for subsequent identification in the laboratory and found to belong to 65 different species and 23 families. After an exhaustive review of the existing literature on the cephalopods and new data obtained from the surveys, an updated checklist of 138 species was generated for the CCLME area. Our knowledge of the known geographic distribution ranges of several species has been expanded: Muusoctopus januarii has been sighted from Guinea–Bissau waters, passing through Western Sahara, to Morocco waters for the first time; Lepidoteuthis grimaldii and Octopus salutii have been sighted off Morocco waters for the first time; Austrorossia mastigophora, Abralia (Heterabralia) siedleckyi, Abralia (Pygmabralia) redfieldi and Sepiola atlantica have been cited off Western Sahara waters for the first time; Magnoteuthis magna, Abralia (Asteroteuthis) veranyi and Octopoteuthis megaptera have been sighted off Moroccan and Western Sahara waters for the first time; Ancistroteuthis lichtensteinii, Opisthoteuthis grimaldii, Onykia robsoni, Muusoctopus levis and Bathypolypus valdiviae have been cited in the Guinea–Bissau coast for the first time; the northern geographic limit of Bathypolypus ergasticus has been expanded to Morocco, Western Sahara and Mauritania and southward to Guinea–Bissau waters. The presence of Muusoctopus johnsonianus in Senegalese waters has been reported for the first time. A Chtenopteryx sicula specimen was reported in Western Sahara waters. A specimen belonging to the poorly known Cirrothauma murrayi species was found in South Moroccan waters. Amphitretus pelagicus, a probably cosmopolitan species, has been reported in the Western Sahara and Guinea–Bissau waters. Some species that were previously recorded in the area, Sepia angulata, Sepia hieronis, Heteroteuthis dagamensis, Helicocranchia joubini and Tremoctopus gelatus, were removed from the final checklist and considered to be not present in the CCLME area. Cycloteuthis akimushkini was substituted with Cycloteuthis sirventi, its senior synonym, in the final checklist. Similarly, Mastigoteuthis flammea and Mastigoteuthis grimaldii were substituted with Mastigoteuthis agassizii.

One of the major mechanisms responsible for the animals’ fitness dynamics is fecundity. Fecundity as a trait does not evolve independently, and rather interacts with other traits such as body and egg size. Here, our aim was to correctly infer the macroevolutionary trade-offs between body length, egg length, and potential fecundity, using cephalopods as study model. The correlated evolution among those traits was inferred by comparative phylogenetic methods. Literature data on biological and reproductive traits (body length, egg length, and potential fecundity) was obtained for 90 cephalopod species, and comparative phylogenetic methods based on a previous molecular phylogeny were used to test the correlated evolution hypothesis. Additionally, we estimated the phylogenetic signal and fitted five different evolutionary models to each trait. All traits showed high phylogenetic signal, and the selected model suggested an evolutionary trend toward increasing body length, egg length, and fecundity in relation to the ancestral state. Evidence of correlated evolution between body length and fecundity was observed, although this relationship was not detected between body length and egg length. The robust inverse relationship between fecundity and egg length indicates that cephalopods evolved a directional selection that favored an increase of fecundity and a reduction of egg length in larger species, or an increase in egg length with the concomitant reduction of fecundity and body length in order to benefit offspring survival. The use of phylogenetic comparative methods allowed us to properly detect macroevolutionary trade-offs.

AbstractThe Patagonian longfin squid Doryteuthis gahi has an annual life cycle with two seasonal cohorts (autumn and spring spawners). Earlier studies on the Patagonian shelf found a predominance of Euphausiacea in the D. gahi diet, but no studies to date have investigated differences between feeding spectra of the two cohorts or decadal diet shifts. The present study investigated differences in diet of D. gahi on the Patagonian shelf sampled two decades apart, and differences between seasonal cohorts. Classical stomach content analysis and generalized additive models were used to investigate and model the influence of mantle length, sampling period and spawning cohort on the diet. Results revealed an ontogenetic diet change from ~70% Frequency of Occurrence of Euphausiacea in small squid to more than 60% FO of fish and Cephalopoda at larger sizes. Cannibalism was also frequently observed. Euphausiacea were ingested more frequently and in higher amounts during the austral summer and therefore were consumed more by the autumn spawning cohort, whereas fish was more frequently fed upon during austral winter and also by the spring spawning cohort. Cannibalism was also recorded more in austral winter months but, contrary to feeding on fish, was more prevalent in the autumn spawning cohort. Increased predation of Munida gregaria was observed in 2020 compared with 2001. This study is an important step towards improving the knowledge of D. gahi's two seasonal cohorts, providing data that can be used for future ecosystem modelling.

A central question in the evolution of life-histories is whether organisms reproduce once or repeatedly. For cephalopods, the main differences between semelparous and iteroparous are based on ovulation pattern and spawning type. The different reproductive strategies in coleoid cephalopods could be related to the habitat in which the species dwell (coastal vs. oceanic) and/or to environmental forces, thus, both aspects should be quantitatively evaluated under an evolutionary perspective to reconstruct: (a) the ancestral ovulation type of coleoid cephalopods, and (b) the potential of correlated evolution between ovulation type versus habitat and environment. Ancestral states of ovulation type were estimated using stochastic mapping based on literature data (i.e. synchronous or asynchronous), and this information was combined with a new molecular phylogeny including 165 species. The evolutionary correlation between ovulation type, habitat, and environment was estimated by means of the Markov model comparing the rates of gain and loss. The estimates of ancestral states of ovulation type for coleoid cephalopods resulted in a high probability that Octopodiformes evolved from synchronous ovulation type, and Decapodiformes from asynchronous ovulation type. The three traits evaluated presented phylogenetic signal, although no correlation was found between habitat and ovulation type. Overall, species in stable environments showed a tendency towards synchronous ovulation type, while the asynchronous ovulation pattern was found more frequently in species that live in unstable environments, being this last trait also responsible for triggering the change of ovulation type in some species throughout evolution.

Cephalopods are a diverse group of species, with a high ecological and economic relevance. Despite this, its species diversity has been studied in few places at regional scale. We herein aim to update the current state of knowledge and diversity of cephalopods fauna of the Canary Islands. We carried out a systematic review of the available literature regarding cephalopod species in the area spanned from 1834 to 2019. More specifically, we reviewed (a) records of historic and recent research cruises; (b) records of species from scientific literature and technical reports; and (c) stomach contents analysis of top predators. A total of 48 documents, including scientific literature, technical reports, and species referenced in museums collections of cephalopods caught around the Canary Islands were identified. The current species richness in different habitats from coastal to deep-sea zones was determined according to records and previous information on the ecology of each species. These records revealed that this small archipelago holds 85 confirmed species belonging to 31 families, representing ca. 10% of the overall known cephalopod diversity. The cephalopod community was dominated by oceanic cephalopods, followed by shelf-slope and coastal cephalopods species with 65, 11, and 9 species, respectively. 47% of the species showed a wide geographic distribution (33 cosmopolitan and 7 presents in more than one ocean), whereas 19 are only encountered in the Atlantic Ocean and Mediterranean Sea and 26 are exclusively Atlantic. This species richness is comparable to other cephalopod biodiversity hotspots, such as the Indian Ocean Ridge or the Caribbean. The Canarian cephalopod diversity likely to be underestimated, since scarce information exists on species inhabiting the deeper water layers around the Canary Islands. This work represents the first baseline of cephalopod biodiversity around the Canary Islands; hence, it constitutes a first step to develop future research on this taxonomic group. (C) 2020 Elsevier B.V. All rights reserved.

Two octopod species are reported from the Canary Islands (eastern Atlantic Ocean) for the first time: the deep sea four-horn octopus, Pteroctopus tetracirrhus (Delle Chiaje, 1830) and the gelatinous giant octopus, Haliphron atlanticus Steenstrup, 1861. Both female specimens were caught in Tenerife. Haliphron atlanticus is described from fresh remains found floating close to the southwest coast and the second species, P. tetracirrhus, is described from a specimen captured in a shrimp trap at 200 m depth on the southeastern coast of Tenerife. With these two additions the revised and updated list of octopod species of the Canary Islands now comprises eight families and 18 species, all of them incirrate octopods. The zoogeographic relationships of octopod species from other Atlantic regions, including the Mediterranean Sea, were studied. The likely directions of faunal flows were inferred based on affinity indices, showing that Mauritania could be the most probable source of the octopod species of the Canary Islands and the rest of the Macaronesian archipelagos.

Age and growth of Octopus vulgaris were estimated for the first time by using stylets of 200 specimens (97 males, 103 females) collected from the Tunisian southern coasts (the Gulf of Gabes), between June 2011 and May 2012. Females ranged in age from 215 days (7.5 months) to a maximum of 889 days (29.6 months), corresponding to weights of 380 to 5800 g. Males ranged in age from 102 days (3.4 months) to a maximum of 1251 days (41.7 months), corresponding to weights of 280 to 6350 g. A strong positive relationship between estimated age and both dorsal mantle length and body weight was observed. Our results indicated that under favourable conditions the life cycle of Octopus vulgaris could be extended to 2.5 years for most of the population and exceptionally to 3.5 years for some males in the Tunisian waters. Our data provided also a high growth individual variability and suggest the existence of octopus sub-annual cohorts which hatch through the year. The highest growth rate for both sexes was observed for individuals hatched in summer.

This study reports a detailed anatomical and histological study of the digestive system of Octopus vulgaris. Emphasis was placed on characterising the glands and glandular cells and their distribution throughout the digestive tract. The use of classic histological and histochemical techniques revealed two morphological types of glandular cells: granular and mucous. Moreover, the histochemical analysis indicated specialisation of mucous glandular cells in the buccal mass, the submandibular gland and the caecum for secreting acid and neutral glycoconjugates. The cells of the anterior salivary glands are specialised for secreting neutral glycoproteins, and those of the posterior salivary glands are specialised for granular and mucous secretion. The oesophagus, crop and stomach lack glandular cells, but both granular and mucous glandular cells are found in the intestine. An unusual structure resembling the typhlosole of bivalves is described for the first time in the intestine of O. vulgaris. The highly ciliated epithelium and location of the structure in the anterior part of the intestine suggest a possible role in bypassing the caecum, stomach and intestine. We discuss how these cells and organs contribute to the process of digestion in the light of the present histological and histochemical data and of previously published information on the morphology and physiology of digestion in the octopus.

Event Abstract Back to Event Cephalopods from the Canary Current upwelling ecosystem (Northwest Africa) Amanda Luna1, 2*, Ana Ramos2, Francisco J. Rocha1 and Catalina Perales-Raya3 1 University of Vigo, Spain 2 Instituto Español de Oceanografía (IEO), Spain 3 Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Canarias, Spain Cephalopods from the Canary Current upwelling ecosystem (Northwest Africa) Luna, A. (University of Vigo, IEO Vigo), Rocha, F. (University of Vigo), Ramos, A. (IEO Vigo). The Canary Current Large Marine Ecosystem (CCLME) constitutes one of the four great marine systems of upwelling in the world, being the third in primary productivity and supporting the largest fisheries of the African coast, with an annual production of around 2-3 million tons (Valdés and Déniz-González, 2015). The cephalopod’s fauna of Northwest African region is diverse and abundant and includes species of wide distribution and elevated commercial value, among which are found squids, cuttlefish, and octopuses, whose catches in the area reach 80,000 - 120,000 tons per year. Although most of the fishery target species have been well studied, the knowledge of the unexploited species is very scarce (Rocha et al., 2017). Between 2002 and 2012 the Spanish Institute of Oceanography (IEO) and the FAO carried out eleven multidisciplinary surveys in northwest Africa, covering the shelf and continental slope from Morocco to Guinea. Quantitative data by species and important collections of benthic and pelagic cephalopods were gathered in 1334 trawl stations over the soft bottoms between 20 and 2000 m depth. Besides, oceanographic data were recorded in 1180 stations by different CTD devices. Almost 140 species have been currently identified. Among them, Sepiidae, Lolliginidae and shallow-water octopus dominate the coastal assemblages, while at the slope waters Ommastrephidae and deep‐water octopuses are more abundant. The collections and databases taken during these 11 trawl surveys represent an exceptional source of regional information on the biodiversity, composition, and distribution of cephalopod’s assemblages inhabiting North-west African continental margin. References Déniz-González, I. and Valdés, L. (2015). Introduction. In: Valdés, L. and Déniz-González, I. (eds.) Oceanographic and biological features in the Canary Current Large Marine Ecosystem. IOC-UNESCO, Paris. IOC Technical Series, 115: 19-22. Rocha, F., Fernández-Gago, R., Ramil, F. and Ramos A. (2017). Cephalopods in Mauritanian Waters. In: Ramos, A., Ramil, F. and Sanz, J.L. (eds.) Deep-sea ecosystems off Mauritania: Research of marine biodiversity and habitats in the Northwest African margin, pp. 393-418, Dordrecht, Springer. Keywords: cephalopods, Canary current, upwelling, Northwest Africa, Biodiversity Conference: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) , Braga, Portugal, 9 Sep - 12 Sep, 2019. Presentation Type: Oral Presentation Topic: Fisheries, Aquaculture and Biotechnology Citation: Luna A, Ramos A, Rocha FJ and Perales-Raya C (2019). Cephalopods from the Canary Current upwelling ecosystem (Northwest Africa). Front. Mar. Sci. Conference Abstract: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) . doi: 10.3389/conf.fmars.2019.08.00038 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 05 Jun 2019; Published Online: 27 Sep 2019. * Correspondence: Mx. Amanda Luna, University of Vigo, Vigo, Spain, redlunel@hotmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Amanda Luna Ana Ramos Francisco J Rocha Catalina Perales-Raya Google Amanda Luna Ana Ramos Francisco J Rocha Catalina Perales-Raya Google Scholar Amanda Luna Ana Ramos Francisco J Rocha Catalina Perales-Raya PubMed Amanda Luna Ana Ramos Francisco J Rocha Catalina Perales-Raya Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Two well conserved female specimens of the uncommon soft-scaled squid Lepidoteuthis grimaldii Joubin, 1895 (Lepidoteuthidae, Oegopsida) were caught in Canary Island waters: a maturing female of 580 mm dorsal mantle length found dead on the surface at 27 degrees 38'N, 18 degrees 01' W (near El Hierro Island); an immature female of 350 mm dorsal mantle length captured by commercial open midwater trawl at 28 48'N, 16 degrees 00' W (north of Tenerife Island), between 342 and 487 m depth. This is the first report of an adult of this species from the Canary Islands. Morphological data are presented and the bathymetric distribution of this species in Canary waters is discussed.

Octopus vulgaris aquaculture is limited due to poor biological knowledge of the paralarval stages (e.g. digestive system functionality), their nutritional requirements (e.g. adequate live diet) and standardization of rearing techniques. These factors are important in explaining the high mortality rate observed in this developmental stage under culture conditions. For a better understanding of nutrition biology of this species, we investigated the 3D microanatomy of the digestive tract of the embryo and paralarvae during the first month of life. O. vulgaris paralarvae digestive system is similar to that in the adult. The "descending branch" has a dorsal position and is formed by the buccal mass, oesophagus and crop. Ventrally, the "ascending branch" is formed by the intestine and the anus. The digestive gland, the posterior salivary glands and the inner yolk sac (in the case of the embryo and hatched paralarvae) are located between the "ascending" and "descending" branches. In the curve of the U-shaped digestive tract, a caecum and the stomach can be found. The reconstructions reveal that anatomically the digestive system is already complete when the paralarvae hatch. The reconstruction of the buccal mass at different post-hatching days has demonstrated that all the necessary structures for food intake are present. However, the radula surface in contact with the pharynx is very small on the first day of life. Although the digestive system has all the structures to feed, the digestive gland and radula take longer to reach full functionality. We have established four development periods: embryonic, early post-hatching, late post-hatching and juvenile-adult. The differentiation between these periods was done by type of feeding (endogenous or exogenous), the state of maturation and hence functionality of the digestive gland, type of growth (linear, no net or exponential), and measurement of the arm lengths with respect to the mantle length. 3D reconstruction represents a new tool to study the morphology and functionality of the cephalopod digestive system during the first days of life.