Roger Villanueva

• PhD
• Spanish National Research Council

Meropelagic octopuses hatch as planktonic paralarvae, being the subject of progressive morphological and behavioural changes ending with settlement on the seafloor as juveniles. The comparative morphological study of digestive systems can help to understand the adaptation to particular niches during this challenging plankton-benthos transition. Her...

The settlement phase is a challenging period for meropelagic octopus, as they adapt to their new life in the sea bottom after a planktonic period. Their ecology and trophic interactions with the surrounding fauna in the wild are practically unknown. To understand their predatory role in the littoral zone, the diet of recently settled Octopus vulgar...

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...

The common octopus, Octopus vulgaris Cuvier, 1797, is a meroplanktonic species with planktonic hatchlings and benthic juveniles and adults, which is found throughout the northeast and eastern central Atlantic Ocean, including central Atlantic islands and the Mediterranean Sea. Embryonic development time is approximately 23–25days at 25°C, but below...

This chapter provides an updated overview of extant octopus species richness from the aspects of taxonomic rank, lifestyles, and habitat and identifies global hotspots of coastal species richness (at both realm and ecoregion levels) for the ranks of family and genus. Also assessed are global patterns of coastal endemicity and modality types of the...

Synopsis Cryptic species complexes represent an important challenge for the adequate characterization of Earth’s biodiversity. Oceanic organisms tend to have greater unrecognized cryptic biodiversity since the marine realm was often considered to lack hard barriers to genetic exchange. Here, we tested the effect of several Atlantic and Mediterranea...

WGCEPH worked on six Terms of Reference. These involved reporting on the status of stocks; reviewing advances in stock identification, assessment for fisheries management and for the Marine Strategy Framework Directive (MSFD), including some exploratory stock assessments; reviewing impacts of human activities on cephalopods; developing identificati...

Phylogenies for Octopoda have, until now, been based on morphological characters or a few genes. Here we provide the complete mitogenomes and the nuclear 18S and 28S ribosomal genes of twenty Octopoda specimens, comprising 18 species of Cirrata and Incirrata, representing 13 genera and all five putative families of Cirrata (Cirroctopodidae, Cirrote...

Cephalopod beaks are essential for prey acquisition and fragmentation during feeding. Thus, it is expected that ecological pressures affect cephalopod beak shape. From a practical perspective, these structures are also used to identify gut contents of marine megafauna, such as toothed whales, sharks, seabirds, and large pelagic fishes. Here, we inv...

Cuttlefish are an important global fisheries resource, and their demand is placing increasing pressure on populations in many areas, necessitating conservation measures. We reviewed evidence from case studies spanning Europe, Africa, Asia, and Australia encompassing diverse intervention methods (fisheries closures, protected areas, habitat restorat...

Phylogenies for the Octopodiformes have, until now, been based on morphological characters or several genes. Here we provide the complete mitogenomes and the nuclear 18S and 28S ribosomal genes of twenty Octopoda specimens, comprising 18 species of Cirrata and Incirrata representing 13 genera and all four families of Cirrata (Cirroctopodidae, Cirro...

After a period of weeks or months in the plankton, meropelagic octopuses descend to the sea bottom where they will remain for the rest of their lives. This transition to a benthic lifestyle requires dramatic morphological, behavioural and trophic changes that are poorly understood so far. Information on wild recently settled octopus individuals are...

Cephalopod beaks are important chitinous hard structures, used for preying upon and fragmenting prey. Thus, it is expected that ecological pressures drive cephalopod beak shape. These structures, which are used in species identification, may exhibit a certain association with phylogenetic relationships among cephalopod species. Here, we investigate...

Historically, marine oceanic open environments have been considered without barriers to dispersal, and the subsequent speciation of lineages present in distant areas. As a consequence, many marine pelagic invertebrates are considered as monotypic cosmopolitan taxa. However, this view has been consistently challenged in the last decades by the disco...

Presentation of the Marine Biological Reference Collections of the ICM-CSIC, Barcelona, Spain. The Marine Biological Reference Collections (CBMR) are specialized mainly in Chordata (fish), Arthropoda and Mollusca, mostly from the Mediterranean Sea, but also with important contributions from the Atlantic Ocean and the rest of the world’s oceans (see...

Oceanic squids of the order Oegopsida are ecologically and economically important members of the pelagic environment. They are the most diverse group of cephalopods, with 24 families that are divergent morphologically. Despite their importance, knowledge of phylogenetic relationships among oegopsids is less than that among neritic cephalopods. Here...

Cephalopods are a group of marine invertebrates that have received little attention as sentinel species in comparison to other molluscs, such as bivalves. Consequently, their physiological and biochemical xenobiotic metabolism responses are poorly understood. Here we undertake a comparative analysis of the enzymatic activities involved in detoxific...

Stable isotope compositions of carbon and nitrogen (expressed as δ ¹³ C and δ ¹⁵ N) from the European common cuttlefish ( Sepia officinalis ) were measured in order to evaluate the utility of using these natural tracers throughout the Northeast Atlantic Ocean and Mediterranean Sea (NEAO-MS). Mantle tissue was obtained from S. officinalis collected...

The entire skin surface of octopus embryos, hatchlings and juveniles bears scattered tufts of tiny chitinous setae within small pockets, from which they can be everted and retracted. Known as Kölliker’s organs (KO), they disappear before the subadult stage. The function of these structures during the early life of the octopus is unknown, despite ha...

Historically, marine oceanic open environments have been considered without barriers to dispersal, and the subsequent speciation of lineages from distant areas. As a consequence, many marine pelagic invertebrates are considered as monotypic cosmopolitan taxa, sometimes even including divergent geographic morphotypes. However, this view has been con...

Cirrate octopods are considered to resemble the ancestor of all octopuses. Cirrates inhabit the deep ocean and are characterized by the presence of fins, a cartilaginous inner shell and a single row of suckers alternating with pairs of cirri thus comprising uniserial suckers and biserial cirri. The objective of this contribution is to improve the t...

Molecular species delimitation assists taxonomic decisions for challenging species, like cryptic species complexes. Bobtail squids (Family Sepiolidae Leach, 1817) are a very diverse group of benthic and nektonic small to medium size cephalopods with many taxonomic questions to solve. In this study we provided new sequence data for 12 out 17 Mediter...

Planktonic stages of benthic octopuses can reach relatively large sizes in some species, usually in oceanic, epipelagic waters while living as part of the macroplankton. These young octopuses appear to delay settlement on the seabed for an undetermined period of time that is probably longer than for those octopus paralarvae living in coastal, nerit...

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....

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....

Cryptic speciation among morphologically homogeneous species is a phenomenon increasingly reported in cosmopolitan marine invertebrates. This situation usually leads to the discovery of new species, each of which occupies a smaller fraction of the original distributional range. The resolution of the taxonomic status of species complexes is essentia...

Members of the family Cranchiidae Prosch, 1847, commonly known as glass or bathyscaphoid squids, range from small translucent species to the massive-sized colossal squid. Those cephalopods are widely distributed in all oceans, also representing one of the more diverse families of squids and, despite their ecological importance, their diet is almost...

Fernández-Álvarez, Fernando Ángel; Farré, Marc; Sánchez Márquez, Antoni; Villanueva, Roger; Escolar Sánchez, Oscar; Navarro, Joan; 2020; "Length/weight relationship for horned octopus based on Jereb et al. (2015). Equation: W = 1.62(ML)^2.27. Abbreviations: W = weight (g), ML = mantle length (cm). Reference: P. Jereb, A.L. Allcock, E. Lefkaditou, U...

Despite the ecological and economic importance of oceanic squids of the order Oegopsida Orbigny 1845, they are among the most mysterious groups of pelagic organisms. Starting in October 2019, the 2-year postdoc project GOIPD/2019/460 “Genome and specific biodiversity of oceanic squids assessed through Next Generation Sequencing”, funded by the Iris...

Natural markers (δ13C and δ18O stable isotopes) in the cuttlebones of the European common cuttlefish (Sepia officinalis) were determined for individuals collected across a substantial portion of their range in the Northeast Atlantic Ocean (NEAO) and Mediterranean Sea. Cuttlebone δ13C and δ18O were quantified for core and edge material to characteri...

The marine Biological Reference Collections (CBR) are located at the Institute of Marine Sciences (ICM-CSIC) in Barcelona, Spain. The CBR are a Unit of Service where around 15000 referenced species are preserved, catalogued and maintained for their study. The most represented groups at the CBR are fish, crustaceans, molluscs and echinoderms, but al...

I'm interested in cephalopod phylogenetics, systematics, taxonomy, natural history, reproductive biology and trophic ecology of cephalopods, especially oceanic squids. Currently, as an Irish Research Council postdoc fellow, my research is focussed on the phylogenetics of oegopsid squids, assessed through shallow whole genome sequencing (Genome Skim...

Cryptic speciation among morphologically homogeneous species is a phenomenon increasingly reported in cosmopolitan marine invertebrates. This situation usually leads to the discovery of new species, each of which occupies a smaller fraction of the original distributional range. The resolution of the taxonomic status of species complexes is essentia...

Recent studies have shown that coastal and shelf cephalopod populations have increased globally over the last six decades. Although cephalopod landings are dominated by the squid fishery, which represents nearly 80% of the worldwide cephalopod catches, octopuses and cuttlefishes represent ∼10% each. Total reported global production of octopuses ove...

Recent studies have shown that coastal and shelf cephalopod populations have increased globally over the last six decades. Although cephalopod landings are dominated by the squid fishery, which represents nearly 80% of the worldwide cephalopod catches, octopuses and cuttlefishes represent ∼10% each. Total reported global production of octopuses ove...

Los miembros de la familia de calamares oceánicos Ommastrephidae (Steenstrup, 1857), vulgarmente conocidos como potas, desarrollan todo su ciclo vital en la columna de agua, como paralarvas planctónicas y luego como subadultos y adultos nectónicos. Se trata del grupo de cefalópodos con mayor relevancia pesquera, representando casi la mitad de las c...

Within the context of global climate change and overfishing of fish stocks, there is some evidence that cephalopod populations are benefiting from this changing setting. These invertebrates show enhanced phenotypic flexibility and are found from polar regions to the tropics. Yet, the global patterns of species richness in coastal cephalopods are no...

Currently, three species in the squid family Bathyteuthidae are recognized as valid: Bathyteuthis abyssicola Hoyle 1885, Bathyteuthis bacidifera Roper 1968, and Bathyteuthis berryi Roper 1968. Using morphology and DNA sequencing (COI, 16S), we discovered three additional species of bathyteuthids collected from the North Atlantic Ocean and adjacent...

Cryptic speciation, where distinct species share morphological features, has been increasingly reported among marine invertebrates. In general, the recognition of these distinct species leads to a scenario in which the distribution of each newly discovered species represents a small fraction of the original distribution range. Because conservation...

Traditionally, three subfamilies for the family Ommastrephidae Steenstrup, 1857 have been recognized: Illicinae Posselt, 1891, Todarodinae Adam, 1960 and Ommastrephinae Posselt, 1891. Controversy exists regarding the actual number of subfamilies. Particularly difficult is the taxonomic position of Todaropsis eblanae (Ball, 1841), whose placement va...

Sperm storage is common in internally fertilizing animals, but is also present in several external fertilizers, such as many cephalopods. Cephalopod males attach sperm packets (spermatangia) to female conspecifics during mating. Females of eight externally fertilizing families comprising 25% of cephalopod biodiversity have sperm-storage organs (sem...

Squids are fast swimmers that are difficult to catch by nets and to record with echosounders in the open ocean. A rare detection of orangeback flying squid Sthenoteuthis pteropus in the Central Eastern Atlantic Ocean off the coast of Senegal was accomplished during the MAFIA oceanographic survey carried out between Brazil and the Canary Islands in...

Cephalopods are primarily active predators throughout life. Flying squids (family Ommastrephidae) represents the most widely distributed and ecologically important family of cephalopods. While the diets of adult flying squids have been extensively studied, the first feeding diet of early paralarvae remains a mystery. The morphology of this ontogene...

Cephalopods are primarily active predators throughout life, with a few exceptions. Flying squids (family Ommastrephidae) represents the most abundant, widely distributed and ecologically important family of cephalopods. While the diets of adult flying squids have been extensively studied, the first-feeding diet of early paralarvae remains a mystery...

The eggs of the European cuttlefish, Sepia officinalis, develop attached to the seafloor in shallow water habitats and possess a relatively thick black capsule that protects them from the surrounding environment. Since embryological development may take several months, eggs are vulnerable to a variety of threats present in shallow waters, including...

Table A.1. Definition of the levels of the biological categories trophic group, feeding strategy and capture strategy, as used in this study to characterize the feeding biology of the potential predator species.

The diversity of cephalopod species and the differences in morphology and the habitats in which they live, illustrates the ability of this class of molluscs to adapt to all marine environments, demonstrating a wide spectrum of patterns to search, detect, select, capture, handle, and kill prey. Photo-, mechano-, and chemoreceptors provide tools for...

Oceanic squids of the family Ommastrephidae are an important fishing resource worldwide. Although cumulative knowledge exists on their subadult and adult forms, little is known about their young stages. Their hatchlings are among the smaller cephalopod paralarvae. They are characterized by the fusion of their tentacles into a proboscis and are very...

We describe the morphology of egg masses and hatchlings of the squid, Lolliguncula diomedeae (Hoyle, 1904) based on individuals hatched in the laboratory from two egg masses collected in the Gulf of California near Santa Rosalía, Baja California Sur, Mexico, and identified with molecular techniques. The characteristics of the egg mass are described...

Cephalopods (nautiluses, cuttlefishes, squids and octopuses) exhibit direct development and display two major developmental modes: planktonic and benthic. Planktonic hatchlings are small and go through some degree of morphological changes during the planktonic phase, which can last from days to months, with ocean currents enhancing their dispersal...

The genus Ommastrephes d'Orbigny, 1834 in 1834–1847 is currently accepted to be formed only by a widely distributed species: O. bartramii (Lesueur, 1821). According to its known antitropical distribution, the species occur in temperate waters of the Atlantic, Pacific and Indian Oceans. Current taxonomic status proposed that O. bartramii is formed b...

DNA barcoding, a method for molecular identification at species-level, has been developed and widely used in many biological disciplines. It is especially useful for taxonomically-difficult groups which need of highly-specialized methods for identification, or those that can only be specifically assigned in some phases of their vital cycle. However...

Cephalopods (Mollusca: Cephalopoda) play an important role as keystone invertebrates in various marine ecosystems, as well as being a valuable fisheries resource. At the World Malacological Congress, held 21–28 July 2013 in Ponta Delgada, Azores, Portugal, a number of cephalopod experts convened to honour the contribution of the late Malcolm R. Cla...

This report summarizes current knowledge on the identification, geographical distribution, nomenclature, taxonomy, life history, ecology, and exploitation of cephalopod species of interest to fisheries in European waters. The 17 species range from those currently of significant fishery importance and targeted in at least part of their range (Octopu...

A recent revival in using cephalopods as experimental animals has rekindled interest in their biology and life cycles, information with direct applications also in the rapidly growing ornamental aquarium species trade and in commercial aquaculture production for human consumption. Cephalopods have high rates of growth and food conversion, which for...

This chapter presents an overall perspective on the current status of cephalopod culture, its bottlenecks and future challenges. It focuses on the species that have received more research effort and consequently accumulated more scientific literature during the present century, namely Sepia officinalis, Sepioteuthis lessoniana, Octopus maya and Oct...

Provides details on methods used in the different stages of cephalopod culture: obtaining and maintaining brood stock, the spawning process, larval rearing and on growing ▶ Includes recent breakthroughs (i.e. successful rearing of large octopus hatchlings on a wholly artificial diet of squid paste) ▶ Emphasis on the additional economic benefits of...

Cephalopod biology is briefly surveyed in the context of cephalopod culture, considering its promises and limits. The motivations for undertaking culture work vary greatly, both in a basic and applied science perspective. Under most circumstances, the outcome of an experimental culture remains uncertain until a second generation is achieved. Cultur...

Cephalopods have been utilised in neuroscience research for more than 100 years particularly because of their phenotypic plasticity, complex and centralised nervous system, tractability for studies of learning and cellular mechanisms of memory (e.g. long-term potentiation) and anatomical features facilitating physiological studies (e.g. squid giant...

Cephalopod Culture is the first compilation of research on the culture of cephalopods. It describes experiences of culturing different groups of cephalopods: nautiluses, sepioids (Sepia officinalis, Sepia pharaonis, Sepiella inermis, Sepiella japonica Euprymna hyllebergi, Euprymna tasmanica), squids (Loligo vulgaris, Doryteuthis opalescens, Sepiote...

The present invention claims a method for long-term preservation of cephalopod sperm by means of the cryopreservation of the spermatophores and spermatangia thereof. Cryopreservation is obtained by means of the use of optimum protocols for incorporation and elimination of permeable cryoprotectants (alcohols,sulphoxides and formamides in aqueous sol...

Cephalopod culture is expected to increase in the near future and sperm cryopreservation would be a valuable tool to guarantee sperm availability throughout the year and to improve artificial insemination programs. We have studied the tolerance of spermatophores from the oceanic squid Illex coindetii to several cryoprotectants, in two toxicity expe...

In vitro fertilization of oceanic squid is a necessary step to develop their larval culture and creates new opportunities to study and understand cephalopod development, taxonomy and ecology. The techniques described here in the form of a laboratory guide represent an attempt to refine and standardize the general methodology by indicating suitable...

Cephalopods play a key role in many marine trophic food webs and also constitute alternative fishery resources in the context of the ongoing decline in finfish stocks. Most coastal cephalopod species of commercial importance migrate into shallow waters during the breeding season to lay their eggs, and are consequently subjected to coastal contamina...

The common octopus, Octopus vulgaris, weighing 1.4 mg at hatching and reared in the laboratory (mean 21.2 °C), doubled their weight roughly every 8.5 days to a mean of 173.2 mg after 60 days when they became benthic. Changes in paralarval allometry during development were strongly marked in the case of arm length: suckers were added and the arms gr...

The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major...

Over the past two decades, cephalopod molluscs have attracted increased attention from marine biologists and fishery scientists. Several species are important for European fisheries, as targets of small‐scale coastal fisheries and/or as bycatch in multispecies fisheries for demersal fish. The present report draws on a series of reviews prepared in...

Eye development, optical properties and photomechanical responses were examined in embryos and hatchlings of the southern calamary, Sepioteuthis australis. This species occurs in shallow coastal waters in Australia and New Zealand, and the egg masses were collected in October and December 2004 from Great Oyster Bay, Tasmania. At the earliest develo...

The cephalopod fauna collected during six surveys carried out in the bathyal basin of the north-western Mediterranean is discussed. Samples were taken at depths mainly between 1000 and 2000 m. Ten species were identified. Bathypolypus sponsalis and Neorossia caroli were the commonest species. Small individuals of both these species occurred at grea...

The present study was designed to provide a look at the vitamin content of the early stages of cephalopods as an approach to their vitamin requirements in culture. Vitamin A and E profiles of the European cuttlefish Sepia officinalis, European squid Loligo vulgaris and common octopus Octopus vulgaris laboratory hatchlings and wild juveniles were an...

Octopuses of the family octopodidae adopt two major life-history strategies. The first is the production of relatively few, large eggs resulting in well-developed hatchlings that resemble the adults and rapidly adopt the benthic habit of their parents. The second strategy is production of numerous small eggs that hatch into planktonic, free-swimmin...

Statolith size and growth was used to determine the influence of abiotic factors on the growth of Loligo vulgaris and Sepioteuthis australis embryos. Recently spawned egg masses collected from the field were incubated in the laboratory under different levels of light intensity, photoperiod, or short periods of low salinity (30‰). Double tetracyclin...

When using cephalopods as experimental animals, a number of factors, including morality, quality of information derived from experiments, and public perception, drives the motivation to consider welfare issues. Refinement of methods and techniques is a major step in ensuring protection of cephalopod welfare in both laboratory and field studies. To...

Due to the high mortality rates and poor growth generally observed in Octopus vulgaris paralarval rearing experiments, it was decided to organize a working group in order to formulate recommendations to tackle this problem. Over a dozen scientists representing the most active current research groups related to this subject attended the meeting in V...

During the present study, we aimed at providing a first look at the elemental composition of the early stages of cephalopods as an approach to their elemental requirements in culture. Essential and non-essential elemental profiles of the European cuttlefish Sepia officinalis, the European squid Loligo vulgaris and the common octopus Octopus vulgari...

The cirrate octopods are deep-sea, cold-adapted cephalopod molluscs that are found throughout the world's oceans, usually at depths in excess of 300 m, but shallower in cold water at high latitudes. The gelatinous bodies of the cirrates, which deform when preserved, coupled with low capture rates have caused considerable confusion in the systematic...