Angel Guerra

• PhD
• Research Director at Spanish National Research Council

Link to download: https://authors.elsevier.com/c/1kr8o8MvAu3fJ1

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...

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 o...

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 s...

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 literatu...

To improve limited knowledge of the predation behaviour of the loliginid species, this study is the first to examine the hunting and feeding behaviour of Loligo vulgaris. Hunting and feeding strategy, as well as body patterning of the squid were described in laboratory experiments during which, two prey types, characterised by different size and mo...

First morphological description of Octopus vulgaris Type I and II and a sugestion to use the Octopus americanus Baker in Denis de Montfort, 1802 scientific name. We also provide morphologic differences between Octopus americanus, Octopus insularis Leite & Haimovici and 2008 and Octopus vulgaris Cuvier, 1797.

In the majority of the shallow-water cephalopod species, senescence is a short stage of their lifespan, which takes place at the end of sexual maturity. Senescence is not a disease, although senescent cephalopods can be frequently mistaken with diseased animals. Senescence is accompanied by physiological, immunological and behavioural changes, whic...

The aim of this open access book is to facilitate the identification and description of the different organs as well as pathogens and diseases affecting the most representative species of cephalopods focussed on Sepia officinalis, Loligo vulgaris and Octopus vulgaris. These species are valuable ‘morphotype’ models and belong to the taxonomic groups...

Molecular studies have shown that several morphotypes of octopus have been under the name of Octopus vulgaris Cuvier, 1797, considered as cosmopolitan specie. Due to the significant oceanographical barriers that exist between the geographical distributions of these forms and the absence of any plausible gene flow mechanisms, this species group at p...

Octopus resource in Mexican Atlantic waters comprises two species Octopus vulgaris and O. maya. This resource has been exploited since 1949 in Campeche and since 1970 in Yucatan and Quintana Roo. The O. vulgaris exploitation is carried out without an adequate knowledge of many aspects of its biology and ecology in these areas. This scenario can hav...

The red octopus (Octopus maya) is an endemic species of the Campeche Bank. Its habitat depths range from 0 to 60 m. Nevertheless, the knowledge about many aspects of population dynamics of the species at depths greater than 20 m is scarce. This study aims to identify spatio-temporal variations and population structure of the red octopus between 30...

Global ecosystem models are essential tools for predicting climate change impacts on marine systems. Modeled biogenic carbon fluxes in the ocean often match measured data poorly and part of this could be because small copepods (<2 mm) are modeled as unicellular feeders grazing on phytoplankton and microzooplankton. The most abundant copepods from a...

We presented the most updated list of cephalopods in Galician waters (NW Iberian Peninsula). Species of temperate northwest Atlantic are registered.The list is composed by 92 species belonging to 62 genera and 40 families.

The systematics of the comb-fin squid species is problematic and poorly resolved. In total, 53 specimens of comb-fin squids (Chtenopteryx spp.) were caught at depths ranging from 30 to 800 m off the Canary Islands (NE Atlantic Ocean). Mantle lengths of the individuals ranged from 18 to 43 mm and the sample included immature, mature male and mature...

La nueva guía de los moluscos marinos de Galicia es una obra en la que se tratan un total de 630 especies de moluscos diferentes. Considerando que las conocidas en nuestras aguas rondan las 900, se puede decir que aparecen en esta guía prácticamente todas las que pueden encontrarse entre el nivel intermareal y los 200 metros de profundidad. Cuenta...

A total of eight specimens of the squid family Chiroteuthidae were captured with a large semi-pelagic trawl net over bottom depths of 252–256 m in the NE Atlantic off NW Spain (Galicia, 42°34′N–8°08′E) in April 2016. Three of these specimens were morphologically identified as Chiroteuthis mega. The identification was genetically confirmed using seq...

Although there are several previous records of giant squid (Architeuthis dux) stranding on the north coast of Spain and elsewhere in Europe, this is the first time one is known to have stranded alive, dying soon afterwards. But how did it die? We suspect foul play and the forensic evidence provides indications of means, opportunity and motive. Resu...

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°38'N, 18°01'W (near El Hierro Island); an immature female of 350 mm dorsal mantle length capture...

Growing concern over sustainability of some fisheries has led to a shift in the focus of fisheries management, from a single-target species towards an ecosystem-based management. This process involves identification a suite of indicators, among which ontogenetic and environmental factors affecting prey ingestion should be considered. The present st...

Atresia has been poorly examined in cephalopods. We here provide a histological description of this process along the whole ovary development for Octopus vulgaris. Additionally, we related its occurrence to morphometric parameters, and its seasonal cycle was further analysed. Atresia occurred all year round in immature and mature females and in pre...

Global ecosystem models are essential tools to predict climate and anthropogenic impacts on marine ecosystems. These models include all pelagic components –abiotic and biotic- and their accuracy depends on our ability to model their complex relationships at different spatio-temporal scales. However, uncertainties or misconceptions coupling differen...

With nearly 200 hours of underwater images filmed during the CEFAPARQUES project, aerial images taken from drones, interviews with members of ECOBIOMAR (Institute of Marine Research, CSIC), and interviews with brotherhoods fishing in the Ria de Vigo (NW Spain), it has made a documentary whose protagonist is the common octopus (Octopus vulgaris). In...

We evaluated specific habitat features (bottom substrate type, depth, temperature, season and latitudelongitude) at random locations in the Cíes Islands (Galician Atlantic Islands National Park, Northwest Spain) to determine their impact on Sepia officinalis spawning habitat use. We performed underwater visual transects via scuba diving. In total,...

We evaluated specific habitat features (bottom substrate type, depth, temperature, season and latitude-longitude) at random locations in the Cíes Islands (Galician Atlantic Islands National Park, NorthwestSpain) to determine their impact on Sepia officinalis spawning habitat use. We performed underwatervisual transects via scuba diving. In total, 9...

The early life stages of cephalopods - octopods, squids, sepiolids and ommastrephids -, are uncommon in zooplankton samples and little is known about their life strategies. Accordingly, cephalopod paralarvae were examined in the upwelling ecosystem of the Ría de Vigo (NW Spain) at night from 2008 to 2010. Multivariate analyses and generalized linea...

A brooding Octopus vulgaris female was monitored for 128 days in her natural habitat. The main reproductive events and embryonic development in relation to the temperature inside the spawning den, which was recorded by long-battery-life mini-data loggers, are described in the wild. The den temperature ranged from 12.9 to 19.3°C. The total number of...

The planktonic stage of Octopus vulgaris is the least studied part of their life cycle and is the bottleneck in making their aquaculture viable. All octopus paralarvae captured to date over the continental shelf (<200 m depth) were early stages with only three suckers per arm. Captive studies have shown that octopuses settle with around 23 suckers...

The cephalopod paralarvae collected during the surveys CAIBEX-I (NW Iberian Peninsula, n=133) and CAIBEX-III (Morocco, n=244), were identified in collaboration with the Barcoding of Life Database (BOLD) within the project CEPAR: Cephalopod paralarvae of the Northeastern Atlantic. The project amassed COI data for 87.5% specimens (NW Iberian Peninsul...

The European market is one of the most important markets in the world for cephalopods. Cephalopod fisheries are especially important in southern European waters where more cephalopod species are consumed as part of the traditional diet and the small-scale fishingindustry targeting these species is of considerable social and economic importance. Cur...

The embryonic development of the squid Loligo vulgaris was observed from 183 egg 30 masses collected from special devices deployed throughout Cabrera National Park 31 (Baleares Islands, Western Mediterranean Sea). The sequence alignment analysis of 32 gene cytochrome oxidase I revealed that all embryos belonged to L. vulgaris. In total, 33 549 egg...

Small copepods (<2 mm) are the most abundant metazoans in the world’s oceans, a keystone in pelagic food webs. Small copepods are considered to be omnivorous, feeding on unicellular protists and phytoplankton, with carnivorous feeding –i.e. preying on zooplankton- restricted to larger copepods and cyclopoid copepods. We developed a PCR based techni...

Some 290 species of squids comprise the order Teuthida that belongs to the molluscan Class Cephalopoda. Of these, about 30–40 squid species have substantial commercial importance around the world. Squid fisheries make a rather small contribution to world landings from capture fisheries relative to that of fish, but the proportion has increased stea...

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...

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...

The selection of spawning habitat of a population of Octopus vulgaris that is subject to a small scale exploitation was studied in the Cíes Islands within the National Park of the Atlantic Islands of Galicia (NW Spain). The technique used was visual censuses by scuba diving. We conducted 93 visual censuses from April 2012 to April 2014. The total s...

The selection of spawning habitat of a population of Octopus vulgaris that is subject to a small-scale exploitation was studied in the Cíes Islands within the National Park of the Atlantic Islands of Galicia (NW Spain). The technique used was visual censuses by scuba diving. We conducted 93 visual censuses from April 2012 to April 2014. The total s...

Age and growth of the horned octopus Eledone cirrhosa are estimated for the first time by stylet increment analysis. Specimens were collected between March 2009 and March 2010 from the commercial trawl fishery operating off northwestern Iberian coasts. A pool of stylets representing all size classes were defined by means of modal progression analys...

El dinamismo de la información en la Naturaleza Ángel Guerra Ediciones Encuentro, 2015. Madrid. 271 págs. Hasta no hace mucho se pensaba en la materia como un sujeto pasivo e inerte de las transformaciones que suceden a todos los niveles en la naturaleza, desde el fisicoquímico al biológico, pasando por el astrofísico y geológico. Sin embargo, los...

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he first description of cannibalism in wild adult Octopus vulgaris is presented from 3 observations made in the Ría de Vigo (NW Spain), which were filmed by scuba divers. These records document common traits in cannibalistic behavior: (a) it was intercohort cannibalism; (b) attacks were made by both males and females; (c) in 2 of the records, the p...

Four visual censuses targeting Octopus vulgaris living in dens on sandy bottoms were carried out from June to October 2013 in the National Park of the Atlantic Galician Islands (NW Spain). Censuses were undertaken by scuba diving between 5 and 21 m depth in daytime. The total area swept was 13.75 ha. There were no significant differences between oc...

Oceanic cephalopods, especially squids, are one of the main animals in oceanic ecosystems and constitute a key group in marine food webs. Despite of their importance a small number of research cruises targeting on this group have been conducted in the Canary Islands. We report herein on the micronektonic component of the pelagic assemblage in the C...

INTRODUCTION Oceanic cephalopods, especially squids, are one of the main animals in oceanic ecosystems and constitute a key group in marine food webs. Despite of their importance a small number of research cruises targeting on this group have been conducted in the Canary Islands. We report herein on the micronektonic component of the pelagic assemb...

Cephalopod life cycles generally share a set of stages that take place in different habitats and are adapted to specific, though variable, environmental conditions. Throughout the lifespan, individuals undertake a series of brief transitions from one stage to the next. Four transitions were identified: fertilisation of eggs to their release from th...

We contrasted histological characteristics with a macroscopic maturity scale in Octopus vulgaris. Seven histological stages of maturation were identified, and a stereological method was used to develop a new histological maturity index (HMI). This index was related to the gonadosomatic index giving the possibility to estimate the histological stage...

La vida en las grandes profundidades Life at great depths  Jorge Hernández-Urcera y Ángel Guerra* Resumen Una rápida y rigurosa mirada a los inmensos y extraordinarios eco-sistemas que están presentes en las grandes profundidades marinas permite describir sus principales características, las adaptaciones biológicas más relevantes de los orga-nismo...

Sustainable management of exploited stocks demands, among others issues, to identify the spawning spatio-temporal patterns and eventually to protect the spawning grounds of the target species. Squid seems to aggregate at this crucial period of the life-history, which implies increasing vulnerability to fishing. Unlike those of other loliginid speci...

The USA National Academies defined interdisciplinary research (IDR) as ‘a mode of research by teams or individuals that integrates information, data, techniques, tools, perspectives, concepts, and/or theories from two or more disciplines or bodies of specialized knowledge to advance fundamental understanding or to solve problems whose solutions are...

Architeuthis dux diet has been analysed according to information available from literature and from the analysis of gut contents of five females and two males from Mediterranean and Atlantic Iberian waters (20 specimens in total). This is the first time that A. dux diet from Atlantic and Mediterranean waters is described. Body weight of specimens r...

FAO Species Identification Guide for Fisheries Purposes. Cephalopod species to the Eastern Central Atlantic

This paper constitutes an updated review of the biology, ecology and fisheries of the ommastrephid short-finned squid Illex coindetii, an oceanic and neritic species widely distributed in Atlantic and Mediterranean waters. I. coindetii seem to produce large numbers of small eggs. Their rhyncoteuthion paralarvae are small, less than 2 mm total lengt...

This article presents an updated review of the biology, ecology and fisheries of ommastrephid squid Todaropsis eblanae, and the first preliminary identification of the early life stages (Rhynchoteuthion) is also given. Estimations from growth increments in statoliths show average growth rates of 0.30 mm mantle length (ML) day-1 in males and 0.67 ML...

Length–weight relationships, sex-ratio, maturity patterns, size at first maturity, reproductive outputs, fecundity and spawning period of horned octopus Eledone cirrhosa in north-west Iberian coast are presented for the first time. Samples were collected between February 2009 and July 2011 in four fishing ports along the north-west Iberian coast: B...

This work was made under the framework of the multidisciplinary project “Canaries–Iberian Marine Ecosystem Exchanges (CAIBEX)”, to define and compare the cephalopod assemblage in relation with mesoscale dynamics between the coastal-shelf areas and the adjacent ocean. Lagrangian experiments were carried out to track upwelled water masses with a drif...

Despite its charismatic appeal to both scientists and the general public, remarkably little is known about the giant squid Architeuthis, one of the largest of the invertebrates. Although specimens of Architeuthis are becoming more readily available owing to the advancement of deep-sea fishing techniques, considerable controversy exists with regard...

Despite its charismatic appeal to both scientists and the general public, remarkably little is known about the giant squid Architeuthis, one of the largest of the invertebrates. Although specimens of Architeuthis are becoming more readily available owing to the advancement of deep-sea fishing techniques, considerable controversy exists with regard...

The short-term, meso-scale variability of the mesozooplankton community present in the coastal upwelling system of the Ría de Vigo (NW Spain) has been analysed. Three well-defined communities were identified: coastal, frontal and oceanic, according to their holoplankton-meroplankton ratio, richness, and total abundance. These communities change...

The seven-arm octopus Haliphron atlanticus Steenstrup 1861 belongs to one of the four families of Argonautoidea Naef, 1912, which are primarily distinguished by an unusual means of copulation which involves transferring a detached hectocotylus from the male to the female. H. atlanticus coils the hectocotylus into a sac beneath the right eye. Althou...

Variation in sperm morphology is widespread throughout the metazoa, and has been used as an informative taxonomic character. Electron microscopy techniques allowed spermatozoa ultrastructure analyses of three sepiolid squid species with restricted habitats at different geographical locations —Sepiola atlantica from the Northeastern Atlantic, Euprym...

We found discrepancies which would drive us to underline that: i) our three first specimens could belong to C. canariensis, but the diagnostic characters related to the light organs on the eyeball should be improved from the original description, and ii) the remaining specimens belong to C. sicula, thus confirming the presence of this species outsi...

We found discrepancies which would drive us to underline that: i) our three first specimens could belong to C. canariensis, but the diagnostic characters related to the light organs on the eyeball should be improved from the original description, and ii) the remaining specimens belong to C. sicula, thus confirming the presence of this species outsi...

A specimen of Batoteuthidae was caught during the research cruise ATLANTIS 2009 on 21 March 2009 at 45°09.51' S - 45°08.07' S - 59°29.04' W - 59°27.98'W (Patagonian slope), depth 1195-1221 m. This specimen is a juvenile male, 105 mm mantle length. It is the largest Batoteuthis with complete tentacles captured to date. It shares the main diagnostic...

Data on opportunistic sightings of diamond-shaped squid Thysanoteuthis rhombus egg masses in the Canary Islands (Atlantic Ocean) are presented. A total of 16 egg masses of this species were recorded and photographed from 2000 to 2010 around the western islands of the archipelago (El Hierro, Tenerife and La Gomera). These data reveal the existence o...

Data on opportunistic sightings of diamond-shaped squid Thysanoteuthis rhombus egg masses in the Canary Islands (Atlantic Ocean) are presented. A total of 16 egg masses of this species were recorded and photographed from 2000 to 2010 around the western islands of the archipelago (El Hierro, Tenerife and La Gomera). These data reveal the existence o...