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12 pages, 4 figures, 1 table, Only 50% – 60% of total seafood catch is used for human consumption, seafood processing being consid- ered as one of the main sources of by-products. Among marine species, jumbo squid (JS; Dosidicus gigas ) represents the most important squid fishery, showing an increasing economic interest in many countries. As for any other marine species, the regular cleaning, dressing and processing produce high quantities of by-products (skin, head, fins, viscera, tentacles, unclaimed mantle, etc.) that are rich in many nutrients (proteins, lipids, minerals, vitamins, enzymes, biopolymers, etc.). This review compiles information about extraction and employment of JS by-products with the aim of enhancing their economic value and reduce environmental drawbacks. A special emphasis is given to the relevance in developing methods susceptible to transform by-products into useful and profitable products susceptible to be applied in several industries such as food, medicine, agrochemical or pharmaceutical. Future possible trends for widening this prof- itable use are mentioned

The purpose of the research was to determinate proximal composition and functional properties of the giant squid freeze-dried surimi (Dosidicus gigas). Surimi elaborated from giant squid and it lyophilized until obtaining surimi powder to evaluate its characteristics and functional properties. The protein content was 58.7% and carbohydrate 30.5%. Protein solubility in water and salt (3%) were 21.1% and 40.6% respectively, these values being higher than surimi powder of commercial species. The gelling capacity was 2.4% and the emulsifying capacity was 79.9% at a concentration of 1.0%. The color on the Hunter scale was L*: 91.5; a*: 0.5; b*: 7.0. Giant squid powder surimi considered as a functional protein powder due to its percentage protein content, and had good technological characteristics and great potential in the food industry. El propósito de la investigación fue determinar la composición proximal y propiedades funcionales del surimi liofilizado de calamar gigante (Dosidicus gigas). Se elaboró surimi a partir de calamar gigante y fue liofilizado hasta obtener surimi en polvo para evaluar sus características y propiedades funcionales. El contenido de proteínas fue 58,7% y carbohidratos 30,5%. La solubilidad proteica en agua y sal (3%) fueron 21,1% y 40,6% respectivamente, siendo estos valores superiores a surimi en polvo de especies comerciales. La capacidad de gelificación fue 2,4% y la capacidad emulsificante fue 79,9% a una concentración del 1,0%. El color en la escala de Hunter fue L*: 91,5; a*: 0,5; b*:7,0. El surimi en polvo de calamar gigante fue considerado como un polvo proteico funcional debido a su contenido porcentual proteico, y tuvieron buenas características tecnológicas y de gran potencial en la industria alimentaria.

27 pages, 5 tables, 3 figures, Jumbo squid (Dosidicus gigas) is one of the largest cephalopods, and represents an important economic fishery in several regions of the Pacific Ocean, from southern California in the United States to southern Chile. Large and considerable discards of this species, such as skin, have been reported to constitute an important source of potential by-products. In this paper, a shotgun proteomics approach was applied for the first time to the characterization of the jumbo squid (Dosidicus gigas) skin proteome. A total of 1004 different peptides belonging to 219 different proteins were identified. The final proteome compilation was investigated by integrated in-silico studies, including gene ontology (GO) term enrichment, pathways, and networks studies. Potential new valuable bioactive peptides such as antimicrobial, bioactive collagen peptides, antihypertensive and antitumoral peptides were predicted to be present in the jumbo squid skin proteome. The integration of the global proteomics results and the bioinformatics analysis of the jumbo squid skin proteome show a comprehensive knowledge of this fishery discard and provide potential bioactive peptides of this marine by-product., This research was funded by Ramón Areces Foundation (XVII National Grant), GAIN-Xunta de Galicia Project (IN607D 2017/01) and by CONACyT-Mexico under grant 2174. M.C. is supported by the Ramón y Cajal Contract (Ministry of Science, Innovation and Universities of Spain).

9 pages, 3 figures, 1 table, 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 (seminal receptacles) in their buccal area, which are not in direct physical contact with the deposited spermatangia. The mechanism of sperm transmission between the implantation site and the storage organ has remained a major mystery in cephalopod reproductive biology. Here, jumbo squid females covering almost the entire life cycle, from immature to a laboratory spawned female, were used to describe the internal structure of the seminal receptacles and the process of sperm storage. Seminal fluid was present between the spermatangia and seminal receptacles, but absent in regions devoid of seminal receptacles. The sperm cellular component was formed by spermatozoa and round cells. Although spermatozoa were tracked over the buccal membrane of the females to the inner chambers of the seminal receptacles, round cells were not found inside the seminal receptacles, suggesting that spermatozoa are not sucked up by the muscular action of the seminal receptacles. This finding supports the hypothesis that spermatozoa are able to actively migrate over the female skin. Although further experimental support is needed to fully confirm this hypothesis, our findings shed light on the elusive process of sperm storage in many cephalopods, a process that is fundamental for understanding sexual selection in the sea, This study was funded by the research project CALOCEAN-2 (AGL2012-39077) from the Ministry of Economy and Competitiveness (MINECO) of Spain. FAFA was supported by two Grants (BES-2013-063551 and EEBB-I-15-09631) from MINECO. HJTH was financed by a Grant (CP1218) of the Cluster of Excellence 80 “The Future Ocean”, funded within the framework of the Excellence Initiative by the Deutsche Forschungsgemeinschaft (DFG) on behalf of the German federal and state governments. Support from Grants OCE-1338973 RAPID, IOS-142093 EAGER, OCE 0850839 and IOS-1557754 (US National Science Foundation), and N000140911054 (US Office of Naval Research) is also acknowledged

6 páginas, 4 tablas, 2 figuras, During the industrial processing of jumbo squid (Dosidicus gigas), large amounts of by-products containing biological active compounds are generated. In this study, aqueous solutions including acetic acid-ethanol extracts of jumbo squid skin (JSS) were tested at three different concentrations as icing media. The effects of the JSS extracts on the quality evolution of chilled mackerel (Scomber scombrus) were monitored. A significant inhibition (p < 0.05) of microbial activity was determined in the fish batch corresponding to the icing condition including the highest JSS concentration. Additionally, fish specimens corresponding to batches including any of the JSS concentrations tested showed lower (p < 0.05) proteolytic counts and pH values than control mackerel. Sensory analysis revealed a marked shelf life extension in chilled mackerel stored in ice including the highest JSS concentration; specimens from such batch were found to be still acceptable after 13 days of storage, while all other mackerel batches were rejectable. The marked microbial activity inhibition observed could be explained on the basis of the presence in ice of lipophilic compounds obtained by acetic acid-ethanol extraction of JSS, This work was supported by the CONACYT-Mexico grant 154046 and the Consejo Superior de Investigaciones Científicas (CSIC) through Research Project PIE 201370E001

The use of mark-recapture data can be an alternative to other methods for estimating abundance of the jumbo squid Dosidicus gigas and can be used when catch-per-unit-effort data applied to depletion models or estimates from survey research are not available. Two mark-recapture events were analyzed in the central Gulf of California, Mexico, during October 2001 and April 2002 to assess the status of jumbo squid. Results from October 2001 yielded a population size of 20.2 million squid with a 95% CI of 16 to 26.5 million squid (p < 0.05). In April the population size was estimated at 132.6 million squid with a 95% CI of 85.5 to 222 million squid (p < 0.05). The results for October and April show 2 different periods of abundance. Estimates of tag return rates were higher in April (5.5%) than in October (1.7%), and recruitment is the most plausible explanation. In the Gulf of California, recruitment of jumbo squid commonly occurs during April and May.

The population structure of the jumbo squid (Dosidicus gigas) is complex, containing several cohorts and three groups defined by their size (small, medium, and large) and by differences in maturation, growth, and life span. Several authors have indicated the possibility of such groups representing discrete genetic units even at level subspecies or species in statu nascendi. Genetic divergence was tested in samples from the Gulf of California (Mexico) and Peruvian Sea by estimation of population divergence statistics, an exact test of homogeneity of allele frequencies, analysis of molecular variance, and genealogical trees applied to data obtained with two molecular markers: RAPDs and mtDNA sequences identified by SSCPs. Neither significant values of θ (FST) nor significant heterogeneity in allele frequencies were detected. Lack of evidence does not imply complete lack of differentiation among the groups but supports the fact that a geographically spread population can have different size groups without relevant genetic differentiation, implying that the hypothetical genetically differentiated groups can occur in different ecological niches.

We analyzed the effect of outliers of the catch-per-unit effort on the catchability coefficient estimated by using a depletion model. When we used catch-per-unit effort in the Delury model, we observed a curve in the regression of depletion against time. When we then solved the model with a normal probability distribution, the catchability coefficient was poorly estimated. We improved the estimation of catchability using an algorithm that used a two-component-mixture probability distribution. The estimations for catchability (q) and recruitment (N0) were q = 0.41 X 10–3, N0 = 9.13 X 106, and the estimated likelihood was 2.65 X 104 using an algorithm of the normal probability distribution, whereas the estimations made using the algorithm of a two-component-mixture probability distribution were q = 0.23 X 10–3, N0 = 18.07 X 106, and the estimated likelihood was 4.89 X 106. The maximum likelihood estimated with the mixture-distribution algorithm was greater than the maximum likelihood estimated with the normal-distribution algorithm. We believe the two-component-mixture probability distribution fit the data better than the normal probability distribution. From this we determined the consequences on management when overestimations or underestimations of catchability are estimated.

Sperm whales occur worldwide and feed largely on meso- and bathypelagic squid, but little is known about the behavioral ecology of this predator and its prey. In the Gulf of California, sperm whales are thought to feed on the abundant jumbo (Humboldt) squid, an ecologically and com- mercially important species. In this study, we attached satellite-linked dive recorders to 5 sperm whales and pop-up archival transmitting tags to 3 jumbo squid in the same area and time period in or- der to record their diving behavior and movements. Most (91%) deep dives by whales ranged from 100 to 500 m (average 418 ± 216.0 m) and lasted 15 to 35 min (average 27 ± 9.1 min). During daytime hours, jumbo squid spent about 75% of the time in the 200 to 400 m depth range, and sperm whales showed a similar dive-depth preference. The vertical distribution pattern of squid changed during the night, with squid spending about half the time at depths of

The technological effect of wheat dietary fibre was studied in surimi gel products obtained from giant squid (Dosidicus gigas). Three and six percent wheat dietary fibre with different particle sizes was added at the same time as water to maintain similar moisture levels in all samples. Under scanning electronic microscopy (SEM), gel samples with added dietary fibre presented a regular distribution of dietary fibre: however, the dietary fibres were larger than the cells of the gel matrix, making the protein network less homogeneous. This, combined with a smaller proportion of protein, reduced the gel strength, hardness, cohesiveness and water binding capacity (WBC) of gels. Addition of wheat dietary fibre to giant squid surimi also made gels yellower and reduced their lightness. The sensory panel detected no differences in the appearance of samples, but they did detect differences in textural properties., This work has been supported by the Spanish Ministerio de Educación y Ciencia under Project AGL2002-04104- C04-03, and by the EU under Integrated Project SEAFOODplus (Ref. FP6/506359).

El presente trabajo estudia la biología reproductiva de la jibia o calamar gigante, Dosidicus gigas frente a la costa de Chile central capturados en julio-agosto (invierno) y octubre-noviembre (primavera) de 1993. En 254 hembras (93 de invierno y 161 de primavera) se analizó el estado de madurez microscópico, determinándose un predominio de hembras en maduración, y en menor porcentaje a punto de desovar. El índice gonadosomático (IGS) y el índice del peso del complejo oviductual (IPCO) indicaron que las hembras estaban en un proceso de maduración gonádica. En hembras, el IGS y el IPCO muestran diferencias significativas en los valores promedio entre invierno y primavera (p= 0,000 y p= 0,002, respectivamente). Sólo para el IPCO de invierno existió una relación lineal con la longitud dorsal del manto (p=0,009, r²=0,067). En aguas chilenas la presencia de hembras maduras de D. gigas abarcaría gran parte del año, alcanzando los ejemplares de invierno una mayor talla de madurez sexual. The present study examines the reproductive biology of the giant squid, Dosidicus gigas collected off the coast of north-central Chile from july-august (winter) to october-november (spring) of 1993. In 254 females (93 in winter and 161 in spring) the microscopic stage of maturity was analyzed, being determined a prevalence of females in maturation, and in smaller percentage near the spawning. The Gonadosomatic Index (IGS) and the Index of the Weight of the Oviductual Complex (IPCO) indicated females were in process of gonadic maturation. Seasonal significant differences for IGS and IPCO were found between winter and spring (p=0,000 and p=0,002, respectively). Only winter IPCO showed a lineal relationship with the mantle dorsal length (p=0,009, r²=0,067). In Chilean waters mature females of D. gigas were found the major part of the year, but the winter individuals had bigger size of sexual maturity.