Search

The snow/pink crab (Chionoecetes opilio) and Northern shrimp (Pandalus borealis) are widely distributed in the North Atlantic Ocean. During processing/consumption, about 80% of the harvest is discarded as processing waste, which is a rich source of protein, chitin, minerals, and carotenoids. This study, for the first time, investigated the proximate composition and individual amino acids, minerals, and carotenoids from different body parts (carapace, shoulder, claw, tip, and leg) of snow crabs and shrimp shells. Shrimp proteins were found to be abundant and well-balanced in their amino acid composition. Compared to shrimp shells, a lower content of amino acids was found in the snow crab, depending on the part of the shell used. Moreover, crab shells, mainly crab claws, contained a higher (p < 0.05) level of chitin compared to shrimp shells. Seven micro-elements (Mn, Fe, Cu, Zn, As, Ba, and Ce) and six macro-elements (Ca, Na, K, Mg, P, and Sr) were identified using inductively coupled plasma-mass spectrometry (ICP-MS). Among them, calcium and iron were higher in crab carapaces (p < 0.05), followed by shrimp shells and other crab shell segments. Additionally, shrimp and crab carapaces contained a significant level of carotenoids, and these were mainly composed of astaxanthin and its mono- and diesters, along with zeaxanthin, astacene, canthaxanthin, and lutein. Thus, this investigation provides detailed information to allow upcycling of shellfish waste and addresses the knowledge gap concerning the availability of various nutrients in different crab sections and shrimp shells. [ABSTRACT FROM AUTHOR]

Abstract Shrimps are the most consumed species among crustaceans and are well appreciated for their flavor and high nutritional value. This work investigated the antioxidative compounds of Northern shrimp (Pandalus borealis) and its processing discards (shells and heads) using various solvents and chromatographic techniques as well as mass spectrometry. Ethanol served as the best extraction medium, and the extracts obtained demonstrated strong antioxidant activity in a β-carotene-linoleate emulsion system. The antioxidative compounds of the extract were isolated using a silica gel column chromatography, followed by thin layer chromatography. This led to the identification of two highly polar and two low polarity compounds. These compounds, for the first time, were isolated and purified by using reversed-phase HPLC. Their structures were tentatively elucidated using electrospray mass spectrometry. These unique compounds were heterocyclic phenolic compounds and identified as 7-(3-butenyl)-2-hydroxy-6-(1,2,5,6-tetrahydropyridin-2-yl) quinoline and 7-(3-butenyl)-2-hydroxy-6-(1,2,5,6-tertahydropyridin-2-yl)-7,8-dihydroquinoline and their isomers. The proposed novel compounds in shrimp provide a reason for their oxidative stability and potential benefits, as well as possibly serving as substrates for the discoloration of shrimp. Graphical Abstract

The snow/pink crab (Chionoecetes opilio) and Northern shrimp (Pandalus borealis) are widely distributed in the North Atlantic Ocean. During processing/consumption, about 80% of the harvest is discarded as processing waste, which is a rich source of protein, chitin, minerals, and carotenoids. This study, for the first time, investigated the proximate composition and individual amino acids, minerals, and carotenoids from different body parts (carapace, shoulder, claw, tip, and leg) of snow crabs and shrimp shells. Shrimp proteins were found to be abundant and well-balanced in their amino acid composition. Compared to shrimp shells, a lower content of amino acids was found in the snow crab, depending on the part of the shell used. Moreover, crab shells, mainly crab claws, contained a higher (p < 0.05) level of chitin compared to shrimp shells. Seven micro-elements (Mn, Fe, Cu, Zn, As, Ba, and Ce) and six macro-elements (Ca, Na, K, Mg, P, and Sr) were identified using inductively coupled plasma-mass spectrometry (ICP-MS). Among them, calcium and iron were higher in crab carapaces (p < 0.05), followed by shrimp shells and other crab shell segments. Additionally, shrimp and crab carapaces contained a significant level of carotenoids, and these were mainly composed of astaxanthin and its mono- and diesters, along with zeaxanthin, astacene, canthaxanthin, and lutein. Thus, this investigation provides detailed information to allow upcycling of shellfish waste and addresses the knowledge gap concerning the availability of various nutrients in different crab sections and shrimp shells.

The offshore Northern shrimp (Pandalus borealis) bottom trawl fishery in eastern Canada currently uses 22 and 28 mm bar spacing Nordmøre grids to limit bycatch from using small mesh codends. However, a recent rebound of juvenile redfish (Sebastes spp.), that can pass through the grids, has greatly increased bycatch. To address this concern, this study investigated the effectiveness of 17 and 15 mm bar spacing Nordmøre grids in a twin-trawl (paired) configuration against the traditional 22 mm bar spacing grid. Size selectivity analyses showed that the 17 and 15 mm grids resulted in no significant reduction in shrimp catch across all length classes. The 17 mm grid significantly reduced redfish bycatch for all length classes and the 15 mm grid significantly reduced redfish bycatch for individuals larger than 95 mm total length. Less redfish entered the codend with the experimental grids, however, the overlap in width between redfish and Northern shrimp limits the overall sorting efficiency of the grids, leaving some redfish still vulnerable to capture. [ABSTRACT FROM AUTHOR]

Bio-inorganic chemistry is found as an endearing aspect to research in today's epoch. It deals with chemical reactions between the metals with natural resources, such as air, soil, water and byproducts (foods). To assess the decline in the quality of southern pink shrimps and water quality on samples from the Lagos lagoon, the morphometric assessment of the crustacean (Farfantepenaeus notialis -- F. notialis), physicochemical parameters (pH, temperature, salinity, conductivity, total hardness, total dissolved solids, total suspended solids, biological oxygen demand, chemical oxygen demand, dissolved oxygen, sulphates, nitrate and phosphate) and levels of six (6) trace metals (cadmium, chromium, zinc, iron, manganese and copper) were collected from three sampling points with renowned anthropogenic activities along the stretch of the Lagos Lagoon using standard analytical procedures and the results were compared with standard acceptable limits. The crustaceans used had total length (4.0 - 14.4 cm), carapace length (1.6 -- 6.4 cm), total weight (1.1 -- 20.8 g) and carapace weight (0.9 - 11.5 g). The results obtained in the physicochemical analysis revealed that a few parameters such as biochemical oxygen demand and total suspended solids were beyond acceptable limits, while the trace metals were present in the samples at different levels but still within the maximum residual levels in the edible tissues of the pink shrimps. The obtained results showed that the crustacean and water from the lagoon contained metals but did not exceed both local and international standards of limit and thus, they are still safe for consumption and domestic uses. [ABSTRACT FROM AUTHOR]

Impacts of global ocean changes on species have historically been investigated at the whole-organism level. However, acquiring an in-depth understanding of the organisms’ cellular metabolic responses is paramount to better define their sensitivity to environmental challenges. This is particularly relevant for species that experience highly different environmental conditions across their distribution range as local acclimatization or adaptation can influence their responses to rapid global ocean changes. We aimed at shedding light on the cellular mechanisms underpinning the sensitivity to combined ocean warming (OW) and acidification (OA) in the northern shrimp Pandalus borealis, from four different geographic origins defined by distinctive environmental regimes in the northwest Atlantic: i.e. St. Lawrence Estuary (SLE), Eastern Scotian Shelf (ESS), Esquiman Channel (EC) and Northeast Newfoundland Coast (NNC). We characterized targeted metabolomics profiles of the muscle of shrimp exposed to three temperatures (2, 6 or 10°C) and two pH levels (7.75 or 7.40). Overall, shrimp metabolomics profiles were modulated by a significant interaction between temperature, pH and origin. Temperature drove most of the metabolomics reprogramming, confirming that P. borealis is more sensitive to OW than OA. Inter-origin differences in metabolomics profiles were also observed, with temperature*pH interactions impacting only shrimp from SLE and ESS, pH affecting only shrimp from SLE and temperature impacting shrimp from all origins. Temperature influenced metabolomics pathways related to the tricarboxylic acid cycle (TCA) and amino acid metabolism, resulting mainly in an accumulation of TCA intermediates and tyrosine. Temperature*pH and pH in isolation only affected amino acid metabolism, leading to amino acids accumulation under low pH. However, the ratio of ATP : ADP remained constant across conditions in shrimp from all origins suggesting that their energetic status is not affected by OW and OA. Still, the accumulation of TCA intermediates and tyrosine suggests the possible enhancement of immune responses under future OW and OA conditions. Our findings suggest that shrimp from SLE are more sensitive at the molecular level, compared to others, to future complex environmental conditions. This underlines the importance of investigating intraspecific variation in mechanisms of responses to combined drivers when trying to define species’ sensitivity to global ocean changes.

The size selectivity and usability of three codends were quantified and compared for the first time in the inshore Northern shrimp (Pandalus borealis) trawl fishery of Iceland using the covered codend method: a conventional diamond-mesh codend (T0), conventional square-mesh codend (T45), and a 90° turned mesh codend (T90) constructed of four panels and with shortened lastridge ropes. Fishers, wanting to increase the average-individual size of captured shrimp, had requested the T90 codend to be compared with conventional codends for consideration in the fishery. Results showed that, on average, the T45 and T90 codends had better size selectivity than the T0 codend in terms of releasing individuals smaller than 13 mm carapace length (Minimum References Size; MRS). The T90 codend retained significantly less Northern shrimps between 9 and 19 mm than the T0 codend and between 15 and 19 mm than the T45 codend. No significant difference of size selectivity between T45 and T0 codends was observed. All three codends presented high retention ratios of Northern shrimps above MRS (>63%) for the population encountered. However, the T0 codend was not effective at sorting out small Northern shrimps; at least 86% of Northern shrimps smaller than 13 mm were retained in the T0 codend if encountered. Catches from T45 and T90 codends had a lower proportion of shrimp below MRS. Since discarding of undersized Northern shrimps is prohibited in Iceland and fishers wanted to catch on average larger shrimp, using the novel T90 codend would enable fishers to use their quotas more efficiently.

Information about the dietary composition of a species is crucial to understanding their position and role in the food web. Increasingly, molecular approaches such as DNA metabarcoding are used in studying trophic relationships, not least because they may alleviate problems such as low taxonomic resolution or underestimation of digestible taxa in the diet. Here, we used DNA metabarcoding with universal primers for cytochrome c oxidase I (COI) to study the diet composition of the northern shrimp (Pandalus borealis), an Arctic keystone species with large socio‐economic importance. Across locations, jellyfish and chaetognaths were the most important components in the diet of P. borealis, jointly accounting for 40%–60% of the total read abundance. This dietary importance of gelatinous zooplankton contrasts sharply with published results based on stomach content analysis. At the same time, diet composition differed between fjord and shelf locations, pointing to different food webs supporting P. borealis in these two systems. Our study underlines the potential of molecular approaches to provide new insights into the diet of marine invertebrates that are difficult to obtain with traditional methods, and calls for a revision of the role of gelatinous zooplankton in the diet of the key Arctic species P. borealis, and in extension, Arctic food webs. [ABSTRACT FROM AUTHOR]

The main fisheries of northern shrimp in Icelandic waters are located west and north of Iceland. These locations are studied in an annual survey to estimate stock size and distribution of northern shrimp. In July 2015, an additional survey was conducted to study the benthic community structure and function to describe the habitat where the northern shrimp fisheries take place. Underwater images were taken from 26 stations, grab samples were collected at 11 stations and in addition, by-catch was collected from the annual Icelandic shrimp survey in August 2015. The sampling sites, despite being distributed throughout a relatively large area north of Iceland, were rather uniform in relation to sediment type and fauna composition. The stations were similar in grain size and dominated by soft sediment of sand and silt/mud and soft sediment fauna. The infauna was mainly burrowing infauna with affinity to soft sediment and surface deposit feeding. The epifauna were free-living crawlers with affinity for predation feeding habit. No relationship with environment was observed for either the epifauna or the infauna. Species diversity and community composition did not vary with depth, probably because of the narrow depth range of the sites. This study provides the first data on benthic in- and epifauna in northern shrimp fishery locations north of Iceland, which can later be used to estimate possible changes and/or the effect of shrimp fishing within this area. [ABSTRACT FROM AUTHOR]

Main technological and chemical characteristics of small-sized shrimps Pandalus borealis, P. goniurus and krill Euphausia superba are presented. The main processes of this kind of shrimp processing are described, with usage of its own complex of proteinases to produce autoproteolysis products. Lysates of these shrimps have high nutritional value comparable with the value of low-fat cottage cheese, though the shrimp lysate protein is a completely animal protein similar to beef one. As a source of low-fat protein, the shrimp lysates belong to the category of specialized and functional food and food ingredients; they also can de considered as the source of omega-3 fatty acids and astaxanthin. Volatile components of the shrimp lysates contain 30 compounds responsible for taste and aroma properties of crabs and shrimps, as thiran, methylthiran, dimethyldisulfide, thioacetic acid, 2-mercaptopropanoic acid, etc. Safety of shrimps and their lysates is provided by low content of organochlorine compounds, radionuclides, toxic elements and low values of microbiological parameters, below of the maximum permissible levels. The shrimp lysates are suitable for using in manufacture of emulsion and pasty products with high commodity properties, classified as gastronomic products with high taste and nutritional value.

Bioluminescence is a prevalent phenomenon throughout the marine realm and is often the dominant source of light in mesophotic and aphotic depth horizons. Shrimp belonging to the superfamily Oplophoroidea are mesopelagic, perform diel vertical migration, and secrete a bright burst of bioluminescent mucous when threatened. Species in the family Oplophoridae also possess cuticular light-emitting photophores presumably for camouflage via counter-illumination. Many species within the superfamily express a single visual pigment in the retina, consistent with most other large-bodied mesopelagic crustaceans studied to date. Photophore-bearing species have an expanded visual opsin repertoire and dual-sensitivity visual systems, as evidenced by transcriptomes and electroretinograms. In this study, we used immunohistochemistry to describe opsin protein localization in the retinas of four species of Oplophoroidea and non-ocular tissues of Janicella spinicauda. Our results show that Acanthephyra purpurea (Acanthephyridae) retinas possess LWS-only photoreceptors, consistent with the singular peak sensitivity previously reported. Oplophoridae retinas contain two opsin clades (LWS and MWS) consistent with dual-sensitivity. Oplophorus gracilirostris and Systellaspis debilis have LWS in the proximal rhabdom (R1-7 cells) and MWS2 localized in the distal rhabdom (R8 cell). Surprisingly, Janicella spinicauda has LWS in the proximal rhabdom (R1-7) and co-localized MWS1 and MWS2 opsin paralogs in the distal rhabdom, providing the first evidence of co-localization of opsins in a crustacean rhabdomeric R8 cell. Furthermore, opsins were found in multiple non-ocular tissues of J. spinicauda , including nerve, tendon, and photophore. These combined data demonstrate evolutionary novelty and opsin duplication within Oplophoridae, with implications for visual ecology, evolution in mesophotic environments, and a mechanistic understanding of adaptive counter-illumination using photophore bioluminescence. [ABSTRACT FROM AUTHOR]

The Northern shrimp (Pandalus borealis) is an important fishery resource of the Northern hemisphere. Caught by large offshore trawlers, this species is mainly landed as a cooked and frozen product. However, for boats fishing close to the shore, the landing of live shrimp could be a preferable option, as higher prices could be attained for this type of product. We hypothesize that landing and transport of live shrimp is feasible, if key factors for survival and suitable transportation methods are identified. To increase our understanding of post-harvest handling and its effect on shrimp survival, we conducted a set of dry (out of water) and wet (in water) transport experiments. Different cooling methods and temperatures were tested as well as the use of the sedative AQUI-S®. Additionally, a set of pilot studies was conducted to determine the time frame for post-harvest recovery and to identify a favorable water temperature to ensure optimal revitalization. A post-transport recovery period of 48 hours at water temperatures below 8°C was found to be appropriate and was applied to experimental animals before simulating different transport conditions. Live shrimp, transported dry for 24 hours at −0.5°C, showed a significantly lower mortality rate (14.4%) compared to shrimp transported dry at 2°C (67.8%). Transport of shrimp in water (3.0°C) at two different densities (~80 and ~165 kg/m3) did not reveal any significant difference in mortality after a 4-day period, with an overall survival of 92.5%. Although survival was not improved by post-transport treatment with AQUI-S®, our results show that it is possible to deliver vital live shrimp to the market, given optimal post-harvest revitalization and careful choice of transportation method. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Black spot gill syndrome in Pandalus borealis is caused by the apostome ciliate Synophrya sp. • The ciliate infects the gill tissues and undergoes metamorphosis into histotrophic life stages. • Parasitization by Synophrya sp. leads to the formation of melanized nodules and the distinct gross pathology. • Synophrya sp. epizootics could contribute to decline of P. borealis in North Atlantic commercial fisheries. Abstract Black spot gill syndrome in the northern shrimp, Pandalus borealis , is caused by an apostome ciliate, Synophrya sp., found within the gill lamellae. Whole mount staining, thin section histology, electron microscopy, and molecular studies were carried out on infected gills. The Synophrya 18S rRNA from Pandalus borealis (Genbank accession no. KX906568) and from two portunid crab species, Achelous spinimanus (Genbank accession no. MH395150) and Achelous gibbesii (Genbank accession no. MH395151) was sequenced. Phylogenetic analyses confirmed the identity of these ciliates as apostomes. The 18S rRNA sequence recovered from P. borealis shared 95% nucleotide similarity with the sequences recovered from the portunid crab species suggesting that it is a different species of Synophrya. The invasive hypertrophont stages, with a distinctive macronuclear reticulum, ranged in size from 300 to 400 µm with as many as 5 large forms/mm2 of gill tissue. Histotrophic hypertrophont stages and hypertomont stages were observed in these studies. The presence of the parasite was linked to the formation of melanized nodules (up to 9 nodules/mm2 of gill tissue) by the host and in some cases to extensive necrosis. Other studies have reported Synophrya sp. infections in P. borealis from Greenland, Labrador and Newfoundland, but further studies are necessary to determine the prevalence of this parasite in the dense schools of northern shrimp in the North Atlantic. Questions remain as to the possibility of epizootics of this pathogen and its impact on northern shrimp populations. [ABSTRACT FROM AUTHOR]

Northern shrimp (Pandalus borealis) oil, which is rich in omega-3 fatty acids, was recovered from the cooking water of shrimp processing facilities. The oil contains significant amounts of omega-3 fatty acids in triglyceride form, along with substantial long-chain monounsaturated fatty acids (MUFAs). It also features natural isomeric forms of astaxanthin, a nutritional carotenoid, which gives the oil a brilliant red color. As part of our efforts in developing value added products from waste streams of the seafood processing industry, we present in this paper a comprehensive characterization of the triacylglycerols (TAGs) and astaxanthin esters that predominate in the shrimp oil by using HPLC-HRMS and MS/MS, as well as 13C-NMR. This approach, in combination with FAME analysis, offers direct characterization of fatty acid molecules in their intact forms, including the distribution of regioisomers in TAGs. The information is important for the standardization and quality control, as well as for differentiation of composition features of shrimp oil, which could be sold as an ingredient in health supplements and functional foods.

Abstract Trawlers targeting Deep-water Shrimp (Pandalus borealis) in the North Atlantic use a Nordmøre sorting grid ahead of a small-meshed codend. Based on experimental fishing, the effect of adding a 9 mm spaced release grid behind the mandatory 19 mm spaced Nordmøre sorting grid, was determined. The performance in terms of size selection of the release grid and the two grids combined were assessed for target Deep-water Shrimp and for juvenile Redfish (Sebastes spp.) and American Plaice (Hippoglossoides platessoides), two of the most common bycatch species in the fishery. The aim of using the release grid was to improve the escape of undersized shrimp and the bycatch of juvenile fish from the gear. The results demonstrated that the release grid improved the escape of the smallest Deep-water Shrimp significantly. The fraction of small shrimp released through this grid was estimated to be 45%. However, the results also revealed the need for further improvements in the design of the release grid to increase the reduction of small shrimp and juvenile fish bycatch. For Redfish and American Plaice the fractions of juveniles escaping through the release grid were estimated to be 16% and 32%, respectively. In addition, the release grid only led to the escape of the smallest juvenile individuals, in particular for Redfish. [ABSTRACT FROM AUTHOR]

The Biscayne Bay Coastal Wetlands (BBCW) project of the Comprehensive Everglades Restoration Plan (CERP) aims to reduce point-source freshwater discharges and spread freshwater flow along the mainland shoreline of southern Biscayne Bay. These actions will be taken to approximate conditions in the coastal wetlands and bay that existed prior to construction of canals and water control structures. An increase in pink shrimp (Farfantepenaeus duorarum) density to ≥ 2 individuals m-2 during the wet season (i.e., August-October) along the mainland shoreline was previously proposed as an indication of BBCW success. This study examined pre-BBCW baseline densities and compared them with the proposed target. Densities were monitored by seasonal (wet, dry) throw-trapping (1 m2 replicated in triplicate) at 47 sites along ~22 km of the southwestern Biscayne Bay coastline over 10 years (2007–2016). Densities varied across years and were most often higher in dry seasons. Quantile regression revealed density limitation by four habitat attributes: water temperature (°C), depth (m), salinity (ppt), and submerged aquatic vegetation (SAV: % cover). Procrustean analyses that tested for concordance between the spatial and temporal distributions of shrimp densities and habitat metrics found that water temperature, water depth, and salinity explained ~ 28%, 28%, and 22% of density variability, respectively. No significant relationship with SAV was observed. Hierarchical clustering was used to identify spatially and temporally similar groupings of pink shrimp densities by sites or season-years. Significant groupings were then investigated with respect to potentially limiting habitat attributes. Six site and four year-season clusters were identified. Although habitat attributes significantly differed among spatial clusters, within-cluster median pink shrimp densities did not correlate with within-cluster minima, maxima, medians, or standard deviations of habitat attributes. Overall, pink shrimp density ( = 0.86, SD = 1.32 shrimp m-2) was significantly lower (t(α = 0.10,2),939 = -26.53, P <0.0001) than the 2 shrimp m-2 CERP Interim Goal target. Pink shrimp density corresponded significantly with salinity and appeared limited to density < 2 shrimp m-2 by salinity < ~18 ppt. Salinity is an environmental attribute that will be directly influenced by CERP implementation. [ABSTRACT FROM AUTHOR]

We examined how catches of ocean shrimp (Pandalus jordani), eulachon (Thaleichthys pacificus), and juvenile groundfish could be affected by altering the level of artificial illumination along the fishing line of an ocean shrimp trawl. In the ocean shrimp trawl fishery, catches of eulachon are of special concern, as the species' southern Distinct Population Segment is listed as "threatened" under the US Endangered Species Act. Using a double-rigged trawl vessel, with one trawl illuminated and the other unilluminated, we compared the catch efficiencies for ocean shrimp, eulachon, and juvenile groundfish between an unilluminated trawl and trawls illuminated with 5, 10, and 20 LED fishing lights along their fishing line. The addition of artificial illumination along the trawl fishing line significantly affected the average catch efficiency for eulachon, rockfish (Sebastes spp.), and flatfish, with the three LED configurations each catching significantly fewer individuals than the unilluminated trawl without impacting ocean shrimp catches. For Pacific hake (Merluccius productus), the ten LED-configured trawl caught significantly more fish than the unilluminated trawl. For the five and 20 LED configurations, mean Pacific hake catches did not differ from the unilluminated trawl. This study contributes new data on how artificial illumination can affect eulachon catches (and other fish) and contribute to their conservation. [ABSTRACT FROM AUTHOR]

In this paper, we report some morphological abnormalities for the deep-sea shrimp Glyphocrangon aculeata A. Milne-Edwards, 1881, collected from the western South Atlantic. All specimens analysed herein were collected in Potiguar Basin, located in northeastern Brazil, through bottom trawls along the continental slope between 150 and 2068 m depth in 2009 and 2011. Out of 59 specimens, one ovigerous female, collected at 1074 m depth, was registered with abnormalities in some regions of the carapace, abdomen and telson. Factors such as genetic mutations, nutritional alterations, or deformities during ecdysis are suggested as being the most probable cause of the deformities reported here. [ABSTRACT FROM AUTHOR]

A novel, standardized method has been developed in order to provide a quantitative description of shrimp peelability. The peeling process was based on the measure of the strength of the shell-muscle attachment of the shrimp using a texture analyzer, and calculated into the peeling work. The self-consistent method, insensitive of the shrimp size, was proven valid for assessment of ice maturation of shrimps. The quantitative peeling efficiency (peeling work) and performance (degree of shell removal) showed that the decrease in peeling work correlated with the amount of satisfactory peeled shrimps, indicating an effective weakening of the shell-muscle attachment. The developed method provides the industry with a quantitative analysis for measurement of peeling efficiency and peeling performance of shrimps. It may be used for comparing different maturation conditions in relation to optimization of shrimps peeling. [ABSTRACT FROM AUTHOR]

The Nordmøre grid is widely used in shrimp trawls to reduce the bycatch of fish species. However, small-sized fish species and juveniles still pass through the grid and enter the codend, along with the targeted shrimp. This bycatch of small fish has a negative impact on the ecosystem due to increased fish mortality, and leads to additional sorting work onboard. Some small-sized fish that enter the trawl avoid entering the codend by escaping through the outlet above the grid, without making contact with the grid itself. Design changes that promote this behavior could potentially reduce bycatch in shrimp trawl fisheries. Light-emitting diodes (LEDs) mounted around the escape outlet have previously been found to have either a negative effect, or no effect at all, on fish bycatch species. This study investigates the effect of mounting green LEDs on the lower part of a Nordmøre grid, to determine if their presence would encourage bycatch fish to rise towards the escape outlet prior to contacting the grid. Experimental fishing trials were conducted to assess the size selective properties of a 19 mm bar spaced Nordmøre grid with and without LEDs, mounted on a bottom trawl targeting Deep-water shrimp ( Pandalus borealis ). For the four bycatch species investigated, 51–100% of small fish passed through the Nordmøre grid. The addition of green LEDs to the Nordmøre grid did not significantly affect the escape probability or the size selectivity of any of the investigated species. Very few Deep-water shrimp were found to escape through the escape outlet independent of the presence of the LEDs mounted on the grid. [ABSTRACT FROM AUTHOR]

An enzymatic method to facilitate the peeling of cold water shrimps ( Pandalus borealis ) was developed. The protease solutions were used to mature the shrimps to promote shell-loosening prior to peeling. The efficiency of peeling enzyme-treated shrimps was evaluated by a new quantitative measurement based on the tensile force, presented as a peelability profile. It was found that enzymatic maturation efficiently improved the peelability of shrimps. The factors affecting the peelability of the enzyme-matured shrimps were the type of enzyme, enzyme concentration and maturation duration, while changes in pH had no impact. Maturation of shrimps in solutions of the endoproteases Endocut-01L (180 NU/g) and Endocut-03L (60 U/g) and the exoprotease Exocut-A0 (100 U/g) resulted in better peelability compared to shrimps matured in endoprotease Tail21 (65 U/mL) and 2% NaCl. A combination of 0.25% Endocut-03L and 0.25% Exocut-A0 for 20 h resulted in the best peeling of shrimps (100% completely peeled shrimps, 3 mJ/g work and 89% meat yield). Reuse of the enzyme solution was possible due to a 95% retention rate of proteolytic activity after two 20-h cycles of maturation. The studied enzymatic maturation offered a better shrimp product with respect to texture and color in comparison with an industrial brine-matured reference, i.e., ~22% higher redness and ~31% higher hardness. Industrial relevance Enzymatic maturation is an attempt made as a pre-treatment to facilitate the removal of the shell from meat of shrimp. This approach would benefit the shrimp processing industry by 1) enhancing peeling efficiency that includes least efforts to remove the shell, high rate of completely peeled shrimps and high meat yield; 2) shortening the duration of maturation but still sufficiently loosening the shell for machine peeling; 3) performing as a chemical-free peeling aid, which may increase the preference of consumers over chemical compounds; and 4) being environmentally friendly since disposal of enzyme waste is harmless to the environment. [ABSTRACT FROM AUTHOR]

The potential of power ultrasound (24-kHz frequency) as an individual treatment and in combination with proteolytic enzyme to promote the shell-loosening of cold-water shrimp ( Pandalus borealis ) was investigated. Textural properties of shrimp were highly dependent on temperature control during the ultrasonic process (27.6-μm amplitude, 120 min duration and 0.9-s pulse), while the peelability of shrimp monitored as peeling work, meat yield and proportion of completely peeled shrimp were less dependent on the temperature. Increasing amplitude (0–46 μm) and time (0–45 min) of ultrasound prior to enzymatic maturation (0.5% Endocut-03L, 6 h, and 3 °C) increased the peelability of shrimp. The parallel combination of ultrasound and enzyme (18.4-μm amplitude, 0.9-s pulse, 0.5% Endocut-3L, 3-h and 4-h duration, and T  ≤ 5 °C) considerably improved the shrimp peelability without detrimental effect on the texture and color of shrimp. Ultrasound was found to inactivate proteolytic enzyme in solution and to modify the structural properties of shrimp shells. From scanning electron micrographs (SEM), we proposed a mechanism for the ultrasound-enzyme-induced shell-loosening based on ultrasonic shell surface erosion and enzyme diffusion. Cavitation bubbles generated from sound waves pitted the surface of shrimp shell, generating pathways for enzyme diffusion into the muscle-shell attachment. Industrial relevance The shrimp industry is seeking green alternatives to the conventional shell-loosening methods i.e. , in brine/on ice maturations. The present study provides an investigation regarding the efficiency of power ultrasound with and without combination with proteolytic enzyme to enhance the shell-loosening and therefore improve the peelability. The findings show that ultrasound is a potential technique for shell-loosening and its efficiency is highest when simultaneously combined with enzyme. Ultrasound introduces spiral pathways in the shell and accelerates diffusion of enzyme through the pathways into the muscle-shell attachment. Thus, the use of simultaneous ultrasound-enzyme combination will shorten the shell-loosening time as compared to the conventional methods and increase the peelability without compromising the color and texture quality of shrimp. [ABSTRACT FROM AUTHOR]

Northern shrimp (Pandalus borealis) are protandrous hermaphrodites that reproduce first as males, go through a transition phase and transform to females, and then spawn as such for the rest of their lives. No clear consensus exists as to which factors influence the activation of the sex change process, but one possible factor is population density. Here, we investigate whether changes in stock size can influence the ogive of sex change, and use a 26-year time series (i.e. 1990-2015) of survey data on shrimp biomass from three different stocks in Iceland as a test case. Two of the stocks experienced periods of high biomass during the 1990 s, with a pronounced and prolonged depletion observed after 2000. In contrast, stock biomass of the third stock decreased only slightly during the time series. We found that the ogives of sex change of the two stocks where the biomass decreased to very low levels have changed significantly, and that shrimp now change sex at a lower size compared to earlier. Furthermore, Lmax has decreased significantly. [ABSTRACT FROM AUTHOR]

In this study, the tunable properties of a bio-lens from a deep-sea shrimp were investigated for the first time using magnetic fields. The skin of the shrimp exhibited a brilliantly colored reflection of incident white light. The light reflecting parts and the oil droplets in the shrimp’s skin were observed in a glass slide sample cell using a digital microscope that operated in the bore of two superconducting magnets (maximum strengths of 5 and 13 T). In the ventral skin of the shrimp, which contained many oil droplets, some comparatively large oil droplets (50 to 150 μm in diameter) were present. A distinct response to magnetic fields was found in these large oil droplets. Further, the application of the magnetic fields to the sample cell caused a change in the size of the oil droplets. The phenomena observed in this work indicate that the oil droplets of deep sea shrimp can act as lenses in which the optical focusing can be modified via the application of external magnetic fields. The results of this study will make it possible to fabricate bio-inspired soft optical devices in future. [ABSTRACT FROM AUTHOR]

Increasing use of fish feed containing the chitin synthesis inhibiting anti-parasitic drug diflubenzuron (DFB) in salmon aquaculture has raised concerns over its impact on coastal ecosystems. Larvae of Northern shrimp ( Pandalus borealis ) were exposed to DFB medicated feed under Control conditions (7.0 °C, pH 8.0) and under Ocean Acidification and Warming conditions (OAW, 9.5 °C and pH 7.6). Two weeks’ exposure to DFB medicated feed caused significantly increased mortality. The effect of OAW and DFB on mortality of shrimp larvae was additive; 10% mortality in Control, 35% in OAW, 66% in DFB and 92% in OAW + DFB. In OAW + DFB feeding and swimming activity were reduced for stage II larvae and none of the surviving larvae developed to stage IV. Two genes involved in feeding ( GAPDH and PRLP ) and one gene involved in moulting ( DD9B ) were significantly downregulated in larvae exposed to OAW + DFB relative to the Control. Due to a shorter intermoult period under OAW conditions, the OAW + DFB larvae were exposed throughout two instead of one critical pre-moult period. This may explain the more serious sub-lethal effects for OAW + DFB than DFB larvae. A single day exposure at 4 days after hatching did not affect DFB larvae, but high mortality was observed for OAW + DFB larvae, possibly because they were exposed closer to moulting. High mortality of shrimp larvae exposed to DFB medicated feed, indicates that the use of DFB in salmon aquaculture is a threat to crustacean zooplankton. [ABSTRACT FROM AUTHOR]

The Arabian red shrimp, Aristeus alcocki Ramadan, 1938, is one of the targets of commercial trawlers operating since 2000 along the Indian coasts at depths of 200-850 m. We report for the first time on the reproductive biology, insemination frequency, ovarian maturation, gonadosomatic index (GSI), size at maturity, and fecundity of A. alcocki investigated macroscopically and validated histologically using monthly trawl samples from the southwestern coast of India. Females have an open thelycum with five gonad developmental stages (I to V) and two stages (I and II) in males. A total of 4,170 specimens were examined and 68.6% of the females had been inseminated (carapace length (CL) 22.0-53.0 mm), predominantly during January to May. Females in stage I (immature) measured on average CL 25.5 ± 0.87 mm, those in stages IV and V (mature) CL 41.5 ± 0.62 mm. Immature males were smaller, mean CL 20.5 ± 0.5 mm. Size at first sexual maturity for females was estimated as CL 35.07 mm (total length (TL) 120-170 mm) and the inseminated specimens (CL50is) were mature at CL 31.45 mm using a non-linear method. The smallest mature female was CL 35 mm, whereas the size at maturity (CL50ms) of males was estimated as CL 19.6 mm (TL 75-96 mm). We also report synchronous oocyte development and continuous spawning activity with a peak during January to April. Information on the reproduction of this deep-water shrimp will help fishery managers estimate the stock sustainability and develop resource management measures. [ABSTRACT FROM AUTHOR]

In the deep sea trawl fishery targeting shrimp (Pandalus borealis) and other cold-water shrimp species, fishers often use a Nordmöre sorting grid ahead of a small mesh codend to avoid bycatch. However, small fish can pass through the grid and are subsequently retained in the codend. This makes shrimp size selection complex and the size-dependent curve for both the shrimp and the bycatch species often exhibits a bell-shaped signature. In this study we developed a new model and method to estimate size selection in this fishery, conducted fishing trials in the Northeast Barents Sea, and applied the new method to quantify the individual and combined size selection of the Nordmöre grid and codend for deep water shrimp and two bycatch species. The size selectivity for both bycatch species showed the expected bell-shaped signature with low retention probability of very small and larger fish. The Nordmöre grid had high passage probability for all sizes, although it decreased slightly for the largest shrimps. The smallest shrimps were released by the codend. [ABSTRACT FROM AUTHOR]

Pandalus borealis is an important indicator species to study the state of the Arctic ecosystem. The mitochondrial genome of P. borealis is 15,956 bp in length and encodes 13 protein-coding genes. The phylogenetic tree of eleven shrimps revealed that P. borealis belonged to Pandalidae family and was closely related to C. crassicornis. This mitogenome will be of significance to study the Arctic ecosystem state and perform the resource protection of this species.

In order to define the relative vulnerability of northern shrimp ( Pandalus borealis ) populations to the ongoing global warming, we compared the thermal performance curves for survival and growth in the first three pelagic larval stages from three populations of the Northwest Atlantic. Egg carrying females were obtained from different regions characterized by distinct sea surface temperature (SST) conditions for larval development in spring. Two independent experiments were conducted in two different years. In spring 2012, larvae from females captured in the Lower St Lawrence Estuary (LE) and in the Northeast Gulf of St Lawrence (GSL) were compared. In spring 2014, larvae from females captured in the LE and on the Labrador–Newfoundland Shelf (Northwest Atlantic, NWA) were used. The LE larvae were used both years and served as the reference population for comparisons. In 2012 and 2014, groups of 25 newly hatched northern shrimp larvae from each source population were incubated at six temperatures (0, 3, 6, 9, 12, and 15 °C) to monitor and compare survival and growth at moult. Northern shrimp larvae from the LE (warmer May–June SST) had a higher optimal temperature range for survival compared to larvae from the GSL and the NWA (colder May–June SST) populations. However, in 2012 growth performance at moult was reduced at higher temperatures for the LE population compared to the GSL population. The differences in thermal performance curves observed may suggest the presence of a certain level of local adaptation in response to the different regional SST regimes in spring–early summer. Northern shrimp larvae in the Northeast Gulf of St Lawrence and Northwest Atlantic shelf could benefit from warmer early-spring temperatures; however, larvae from the Lower Estuary may be closer to their upper tolerance limits and thus more likely at risk of negative impact of future warming of surface water masses. [ABSTRACT FROM AUTHOR]

Estimated trends in relative stock abundance are a primary input to fish stock assessments. Accurate and precise estimates are essential for successful conservation and management. Scientifically designed data collection ensures that estimates of relative abundance are unbiased. However, the statistical efficiency of a design-based estimator may be low under certain circumstances. We apply a recently developed spatiotemporal model that incorporates habitat variables to estimate a model-based abundance index for northern shrimp ( Pandalus borealis) in the Gulf of Maine. We contrast this spatiotemporal index with a classical design-based index and evaluate the impacts of differences between the two abundance indices on the stock assessment. We show that using the spatiotemporal index in the assessment model greatly alters the estimates of recruitment and spawning stock biomass and the determination of stock status. Also, incorporating the spatiotemporal index leads to less retrospective bias and outperforms the model with design-based index in terms of predictive performance through a retrospective cross-validation test. Our results suggest that temporal variability of population abundance could be exaggerated by the design-based estimator, and such imprecision may greatly affect the performance of a stock assessment and subsequent development of management decisions. [ABSTRACT FROM AUTHOR]

The pink shrimp ( Farfantepenaeus duorarum ) has been selected as an ecological indicator to assess ecological effects on estuaries of implementation of the Comprehensive Everglades Restoration Plan that seeks to restore historical freshwater flows and nearshore salinity regimes in southern Florida. Concern over altered freshwater delivery impacts on pink shrimp productivity was expressed as early as the 1960s. The present review assessed pink shrimp scientific literature of the past 75+ years (>500 publications) to glean information relevant to understanding potential influence of freshwater management on pink shrimp productivity. The review was organized around “Essential Fish Habitat” metrics concerning abundance, growth, survival, distribution, productivity, and behavior. It summarizes previous pink shrimp field, laboratory, and modeling studies. Where possible, statistical analyses and meta-analyses of previously published data were performed to investigate consistency among independent findings. Pink shrimp occur in a wide range of salinities (0.5–67 ppt). A majority of studies (53.3%) reported maximal abundance between ∼20 to 35 ppt salinities. One laboratory study reported maximal growth at 30 ppt. Meta-analysis of reported growth rates did not yield results due to non-convergence of regression models. Reported survival was maximal at ∼30 ppt and remained high (>80% survival) across salinities of ∼15 to 40 ppt. A regression model that combined survival data across studies confirmed a previously reported parabolic relationship between salinity and survival; in this regression, 35 ppt maximized survival. Productivity, conditional upon survival and growth, was maximized at polyhaline (18–30 ppt) conditions. Inshore hypersalinity (>40 ppt) may elicit young pink shrimp behavioral cues counterproductive to settlement in nearshore areas. Virtually no information exists regarding postlarval pink shrimp movement or preference relative to salinity gradients. Realization and preservation of nearshore polyhaline conditions and elimination of hypersalinity should maximize growth, survival, and density, thus improving pink shrimp productivity. New and updated statistical models predicting pink shrimp distribution, abundance, growth, survival, and productivity relative to salinity conditions are needed to better guide freshwater management decisions. [ABSTRACT FROM AUTHOR]

Use of the chitin synthesis inhibitor diflubenzuron (DFB) as an antiparasitic drug in salmon aquaculture raises concern over its impact on marine ecosystems. Further, global drivers, such as ocean warming and acidification (OAW), may increase the toxicity of hazardous substances including DFB. The aim of the present study was to examine the combined effects of DFB-medicated salmon feed on ovigerous Northern shrimp (Pandalus borealis) under Control (pHNBS8.0, 7.0ºC) and OAW conditions (pHNBS7.6, 9.5ºC). DFB-exposed shrimp consumed on average 0.1–0.3 g medicated feed during the 2-week exposure period, and high mortality (61–73%) was documented at both environmental conditions. There was no significant interaction between OAW and DFB. Only 2–7% of DFB-exposed shrimp molted successfully compared to 65% in Control and 63% in OAW. The shrimp molted earlier (shorter intermolt period) and exhibited higher feeding rate at OAW compared to Control conditions. An additional experiment, where female shrimp were exposed to DFB closer to molting, noted increased mortality after only 4 d exposure, and successful molting for some shrimp after 2 to 3 weeks of depuration. High mortality of shrimp exposed to DFB-medicated feed indicates that the use of this feed in aquaculture could affect local shrimp populations. [ABSTRACT FROM PUBLISHER]

Fishing vessel and permit buyback programs have been implemented to reduce excess capacity and improve profitability in a number of fisheries around the world. These programs are generally publicly funded, but in a few cases they have been financed by loans to be paid back by the remaining fleet. In 2003, a buyback permanently removed 91 vessels and 239 fishing permits from the Pacific groundfish trawl fishery and associated corollary fisheries of Dungeness crab and pink shrimp. The buyback was financed with $10 million in public funding and a $36 million loan to be repaid over 30 years with fees on landings. In the same year, a control date was set for catch share program in the groundfish trawl fishery. When the catch share program was implemented in 2011, the permit owners that remained in the fishery after the buyback were allocated the quota shares that would otherwise have been issued to the permits bought back in 2003. Estimates of the annual profits generated by this quota are compared to the cost of servicing the buyback loan. The results provide evidence that a buyback program, when implemented in conjunction with catch shares, can enable a sustained increase in profitability for the remaining vessels sufficient to justify its cost. However, using landings taxes as the mechanism to repay the loan may result in a mismatch between those who benefit from and pay for the buyback. [ABSTRACT FROM AUTHOR]

A new species of the deep-sea spongicolid genus Spongicoloides Hansen, 1908 is described and illustrated based on material from the northwestern Pacific. Spongicoloides weijiaensis sp. n. was found inside a hexactinellid sponge, Euplectella sp., sampled by the Chinese manned submersible "Jiaolong" at depths of 2279 m near the Weijia Guyot, in the Magellan Seamount Chain. The new species can be distinguished from all congeneric species by several morphological features, involving gill formula, spination of the carapace, antennal scale, third pereiopod, telson and uropod, posteroventral teeth of the pleura, and dactyli of the fourth and fifth pereiopods. An identification key to the Pacific species of Spongicoloides is provided. [ABSTRACT FROM AUTHOR]

The commercial deep-sea caridean shrimp Heterocarpus gibbosus Spence Bate, 1888 has long been recorded from India and constitutes an important part of the catches in the context of the further development of deep-sea fisheries in India. A recent survey in some deep-sea fishing ports in southern India, however, revealed that all material previously reported as "H. gibbosus" is actually a misidentification of its closely related species H. chani Li, 2006, which has only recently been reported from India. More detailed comparisons allowed the discovery of more distinctive characters between H. chani and H. gibbosus. [ABSTRACT FROM AUTHOR]

In Greenland waters, Atlantic cod ( Gadus morhua) is showing signs of recovery following a collapse in the early 1990s, and quantitative diet studies are needed to address predation on highly commercial species such as northern shrimp ( Pandalus borealis). We analyzed 2483 Atlantic cod stomachs from Greenland offshore waters and the correlation between Atlantic cod and northern shrimp abundance. Fish and crustacean prey accounted for 96% of the prey by weight, with the relative importance shifting from crustaceans to fish with increasing cod size. Spatial differences were distinct and northern shrimp dominated the diet in Northwest Greenland (>50% by weight), but declined in importance in Southwest Greenland and was absent from the diet in East Greenland. Instead, other crustacean preys such as krill were important in Southwest Greenland while fish prey was most important in East Greenland. Southwest Greenland was sampled in both summer and autumn, and there was a significant seasonal effect on most prey groups, but most pronounced for Atlantic cod and krill both of which increased in importance. Extensive cannibalism was limited to the largest cod (]70-100 cm]) and mainly in Southwest Greenland. In Southwest Greenland, Atlantic cod and northern shrimp biomass were significantly negatively correlated, while no significant trends were found in Northwest or East Greenland. [ABSTRACT FROM AUTHOR]

In this study, effect of chitosan films combined with orange ( Citrus sinensis (L.) Osbeck) peel essential oil on the shelf life of deepwater pink shrimp ( Parapenaeus longirostris Lucas 1846) was aimed. Chitosan (CH) and 2% orange peel essential oil (OPEO) combinated chitosan (CH+OPEO) were used for preparing film forming solution. Thickness and microstructure of the films, nutritional composition, sensory and melanosis evaluation, chemical, physical, and microbiological analyses were performed periodically and shelf-life was performed during the storage period of 15 days. The combination of chitosan film with OPEO was effective in prolonging the shelf life of fresh shrimps to 15 days (CH+OPEO), whereas the only chitosan-coated group had a shelf life of 10 days (CH) and the samples packaged without chitosan film had a shelf life of 7 days (control). The results of the study suggested that edible chitosan coatings together with OPEO preserved the shrimps and maintained the shelf life throughout the refrigerated storage period. [ABSTRACT FROM AUTHOR]

Northern shrimp (Pandalus borealis) is targeted by commercial fisheries, but is also an important prey in the marine food web. In this study, stomach content data were used to study predation on shrimp by three gadoid species, cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and whiting (Merlangius merlangus), in six inshore areas around Iceland. The results showed that shrimp was more important in the diet of cod compared with the other two predators. However, the overall predation pressure was similar for cod and haddock due to the high abundance of haddock. Therefore, even though shrimp is not the primary source of food for haddock, this species can have a substantial effect on shrimp stocks when haddock abundance is high. In addition, while cod and haddock did not select for any particular size of shrimp, whiting seemed to preferentially target juvenile shrimp. The results suggest that due to the overall effects of these three predators on shrimp stocks, gadoids need to be included in the management of shrimp stocks as predation is one of the major drivers in the development of this important prey stock. [ABSTRACT FROM AUTHOR]

Multispecies modeling is being increasingly accepted in stock assessment, especially in the context of an ecosystem approach to fisheries management (EAF). To achieve a future implementation of an EAF in the Flemish Cap, we present a multispecies model developed in Gadget, which covers the main commercial stocks over the period 1988-2012: cod ( Gadus morhua), redfish ( Sebastes spp.), and northern shrimp ( Pandalus borealis). The model highlights the interdependent dynamic of these stocks and reveals strong interactions among recruitment, fishing, and predation (including cannibalism). These drivers have shown marked changes in their relative importance by species, age, and length over time, producing a transition from a traditional redfish- and cod-dominated system in the early 1990s to an intermediate shrimp and other fish species state by the late 1990s and in turn back to something close to the initial state by the late 2000s. The multispecies model developed in this paper shows that disregarding the species interactions would lead to serious underestimates of natural mortality and overestimations of the exploitable biomass and highlights the need to move beyond single-species management in this highly coupled ecosystem. [ABSTRACT FROM AUTHOR]

The pink shrimp, Farfantepenaeus duorarum is an important commercial species in the Gulf of Mexico, which supports significant commercial fisheries near Dry Tortugas, in Southern Florida and in Campeche Sound, Southern Gulf of Mexico. There is information about the nictemeral behavior of the pink shrimp related to sunset, what is crucial to more accurate estimation of shrimp population biomass, and to assess the potential of this resource and its proper management. To contribute to the knowledge and the population dynamics of the species, shrimp surveys were conducted in a nursery area near "El Cayo" in the Northeastern part of Terminos Lagoon, Mexico during October 2010. Three sampling sites with substrate covered by submerged vegetation were chosen; two set of samples were collected at each site, one in the morning and the other just after sunset. Three trawls were performed per sampling site using a small otter trawl. A total of 1 418 shrimp (between 5.5 to 28.8 mm Carapace Length (CL)) were collected during the study; 1 416 F. duorarum and only two individuals of Litopenaeus setiferus. Shrimps CL and Total Length (TL) were measured in mm and individuals were weighted to the nearest 0.01 g. In general, shrimp biomass and density were significantly higher in all sites during dusk (biomass= 46.36 g.100 m-2, n= 1 344), than daylight samples (biomass= 2.78 g.100 m-2, n= 72). The One-way ANOVA and the Tukey test performed to evaluate variability in CL found significant differences between sites (CL= 14.12 mm, 12.46 mm and 15.13 mm, for site 1, 2 and 3 respectively, F= 64.92, P < 0.001) which might be related to the substrate type. The length-weight relationships reflected positive allometric growth for juveniles but isometric for subadults and two nonlinear power functions were estimated (W= 0.0004CL3.157 for juveniles, and W= 0.0009CL2.902 for subadults). The results of the analysis of covariance (ANCOVA) test indicated that the Total Length - Carapace Length (TL-CL) relationships were significantly different between juveniles and subadults, and two linear equations (TL= 2.615 + 4.476CL and TL= 8.931 + 4.062CL for juveniles and subadults respectively) were fitted. It is important that population assessment takes into account the day or night period as a bias factor when sampling the abundance of the juveniles of F. duorarum in this important nursery ground of the Campeche Sound. Rev. Biol. Trop. 65 (1): 65-75. Epub 2017 March 01. [ABSTRACT FROM AUTHOR]

A shared origin with fresh and dredged cultch and availability via mining have made fossil cultch a commonly used reef restoration substrate. However, important differences in shape and size between whole-shell cultch and fossil cultch may impact the complexity of reefs constructed from these materials. To determine if these differences may impact the development of restored reefs, we quantified the interstitial space each cultch type provides and constructed reef mesocosms to measure (1) the immediate effects of exposure to each cultch type on mortality of blue crab ( Callinectes sapidus) and pink shrimp ( Farfantepenaeus duorarum); (2) the tendency of crab, shrimp, and Florida crown conch ( Melongena corona) to be found on habitats composed of each substrate type and their position within each in split-substrate mesocosms; and (3) the influence of cultch type on predation of Eastern oysters ( Crassostrea virginica) by crabs and conch. Aggregation of fossil cultch contains more shells and provides less interstitial space than an equivalent volume of whole-shell cultch. Although immediate mortality following deployment was low and did not differ among cultch types, we found that all species were more likely to be found on fresh cultch over fossil cultch in choice experiments and used each habitat type differently. Cultch type also impacted the size of oysters consumed by crabs in short-term feeding trials. The structure and traits of habitats created by various materials should be added to the growing list of issues considered when natural communities are to be restored in oyster reefs and other environments. [ABSTRACT FROM AUTHOR]

Species with a wide distribution can experience significant regional variation in environmental conditions, to which they can acclimatize or adapt. Consequently, the geographic origin of an organism can influence its responses to environmental changes, and therefore its sensitivity to combined global change drivers. This study aimed at determining the physiological responses of the northern shrimp, Pandalus borealis, at different levels of biological organization and from four different geographic origins, exposed to elevated temperature and low pH to define its sensitivity to future ocean warming and acidification. Shrimp sampled within the northwest Atlantic were exposed for 30 days to combinations of three temperature (2, 6 or 10°C) and two pH levels (7.75 or 7.40). Survival, metabolic rates, whole-organism aerobic performance and cellular energetic capacity were assessed at the end of the exposure. Our results show that shrimp survival was negatively affected by temperature above 6°C and low pH, regardless of their origin. Additionally, shrimp from different origins show overall similar whole-organism performances: aerobic scope increasing with increasing temperature and decreasing with decreasing pH. Finally, the stability of aerobic metabolism appears to be related to cellular adjustments specific to shrimp origin. Our results show that the level of intraspecific variation differs among levels of biological organization: different cellular capacities lead to similar individual performances. Thus, the sensitivity of the northern shrimp to ocean warming and acidification is overall comparable among origins. Nonetheless, shrimp vulnerability to predicted global change scenarios for 2100 could differ among origins owing to different regional environmental conditions., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)