Argentine Red Shrimp Research Articles

First descriptions of diurnal pelagic aggregations of the Argentine red shrimp (Pleoticus muelleri) using a broadband echosounder operating at multiple frequencies

This is the first description of diurnal pelagic aggregations of the bottom-dwelling Argentine red shrimp (Pleoticus muelleri) registered with a broadband scientific echosounder. A pelagic trawl net and an underwater video camera were used to validate all the information presented in this paper. Shrimp aggregations were characterized by increasing frequency response, more evident at frequencies greater than 120 kHz. Identification of the acoustic signature of this resource is of particular interest for the development of new methodologies to complement the traditional swept area method of estimation.

Physical and Oxidative Water-in-Oil Emulsion Stability by the Addition of Liposomes from Shrimp Waste Oil with Antioxidant and Anti-Inflammatory Properties.

Liposomes made of partially purified phospholipids (PL) from Argentine red shrimp waste oil were loaded with two antioxidant lipid co-extracts (hexane-soluble, Hx and acetone-soluble, Ac) to provide a higher content of omega-3 fatty acids. The physical properties of the liposomes were characterized by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). The antioxidant and anti-inflammatory activity of the lipid extracts and liposomal suspensions were evaluated in terms of Superoxide and ABTS radical scavenging capacities and TNF-α inhibition. Uni-lamellar spherical liposomes (z-average ≈ 145 nm) with strong negative ζ potential (≈ -67 mV) were obtained in all cases. The high content of neutral lipids in the Hx extract caused structural changes in the bilayer membrane and decreased entrapment efficiency regarding astaxanthin and EPA + DHA contents. The liposomes loaded with the Hx/Ac extracts showed higher antioxidant and anti-inflammatory activity compared with empty liposomes. The liposomal dispersions improved the physical and oxidative stability of water-in-oil emulsions as compared with the PL extract, inducing pronounced close packing of water droplets. The liposomes decreased hydroperoxide formation in freshly made emulsions and prevented thio-barbituric acid-reactive substances (TBARS) accumulation during chilled storage. Liposomes from shrimp waste could be valuable nanocarriers and stabilizers in functional food emulsions.

Extraction and characterization of Argentine red shrimp (Pleoticus muelleri) phospholipids as raw material for liposome production

Phospholipids rich in omega-3 fatty acids from Argentine red shrimp waste were explored as a source to produce food-grade liposomes. Partially purified phospholipids (PL-AS), hexane-soluble (HxSE) and acetone-soluble (Ac-SE) lipid co-extracts, were characterized in terms of extraction yield (2.0%, 1.46% and 4.51%, respectively), chemical composition (fatty acids, tocopherols, sterols, astaxanthin) and thermal stability. Based on lipid fractionation, PL-AS presented 85% phospholipids, while neutral lipids were mostly present in HxSE (75%) and free FA in AcSE (34%), the latter suggesting significant fat hydrolysis. Palmitic, oleic, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids predominated in the phospholipid fraction of PL-AS, mainly constituted by phosphatidylcholine (PC) (96%). The most abundant phospholipid was identified at m/z 760.59, composed of PC, with C16:0/C18:1 as the most probable FA combination. Unilamellar spherical liposomes were successfully made of PL-AS (≈140 nm, 0.248 PDI, −68.5 mV ζ potential), showing high stability for 28 days at 4 °C.

Anticancer Potential of Lipophilic Constituents of Eleven Shellfish Species Commonly Consumed in Korea.

The present study was aimed to investigate the composition and contents and the major lipophilic compounds, including the sterols, fatty acids, and tocols of shellfish species. Moreover, to explore the antitumor activity of these lipophilic constituents, their cytotoxicity potentials were determined against five different human cancer cells, including colon carcinoma (HCT116), epithelial melanoma (A2058), glioblastoma multiforme (T98G), lung carcinoma (A549), and adenocarcinoma (HeLa). The results show a significant variation in the contents and composition of lipophilic constituents among the studied species. The highest omega-3 (n-3) polyunsaturated fatty acids (PUFAs) were recorded from arrow squid and pacific oysters, accounting for 53.2% and 53.0% of their total fatty acids, respectively. However, the highest cholesterol content was also recorded in arrow squid (154.4 mg/100 g; 92.6% of total sterols). In contrast, in the Japanese littleneck, Yesso scallop, and common orient clam, cholesterol was just 17.1%, 18.3%, and 18.9% of total sterols, respectively, making them the richest source of non-cholesterol sterols (NCS). Lipids extracted from shellfish species showed ABTS+•- and DPPH•-scavenging activities. In the cytotoxicity analysis, lipids extracted from the Argentine red shrimp showed the highest cytotoxicity against glioblastoma multiforme T98G cells, with an IC50 value of 12.3 µg/mL. The composition and cytotoxicity data reported herein may help explore the nutritional and anticancer potentials of shellfish species.

Fish functional diversity as an indicator of resilience to industrial fishing in Patagonia Argentina.

The relationship between fish functional diversity and fishing levels at which its baselines shift is important to identify the consequences of fishing in ecosystem functioning. For the first time, the authors of this study implemented a trait-based approach in the Argentine Patagonian Sea to identify the vulnerability and spatiotemporal changes in functional diversity of fish assemblages incidentally captured by a trawling fleet targeting the Argentine red shrimp Pleoticus muelleri (Spence Bate, 1888) between 2003 and 2014. The authors coupled seven fish trophic traits to a reconstructed fish assemblage for the study area and by-catch and evaluated changes in fish species richness and four complementary functional diversity measures (functional richness, redundancy, dispersion and community trait values) along with fishing intensity, temporal use, latitudinal location and depth of fishing grounds, and vessel length. Resident fishes larger than 30 cm in length, with depressed and fusiform bodies, intermediate to high trophic levels, and feeding in benthic, demersal and midwater areas were vulnerable to by-catch. In addition, fish assemblages exhibited a low functional trait redundancy, likely related to species influxes in a biogeographic ecotone with tropicalisation signs. Significant increases in fish trait richness and dispersion poleward and deep suggested new functional roles in these grounds, matching trends in community body size, reproductive load, maximum depth and trophic level. Finally, a temporal increase in fish species and functional trait removal in fishing grounds led to trait homogenisation since 2003. The authors identified that tipping points in temperate fish functional trait diversity showed the importance of trait-based approaches within ecosystem-based fisheries management.

Evidence of Marine Microplastics in Commercially Harvested Seafood.

Microplastic pollution is a global issue that has a detrimental impact on food safety. In marine environments, microplastics are a threat to marine organisms, as they are often the same size range as prey and are mistaken as food. Consumption of microplastics has led to the damage of digestive organs and a reduction in growth and reproductive output. In this study, microplastic pollution was assessed across three commercially available shrimp species that were obtained from the supermarkets of Singapore. A total of 93 individuals were studied from the Pacific white leg shrimp, Litopenaeus vannamei, the Argentine red shrimp Pleoticus muelleri and the Indian white shrimp Fenneropenaeus indicus. Microplastic fibers, fragments, film and spheres were identified from the digestive tract of these organisms. Microplastic abundance ranged from 13.4 to 7050 items. F. indicus exhibited the highest number of microplastics. Microplastic film was the most abundant in L. vannamei individuals (93–97%) and spheres were the most abundant in P. muelleri (70%) and F. indicus (61%) individuals. This study demonstrates that microplastic contamination is evident in commonly consumed shrimp and highlights the role of shrimp in the trophic transfer and accumulation of microplastics in seafood. The consumption of microplastic-containing seafood is a route of exposure to humans and has implications on human health and food security. Capsule: Microplastics were examined in three shrimp species from the supermarkets of Singapore. Microplastics ranged from 13.4 to 7050 items of shrimp.

Red Shrimp Are a Rich Source of Nutritionally Vital Lipophilic Compounds: A Comparative Study among Edible Flesh and Processing Waste.

This study was aimed at comparatively analyzing the sterols, tocopherols and fatty acids from edible flesh and processing waste obtained from three shrimp species, utilizing rapid liquid chromatography (LC)-atmospheric-pressure chemical ionization (APCI)-tandem mass spectrometry (MS/MS) and gas chromatography-mass spectrometry (GC-MS). Results revealed the presence of significantly (p < 0.05) high proportions of health-beneficial omega-3 (n3) polyunsaturated fatty acids (PUFAs) in Argentine red shrimp (34.3% in waste and 38.2% in the flesh), compared to black tiger shrimp (16.5–24.2%) and whiteleg shrimp (13.2–22.6%). Among sterols, cholesterol was found most dominant, accounting in the range 349.4 (white shrimp flesh) to 559.3 µg/g fresh weight (FW) (black shrimp waste). Surprisingly, waste was found to contain a substantially higher amount of α-tocopherol, for instance, 21.7 µg/g FW in edible flesh and 35.3 µg/g FW in the waste of black tiger shrimp. The correlation analysis indicated that shrimp with low total contents of lipids might have higher proportions of health-beneficial long-chain (LC)-n3-PUFAs eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). The fat quality indices, including the high ratios of hypocholesterolemic (h)/hypercholesterolemic (H) fatty acids, and lowest values of the atherogenic index (AI) and thrombogenic index (TI) indicated the health-beneficial potential associated with fat intake from red shrimp. Overall, a significant amount of health-beneficial compounds in edible flesh of studied shrimp confers its extraordinary nutritional benefits. Moreover, considering the richness of processing waste with these compounds, their valorization can be prompted.

Lipid Fraction from Industrial Crustacean Waste and Its Potential as a Supplement for the Feed Industry: A Case Study in Argentine Patagonia

In central Patagonia, the most important crustaceans caught are the Argentine red shrimp (ARS) (Pleoticus muelleri) and the southern king crab (SKC) (Lithodes santolla). Their industrial processing generates large amounts of waste, which cause environmental pollution and ecological imbalances. The recovery of valuable compounds from this waste could bring economic benefits to the region. Comparative dry-basis proximal analysis of shells of ARS and SKC showed similar values of chitin (19 and 20%, respectively), slight but significant differences in proteins and ashes (18 and 48% for SKC and 26 and 55% for ARS), and 8 times higher content of lipids in ARS (4%) than in SKC (0.5%) shells. Nowadays, the waste generated by the processing of ARS (18000 t/year) is almost 180 times higher than that of SKC (100 t/year) and comprises not only shells but also heads (S + H). Nevertheless, taking into account that the amount of waste of SKC could increase in the future, the information about its chemical composition becomes relevant and is thus also reported in this work. The analysis of S + H of ARS showed the highest lipid content (11%), and the wet basis analysis of its fatty acids and carotenoids at different catch times showed a constant high level of the omega-3 polyunsaturated fatty acids (n-3 PUFAs) eicosapentaenoic and docosahexaenoic (5.0 g kg−1) and statistically significant variation in the carotenoid content, which can reach up to 158.8 mg kg−1. The results suggest potentials for recovering valuable n-3-PUFAs and carotenoids from ARS waste.

Properties and Some New Applications of Enzymes from Wastes of the Shrimp Pleoticus muelleri (Decapoda, Penaeoidea)

The shrimp Pleoticus muelleri (Bate, 1888) is an important fishing product from the Southwest Atlantic waters which is frequently captured as a bycatch and discarded. Wastes and by-products of shrimp are an excellent source of protein and enzymes. This review highlights the biochemical and catalytic properties of proteases from shrimp. Previous studies on P. muelleri enzymes have found different activities of alkaline proteases ranging from 0.01 to 0.78 Abs/min/mg of protein. These changeful results might be explained by the great influence that several biological and experimental factors, such as molting and developmental stages, type of diet, and culture conditions, have on the enzyme function. Regarding acid protease, it has been demonstrated that they have activities between 0.3 and 0.4 Abs/min/mg of protein. Processing Argentine red shrimp waste could offer many higher value products without increasing wild catch volumes; therefore, it is essential to conduct further studies that allow the development of more value-added products derived from the practical usage of shrimp processing waste.

Monitoring of the white spot syndrome virus (WSSV) in Argentine red shrimp (Pleoticus muelleri) samples during 2010-2014 in Argentina

Monitoring of the white spot syndrome virus (WSSV) in Argentine red shrimp (Pleoticus muelleri) samples during 2010-2014 in Argentina

Monitoreo del virus del síndrome de la mancha blanca (WSSV) en muestras de langostino (Pleoticus muelleri) durante los años 2010 a 2014 en la Argentina

La pesquería de langostino (Pleoticus muelleri), una de las más importantes del Mar Argentino, superó en 2016 el 50% del valor total de las exportaciones pesqueras. La implementación y desarrollo de controles sanitarios son requisitos del comercio internacional. Entre los patógenos que afectan a los crustáceos se encuentra el virus del síndrome de la mancha blanca (White spot syndrome virus: WSSV) y, según lo establecido por la Organización Mundial de Sanidad Animal (OIE), la enfermedad es de declaración obligatoria. Debido a la necesidad de contar con datos científicos para establecer el estado sanitario del recurso respecto del WSSV, el objetivo del presente trabajo fue relevar en forma continua la infección viral en langostinos salvajes. Se trabajó con muestras capturadas durante 2010-2014 en áreas cercanas a puerto Rawson y el Golfo San Jorge. El total de 506 ejemplares analizados con la técnica de PCR anidada utilizando el Kit Comercial IQ2000TM WSSV, método validado por la OIE, resultaron negativos al virus. Se concluye que en los cinco años de monitoreo continuo no se evidenció presencia de WSSV en langostino. Este estudio ofrece una base de datos científicos que ayudaría a garantizar la calidad sanitaria y el comercio internacional de esta pesquería de interés comercial en la Argentina. Además, proporciona herramientas que permitirán proteger el producto ante posibles sanciones y barreras comerciales innecesarias.

Odor-active compounds contributing to the characteristic aroma of shrimp cooked whole, including shells and viscera

Shrimps and prawns are known to generate a characteristic and pleasant aroma when cooked whole, including their shells and viscera. This study investigated this characteristic aroma of whole-roasted shrimp using Argentine red shrimp (Pleoticus muelleri). Shrimps were roasted in an oven, and the aroma changed upon the usage of whole shrimp. The aroma attributes of “roasted” and “rich” were significantly improved. We performed an analysis of volatile compounds to identify the contributors to roasted and rich aromas and identified 17 odor-active compounds. Heterocyclic compounds including pyrazines, thiazolines, and thiazoles were major contributors to the aroma of whole roasted shrimp. In aroma extract dilution analysis, 2,6-dimethylpyrazine, trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine, 2-acetyl-2-thiazoline, methional, 2-acetylthiazole, 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, and indole were detected with higher flavor dilution factors than were other odor-active compounds. Furthermore, sensory evaluation analysis confirmed that pyrazines contributed to the roasted aroma, and thiazolines and thiazoles contributed to both the roasted and rich aromas. In conclusion, pyrazines, thiazolines, and thiazoles derived from shrimp shells or viscera were the major contributors to the characteristic aroma of whole roasted shrimp and strongly influenced the aroma impression of shrimp dishes.

The complete mitochondrial genome of the Argentine red shrimp Pleoticus muelleri (Bate, 1888) (Crustacea, Decapoda, Solenoceridae)

The complete mitochondrial genome of Argentine red shrimp, Pleoticus muelleri (Bate, 1888) was determined using the MiSeq platform. Its mitogenome (16,189 bp) encoded the canonical 13 protein-coding genes, 22 tRNA genes, two rRNA genes. Start codons of all protein-coding genes were ATN except for ATP8, while incomplete stop codons (T–) were identified in six genes including COXI, COXII, COXIII, NAD3, NAD5, and NAD6. The mitogenome of P. muelleri showed highest sequence identity with Parapenaeopsis hardwickii (82%) and Solenocera crassicornis (81%). Phylogenetic analysis showed three shrimps in Solenoceridae including P. muelleri were grouped together from those in Penaeidae, which suggests taxonomic reexamination for those in those family.

A LPUE (LANDING PER UNIT EFFORT) ANALYSIS OF THE TRAWL FISHERY FOR THE COASTAL SHRIMPS Artemesia longinaris AND Pleoticus muelleri OFF SOUTHERN BRAZIL

The Argentine stiletto shrimp (Artemesia longinaris) and the Argentine red shrimp (Pleoticus muelleri) currently sustain an important fishery in terms of tonnage and revenues in southern Brazil. This study analyzed the factors affecting the abundance of both species through the application of Generalized Linear Models to landing-per-unit-of-effort (LPUE) data of the trawl fleet operating on the main fishing grounds between 1998 and 2005. The main patterns of LPUE variability of both species were attributed do the effect of seasons and annual cycles. Larger yields were obtained in the southern shallow areas of Rio Grande do Sul State. No tendency either to an increase or a decline in stock abundance was observed, but the effort in one year was affected by the success of the captures of the previous year. In the last two years analyzed the abundance and the total captures declined.

Factors affecting Magellanic Penguin mortality at coastal trawlers in Patagonia, Argentina

Incidental capture at trawlers has been recognized as a significant source of seabird mortality, and is considered one of the main threats to seabirds at sea. The understanding of seabird–fishery interactions and of factors influencing individual mortality is fundamental to develop management actions and help protect seabird populations. We quantified seasonal and annual variability in Magellanic Penguin (Spheniscus magellanicus) incidental captures and explored factors which may be influencing their by-catch at coastal trawlers targeting either Argentine Red Shrimp (Pleoticus muelleri) or Argentine Hake (Merluccius hubbsi) in the Isla Escondida fishing area, Argentina, for the months encompassing most of the penguin's breeding period (October–February) of the 2008, 2009, 2011 and 2012 fishing seasons (n = 2 336 hauls). A total of 203 penguins were incidentally caught in nets, with rates that varied between months and years. Mean monthly capture rate was 0.087 birds haul−1, and ranged between 0.01 and 2.07 birds per haul. All captured penguins were adult individuals. Incidental capture occurred almost exclusively when targeting Argentine Hake (97.5% of cases) and during 2009. Incidental captures were more likely to occur when vessels operated closer to penguin colonies, with 85% of incidental captures occurring at less than 45 km. Vessels targeting hake operated significantly closer to the colonies than those targeting shrimp. Incidental capture of Magellanic Penguins in coastal trawlers in the study area appears to be highly variable and relatively low. Our results suggest that in the event Magellanic Penguin mortality at coastal trawlers becomes a conservation issue, spatial and temporal closures focused on the Argentine hake could be used as potential measures to reduce penguin by-catch, complementing the effective implementation of a marine protected area.

Caracterizacion de las principales pesquerias del golfo San Jorge Patagonia, Argentina

In San Jorge Gulf, several important economic activities are developed, including two industrial fisheries: hake ( Merluccius hubbsi Marini, 1933) and Argentine red shrimp ( Pleoticus muelleri Bate, 1888). Both overlap spatially and temporally. The San Jorge Gulf hake fishery consists of a high-seas ice trawler fleet (n = 20 fishing vessels) and a coastal fleet (n = 30 fishing vessels). These fisheries capture about 10% of the catch of the southern hake stock. The Argentine red shrimp fishery consists of a double-beam trawler fleet with 80 freezer vessels, responsible for more than 75% of shrimp landings in Argentina. The main problem of both fisheries is the bycatch of hake in one of its principle nursery areas. The present work describes the current management of the fisheries of San Jorge Gulf, which consists primarily of spatial and temporal closures for the Argentine red shrimp and zoning by stratum of the fleet for hake. Neither of these two fisheries has taken measures that effectively reduce bycatch.

Fishery Discards and Incidental Mortality of Seabirds Attending Coastal Shrimp Trawlers at Isla Escondida, Patagonia, Argentina

We evaluated seabird attendance and incidental mortality at coastal trawl vessels targeting Argentine red shrimp (Pleoticus muelleri) in the Isla Escondida fishing area, Argentina, during 2006–2007 and 2007–2008. Eight seabird species attended vessels, and the most frequent and abundant seabird (percent occurrence, mean number per haul) in the two seasons was the Kelp Gull (Larus dominicanus) (100%, 112.3 and 100%, 263.4, respectively), followed by the Black-browed Albatross (Thalassarche melanophris) (85%, 17.6, and 90%, 32.4, respectively). Eleven Magellanic Penguins (Spheniscus magellanicus) and one Imperial Shag (Leucocarbo atriceps) were killed in nets with a mean capture rate of 0.003 and 0.0003 birds per haul, respectively. The estimated total number of birds killed was 53 penguins and five shags considering the total number of hauls made by the fishery in the two seasons. No contacts between seabirds and warp cables were recorded. Coastal shrimp vessels generally operated between 15 and 20 km offshore, at a mean distance from the main Kelp Gull colony (Punta Tombo) of 43.9 km. At least 100 fish and invertebrate species were discarded, mostly Argentine hake (Merluccius hubbsi). Total amount discarded per season by this coastal fishery in the two seasons was estimated at 3,284 and 6,590 tonnes, respectively. The coastal shrimp fishery in the Isla Escondida area appears to have a small impact on seabirds in terms of incidental mortality but provides significant amounts of supplementary food during the breeding season of the Kelp Gull.

Analysis of the relationship between relative abundance of mature, impregnated females of Pleoticus muelleri (Bate, 1888) (Crustacea, Decapoda) and environmental variables through statistical models

The relationship between the relative abundance of mature and impregnated females of the Argentine red shrimp Pleoticus muelleri (Bate 1888) and environmental variables was analyzed using statistical methods. Analyzed data came from the research cruises of the Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) carried out during January 2000, 2001, 2005, and 2007; March 2006; and November 2004, 2005, and 2006 in San Jorge Gulf (Argentina). The biological variables considered were the relative abundances of mature and impregnated female shrimp, whereas the environmental variables corresponded to depth, bottom water temperature and salinity, and the difference between surface and bottom water temperature and salinity. Generalized additive models were used as an exploratory tool for the numerical data and the general linear models as a confirmatory tool. The results showed that the distributions and abundances of mature and impregnated females were related to the bottom water temperature and salinity and to depth. The relationship increased along with temperature; with salinity, however, it decreased for mature females and increased for impregnated females. An optimal depth range was evidenced, where the largest concentrations of these individuals were located.

Seabird attendance and incidental mortality at shrimp fisheries in Golfo San Jorge, Argentina

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 432:125-135 (2011) - DOI: https://doi.org/10.3354/meps09146 Seabird attendance and incidental mortality at shrimp fisheries in Golfo San Jorge, Argentina Diego González-Zevallos1, Pablo Yorio1,2,*, Walter S. Svagelj1 1Centro Nacional Patagónico (CONICET), Blvd. Brown 2915, U9120ACD, Puerto Madryn, Chubut, Argentina 2Wildlife Conservation Society, Amenabar 1595, P 2, Of. 19, C1426AKC, Ciudad de Buenos Aires, Argentina *Corresponding author. Email: yorio@cenpat.edu.ar ABSTRACT: Many seabirds are attracted to trawl vessels to make use of fishery waste, and often this attraction results in increased incidental mortality. We assessed seabird attendance and associated incidental mortality at the Argentine red shrimp Pleoticus muelleri trawl fishery in Golfo San Jorge, Argentina. Information on seabird numbers was gathered in the autumn and winter 2006 and spring 2008, while information on seabird incidental captures was obtained for the period 2005–2007. Eighteen seabird species attended vessels, and the 2 most frequent and abundant seabirds (percent occurrence, median no. haul–1) were the kelp gull Larus dominicanus (>94%, <100) and black-browed albatross Thalassarche melanophrys (>94%, <55). Seabird numbers were significantly lower in winter than the other 2 seasons and highest during discarding activities. Species incidentally killed in nets were the Magellanic penguin Spheniscus magellanicus and imperial cormorant Phalacrocorax atriceps, with a mean capture rate of 0.048 birds haul–1, and for both species, mortality decreased with distance to the coast. Considering the fishery’s fishing effort during each month, the estimated total mortality in the study period was 895 (95% CI: 572 to 1339) penguins and 172 (95% CI: 69 to 305) cormorants. Over 95% of the recorded mortality occurred in 2005, the year when the trawling moratorium generally implemented in the area was not enforced. No interactions with warp cables were recorded. Results highlight the relevance of complying with the current moratorium scheme, as adjusting it to the penguin and cormorant breeding seasons may by a potentially effective management tool. The proximity to the coast of the recorded incidental mortalities indicates the need to re-evaluate the spatial design of the park and/or the definition of management actions beyond the boundaries of the Marine Protected Area. KEY WORDS: Seabird–fishery interactions · Seabird by-catch · Trawlers · Fishing discards · ­Patagonia Full text in pdf format PreviousNextCite this article as: González-Zevallos D, Yorio P, Svagelj WS (2011) Seabird attendance and incidental mortality at shrimp fisheries in Golfo San Jorge, Argentina. Mar Ecol Prog Ser 432:125-135. https://doi.org/10.3354/meps09146 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 432. Online publication date: June 27, 2011 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2011 Inter-Research.

Infestation of the squat lobster Munida gregaria (Anomura: Galatheidae) by Pseudione galacanthae (Isopoda: Bopyridae) in San Jorge Gulf, Argentina

We estimated the prevalence of the bopyrid Pseudione galacanthae parasitizing the population of the squat lobster Munida gregaria in San Jorge Gulf and analysed some aspects concerning the effect of the parasite on host reproductive potential. The relationship between the development stages of the parasite and the host size was also analysed. The squat lobsters were caught as by-catch in the coastal area of the gulf from vessels operating in the fisheries of hake Merluccius hubbsi, southern king crab Lithodes santolla and Argentine red shrimp Pleoticus muelleri. The samples were collected between October 1997 and June 2009. In the laboratory, squat lobsters were sexed and the length of their carapace was measured. In males, the length of the right cheliped was recorded and gonadal development was examined. In females, the size and number of carried eggs were determined and the length of the pleopods III, IV and V were measured. All squat lobsters parasitized exhibit a gross bulge in the right side of carapace. Prevalence ranged between 0 and 1.43% (N = 21,519). No significant differences in prevalence were found for sexes, depths and seasons. The prevalence was higher for the size interval 7–10 mm CL (0.79%) than for the rest of the intervals. Parasitism had no effect on the secondary sex characters. Parasitized males displayed gonad development. There was no difference in prevalence between ovigerous and non-ovigerous squat-lobster females. Parasitized females had smaller eggs than non-parasitized ones, but their fecundity was similar. The linear relationship between the parasite and host sizes and the presence of larvae and immature stages of P. galacanthae in small-sized squat lobsters suggest that the host is infected early in its development. The low prevalence could be related to oceanographic conditions which favour larval dispersal of the parasite and host. The infestation by P. galacanthae has little impact on the M. gregaria population, mostly due to the low prevalences of infestation and the minor impact in reproductive function.