Ovalipes Trimaculatus Research Articles

Spatial overlap and trophic interactions between a native commercial crab and the European green crab in Atlantic Patagonia

The European green crab, Carcinus maenas, is a highly invasive species capable of exerting significant impacts on native biota, particularly on species of ecological and/or economic importance. In Atlantic Patagonia, green crabs have been rapidly expanding their distribution along the coast, yet their biotic interactions with native crab species have not been examined. Here, we investigate the agonistic interactions of invasive green crabs with the native commercially important paddle crab (Ovalipes trimaculatus) in Atlantic Patagonia. This study determined spatial overlap between both species and experimentally evaluated predator-prey interactions and competition for food. Our results indicate coexistence of Carcinus and Ovalipes trimaculatus in sandy bottoms of Nuevo Gulf, with green crabs being much more abundant than paddle crabs. Carcinus was present across all sampled locations, exhibiting highly variable abundances and considerable sex ratio disparity. In aquarium trials, mutual predation only occurred between Carcinus and O. trimaculatus of contrasting sizes, although the time taken to observe predation events significantly differed between both species, with green crabs displaying much higher voracity. Additionally, green crabs were the first to hoard food when it was offered. These findings suggest that predation by green crabs especially on juveniles paddle crabs may play a role in the decline of O. trimaculatus in formerly abundant shallow areas in Nuevo Gulf. Thus, this study lays the groundwork for assessing interactions between Carcinus and a broader range of native crab species, aiming to deepen our understanding of current and potential interactions in the SW Atlantic.

Marine sources for biotechnology: Preliminary digestive enzymes assessment of seven decapod species from the southwest Atlantic

Marine natural compounds are required by industries to improve and reduce costs of many biotechnological processes. In this work, specific activity of midgut gland digestive enzymes was measured in seven species of decapods. Alkaline and acid peptidase, lipase and amylase activities were registered in Pleoticus muelleri (Pm), Artemesia longinaris (Al), Paralomis granulosa (Pg), Lithodes santolla (Ls), Munida gregaria (Mg), Neohelice granulata (Ng), and Ovalipes trimaculatus (Ot). The highest activities for all the analyzed digestive enzymes were obtained in Pg, Ls, Mg and Ot, which were used for optimum temperature and pH measurements and to test their stability at different temperatures and pH. In general, optimal enzyme temperatures were between 30 and 50 °C in the four crustaceans. Peptidases and lipases from these species showed in general alkaline optimal pH except for those from Ot which presented high activity at the whole pH range (2–12). Amylase from Ot presented its optimal at pH 6–8 and 30–50 °C. Thermal stability of peptidases was elevated at 30 °C for the four species tested (Pg; Ls; Mg and Ot), lipases were stable mainly at 30–50 °C and amylase was stable at 10 °C, 30 °C and 50 °C during the first 30 min of the assay. In general, stability of the four enzymes from Pg was greater at alkaline pH than at acid. The other species showed stability at all pH for the four enzymes. The range of temperature and pH of the tested enzymes activity are coincident with those used in various biotechnological processes and therefore indicates the potential of these enzymes to be used for industrial procedures. Further, most of the species studied are converted into fishery residues, either by processing or by-catch, so their reuse would also contribute to the sustainability of the activity.

Effects of dietary administration of two Patagonian probiotics on the zoeae I from the swimming crab Ovalipes trimaculatus

Effects of dietary administration of two Patagonian probiotics on the zoeae I from the swimming crab Ovalipes trimaculatus

Effects of temperature and salinity on the development and survival of the embryos and zoeae I from the southern surf crab Ovalipes trimaculatus (Brachyura: Portunidae).

Ovalipes trimaculatus is a highly valued fisheries resource with high potential for aquaculture production. Still, there is need for experimental information to sustain efficient husbandry practices. In this work we analyze the combined effects of different thermo-haline conditions on the length of development and survival of embryos (6, 10, 13, 15, 18, 22, 24 ⁰C x 30, 33 ‰; 13 ⁰C x 26, 30, 33, 37 ‰) and zoeae I (13, 18, 22 ⁰C x 30, 33 ‰; 13 ⁰C x 26, 30, 33, 37 ‰) from individuals sampled in the Atlantic coast of Patagonian. Among the most relevant results, it was found that the mean length of embryogenesis decreased from 63 to 19 days with increasing temperatures, but was not affected by seawater salinity. Mean embryonic survival was significantly lower at the combination of the highest temperature and salinity tested. Also, it differed between salinity conditions. Both at 30 and 33‰, the length of the Zoea I stage significantly varied between thermal treatments, being significantly longer at 13⁰C. No zoeae I reared at 13 ⁰C survived at 37‰ and mean survival at 26‰ halved that of 30-33‰. Results obtained reduce aquaculture production costs.

Biochemical Composition and Quality Parameters of Raw and Cooked Refrigerated Patagonian Crabmeat (Ovalipes trimaculatus)

ABSTRACT Protein fractions and fatty acids composition, proximal composition, and quality parameters of raw Patagonian crabmeat Ovalipes trimaculatus (meat from claws and body) were analyzed. The effects of the commercial cooking processes (boiling or steaming) on total volatile base nitrogen (TVB-N) content, water-holding capacity, cooking losses, color changes, and oxidation stability were determined. Changes in physical and chemical properties and total microbial counts of boiled crabmeat (claw and body) stored at 4°C for one week were studied. The raw crabmeat showed high values of moisture and protein and a low lipid content. The pattern of all protein fractions was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis. Fatty acids composition was determined by gas chromatography-mass spectrometry. Polyunsaturated fatty acid (PUFA) content was approximately 75% of the total fatty acids composition, while eicosapentaenoic acid (EPA) (20:5(n-3 c)) and docosahexaenoic acid (DHA) (22:6(n-3)) were the most abundant omega-3 fatty acids. The results revealed significant differences between cooking methods. Steam-heated samples showed higher values of total volatile base nitrogen (TVB-N), pH, and cooking losses, and lower meat yield. Microbial counts and sensory analysis showed that boiled crabmeat stored at 4°C remained acceptable for consumption during 7 days of storage.

Rearing enhancement of Ovalipes trimaculatus (Crustacea: Portunidae) zoea I by feeding on Artemia persimilis nauplii enriched with alternative microalgal diets

The southern surf crab Ovalipes trimaculatus (de Haan, 1833) presents a high potential for aquaculture. In this study, we analyze the benefits of different dietary treatments on its molt success and fitness of larval stages. Artemia persimilis nauplii were enriched with monospecific (Nannochloropsis oculata, Tetraselmis suecica, Dunaliella salina, Isochrysis galbana and Chaetoceros gracilis) and multispecific (Mix) microalgal diets twice a day over a 48-h period. Mean total length (TL), growth instar number (I) and gut fullness rate (GFR) of nauplii showed significant differences between dietary treatments at several sampling times, optimal results being observed in those providing Mix. Artemia nauplii grown under most experimental dietary treatments reached the capture size limit for Ovalipes trimaculatus zoea I (700 µm) within 24 h. After that time interval, Mix-enriched nauplii were amongst those with higher protein contents. Ovalipes trimaculatus zoea I fed on Artemia nauplii enriched during 24 h under different dietary treatments showed significant differences in survival, inter-molt duration, molting success to zoea II and motility. Optimal results were observed in zoea I fed on Mix-enriched Artemia nauplii. This work not only represents a first step towards the dietary optimization for O. trimaculatus zoeae rearing but also provides the first results on the use of enriched A. persimilis.

Combining fishers' perceptions, landings and an independent survey to evaluate trends in a swimming crab data-poor artisanal fishery

The fishery for the swimming crab Ovalipes trimaculatus in the southwestern Atlantic started in 2007, with an average catch of 64.36 t⋅y−1 during the period between 2008 and 2013. The fishery is under an open access regime and market demand exceeds the catch which raises concern about its future. It is also data-poor, which prevents researchers from using traditional assessment methods. The factors that limit the fishing effort were identified by analyzing the fishing operation, the decision making process of the fishers and CPUE. Changes in catch composition through space and time, and the distribution of the population along a depth gradient were also studied.Wind, recent yield and the price of crab were perceived by skippers as relevant factors when deciding to go fishing, but there was no relationship between these variables and monthly fishing effort. However, daily fishing effort depended on wind conditions. During the studied period (2008–2013) the CPUE of 2009 was the only one lower than the CPUE of 2008, and the number of fishing grounds as well as their respective area have not increased. The species depth distribution reaches 60 m deep, which is much deeper than the depths divers can reach (about 20 m), however the highest abundance of O. trimaculatus occurs at less than 30 m depth. The fishery did not show signs of depletion likely due to the combination of target species depth distribution and fleet characteristics limiting fishers' operability. This provides a unique opportunity to constrain fishing effort and avoid overcapacity, for example by banning larger vessels from the fishery.

The effect of temperature, salinity, eyestalk ablation, and limb removal on growth and survival of juvenile paddle crab, Ovalipes trimaculatus (Brachyura: Portunidae)

Crustacean growth in nature is affected by hormonal processes and natural stressors. For aquaculture purposes, paddle crab, Ovalipes trimaculatus (De Haan, 1833), juveniles were subjected to experimental eyestalk ablation, limb removal, and a combination 3 × 3 temperature and salinity conditions. Relative lifetime in captivity (RLC), molting success (MS), molting interval (MI), growth in terms of size and weight after molting (SI and WI), specific growth rate in size (SGRs) and weight (SGRw), and hepatosomatic index (HS) were evaluated in eight replicate groups of crabs for each treatment (one crab per tank). RLC was significantly lower in eyestalk-ablated crabs than in those subjected to limb removal and to control conditions (no organ removal, 13 °C, salinity of 33); it was significantly higher in crabs held at a salinity of 30 vs those maintained at 33 and 27. Combinations of 16 or 19 °C and salinity of 30 provided the optimal conditions of growth in size and weight. Results suggest that control of temperature and salinity can improve growth and survival of juveniles in captivity. However, organ removal did not promote molting in captivity, likely to the detriment of survival and physiological condition. Findings from the present study highlight the importance of carefully selecting conditions to rear this valuable commercial crab to promote its aquaculture in the region.

Patterns of habitat partitioning for the portunid crab Ovalipes trimaculatus in coastal Patagonian waters

Animals frequently face trade-offs between their requirements for maximizing growth and minimizing mortality risk. The partition of habitat use in foraging arenas and refuges as an answer to this trade-off has been evaluated in intertidal crabs but is poorly known in subtidal crabs. The subtidal crab Ovalipes trimaculatus lives and is captured by artisanal fishermen on sandy bottoms of the San Matías Gulf (Lat 41 °S; Argentina). Whereas these bottoms are poor in potential prey, the nearby rocky outcrops are much richer with relatively high abundance of potential prey for the species. Hence, we investigated if crabs in this area are using rocky bottoms as a foraging arena. Stomach content and stable isotopes analysis show that none of the evaluated prey (small teleosts, echinoderms, mollusks and crustaceans) contributed to more than 10% of O. trimaculatus diet, however prey from hard bottoms jointly contributed to 50–80% of the diet. Thus, O. trimaculatus is a generalist carnivore that, despite inhabiting mainly open sandy bottoms, uses rocky outcrops habitats as a foraging arena, probably due to their higher prey availability.

Functional morphology of the gastric mill of the swimming crab Ovalipes trimaculatus (Decapoda: Portunidae)

The stomach of Decapod crustaceans is a complex structure with great interspecific variation. Several studies suggest that the anatomy of the gastric mill varies according to the diet of species in different groups. An alternative view suggests the gastric mill's structure is related to phylogenetic aspects rather than to the diet of a species. The morphology of the gastric mill of Ovalipes trimaculatus, a portunid crab target of fisheries in Argentina and Chile, was studied through stereo-microscope and scanning electron microscope images. Ovalipes trimaculatus has a stomach that corresponds to a macrophagous and predatory diet. The gastric mill is similar to that of other portunids, especially those with predominant animal component in their diet. Our results support the idea that this structure has a basic pattern, given by shape and elements forming the gastric mill; and upon that pattern, trophic habits adaptively shape certain traits.

Embryonic development of the southern surf crab <em>Ovalipes trimaculatus</em> (Decapoda: Brachyura: Portunoidea)

The embryogenesis of Ovalipes trimaculatus, a member of the highly valued portunid swimming crabs, was studied under nearly constant temperature (13±1°C), salinity (33) and photoperiod (14 h light:10 h dark) conditions. A five-stage scale of embryonic development was defined for the species. Time required to complete development averaged 35.7±2.11 days, showing no significant differences between embryos located in inner, middle and outer portions of the egg mass. The egg chorion was rounded and showed the highest growth in diameter between stages I (morula-blastula-gastrula) and II (primordium of larval structure) and between stages III (appendage formation) and IV (eye formation). Results reported here provide a baseline for optimizing hatchery operations and useful information for management purposes.

Acoustic signals and behaviour of Ovalipes trimaculatus in the context of reproduction

This study focused on the acoustic behaviour of the paddle crab Ovalipes trimaculatus (De Haan, 1833) in relation to its reproductive status and behaviour. Paired males and females (demonstrating pre-copulatory behaviour) as well as solitary animals were collected a few hundred metres from the coast of Puerto Madryn (Patagonia, Argentina) and kept in indoor tanks. Synchronized acoustic and video monitoring systems were used to record the acoustic signals and other behaviours of single and grouped specimens in an experimental tank. Acoustic data were analysed to characterize crab sounds (duration, pulse number and pulse rate, 1st and 2nd peaks in frequency, amplitude of the frequency peaks and bandwidth) and were counted as behavioural events. Video data were analysed to count behavioural events (i.e. agonistic fight, chela spread) and determine status (locomotor indices, inter-crab distance). O. trimaculatus produced wide frequency band multi-pulse signals with significant differences between males and females: males showed a lower 1st peak in frequency, with a higher amplitude and a higher bandwidth. The sound emission rate was significantly higher in grouped animals than in single individuals. The sound emissions were not accidental events correlated with locomotor activities. In the trials involving pre-copulatory females, the total number of sounds was significantly higher compared to the trials with non-copulatory (control) females, and the sounds were not correlated with the agonistic events between males. Our data indicate that in O. trimaculatus sound emissions play a role in intraspecific communication related to sexual attraction.

Marine pollution effects on the southern surf crab Ovalipes trimaculatus (Crustacea: Brachyura: Polybiidae) in Patagonia Argentina

We compared the carapace shape and thickness as well as the energy density of Ovalipes trimaculatus inhabiting areas comprising a gradient of marine pollution: high, moderate and undetected, in the Nuevo gulf (Patagonia Argentina). The carapace shape was evaluated by means of individual asymmetry scores (=fluctuating asymmetry) whereas the carapace thickness was assessed by measuring the carapace dry weight. The energy density was analyzed through its negative relationship with water content in muscle tissue. The individual asymmetry scores as well as the percentage of water content in muscle tissue were proportional to the marine pollution gradient, whereas the carapaces thickness did not differ among sampling sites. Our results are consistent with previous findings and demonstrate the direct effect of marine pollution on other taxa different from gastropods, cephalopods and polyplacophora and add to long-standing concerns about detrimental effects caused by marine pollution on the benthic community of the Nuevo gulf.

Reproductive system and size maturity of the paddle crab Ovalipes trimaculatus (Brachyura: Portunidae) along the Argentine coast

Fil: Vallina, Micaela Veronica. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Seasonal abundance and vertical distribution of crab larvae from northern Patagonia (Argentina): implications for their transport in a biogeographic boundary region

In species with meroplanktonic larval phases, some reproductive traits (i.e. seasonality and larval behaviour) interact with hydrographic features to determine larval transport. This work reports the seasonal, diel and ontogenetic changes in vertical distribution of crab larvae in the boundary region between the Argentine and the Magellanic biogeographic provinces of the Atlantic coast off northern Patagonia (Golfo Nuevo; 42.75°S, 65.00°W). Larval seasonality was studied from 47 plankton hauls taken from August 2004 to July 2005. Vertical distribution was studied from 45 stratified plankton hauls carried out in August 2005, December 2005 and April 2006. Crab larval stages were detected throughout the year, but abundance was higher from midwinter to midsummer. Species from southern regions – Munida gregaria, Peltarion spinosulum and Halicarcinus planatus – were abundant during winter and aggregated mainly near the surface, regardless of the hour of the day. In contrast, species from northern regions – Platyxanthus patagonicus, Ovalipes trimaculatus, Leucippa pentagona, Leurocyclus tuberculosus, Cyrtograpsus spp. and Pachycheles chubutensis – were abundant during spring and summer and were usually aggregated near the surface during the night and dispersed in subsurface layers during the day. Ontogenetic changes in vertical distribution were not observed. Residual currents reported in the area (3–6 km·day−1) and duration of larval life (approximately 15–70 days) suggests a minimum potential transport on a 100-km scale. Biological information reported in this work could be explicitly incorporated in a circulation model to accurately predict larval transport and connectivity.

Mathematical modeling of the heat transfer process and protein denaturation during the thermal treatment of Patagonian marine crabs

Southern Ocean swimming crab Ovalipes trimaculatus and the Patagonian stone crab Platyxanthus patagonicus are fishing resources with commercial value. Thermal treatment of crabs is necessary to denature muscle proteins, facilitating meat detachment from the crab shell (picking procedure). The proximal composition, protein patterns of crab muscle, thermophysical properties and heat transfer coefficients were determined. Heat transfer during thermal processing of body (i.e., cephalothorax) and claws of both crab species was simulated using a finite element computational code; the simulations were experimentally validated. Color changes in crab muscle during the heating process were measured. Thermal denaturation kinetics of myofibrillar proteins was determined using Differential Scanning Calorimetry (DSC) in small samples previously heated in water under controlled conditions. DSC thermograms of raw crab muscle showed two peaks at 49.0±0.4 and 77.5±0.6°C corresponding to myosin and actin respectively. Activation energies for the denaturation of myosin (145.70kJ/mol) and actin (156.42kJ/mol) were calculated from Arrhenius equation. The degree of denaturation achieved by the myofibrillar proteins at the coldest point of the muscle in body and claws during the heating process was established by considering the protein denaturation kinetics determined by DSC, the activation energies and the heat penetration curves. Adequate conditions for the detachment of meat from the crab exoskeleton were established. The obtained results may help in determining the optimal heating times during the industrialization of these crustaceans.

Experimental trap fishery for the crabs Platyxanthus patagonicus and Ovalipes trimaculatus in the San Matías Gulf, Patagonia, Argentina

Crab species had not been exploited until recently in the San Matías Gulf. An experimental trap fishery plan was developed to provide information on the feasibility of their potential extraction. Sampling was carried out using an artisanal shellfish boat in the San Matías Gulf. Nine baited traps, three of each type (cubical, tubular-conical and tubular-pyramidal) were intercalated along a master line. The total number of crabs of each species caught was compared among lines (N=27), types of trap and soaking times (6, 24 and 48 h). A total of 137 traps of 243 traps employed caught crabs. More crabs were caught in the cubical traps than in the other types. Comparisons of numbers of crabs among lines allowed identification of areas having different relative abundances, with an average of 3.56 crabs per trap. The catch of Ovalipes trimaculatus was significantly greater in lines on the 10-m isobath. Two lines, on the 50-m isobath, showed the best results for Platyxanthus patagonicus. The total number of crabs per trap obtained during a soaking time of 6 h was significantly less than the number caught with longer soaking times. Only individuals exceeding 50 mm in carapace width were caught. The size-frequency distributions differed significantly between sexes for the two species, with males larger than females. In O. trimaculatus, males made up 29% of the catch and the remainder was constituted of non-ovigerous females; mean carapace width was 92.93 mm for females and 105.93 mm for males. Forty per cent of P. patagonicus were males (mean carapace width: 99.33 mm). Females bearing eggs amounted to 45% of the total females. Females' mean carapace width was 90.58 mm. Based on the results obtained, preliminary suggestions for management of a potential fishery for these species are made within a precautionary approach.

Descripción y distribución de cinco crustáceos decápodos recolectados en aguas profundas en torno a las islas Robinson Crusoe y Santa Clara (Archipiélago de Juan Fernández, Chile)

Five decapod crustacean species caught in experimental and exploratory fishing surveys around Robinson Crusoe and Santa Clara islands, Chile (33°38'S, 78°49'W), are identified and described. The fishing operation consisted in setting pots, between 50 and 1000 m depth, from November 1996 to June 1997. The species found were Jasus frontalis (50-100 m), Projasus bahamondei (250 m), Paromola rathbuni (100-300 m), Chaceon chilensis (200-1000 m) and Ovalipes trimaculatus (100 m). The species distribution is discussed, as well as the colonization mechanisms and population renewal of these populations inhabiting islands and submarine mountains of the Southeast Pacific, which are remarkably distant them and from the South American continent.

Pesca exploratoria con trampas alrededor de las islas Robinson Crusoe y Santa Clara, archipiélago de Juan Fernández, Chile

Looking for alternative resources to the Juan Fernandez spiny rock lobster ( Jasus frontalis), the traditional target species of the artisanal fishermen of the archipelago, an exploratory fishing campaign with fishing pots was conducted around Robinson Crusoe and Santa Clara islands. Between November 11, 1996, and March 23, 1997, a total of 71 fishing journeys were conducted, during which 241 pots were set between 50 and 1000 m depth. In these experiences different pot designs were used: conical-trunk, tetragonal, piramidal, and lobster pots with a wicket on one extreme and lobster pot with an upper wicket. The last two, are the ones often used by the archipelago fishermen to catch lobsters. The conical-trunk, tetragonal and piramidal pots were with circular or rectangular wickets. The resources caught were: Juan Fernandez spiny rock lobster ( Jasus frontalis), Juan Fernandez king crab (Paromola rathbuni), rowing crab (Ovalipes trimaculatus) and golden crab (Chaceon chilensis). The spiny rock lobster was captured between 50 and 100 m depth, while the rowing crab was found only in the 100 m isobath; Juan Fernandez king crab between 100 and 300 m and the golden crab between 200 and 1000 m. The only resource with fishing interest is C. chilensis, both by its abundance as well as for its wide distribution in depth and around these islands.

A description ofOvalipes trimaculatus(De Haan, 1833) (Brachyura: Portunidae: Polybiinae) zoeae reared in the laboratory

The zoeae larvae of Ovalipes trimaculatus (De Haan 1833) are described from laboratory-reared specimens, and some evidence is provided to support the division of the genus Ovalipes into subgroups.