Percorrer por autor "Santos, Pedro M."
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- Can artificial diets be a feasible alternative for the gonadal growth and maturation of the sea urchin Paracentrotus lividus (Lamarck, 1816)?Publication . Santos, Pedro M.; Ferreira, Susana M. F.; Albano, Pedro; Raposo, Andreia; Costa, José L.; Pombo, AnaParacentrotus lividus (Lamarck 1816) has high-value reddishorange gonads that are regarded as a delicacy. In this study, three jellified diets have been tested for 90 days to assess the effect of different diets on P. lividus somatic and gonadal growth, gonad color, and reproductive state. All diets contained agar as a gelling agent and consisted of: maize and spinach (A); maize, spinach, and macroalga Laminaria digitata (B); and maize, spinach, and pumpkin Cucurbita maxima (C). Diet B was the most successful in promoting somatic growth with regard to test diameter (1.2 mm month−1) and total wet weight (79.9 mg ind−1 day−1). The individuals from Diet A presented a higher final gonadosomatic index (9.07 ± 2.39%) where all sea urchins initially presented with an index of 3.33 ± 0.02%. Diets A and C led to a marked advance (p < .05) in the gametogenic cycle (66.7% and 46.7% of the individuals with mature gametes, respectively), while Diet B resulted in less-developed gonadal stages, which are more appropriate for commercial purposes in terms of sensorial characteristics appreciated by the consumers. The gonad color analyses confirmed a redder roe in females and also the suitability of C. maxima as a potential gonad color enhancer for P. lividus.
- Comparison of the efficiency of different eradication treatments to minimize the impacts caused by the invasive tunicate Styela plicata in mussel aquaculturePublication . Santos, Pedro M.; Venâncio, Eliana; Dionísio, Maria Ana; Heumüller, Joshua; Chainho, Paula; Pombo, AnaIn 2017, aquaculture producers of the Albufeira lagoon, Portugal, reported an invasion of tunicates that was disrupting mussel production, particularly the tunicate Styela plicata (Lesueur, 1823). A totally effective eradication method still does not exist, particularly for S. plicata, and the effects of the eradication treatments on bivalves’ performance are also poorly understood. Our study examined the effectiveness of eradication treatments using three laboratory trials and five treatments (air exposure, freshwater immersion, sodium hypochlorite, hypersaline solution and acetic acid) for S. plicata, as well as their effects on survival and growth of blue mussel Mytilus edulis Linnaeus, 1758. While air exposure and freshwater immersion caused a 27% mortality rate in S. plicata, the acetic acid treatment was the most effective in eliminating this species (>90% mortality). However, a 33–40% mortality rate was registered in mussels. Both species were not affected by the hypersaline treatment in the last trial, but the sodium hypochlorite treatment led to a 57% mortality rate in mussels. Differences in mussels’ growth rates were not detected. These trials represent a step forward in responding to the needs of aquaculture producers. However, further studies are needed to investigate the susceptibility of tunicates to treatments according to sexual maturation, as well as to ensure minimum mussel mortality in the most effective treatments, and to better understand the effects on mussel physiological performance in the long-term.
- Effect of salinity on somatic growth and gonadal enhancement of the sea urchin Paracentrotus lividus (Lamarck, 1816)Publication . Santos, Pedro M.; Silva, João A.; Costa, José Lino; Pombo, AnaSalinity plays a major role in several physiological processes in sea urchins, including reproduction and growth, ultimately affecting survival. Optimal salinity ranges vary considerably between species, as a consequence of ecological adaptations. However, related research in the context of aquaculture is quite scarce, particularly for the stenohaline sea urchin Paracentrotus lividus (Lamarck, 1816), a target species for aquaculture diversification in Europe. It is thus important to better understand the response of this species to hyposalinity conditions over an extended rearing period. Four salinity treatments (20, 25, 30 and 35 psu) were evaluated, over 120 days, in terms of survival, feed intake, growth, gametogenic development and gonadal colour in P. lividus. While a 100% survival was obtained in all treatments, salinity significantly affected all other parameters. Sea urchins reared at 20 psu presented significantly lower linear and specific growth rates, feed intake, gonadosomatic index, as well as a higher feed conversion ratio. While sea urchins reared at 30 and 35 psu were mostly mature, hyposalinity led to a slower gametogenic progression in the lower salinities, particularly at 20 psu. Gonad colouration was only affected in males, as individuals reared at 20 psu presented less brighter, but more reddish and yellowish gonads. The results clearly demonstrate that despite the absence of mortality, rearing salinities of 20 and 25 psu promote a negative effect on somatic and gonadal yield of P. lividus.
- Effect of three diets on the gametogenic development and fatty acid profile of Paracentrotus lividus (Lamarck, 1816) gonadsPublication . Raposo, Andreia I.G.; Ferreira, Susana M. F.; Ramos, Rodolfo; Santos, Pedro M.; Anjos, Catarina; Baptista, Teresa; Tecelão, Carla; Costa, José L.; Pombo, AnaIn this study, the effects of three diets were investigated to enhance Paracentrotus lividus production for commercial purposes. P. lividus were fed ad libitum for 80 days with: diet A—fresh Codium tomentosum Stackhouse, 1797; diet B—formulated using a jellified mix of macroalgae and vegetables, including C. tomentosum (20%), Coralina sp. Linnaeus, 1758 (17%), cabbage Brassica oleracea var. capitata Linnaeus, 1753 (30%), carrot Daucus carota Linnaeus, 1753 (30%) and agar (3%) as a gelling agent. Diet C consisted of maize Zea mays Linnaeus, 1753 (56%) and New Zealand spinach Tetragonia tetragonoides (Pallas, 1781) Kuntze, 1891 (44%). Their effects on the gonadal and somatic growths, gonadosomatic index (GI) and gametogenesis were evaluated, as well as on the total lipid content and fatty acid composition of sea urchin's gonads. Diet A provided high values of eicosapentaenoic acid (EPA). Gonads of sea urchins fed with diet A were found mostly in growth and maturation stages of ametogenesis and showed the lowest lipid content. Sea urchins fed with diet B presented their gonads in the reabsorption stage and had the highest values of omega‐3 polyunsaturated fatty acids (PUFAs). Sea urchins fed with diet C were in the early stages of gametogenesis and had the highest values of lipid content, plus omega‐6 PUFAs. Once as an ingredient in a balanced mix with vegetables, C. tomentosum can be a key factor to the development of new promising high‐quality and low‐cost feed for P. lividus roe enhancement.
- Effects of single and mixed-diatom diets on growth, condition, and survival of larvae of the sea urchin Paracentrotus lividus (Lamarck, 1816)Publication . Gomes, Ana; Lourenço, Sílvia; Santos, Pedro M.; Raposo, Andreia; Mendes, Susana; Gonçalves, Sílvia C.; Ferreira, Susana M. F.; Pombo, AnaThe development of rearing protocols promoting the larval development, pre and postmetamorphosis are key for echinoculture. Mixed diets combining diatom with other microalgae have been used with success and Rhodomonas sp. (Rho)-based diets showed promising results in larval survival. This study was aimed to evaluate the rearing success of Paracentrotus lividus larvae fed with mixed diets combining Rho with two diatoms, Phaedactylum tricornutum (Phae) and Chaetoceros calcitrans (Chae) in two experiments. In experiment I, the effect of the mixed diet of Rho and Phae (Mix I) was compared with monospecific diets of both species, while in experiment II, Rho was combined with Chae (Mix II) and compared with both monospecific diets. In experiment I, larvae fed with Rho I and Mix I diets grew faster than larvae fed with Phae I diet, attained the competence earlier with survival rates of 15-16%. In experiment II, the larvae fed with Rho were larger and the larvae fed with Mix II attained the highest survival rate (32.22%). The analysis of the larval biometric models showed that the larger larvae, with bigger stomachs, and shorter post-oral arm attained the age-at-competence earlier with higher survival rates. In conclusion, the larvae fed with a combination of Rho with the selected diatoms showed identical growth performance and condition to larvae fed with Rho monospecific diet but obtained higher survival rate. These results indicate that mixed-diatoms diets may be more suitable for P. lividus larval rearing.
- High dietary protein, n − 3/n − 6 ratio and β-carotene enhances Paracentrotus lividus (Lamarck, 1816) larval developmentPublication . Gomes, Ana S.; Lourenço, Sílvia; Santos, Pedro M.; Neves, Marta; Adão, Pedro; Tecelão, Carla; Pombo, AnaThe nutritional characteristics of microalgae affect the growth, survival and fatty acid composition of sea urchin larvae. This study aimed to evaluate the influence of nutritive characteristics of single microalgal diets in Paracentrotus lividus (Lamarck, 1816) larval development, growth, and condition. Larvae of P. lividus were fed with three monospecific microalgal diets, Rhodomonas sp. (Rho), Dunaliella tertiolecta (Duna) and the diatom Chaetoceros calcitrans (Chae), and their development and growth were analysed until competence. Additionally, the fatty acid (FA) profile of larvae was analysed at competence and compared with the FA profile of the correspondent diet. The three groups of larvae attained competence simultaneously with differences in growth performance. The larvae fed with Chae attained the largest stomach and the shortest post-oral arm. The larvae were able to accumulate long-chain polyunsaturated fatty acids (PUFA), such as docosahexaenoic (DHA, C22:6n − 3), eicosapentaenoic (EPA, C20:5n − 3) and arachidonic (ARA, C20:4n − 6) acids, either by assimilation and retention of dietary FA or by the synthesis from α-linolenic acid (ALA, C18:3n − 3) and linoleic acid (LA, C18:2n − 6). Furthermore, the low DHA/EPA ratio and high EPA/ARA and n − 3/n − 6 ratios of Rho and Chae and the high levels of the β-carotene present in Chae improved larval growth and development. In conclusion, the results indicated that of the three microalgal diets tested, C. calcitrans provided important nutritional characteristics, especially in terms of FA composition and carotenoids, improving P. lividus larval growth and condition.
- Morphometric approach to the development of Paracentrotus lividus larvae fed with different microalgae dietsPublication . Lourenço, Sílvia; Gomes, Ana Sofia; Santos, Pedro M.; Raposo, Andreia; Ferreira, Susana; Pombo, Ana
- Motivation and preferences of Portuguese consumers’ towards sea urchin roePublication . Lourenço, Sílvia; Mendes, Susana; Raposo, Andreia; Santos, Pedro M.; Gomes, Ana S.; Ganhão, Rui; Costa, José L.; Gil, Maria M.; Pombo, AnaSea urchin roe is a gastronomic delicacy appreciated worldwide and Portugal is the third largest consumer nation of seafood. However, sea urchin roe is recognized as a seafood by few members of the national coastal communities. Motivated by an increasing interest of gastronomic and aquaculture sectors in producing this seafood, a survey was conducted among the participants of gastronomic festivals aiming to characterize the motivations and preferences regarding sea urchin roe. The results showed that a high percentage of consumers would be willing to eat sea urchin roe in a restaurant, and approximately half of these were not motivated to buy it in the supermarket. The consumers willing to buy sea urchins in the supermarket, would buy it as the whole urchin or the chilled/frozen roe. In conclusion, sea urchin roe can be characterized as a high valued shellfish to be consumed in restaurants.
- Physical and chemical tagging methods for the sea urchin Paracentrotus lividus (Echinodermata: Echinoidea)Publication . Santos, Pedro M.; Quintella, Bernardo Ruivo; Jacinto, David; Gomes, Ana; Saldanha, Carolina; Lourenço, Sílvia; Lopes, Patrícia Mega; Correia, Maria João; Mateus, David; Cruz, Teresa; Pombo, Ana; Costa, José LinoThe sea urchin Paracentrotus lividus (Lamarck, 1816) (Echinodermata: Echinoidea) is an important economic resource in Europe, but intense harvesting has led to the collapse of several natural populations. Echinoculture, associated with restocking and stock enhancement practices, is an alternative to this problem. In these procedures, reliable individual identification through tagging is a valuable source of information. However, very few studies address the effect of tagging methods on P. lividus and the tagging of marine invertebrates still presents several challenges: decreased growth, high mortality rates and low tag retention rates. Under laboratory conditions, the present study evaluated the effectiveness of three tagging methods (passive integrated transponders [PIT-tags], coded wire tags [CWTs] and calcein) on wild P. lividus for 60 days in terms of total wet weight, total weight gain (mg ind.−1 day−1), survival and tag retention. The final total wet weight was significantly higher in the untagged (control) group than in the PIT-tagged group. Survival rate was 100% for the PIT-tag, calcein and control groups, and 97% for the CWT group. Tag retention differed significantly according to the tagging method: 100% in the calcein group, 76.7% in the PIT-tag group and 38.0% in the CWT group.
- Pilot studies for stock enhancement of purple sea urchins (Paracentrotus lividus, Lamarck, 1816): usefulness of refuges and calcein marking for the monitoring of juveniles released into the natural environmentPublication . Correia, Maria João; Lopes, Patrícia Mega; Santos, Pedro M.; Jacinto, David; Mateus, David; Maresca, Francesco; Quintella, Bernardo Ruivo; Cruz, Teresa; Lourenço, Sílvia; Pombo, Ana; Costa, José LinoIn the framework of stock enhancement, field experiments were conducted between March and July 2021 in rocky shores of Central Portugal to test the usefulness of refuges and calcein marking for juvenile sea urchins releases. Individuals with 10–20mmin test diameter were captured in nature and tagged through immersion in a calcein bath with a concentration of 150 mg L 1, during 48 hr. Artificial shelters were used to provide refuge and an acclimatization structure for the released sea urchins, and in situ monitoring was carried out by counting the marked specimens over three months. Results point out to the importance of using shelters to provide protection to sea urchins, and validated the efficiency of the calcein tagging protocol for in situ monitoring. Sea urchins’ test diameter growth during the experiment was estimated to be 0.470mm month 1 (SD = 0.181).