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- Control of zootechnology leads to improved Cuttlefish (Sepia officinalis, L.) reproduction performance up to pre-industrial levelsPublication . Capaz, Juan Carlos; Hernández-Brooke, Daniel; Balvet, Safia; Couto, Ana T.; Alves, Alexandra; Baptista Gonçalves, Rui; Frias, Paulo A.; Andrade, José Pedro; Sykes, AntónioCephalopods are gaining momentum as an alternate group for aquaculture species diversification, not only because they are a good food source (highly appreciated in some worldwide markets) but they also have the potential to quickly reach a market size. However, there are some bottlenecks impeding the transition of culture technology from the laboratory to industry. One is related to control over reproduction in captivity. The objective of the present experiment was to verify the effects of tanks with different bottom areas/volumes on the reproduction performance of S. officinalis breeding stocks, when sex ratios were controlled a priori; and the food cost associated with such performance when individuals are fed a natural frozen diet. One hundred and ninety two juvenile cuttlefish were used to compare three different round-shaped tanks: one type with 3000L volume and two types with 9000L volume (with differences in bottom areas and water column). Individuals had their sex and maturity stage determined to establish a sexual ratio of 2 female:1 male per tank and assure that cuttlefish were still immature. Biological data was collected during both growth and reproduction stages and until the death of all females in each tank. The experiment lasted nearly 300 days. Temperature differences between tank types were registered during both stages. The optimizing of rearing conditions has allowed for higher growth and a higher amount of cuttlefish available for breeding purposes. A total of 123,751 eggs (in 85 batches) was obtained during this experiment, which is a number that may meet a small scale cuttlefish commercial hatchery facility requirements. The present conditions contributed to a better and predictable reproduction performance in specific 9000L tanks, with values reaching pre-industrial numbers (approximate to 24,000 eggs/tank). Moreover, both the amount of eggs per batch and the overall quality of eggs has increased. Three of these 9000L tanks have an overall consumption of approximate to 38.64 Kg tank(-1), which translates in an investment in feed of approximate to 193 (sic) tank(-1), 8.40 (sic) per cuttlefish and an overall daily tank expense of 1.76 (sic) d(-1).
- The impact of dietary supplementation with astaxanthin on egg quality and growth of long snout seahorse (Hippocampus guttulatus) juvenilesPublication . Palma, Jorge; Andrade, José Pedro; Bureau, D. P.This study investigated the effect of dietary astaxanthin supplementation on egg quality and juvenile growth of long snout seahorse (Hippocampus guttulatus). Captive breed seahorse broodstock were fed four diets composed of frozen shrimp [Atlantic ditch shrimp, Palaemonetes varians) used as a vector to deliver artificial diets with increasing levels of astaxanthin (0, 75, 100 and 125 mg kg(-1) dry weight)]. The results indicated that the astaxanthin uptake into eggs from the enriched shrimp diets was highly efficient. Females fed unsupplemented astaxanthin diet produced similar-sized eggs with lower concentration of astaxanthin than females fed diets with astaxanthin. The lower concentration of astaxanthin in the eggs was correlated with the production of smaller juveniles in comparison with the juveniles hatched from parents fed supplemented astaxanthin diets. Juvenile growth and survival was limited by their size on release from the male's pouch as at the end of 28-day postparturition juveniles produced with the diet with no astaxanthin were still significantly smaller (P < 0.05) than those produced from parents fed astaxanthin-supplemented diets. These results demonstrate a significant benefit of dietary astaxanthin supplementation in long snout seahorse diets in terms of improved egg quality and juvenile growth and survival.
- Optimization of live prey enrichment media for rearing juvenile short-snouted seahorse, hippocampus hippocampusPublication . Palma, Jorge; Lima, Ricardo; Andrade, Jose; Lança, Maria JoãoThis study aimed to determine a nutritionally adequate feeding protocol for Hippocampus hippocampus juveniles. In the experimental trial, seahorses were fed copepods from 0–7 days postparturition (DPP) and, from 8–28 DPP, four different dietary treatments: (copepods (control diet) (Cop); microalgae-enriched Artemia with a docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) ratio of 2:1 (ArtDHA/EPA); microalgae-enriched Artemia with a DHA/EPA ratio of 2:1 along with 5% copepods (ArtDHA/EPA5%); and with 10% copepods (ArtDHA/EPA10%)). At the end of the trial, juvenile seahorses fed Cop grew significantly more (p < 0.05) (5.1 mg d−1 ) than those on fish-fed diets ArtDHA/EPA5% or ArtDHA/EPA10% (3.09 and 3.07 mg d−1 , respectively), or those on the fish-fed ArtDHA/EPA (1.83 mg d−1 ) diet, all of which performed poorly. Data suggest that feeding copepods during the first 7 DPP promotes maturation of the digestive tract of juvenile seahorses, and the addition of a limited amount of copepods to the diet improves H. hippocampus juvenile growth performance when compared with the use of Artemia as a single diet due to the improvement of the essential fatty acid profile in the diets
- The effects of feeding with shrimp or fish fry on growth and mantle lipid composition of juvenile and adult cuttlefish (Sepia officinalis)Publication . Almansa, Eduardo; Domingues, Pedro; Sykes, António V.; Tejera, Noemi; Lorenzo, António; Andrade, José PedroIn the present study, cuttlefish (Sepia officinalis) aged 60-day-old (age-group I) and 120-day-old (age-group II) were fed with live shrimp and live fish fry for 60 days, in order to study the diet influence on growth, mantle lipid composition, and astaxanthin content in the skin. The most noteworthy difference was the higher growth observed in shrimp-fed cuttlefish with respect to fishfed cuttlefish in both age groups. Total lipids (TL), lipid classes (LC) and their associated fatty acids (FA) from both diets and mantle of cuttlefish were analysed. The lipid profiles of both diets were clearly different in their LC distribution, with higher levels of Polar Lipids (PL) in shrimp with respect to fish fry. However, both diets did not show outstanding differences in the FA composition of TL except for 20:5n-3 (EPA), which was higher in shrimp than in fish fry. With respect to lipid composition of cuttlefish mantle, the TL content and cholesterol (CHO) percentage increased with age, while phosphatidylinositol (PI) and phosphatidylcholine (PC) percentage decreased. On the other hand, phosphatidylserine (PS), phosphatidylethanolamine (PE) and PC percentages in both cuttlefish age groups were also affected by the different diets, although this difference was higher in agegroup I. The general pattern of fatty acid composition of TL in the mantle of cuttlefish was similar in all groups studied. It is remarkable the low levels of monoene FAs in both age-group cuttlefish mantle, despite of the high level of this FA group in both diets, which suggests that these FAs are not stored in the mantle. An opposite tendency was observed regarding the n-3 HUFA, especially 22:6n-3 (DHA) which remained constant despite the different age or diet. High levels of astaxanthin were found in shrimp with respect to fish, but this was only reflected on skin accumulation in age-group I, showing no differences in age-group II. This suggests differences in the astaxanthin metabolism according to the age. The results suggest that the growth differences observed in shrimp-fed cuttlefish with respect to fish-fed cuttlefish were not reflected in outstanding differences in mantle composition.
- The cuttlefish Sepia officinalis (Sepiidae, Cephalopoda) constructs cuttlebone from a liquid-crystal precursorPublication . Checa, Antonio G.; Cartwright, Julyan H. E.; Sanchez-Almazo, Isabel; Andrade, José Pedro; Ruiz-Raya, FranciscoCuttlebone, the sophisticated buoyancy device of cuttlefish, is made of extensive superposed chambers that have a complex internal arrangement of calcified pillars and organic membranes. It has not been clear how this structure is assembled. We find that the membranes result from a myriad of minor membranes initially filling the whole chamber, made of nanofibres evenly oriented within each membrane and slightly rotated with respect to those of adjacent membranes, producing a helical arrangement. We propose that the organism secretes a chitin-protein complex, which self-organizes layer-by-layer as a cholesteric liquid crystal, whereas the pillars are made by viscous fingering. The liquid crystallization mechanism permits us to homologize the elements of the cuttlebone with those of other coleoids and with the nacreous septa and the shells of nautiloids. These results challenge our view of this ultra-light natural material possessing desirable mechanical, structural and biological properties, suggesting that two self-organizing physical principles suffice to understand its formation.
- A importância da Ria Formosa no ciclo biológico de Solea senegalensis Kaup 1858, Solea vulgaris Quencel 1806, Solea lascaris (Risso, 1868) e Microchirus azevia (Capello, 1868)Publication . Andrade, José Pedro; Arruda, L. M.Existe actualmente unanimidade sobre a posição de relevo que a Ria Formosa asssume entre as formaçOes lagunares da costa portuguesa. Este aspecto resulta não só da importância económica das inúmeras actividades aí desenvolvidas, mas também encerra razões de índole cientifica que têm atraído, de modo crescente, a atenção da comunidade científica internacional.
- A crown for each monarch: a distinguishable pattern using photo-identificationPublication . Correia, Miguel; Antunes, Daniela; Andrade, José Pedro; Palma, JorgePhoto-identification has been proven to be a successful individual recognition tool in seahorse species (e.g., long-snout seahorse Hippocampus reidi (Ginsburg, 1933) and long-snouted seahorse Hippocampus guttulatus (Cuvier, 1829)). Its use was deemed valuable for the assessment of wild populations and to understand variations in abundance over time when capture-recapture methods are needed. In this study, a computer software with a pattern recognition algorithm (I3S® Contour 3.0) was used for individual identification of short-snouted seahorses Hippocampus hippocampus (Linnaeus 1758) in the laboratory. Using this methodology, differences in the shape of each individual’s coronet were tested as a unique and distinguishable characteristic. Two different contours were used as reference and tested to assess the effectiveness of this method in individual identification. A total of 94 captive-bred H. hippocampus, 45 adults (> 1 year old) and 49 young adults (4 months old), were tested. Positive matches were obtained in 55.1 % of the young adults and 84.4 % of the adults using contour 1; and in 77.6 % and 97.8 % for young adults and adults, respectively, using contour 2. All un-matched photos were later successfully matched by visual comparison, using additional traits (e.g., spot patterns) and gender. This methodology yielded very promising results and could be further used in wild individuals to allow population size estimates.
- Predatory responses and feeding behaviour of three Elasmobranch Species in an Aquarium settingPublication . Costa, Sandra; Neves, João; Tirá, Gonçalo; Andrade, JoseMany progressive aquariums worldwide house various elasmobranch species as part of their commitment to conservation awareness and the long-term well-being of these creatures. These aquariums face the challenge of enabling these natural predators to live harmoniously with other fish without triggering natural predation. This research, conducted at Zoomarine Algarve in Southern Portugal, aimed to investigate the behaviour of three elasmobranch species (Carcharhinus melanopterus (1:1:0), Triaenodon obesus (1:0:0), and Pteroplatytrygon violacea (0:3:0)) when exposed to different feeding mechanisms. The goal was to provide them with opportunities for alternative predatory behaviours beyond their typical feeding techniques and to reduce the likelihood of natural predation. The study took place under controlled conditions within a community habitat. Four feeding methods (pole, short buoy, long buoy, and PVC) were tested during morning, afternoon, and evening periods, using five different prey species. The results shed light on which feeding method aligns best with each species’ distinct physiological standards and predatory tendencies and revealed their prey preferences. All three species interacted with all feeding methods, with P. violacea showing a strong preference for the pole method. T. obesus favoured bony fish, while C. melanopterus showed a preference for cephalopods. P. violacea interacted with all prey types but displayed no marked preference. These various feeding methods and prey options also function as environmental enrichment strategies, enhancing the complexity of the habitat and providing the animals with more choices and control, ultimately promoting their welfare in captivity.
- Effects of culture density on growth and broodstock management of the cuttlefish, Sepia officinalis (Linnaeus, 1758)Publication . Correia, Miguel; Domingues, Pedro M.; Sykes, António V.; Andrade, José PedroThe effects of culture density on growth and broodstock management of the cuttlefish S. officinalis were studied. Cuttlefish used were one month old at the start of the experiment, on average; two densities were used (16 and 76 cuttlefish m 2). During the first experiment (until day 43), dead cuttlefish were replaced by individuals of similar weight. From that day onwards, no cuttlefish were replaced. No significant differences in growth and feeding rates, or food conversions were found between densities, during the first experiment. Results indicate that densities up to 76 cuttlefish m 2 are suitable for cuttlefish weighing approximately 10 g. After day 43 until first female layed eggs (second experiment), no statistical differences were found between densities for all the parameters studied with the exception of growth. In this case, cuttlefish cultured at the lower density grew more than those ones cultured at the higher density, with average weights at the start of egg laying of 137.3F21.6 and 91.8F12.3 g, respectively. This difference in growth could be explained mainly by the different culture densities and biomass associated. Fecundity obtained for cuttlefish cultured at the lower density (834 eggs female 1) was higher than for those ones cultured at the higher density (290 eggs female 1), however fertility was higher for the higher density. These results were expected, since fecundity is directly related to the size of females. Significant differences were found in fertility (hatching percentage) between densities. Mean hatching percentage was of 35.8F9.4% and 62.0F16.9% for low and high density, respectively. This difference was unexpected since we expected eggs from females cultured at lower densities to have higher quality. Mean hatchling weight was of 0.079F0.011 and 0.072F0.012 g for low and high density respectively, and significantly different. Results indicate that lower culture density promoted higher growth, larger eggs and hatchlings, but had no influence on juvenile and adult survival. On the contrary, eggs from females cultured at higher densities resulted in higher hatching rates.
- Effects of alterations in fresh water supply on the abundance and distribution of Engraulis encrasicolus in the Guadiana estuary and adjacent coastal areas of south PortugalPublication . Chícharo, Luís; Chicharo, Alexandra; Esteves, E.; Andrade, José Pedro; Morais, P.A reduction of inflow to the Guadiana River on the border between Portugal and Spain may directly contribute to the degradation of fish habitats. Changes are expected to the spawning behaviour of Engraulis encrasicolus adults, to the migration patterns of larvae in the estuary, and to the catches of fisheries in the lower part of the river and adjacent coastal areas. Spawning of E. encrasicolus occurs in the lower part of the estuary and in the adjacent coastal areas. However, high abundances of larvae have been registered in the middle and upper parts of the estuary, the most productive region of the estuary, that with the estuarine turbidity maximum (ETM). In a year of normal inflow, such as the hydrologic year 1987-1988, some retention of larvae occured in this area. However, in an abnormal hydrologic year with a low inflow (1999-2000), and with an increase in freshwater inflow during the spring months, a disturbance to the migration pattern seems to have affected the survival of larvae in the estuary. High river flow, probably associated with an increased input of nutrients, appears to have important und positive effect on adult numbers, because anchovy fishery catches in the adjacent coastal area increased under these conditions.