Although breeding conditions are rather well established for some seahorse species 10 (Hippocampu... more Although breeding conditions are rather well established for some seahorse species 10 (Hippocampus spp.), zootechnics and the effect of non-biological factors are still unknown for 11 many species. The present study is focussed on the effects of aquarium type/design, 12 photoperiod regime and aeration level on the early performance (growth and survival) of 13 Hippocampus guttulatus juveniles. Three aquarium types were evaluated: pseudoKreisel, 14 spherical and rectangular. Juveniles grown in pseudoKreisel aquaria showed lower growth 15 16 (DAR) when compared to either spherical (30 ± 22%) or rectangular (16 ± 12%) aquaria.
Free amino acid and protein contents of start-feeding larvae of turbot (Scophthalmus maximus) at ... more Free amino acid and protein contents of start-feeding larvae of turbot (Scophthalmus maximus) at three temperatures
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 2013
Dietary long chain polyunsaturated fatty acids (FA) have been recognized of crucial importance 28... more Dietary long chain polyunsaturated fatty acids (FA) have been recognized of crucial importance 28 in early development of vertebrates, contributing to the impressive morphological and 29 physiological changes both as building blocks and to energy production. The importance of 30 lipids along development depends on ontogenetic, phylogenic and environmental parameters. 31 The expression patterns of FA metabolism genes have not been characterized in developing fish 32 embryos nor compared to lipid class profiles. Full lipid metabolism only occurred after hatching, as revealed by alterations in lipid profiles and FA gene expression. Nonetheless, 1 transcriptional changes of some FA genes were already present in embryos at notochord 2 formation. Many genes displayed an expression profile opposed to the decrease of lipids along 3 the development, while others responded solely to starvation. Transcription of most genes 4 involved in FA metabolism had a strong correlation to PPARs mRNA levels (α1, α2, β, γ). The 5 comparison of mRNA expression of the genes with the lipid profiles produced new insights into 6 the FA metabolism and regulation during the development of turbot larvae, providing the basis 7 for future studies including comparative approaches with other vertebrate species.
Biomass production and variation in the biochemical profile (total protein, carbohydrates, RNA, l... more Biomass production and variation in the biochemical profile (total protein, carbohydrates, RNA, lipids and fatty acids) of seven species of marine microalgae. Aquaculture, 83: 17-37. Seven species of marine microalgae (Paulooa lutheri, Zsochrysis galbana, Tetraselmis suecica, Chaetoceros calcitrans, Phaeodactylum tricornutum, Rhodomonas sp. and Heterosigma akashiwo) were harvested at three phases in the growth curve and biochemical composition (total protein, carbohydrates, RNA, lipids and fatty acids) was determined. Carbohydrate and lipid contents increased with the development of the culture, while protein levels increased in the later phases of the culture in the case of diatoms and Rhodomonas sp. and decreased in I. galbana, P. lutheri and T. suecica. Saturated fatty acids and, to a lesser extent, monoethylenic fatty acids represent between 70 and 100% of the total fatty acids. Polyunsaturated fatty acids reached their highest values in the exponential phase in Rhodomonas sp. (30.99%), in an early stationary phase in P. tricornutum (19.58%) and C. calcitrans (9.06%) and in a late stationary phase in I. galbana (12.89%), P. lutheri (4.24%) and T. suecica (18.58%). RNA levels never exceeded2.5%. The daily production was calculated for each batch culture in three growth phases and was compared with the production of a semicontinuous culture maintained in the exponential phase. Rhodomonas sp., C. calcitrans and P. tricornutum showed a lower daily production under semicontinuous culture than in batch cultures, while I. galbana, P. lutheri, T. suecica and H. akashiwo showed the opposite. The daily production of each of the biochemical components also varied with the species. INTRODUCTION Marine microalgae constitute the main food source for bivalve molluscs. Considering that the success of a mollusc hatchery
This paper considers the @ects of selected J wior&y undescribed variables on the small-scale prep... more This paper considers the @ects of selected J wior&y undescribed variables on the small-scale preparation of gelazir .acacia microcapsules in order to be used in experimental studies of ntuition in aquaculture. Cod liver oil was chosen as the encapsulated materiaL ik selected variabies were thp gelatinfacacia ratio, colloid concentration, pH, .%ir%g rate, colloidfoil ratio and use was made of sueactans $itd other compounds. Standard methods qf producing gelatin-acacia micrxo osules, with average sizes of 515, 1684 and #54 +un, have been est &-bed Control of pH and addition of Tween-80 before the gelat& step were shown to be important for the production of small microcapsules. Stability of these capsules under agitatio 7 (250 revfmin) in sea water (pH 8.0) at 25°C fir 24 h WID considered acceptable. A positive relatiomhip bet,;-en size and stability was observed. Quamitative &ta COI v!*;~ individual weights, encapsulation efficiencies and lipid contents of microcapsules are given. Most rearing methods for Imarine species oi commercial interest are dependent upon supplies of algae and/or small live. prey such as rotifers and Arternia nauplii. Use of live food has several disadvantages. I& production is expensive and it? biochemical composition is unpredictable and often unsahfactory. Techniques to produce inert food have been developed in order to completely or partially replace natural food. Microcapsules and microparticles are useful for such purposes. Microcapsule sizes usually fall into the range of several to apprwdmateky 200 pm in diameter.
Availability of fingerlings has been one of the most critical factors for commercial success in Ž... more Availability of fingerlings has been one of the most critical factors for commercial success in Ž. marine fish farms. Nowadays, the life cycle of some species e.g., sea bream, sea bass, turbot is under control due to important improvements in zootechnics, nutritional quality of the prey and hygienic conditions of the rearing system. Survival, growth rates and quality of the fingerlings have improved considerably during the last few years. Nevertheless, new efforts are necessary to decrease the cost per juvenile produced. Efforts should be directed towards the optimisation of the rearing procedure and the variability and predictability of the results. This paper provides a general overview to some important aspects of the production techniques and problems in marine larviculture. Rearing techniques, including the benefits of 'green water', how water and light and the respective advantages of the size, nutritional composition and enrichment of live feeds are considered together with aspects of the microbiological composition of the larval environment and pathology development and quality of the larvae. Suggestions are made as to how the production of marine fish larvae maybe improved and optimised.
Enhancing the knowledge of feeding/nutritional requirements is key in the growth of fish developm... more Enhancing the knowledge of feeding/nutritional requirements is key in the growth of fish development and for the optimization of rearing techniques [...]
Additional file 3: Illustrations of main species (medium–high abundance) of macroalgae and bathym... more Additional file 3: Illustrations of main species (medium–high abundance) of macroalgae and bathymetric zonation of seaweed assemblages in transects surveyed on Cíes Archipelago (PNIA).
The effects of diet on reproduction success in fishes are fairly well known for many species. In ... more The effects of diet on reproduction success in fishes are fairly well known for many species. In syngnathids (seahorses, pipefishes and seadragons), almost nothing is known about how diet quality during the pre-breeding period might influence subsequent breeding performance and fry quality. In the present study, the influence of pre-breeding diet was assessed for the first time in seahorses. For that, adult seahorses Hippocampus reidi were submitted to three dietary treatments (based on Artemia and/or mysidaceans) including different timing schedules. The assimilation of the diets by breeders and subsequent newborn batches were evaluated isotopically (δ13C and δ15N). In newborn juveniles, the timing of brood release, brood size, and length, weight and survival were also evaluated. The species followed a mixed capital-income reproduction strategy and showed a higher breeding performance and larger newborn with a mixed diet supplied during the whole pre-breeding period (5 months). The...
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 2021
Seahorse Hippocampus reidi is a vulnerable species, inhabiting estuarine and coastal waters. The ... more Seahorse Hippocampus reidi is a vulnerable species, inhabiting estuarine and coastal waters. The safety of acidic environments for fish has been considered in terms of ocean acidification in nature and decreasing pH in intensive aquaculture systems. This study aimed to investigate the effects of acute exposition (96 h) of juvenile seahorses to different pH (5, 6, 7, and 8) in brackish (BW - salinity 11) or seawater (SW - salinity 33). For that, we studied the responses of cortisol, oxidative stress, and survival, thus covering primary, secondary, and tertiary stress responses. In SW, cortisol levels were not altered for fish maintained at pH 5 and 8. However, in BW, cortisol was higher for fish kept at pH 5. Regarding secondary stress responses, only GST activity increased with acidification in SW. However, acidification in BW caused biochemical alterations at enzymatic level (SOD, GST, GPx) and glutathione metabolism, accompanied by reduction of antioxidant capacity (TEAC) and increased lipid peroxidation (TBARS). Survival was always above 90% and it did not differ significantly among pH levels. Our results suggest that H. reidi juveniles are more vulnerable to acidic exposure in BW than in SW.
Syngnathids are vulnerable ovoviviparous fishes in which males undergo repeated brooding within a... more Syngnathids are vulnerable ovoviviparous fishes in which males undergo repeated brooding within a reproductive season. The isotopic effects of diet on both breeders (pooled sexes) and parent-egg transmission have been demonstrated in a few fish species but never in syngnathids. Quantifying isotopic changes due to diet is necessary to assess parent-newborn conversions and to estimate accurate trophic enrichment factors (TEF). We assessed the isotopic (δ13C and δ15N) effects of 3 experimental diets on TEFs in seahorse Hippocampus guttulatus breeders and isotopic inheritance. Our results suggest that H. guttulatus follows an income-capital continuum pattern for parent-egg transmission. The isotopic variability in diets for breeders and the resulting experimentally derived TEFs were compared with fixed TEFs from reviews to estimate their impact on the relative contribution of potential prey sources in syngnathids from the Cíes archipelago (Atlantic Islands National Park, NW Spain). We e...
Breeding in captivity for research or exhibition (e.g. in aquaria) can replace the capture of wil... more Breeding in captivity for research or exhibition (e.g. in aquaria) can replace the capture of wild specimens of endangered species and allow controlled reinforcement of wild populations. With this aim, diet analysis and establishing the adequate prey are determinant factors for breeding success. However, non-invasive approaches such as faecal DNA analysis are advisable for analysing the diet of these species. Therefore, the aim of the present study was to demonstrate the usefulness of faecal DNA analysis by specific PCR amplification of prey DNA for assessing the diet of the seahorse Hippocampus guttulatus. In a comparison of the suitability of different genes (COI, 18SrRNA and 28SrRNA), 18SrRNA was found to be the most suitable for designing specific primers for the prey types fed to seahorses (Artemia, Palaemonetes and Mysidae). The technique was assessed in feeding experiments in which prey ingestion was recorded daily, and faeces were collected for DNA extraction and presence/absence PCR analysis. Amplification of the prey DNA in faeces was consistent with the sequence of prey supplied (prey eaten the day before was always detected). Differences in the time between feeding and detection in faeces suggested prey-specific gut passage times, which were shorter for Palaemonetes than for Mysidae. This fact highlights the importance of feeding trials to avoid overestimating the consumption of prey with long gut retention when PCR-based methods are used. This molecular technique is thus applicable for studying the feeding behaviour of captive seahorses and could be adapted for use in other marine species.
Journal of Experimental Marine Biology and Ecology, 2012
The effect of temperature (15, 18 and 21°C) on the early development of the long-snouted seahorse... more The effect of temperature (15, 18 and 21°C) on the early development of the long-snouted seahorse Hippocampus guttulatus were analysed, both under feeding (until day 30 post partum) and starving conditions. Fed and starving seahorses maintained at 15°C grew at suboptimal conditions. At this temperature, mortalities started earlier and the swimming activity was reduced. In fed juveniles, final survivals (21.1, 85.9 and 81.1% at 15, 18 and 21°C, respectively) and wet body mass (14.7, 51.9 and 106.43 mg at 15, 18 and 21°C, respectively) were significantly different. The dependency of daily weight specific growth rate (G; %day −1) on temperature (T;°C) was explained by the function: G=−32.905+2.8079 T−0.00166 T 3. Three development scales were compared for temperature-dependency: chronological time (days), day-degrees (D°) and effective day degrees (D°e ff). It was demonstrated, within a viable temperature range, the suitability of D°e ff as a temperature-independent scale to quantify growth in feeding juveniles but not in starving conditions. Seahorse wet weight was modelled as a function of time scales and temperature according to a modification of the Gompertz model. Growth models for single temperatures in the range of 14-26°C were constructed. D°e ff was the only scale that allowed a good temperature-independent fitting of seahorse weight (W; mg) in a unique equation: W=7.409−0.0555 D°e ff +0.0037 D°e ff 2 −0.000006 D°e ff 3. Biological, ecological and biogeographic implications of temperature in the early development of the viviparous fish H. guttulatus are discussed. Finally, from a practical point of view, temperatures of 19-20°C are recommended for the rearing of this species in captivity.
The global trade in seahorses is increasing and new rearing techniques are currently available fo... more The global trade in seahorses is increasing and new rearing techniques are currently available for a few species. One of the main bottlenecks in seahorse production is reproduction success, which is dependent upon the administration of high quality diets to breeders. However, very little is known about the most adequate diets, on how they should be administered and on how they might affect newborn performance. In this study, three homogeneous groups of adult seahorses Hippocampus guttulatus were maintained in captivity. Each group was fed on one of the following diets since the onset of the breeding period: Unenriched adult Artemia (Diet A), unenriched adult Artemia and mysidaceans (Diet AM) and mysidaceans (Diet M). As a positive control we used a wild pregnant male. The mixed diet AM provided the highest overall breeding success and reasonable fatty acid pro les, and better resembled newborn from a wild male. The use of only mysidaceans (Diet M) provided the worse results in spite of the high DHA content. Signi cant differences were observed in newborn characteristics and fatty acid pro les among dietary groups and along the breeding season, especially in total n-3 HUFA and DHA. Monospeci c diets including Artemia or mysidaceans very likely suffered nutritional de ciencies, which were re ected in morphological alterations of the muscle tissue (diet A) or abnormal early mortalities in newborn (diet M). Three progressive stages were identi ed along the whole breeding period: Initial mixed capital-income period (100-120 days since the onset of the breeding period), followed by an in exion period (short transitional stage-income sources), and nally a long period characterized by the use of income sources and the progressive exhaustion of body reserves. Special attention should be deserved to the progressive changes in fatty acid pro les along the breeding season, resulting in a decrease in newborn performance. Considering the time required for a diet to be re ected in newborn, we recommend Hippocampus guttulatus breeders to be fed on a high quality diet for at least three months prior the breeding period. Contribution To The Field The global trade in seahorses is estimated to exceed 20 million animals per year to sustain the aquarium trade, the traditional Chinese medicine and as souvenirs. However, seahorse populations are declining due to the degradation of coastal habitats. Aquaculture represents a valid alternative to wild captured seahorses but ex-situ production still needs to face some constrains. Low spawning quality and juvenile survival rates are the most critical factors for optimizing commercial seahorse production. Only a few studies have focused on the effects of breeder's feeding on breeding success and newborn quality in seahorses. In the present study, the following questions have been addressed: (1) How experimental diets are assimilated (stable isotope analysis) by breeders and re ected in general features and biochemical composition of Hippocampus guttulatus newborn?, (2) Do mixed diets perform better than monospeci c ones?, and (3) Does H. guttulatus follow
3 páginas, 1 tabla, 4 figurasLe premier signalement de l’hippocampe à museau court Hippocampus hi... more 3 páginas, 1 tabla, 4 figurasLe premier signalement de l’hippocampe à museau court Hippocampus hippocampus dans les eaux galiciennes (NO Espagne) est décrit sur la base de neuf spécimens adultes (118-183 mm LS) capturés lors d’inspections en plongée sous-marine entre 2010 et 2012. Les individus ont été identifiés selon les approches morphologiques et moléculaires. Ces données constituent d’importantes informations sur l’espèce, qui pourront être prises en compte lors de l’évaluation des populations et notamment à but de conservation.Le premier signalement de l’hippocampe à museau court Hippocampus hippocampus dans les eaux galiciennes (NO Espagne) est décrit sur la base de neuf spécimens adultes (118-183 mm LS) capturés lors d’inspections en plongée sous-marine entre 2010 et 2012. Les individus ont été identifiés selon les approches morphologiques et moléculaires. Ces données constituent d’importantes informations sur l’espèce, qui pourront être prises en compte lors de l’évaluation...
The great pipefish Syngnathus acus is one of the most representative European syngnathids, being ... more The great pipefish Syngnathus acus is one of the most representative European syngnathids, being highly associated with seagrass and macroalgal beds. Surprisingly, the ecology of this large ovoviviparous marine fish has received scanty attention. The population inhabiting three sites on Cíes Archipelago (Atlantic Islands National Park, NW Spain) was monitored in 2017–2018 for spatial and temporal changes in abundances, reproduction traits, trophic niche occupancy, and dietary regimes across reproduction states, through an isotopic (δ13C and δ15N) approach. Abundances were highly variable across seasons and sites, decreasing significantly from mid-autumn. The population consisted almost exclusively of large adults that migrate by the end of the breeding season, which extended from mid-spring to summer. Operational sex ratios suggest that the species is sex-role reversed. S. acus is a secondary consumer (Trophic position = 3.36 ± 0.05), preferring amphipods but displaying annual and s...
The initial development of seahorse juveniles is characterized by low digestion capabilities. Sta... more The initial development of seahorse juveniles is characterized by low digestion capabilities. Stable isotope analysis is an effective tool in studies of trophic food webs and animal feeding patterns. The present study provides new insights for the understanding of growth and food assimilation in early developing seahorses following a laboratory diet switch. The study was performed in the early life stages of the seahorse Hippocampus reidi by assessing the influence of diet shift on changes and turnovers in carbon (δ13C) and nitrogen (δ15N) stable isotope in juveniles. Newborn seahorses were fed for 60 days following two feeding schedules (A6 and A11) based initially on copepods Acartia tonsa and subsequently on Artemia nauplii (since days 6 and 11, respectively). After the prey shift, we determined δ13C and δ15N turnover rates as functions of change in either body mass (fitting model G) and days of development (fitting model D), contributions of metabolism and growth to those turnov...
Abstract: Knowledge on seahorses is generally scarce but has been increasing in recent years due ... more Abstract: Knowledge on seahorses is generally scarce but has been increasing in recent years due to their conservation status. Seahorse culture is a quite recent activity in the field of marine aquaculture in most countries attempting it, and captive breeding techniques are available only for some species. With the aim of contributing to the development of breeding in captivity for conservative purposes, broodstocks of the European long-snouted seahorse (Hippocampus guttulatus) were established with 32 wild seahorses captured in Galicia (NW Spain). This study describes the methodologies applied to the maintenance of the broodstocks, with special reference to aquaria design, feeding, growth and breeding. Procedures of seahorse identification (morphologically and genetically) as a tool for broodstock management are also considered. The results achieved during the first year demonstrate a rapid adaptation of wild seahorses to captive conditions. Seahorses were fed exclusively on enrich...
The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequence and the recA gene sequence... more The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequence and the recA gene sequence of strain BFLP-4 T are FN421434 and FN421435, respectively.
Simple Summary Seahorses (Hippocampus spp.) are currently exposed to a multitude of anthropogenic... more Simple Summary Seahorses (Hippocampus spp.) are currently exposed to a multitude of anthropogenic pressures worldwide. The illegal, unreported, and unregulated (IUU) fisheries and trade of these flagship species undermine the efforts to manage and protect their wild populations. Here we aim to validate a forensic tool to identify the geographic origin of seahorses and contribute to the ongoing fight against the illegal capture and trade of these organisms. The elemental fingerprints of long-snouted seahorse (Hippocampus guttulatus) bony structures, including the subdermal bony plates that cover their body, revealed that they can be successfully employed to confirm their geographic origin. The results of this first study using seahorses raised in captivity indicate that this tool may also allow to discriminate between different populations of wild specimens and enhance the traceability of traded specimens. Abstract The global market of dried seahorses mainly supplies Traditional Chin...
Although breeding conditions are rather well established for some seahorse species 10 (Hippocampu... more Although breeding conditions are rather well established for some seahorse species 10 (Hippocampus spp.), zootechnics and the effect of non-biological factors are still unknown for 11 many species. The present study is focussed on the effects of aquarium type/design, 12 photoperiod regime and aeration level on the early performance (growth and survival) of 13 Hippocampus guttulatus juveniles. Three aquarium types were evaluated: pseudoKreisel, 14 spherical and rectangular. Juveniles grown in pseudoKreisel aquaria showed lower growth 15 16 (DAR) when compared to either spherical (30 ± 22%) or rectangular (16 ± 12%) aquaria.
Free amino acid and protein contents of start-feeding larvae of turbot (Scophthalmus maximus) at ... more Free amino acid and protein contents of start-feeding larvae of turbot (Scophthalmus maximus) at three temperatures
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 2013
Dietary long chain polyunsaturated fatty acids (FA) have been recognized of crucial importance 28... more Dietary long chain polyunsaturated fatty acids (FA) have been recognized of crucial importance 28 in early development of vertebrates, contributing to the impressive morphological and 29 physiological changes both as building blocks and to energy production. The importance of 30 lipids along development depends on ontogenetic, phylogenic and environmental parameters. 31 The expression patterns of FA metabolism genes have not been characterized in developing fish 32 embryos nor compared to lipid class profiles. Full lipid metabolism only occurred after hatching, as revealed by alterations in lipid profiles and FA gene expression. Nonetheless, 1 transcriptional changes of some FA genes were already present in embryos at notochord 2 formation. Many genes displayed an expression profile opposed to the decrease of lipids along 3 the development, while others responded solely to starvation. Transcription of most genes 4 involved in FA metabolism had a strong correlation to PPARs mRNA levels (α1, α2, β, γ). The 5 comparison of mRNA expression of the genes with the lipid profiles produced new insights into 6 the FA metabolism and regulation during the development of turbot larvae, providing the basis 7 for future studies including comparative approaches with other vertebrate species.
Biomass production and variation in the biochemical profile (total protein, carbohydrates, RNA, l... more Biomass production and variation in the biochemical profile (total protein, carbohydrates, RNA, lipids and fatty acids) of seven species of marine microalgae. Aquaculture, 83: 17-37. Seven species of marine microalgae (Paulooa lutheri, Zsochrysis galbana, Tetraselmis suecica, Chaetoceros calcitrans, Phaeodactylum tricornutum, Rhodomonas sp. and Heterosigma akashiwo) were harvested at three phases in the growth curve and biochemical composition (total protein, carbohydrates, RNA, lipids and fatty acids) was determined. Carbohydrate and lipid contents increased with the development of the culture, while protein levels increased in the later phases of the culture in the case of diatoms and Rhodomonas sp. and decreased in I. galbana, P. lutheri and T. suecica. Saturated fatty acids and, to a lesser extent, monoethylenic fatty acids represent between 70 and 100% of the total fatty acids. Polyunsaturated fatty acids reached their highest values in the exponential phase in Rhodomonas sp. (30.99%), in an early stationary phase in P. tricornutum (19.58%) and C. calcitrans (9.06%) and in a late stationary phase in I. galbana (12.89%), P. lutheri (4.24%) and T. suecica (18.58%). RNA levels never exceeded2.5%. The daily production was calculated for each batch culture in three growth phases and was compared with the production of a semicontinuous culture maintained in the exponential phase. Rhodomonas sp., C. calcitrans and P. tricornutum showed a lower daily production under semicontinuous culture than in batch cultures, while I. galbana, P. lutheri, T. suecica and H. akashiwo showed the opposite. The daily production of each of the biochemical components also varied with the species. INTRODUCTION Marine microalgae constitute the main food source for bivalve molluscs. Considering that the success of a mollusc hatchery
This paper considers the @ects of selected J wior&y undescribed variables on the small-scale prep... more This paper considers the @ects of selected J wior&y undescribed variables on the small-scale preparation of gelazir .acacia microcapsules in order to be used in experimental studies of ntuition in aquaculture. Cod liver oil was chosen as the encapsulated materiaL ik selected variabies were thp gelatinfacacia ratio, colloid concentration, pH, .%ir%g rate, colloidfoil ratio and use was made of sueactans $itd other compounds. Standard methods qf producing gelatin-acacia micrxo osules, with average sizes of 515, 1684 and #54 +un, have been est &-bed Control of pH and addition of Tween-80 before the gelat& step were shown to be important for the production of small microcapsules. Stability of these capsules under agitatio 7 (250 revfmin) in sea water (pH 8.0) at 25°C fir 24 h WID considered acceptable. A positive relatiomhip bet,;-en size and stability was observed. Quamitative &ta COI v!*;~ individual weights, encapsulation efficiencies and lipid contents of microcapsules are given. Most rearing methods for Imarine species oi commercial interest are dependent upon supplies of algae and/or small live. prey such as rotifers and Arternia nauplii. Use of live food has several disadvantages. I& production is expensive and it? biochemical composition is unpredictable and often unsahfactory. Techniques to produce inert food have been developed in order to completely or partially replace natural food. Microcapsules and microparticles are useful for such purposes. Microcapsule sizes usually fall into the range of several to apprwdmateky 200 pm in diameter.
Availability of fingerlings has been one of the most critical factors for commercial success in Ž... more Availability of fingerlings has been one of the most critical factors for commercial success in Ž. marine fish farms. Nowadays, the life cycle of some species e.g., sea bream, sea bass, turbot is under control due to important improvements in zootechnics, nutritional quality of the prey and hygienic conditions of the rearing system. Survival, growth rates and quality of the fingerlings have improved considerably during the last few years. Nevertheless, new efforts are necessary to decrease the cost per juvenile produced. Efforts should be directed towards the optimisation of the rearing procedure and the variability and predictability of the results. This paper provides a general overview to some important aspects of the production techniques and problems in marine larviculture. Rearing techniques, including the benefits of 'green water', how water and light and the respective advantages of the size, nutritional composition and enrichment of live feeds are considered together with aspects of the microbiological composition of the larval environment and pathology development and quality of the larvae. Suggestions are made as to how the production of marine fish larvae maybe improved and optimised.
Enhancing the knowledge of feeding/nutritional requirements is key in the growth of fish developm... more Enhancing the knowledge of feeding/nutritional requirements is key in the growth of fish development and for the optimization of rearing techniques [...]
Additional file 3: Illustrations of main species (medium–high abundance) of macroalgae and bathym... more Additional file 3: Illustrations of main species (medium–high abundance) of macroalgae and bathymetric zonation of seaweed assemblages in transects surveyed on Cíes Archipelago (PNIA).
The effects of diet on reproduction success in fishes are fairly well known for many species. In ... more The effects of diet on reproduction success in fishes are fairly well known for many species. In syngnathids (seahorses, pipefishes and seadragons), almost nothing is known about how diet quality during the pre-breeding period might influence subsequent breeding performance and fry quality. In the present study, the influence of pre-breeding diet was assessed for the first time in seahorses. For that, adult seahorses Hippocampus reidi were submitted to three dietary treatments (based on Artemia and/or mysidaceans) including different timing schedules. The assimilation of the diets by breeders and subsequent newborn batches were evaluated isotopically (δ13C and δ15N). In newborn juveniles, the timing of brood release, brood size, and length, weight and survival were also evaluated. The species followed a mixed capital-income reproduction strategy and showed a higher breeding performance and larger newborn with a mixed diet supplied during the whole pre-breeding period (5 months). The...
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 2021
Seahorse Hippocampus reidi is a vulnerable species, inhabiting estuarine and coastal waters. The ... more Seahorse Hippocampus reidi is a vulnerable species, inhabiting estuarine and coastal waters. The safety of acidic environments for fish has been considered in terms of ocean acidification in nature and decreasing pH in intensive aquaculture systems. This study aimed to investigate the effects of acute exposition (96 h) of juvenile seahorses to different pH (5, 6, 7, and 8) in brackish (BW - salinity 11) or seawater (SW - salinity 33). For that, we studied the responses of cortisol, oxidative stress, and survival, thus covering primary, secondary, and tertiary stress responses. In SW, cortisol levels were not altered for fish maintained at pH 5 and 8. However, in BW, cortisol was higher for fish kept at pH 5. Regarding secondary stress responses, only GST activity increased with acidification in SW. However, acidification in BW caused biochemical alterations at enzymatic level (SOD, GST, GPx) and glutathione metabolism, accompanied by reduction of antioxidant capacity (TEAC) and increased lipid peroxidation (TBARS). Survival was always above 90% and it did not differ significantly among pH levels. Our results suggest that H. reidi juveniles are more vulnerable to acidic exposure in BW than in SW.
Syngnathids are vulnerable ovoviviparous fishes in which males undergo repeated brooding within a... more Syngnathids are vulnerable ovoviviparous fishes in which males undergo repeated brooding within a reproductive season. The isotopic effects of diet on both breeders (pooled sexes) and parent-egg transmission have been demonstrated in a few fish species but never in syngnathids. Quantifying isotopic changes due to diet is necessary to assess parent-newborn conversions and to estimate accurate trophic enrichment factors (TEF). We assessed the isotopic (δ13C and δ15N) effects of 3 experimental diets on TEFs in seahorse Hippocampus guttulatus breeders and isotopic inheritance. Our results suggest that H. guttulatus follows an income-capital continuum pattern for parent-egg transmission. The isotopic variability in diets for breeders and the resulting experimentally derived TEFs were compared with fixed TEFs from reviews to estimate their impact on the relative contribution of potential prey sources in syngnathids from the Cíes archipelago (Atlantic Islands National Park, NW Spain). We e...
Breeding in captivity for research or exhibition (e.g. in aquaria) can replace the capture of wil... more Breeding in captivity for research or exhibition (e.g. in aquaria) can replace the capture of wild specimens of endangered species and allow controlled reinforcement of wild populations. With this aim, diet analysis and establishing the adequate prey are determinant factors for breeding success. However, non-invasive approaches such as faecal DNA analysis are advisable for analysing the diet of these species. Therefore, the aim of the present study was to demonstrate the usefulness of faecal DNA analysis by specific PCR amplification of prey DNA for assessing the diet of the seahorse Hippocampus guttulatus. In a comparison of the suitability of different genes (COI, 18SrRNA and 28SrRNA), 18SrRNA was found to be the most suitable for designing specific primers for the prey types fed to seahorses (Artemia, Palaemonetes and Mysidae). The technique was assessed in feeding experiments in which prey ingestion was recorded daily, and faeces were collected for DNA extraction and presence/absence PCR analysis. Amplification of the prey DNA in faeces was consistent with the sequence of prey supplied (prey eaten the day before was always detected). Differences in the time between feeding and detection in faeces suggested prey-specific gut passage times, which were shorter for Palaemonetes than for Mysidae. This fact highlights the importance of feeding trials to avoid overestimating the consumption of prey with long gut retention when PCR-based methods are used. This molecular technique is thus applicable for studying the feeding behaviour of captive seahorses and could be adapted for use in other marine species.
Journal of Experimental Marine Biology and Ecology, 2012
The effect of temperature (15, 18 and 21°C) on the early development of the long-snouted seahorse... more The effect of temperature (15, 18 and 21°C) on the early development of the long-snouted seahorse Hippocampus guttulatus were analysed, both under feeding (until day 30 post partum) and starving conditions. Fed and starving seahorses maintained at 15°C grew at suboptimal conditions. At this temperature, mortalities started earlier and the swimming activity was reduced. In fed juveniles, final survivals (21.1, 85.9 and 81.1% at 15, 18 and 21°C, respectively) and wet body mass (14.7, 51.9 and 106.43 mg at 15, 18 and 21°C, respectively) were significantly different. The dependency of daily weight specific growth rate (G; %day −1) on temperature (T;°C) was explained by the function: G=−32.905+2.8079 T−0.00166 T 3. Three development scales were compared for temperature-dependency: chronological time (days), day-degrees (D°) and effective day degrees (D°e ff). It was demonstrated, within a viable temperature range, the suitability of D°e ff as a temperature-independent scale to quantify growth in feeding juveniles but not in starving conditions. Seahorse wet weight was modelled as a function of time scales and temperature according to a modification of the Gompertz model. Growth models for single temperatures in the range of 14-26°C were constructed. D°e ff was the only scale that allowed a good temperature-independent fitting of seahorse weight (W; mg) in a unique equation: W=7.409−0.0555 D°e ff +0.0037 D°e ff 2 −0.000006 D°e ff 3. Biological, ecological and biogeographic implications of temperature in the early development of the viviparous fish H. guttulatus are discussed. Finally, from a practical point of view, temperatures of 19-20°C are recommended for the rearing of this species in captivity.
The global trade in seahorses is increasing and new rearing techniques are currently available fo... more The global trade in seahorses is increasing and new rearing techniques are currently available for a few species. One of the main bottlenecks in seahorse production is reproduction success, which is dependent upon the administration of high quality diets to breeders. However, very little is known about the most adequate diets, on how they should be administered and on how they might affect newborn performance. In this study, three homogeneous groups of adult seahorses Hippocampus guttulatus were maintained in captivity. Each group was fed on one of the following diets since the onset of the breeding period: Unenriched adult Artemia (Diet A), unenriched adult Artemia and mysidaceans (Diet AM) and mysidaceans (Diet M). As a positive control we used a wild pregnant male. The mixed diet AM provided the highest overall breeding success and reasonable fatty acid pro les, and better resembled newborn from a wild male. The use of only mysidaceans (Diet M) provided the worse results in spite of the high DHA content. Signi cant differences were observed in newborn characteristics and fatty acid pro les among dietary groups and along the breeding season, especially in total n-3 HUFA and DHA. Monospeci c diets including Artemia or mysidaceans very likely suffered nutritional de ciencies, which were re ected in morphological alterations of the muscle tissue (diet A) or abnormal early mortalities in newborn (diet M). Three progressive stages were identi ed along the whole breeding period: Initial mixed capital-income period (100-120 days since the onset of the breeding period), followed by an in exion period (short transitional stage-income sources), and nally a long period characterized by the use of income sources and the progressive exhaustion of body reserves. Special attention should be deserved to the progressive changes in fatty acid pro les along the breeding season, resulting in a decrease in newborn performance. Considering the time required for a diet to be re ected in newborn, we recommend Hippocampus guttulatus breeders to be fed on a high quality diet for at least three months prior the breeding period. Contribution To The Field The global trade in seahorses is estimated to exceed 20 million animals per year to sustain the aquarium trade, the traditional Chinese medicine and as souvenirs. However, seahorse populations are declining due to the degradation of coastal habitats. Aquaculture represents a valid alternative to wild captured seahorses but ex-situ production still needs to face some constrains. Low spawning quality and juvenile survival rates are the most critical factors for optimizing commercial seahorse production. Only a few studies have focused on the effects of breeder's feeding on breeding success and newborn quality in seahorses. In the present study, the following questions have been addressed: (1) How experimental diets are assimilated (stable isotope analysis) by breeders and re ected in general features and biochemical composition of Hippocampus guttulatus newborn?, (2) Do mixed diets perform better than monospeci c ones?, and (3) Does H. guttulatus follow
3 páginas, 1 tabla, 4 figurasLe premier signalement de l’hippocampe à museau court Hippocampus hi... more 3 páginas, 1 tabla, 4 figurasLe premier signalement de l’hippocampe à museau court Hippocampus hippocampus dans les eaux galiciennes (NO Espagne) est décrit sur la base de neuf spécimens adultes (118-183 mm LS) capturés lors d’inspections en plongée sous-marine entre 2010 et 2012. Les individus ont été identifiés selon les approches morphologiques et moléculaires. Ces données constituent d’importantes informations sur l’espèce, qui pourront être prises en compte lors de l’évaluation des populations et notamment à but de conservation.Le premier signalement de l’hippocampe à museau court Hippocampus hippocampus dans les eaux galiciennes (NO Espagne) est décrit sur la base de neuf spécimens adultes (118-183 mm LS) capturés lors d’inspections en plongée sous-marine entre 2010 et 2012. Les individus ont été identifiés selon les approches morphologiques et moléculaires. Ces données constituent d’importantes informations sur l’espèce, qui pourront être prises en compte lors de l’évaluation...
The great pipefish Syngnathus acus is one of the most representative European syngnathids, being ... more The great pipefish Syngnathus acus is one of the most representative European syngnathids, being highly associated with seagrass and macroalgal beds. Surprisingly, the ecology of this large ovoviviparous marine fish has received scanty attention. The population inhabiting three sites on Cíes Archipelago (Atlantic Islands National Park, NW Spain) was monitored in 2017–2018 for spatial and temporal changes in abundances, reproduction traits, trophic niche occupancy, and dietary regimes across reproduction states, through an isotopic (δ13C and δ15N) approach. Abundances were highly variable across seasons and sites, decreasing significantly from mid-autumn. The population consisted almost exclusively of large adults that migrate by the end of the breeding season, which extended from mid-spring to summer. Operational sex ratios suggest that the species is sex-role reversed. S. acus is a secondary consumer (Trophic position = 3.36 ± 0.05), preferring amphipods but displaying annual and s...
The initial development of seahorse juveniles is characterized by low digestion capabilities. Sta... more The initial development of seahorse juveniles is characterized by low digestion capabilities. Stable isotope analysis is an effective tool in studies of trophic food webs and animal feeding patterns. The present study provides new insights for the understanding of growth and food assimilation in early developing seahorses following a laboratory diet switch. The study was performed in the early life stages of the seahorse Hippocampus reidi by assessing the influence of diet shift on changes and turnovers in carbon (δ13C) and nitrogen (δ15N) stable isotope in juveniles. Newborn seahorses were fed for 60 days following two feeding schedules (A6 and A11) based initially on copepods Acartia tonsa and subsequently on Artemia nauplii (since days 6 and 11, respectively). After the prey shift, we determined δ13C and δ15N turnover rates as functions of change in either body mass (fitting model G) and days of development (fitting model D), contributions of metabolism and growth to those turnov...
Abstract: Knowledge on seahorses is generally scarce but has been increasing in recent years due ... more Abstract: Knowledge on seahorses is generally scarce but has been increasing in recent years due to their conservation status. Seahorse culture is a quite recent activity in the field of marine aquaculture in most countries attempting it, and captive breeding techniques are available only for some species. With the aim of contributing to the development of breeding in captivity for conservative purposes, broodstocks of the European long-snouted seahorse (Hippocampus guttulatus) were established with 32 wild seahorses captured in Galicia (NW Spain). This study describes the methodologies applied to the maintenance of the broodstocks, with special reference to aquaria design, feeding, growth and breeding. Procedures of seahorse identification (morphologically and genetically) as a tool for broodstock management are also considered. The results achieved during the first year demonstrate a rapid adaptation of wild seahorses to captive conditions. Seahorses were fed exclusively on enrich...
The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequence and the recA gene sequence... more The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequence and the recA gene sequence of strain BFLP-4 T are FN421434 and FN421435, respectively.
Simple Summary Seahorses (Hippocampus spp.) are currently exposed to a multitude of anthropogenic... more Simple Summary Seahorses (Hippocampus spp.) are currently exposed to a multitude of anthropogenic pressures worldwide. The illegal, unreported, and unregulated (IUU) fisheries and trade of these flagship species undermine the efforts to manage and protect their wild populations. Here we aim to validate a forensic tool to identify the geographic origin of seahorses and contribute to the ongoing fight against the illegal capture and trade of these organisms. The elemental fingerprints of long-snouted seahorse (Hippocampus guttulatus) bony structures, including the subdermal bony plates that cover their body, revealed that they can be successfully employed to confirm their geographic origin. The results of this first study using seahorses raised in captivity indicate that this tool may also allow to discriminate between different populations of wild specimens and enhance the traceability of traded specimens. Abstract The global market of dried seahorses mainly supplies Traditional Chin...
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