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1.
This study examined the feeding selectivity of Hippocampus kuda juveniles under captive conditions and evaluates different food organisms that could be used to improve hatchery‐rearing of this species. Newly born H. kuda were reared for 10 days in 60‐L capacity tanks and fed rotifers (Brachionus rotundiformis), zooplankton (mostly Pseudodiaptomus annandalei and Acartia tsuensis) alone or both food sources. The size and amount of food ingested increased as seahorses grew. Selective feeding of seahorses appeared to change as they develop, preferring copepod adults over nauplii and rotifers. A. tsuensis was highly selected by juveniles over P. annandalei. Specific growth rate in terms of body weight (SGR‐BW, 15% day–1) was the highest and mortality rate (9% at day 10) the lowest in seahorses fed a mixed food sources. Slowest growth rate (0.3% day–1) and highest mortality rate (60% at day 7) were observed in seahorses fed rotifers alone. These results indicate that copepods are suitable food for seahorse juveniles, but a mixture of food organisms in the rearing tank environment enhances survivorship and growth of H. kuda, thus potentially providing a source of cultured rather than wild specimens for characterizing the life history of this threatened species.  相似文献   

2.
Seahorse aquaculture has been a focus for meeting the demand of traditional medicine and aquarium. Feeble (poor quality) juveniles are commonly found in the commercial seahorse culture. In this study, we compared the growth and survival performances of the feeble and healthy common seahorses Hippocampus kuda. The results show that the feeble juveniles had high growth and survival at the temperature of 27–29 C and salinity of 26–28‰ with frequent feeding (≥three times a day) during first 5 wk. Through a 12‐wk investigation, we found that the air‐bubble disease could significantly affect the specific growth rate and survival of the feeble juveniles. There was a positive and significant correlation between the substrate‐attachment rate and survival rate in the feeble juveniles, and substrate‐attachment rate may be used to assess the quality of the feeble populations in the seahorse H. kuda.  相似文献   

3.
The seahorse has been used for thousands of years as an important traditional Chinese medicine (TCM) in China. Many species of wild seahorse have become endangered, but demand for them continues to grow rapidly. Therefore, it is urgent to cultivate seahorses to relieve the strain on natural populations and meet the market demand for this TCM. In this study, medicinal components of wild and cultured yellow seahorses (Hippocampus kuda Bleeker) were analysed and compared. Different parts of the body (cortex and bone), male and female specimens, and seahorses of different ages were analysed. Crude protein, crude fat, trace elements, calcium, amino acid, fatty acid, steroid and cholesterol content were measured. The results showed that moisture content accounted for 70% of wet weight and ash content increased with growth. Crude protein and fat contents were higher in cultured seahorses than in wild specimens, and the content of Zn in cultured seahorses (93.26 ± 10.44%) was significantly higher than that of same‐aged wild seahorses (74.20 ± 3.83%). Amino acid and fatty acid contents of cultured seahorses also were higher than those of wild seahorses. These findings show that cultured seahorses can also be used in TCMs and that 1‐year‐old cultured seahorses have the best properties.  相似文献   

4.
Seahorse aquaculture has been a focus for meeting the demand of Chinese traditional medicine and aquarium, and one of the bottlenecks for aquaculture is disease. The present study focused on the intestinal microbiota between wild and cultured seahorses. Results showed that the Alcaligenaceae and Enterobacteriaceae were the dominant intestinal flora in intestinal tracts of seahorses, and Achromobacter sp., Serratia marcescens, and Serratia sp. were the dominant intestinal flora. It was the first time that two strains (TPL14 and yb97) of Achromobacter xylosoxidans were found in cultured seahorses and even in fishes. Interestingly, Vibrio, which accounted for 19.35% of the intestinal bacterial communities, only occurred in the cultured seahorses, and it was strongly involved in the intestinal diseases in seahorse H. trimaculatus.  相似文献   

5.
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.  相似文献   

6.
This study evaluated the use of live and frozen copepods collected from shrimp ponds for rearing juveniles of the spotted seahorse Hippocampus kuda. Protein and HUFA contents in frozen copepods were all higher than in Artemia nauplii, the conventional live food for seahorse juveniles. The results of this study showed that copepods can be used as feed for rearing seahorse fry and juvenile. The spotted seahorse showed obvious preference for live copepods and rarely fed on dead copepods on the tank bottom. Furthermore, the combination of frozen copepods and live Artemia nauplii resulted in highest growth and highest survival of the experimental seahorses. Further research on possible effects of DHA:EPA ratio on survival and growth of young H. kuda is recommended.  相似文献   

7.
  • 1. The implications of shrinkage associated with desiccation and ethanol preservation for seahorses (genus Hippocampus) were investigated using Hippocampus guttulatus (European long‐snouted seahorse) as a model. Specifically, this research addressed the implications of preservation for taxonomy and life history studies and the application of minimum size limits (MSL) for managing seahorse trade.
  • 2. In 2004, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) listed all seahorse species on its Appendix II, and recommended a 10 cm MSL as an interim means of ensuring sustainable international trade. Inconsistencies in seahorse measurement methods and repeatability posed challenges for applying the MSL. Moreover, the shrinking effect of desiccation on body length observed in other fish was assumed to be negligible for seahorses because of their high degree of ossification.
  • 3. Changes in seahorse sizes were measured following immersion in ethanol and desiccation. H. guttulatus shrank on average by 0.1–2.3% when preserved in ethanol and 3.0–6.4% when dried, depending on the trait measured. Similar trends were observed in a sample of H. kuda (yellow seahorse). Specimen posture during drying, and measurement methods also influenced estimates of size.
  • 4. Based on the shrinkage observed, 14–44% of captured seahorses that are dried could shrink to below the recommended MSL, even if all seahorses were longer than the MSL at capture. This demonstrates that small changes in body lengths can have significant implications for trade of species managed with size limits.
  • 5. Recommendations are to (1) standardize seahorse measurement methods, (2) consider the effects of preservation and measurement technique on body lengths, and apply appropriate corrections in comparative studies and when developing fisheries management strategies, and (3) adjust size limits at the point of capture to ensure retained seahorses comply with the CITES recommended MSL.
Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

8.
Seahorses, pipefish and seadragons are fish of the Family Syngnathidae. From 1998 to 2010, 172 syngnathid cases from the Toronto Zoo were submitted for post‐mortem diagnostics and retrospectively examined. Among the submitted species were yellow seahorses Hippocampus kuda Bleeker (n = 133), pot‐bellied seahorses Hippocampus abdominalis Lesson (n = 35) and weedy seadragons Phyllopteryx taeniolatus (Lacépède; n = 4). The three most common causes of morbidity and mortality in this population were bacterial dermatitis, bilaterally symmetrical myopathy and mycobacteriosis, accounting for 24%, 17% and 15% of cases, respectively. Inflammatory processes were the most common diagnoses, present in 117 cases. Seven neoplasms were diagnosed, environmental aetiologies were identified in 46 cases, and two congenital defects were identified.  相似文献   

9.
In Tasmania, commercial seahorse culture takes place in tank systems in which approximately 75% of the water is exchanged daily from the Tamar River estuary. The aim of this study was to examine the effect on survival of early juvenile pot‐bellied seahorses, Hippocampus abdominalis, directly transferred and cultured for 9 d in salinities of 5, 10, 15, 20, 25, and 32 g/L. Direct transfer of seahorses to 5 g/L salinity resulted in 100% mortality within 7 d. After 9 d, an improvement in survival was recorded in seahorses cultured in 10 and 15 g/L compared to those cultured in 25 and 32 g/L salinities. This study is the first to report on the tolerance of H. abdominalis in captivity at salinities as low as 10 g/L in early life stages without compromising survival.  相似文献   

10.
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11.
The biochemical composition of six seahorse species from the Chinese coast was analyzed in this study. The crude protein content (% dry weight) of Hippocampus kuda, Hippocampus trimaculatus, Hippocampus kelloggi, Hippocampus spinosissimus, Hippocampus histrix, and Hippocampus comes was 70.70 ± 2.12%, 77.59 ± 1.06%, 78.31 ± 1.74%, 71.15 ± 1.32%, 68.07 ± 1.96%, and 76.59 ± 3.25%, respectively. The major amino acids (>5% of the total) in seahorses were arginine, aspartic acid, glutamic acid, alanine, and glycine, and there were significant differences in essential amino acids (EAA) (as % of total protein) among the six species (P < 0.05). The scores of EAA were balanced in the seahorse species, and the essential amino acid indexes of the six species were 41.63, 40.89, 44.84, 39.60, 39.31 and 45.45, respectively. The content of flavor‐enhancing amino acids of the six seahorse species was generally high, ranging from 28.16 ± 1.12% in H. histrix to 32.90 ± 2.17% in H. kelloggi (P < 0.05). The total lipid content was generally low, ranging from 0.96 ± 0.08% in H. histrix to 2.02 ± 0.24% in H. comes. The most abundant fatty acid was C16:0, ranging from 15.04 ± 0.67% in H. trimaculatus to 31.04 ± 4.32% in H. spinosissimus. The combination of eicosapentaenoic acid and docosahexaenoic acid as the fraction of the total fatty acids was high (0.14–0.35). The polyunsaturated fatty acid/saturated fatty acid ratio ranged from 0.40 in H. kuda to 1.19 in H. histrix. The trace metal concentrations in the seahorses were generally low. The six seahorse species examined provide a food source for humans with low fat, high protein, good levels of EAA, and high beneficial trace elements. These results are valuable in developing diets for culturing seahorse species.  相似文献   

12.
Low survival at early stage is the bottleneck in seahorse aquaculture, particularly in the feeding aspect since newborn seahorses must feed immediately upon birth to sustain themselves. Seahorses are visual predator, therefore preferred live feed such as zooplankton. In aquaculture, the most common live feed used is Artemia. In this study, two experiments were conducted to determine the effect of different Artemia enrichment on the growth and survival of newborn Hippocampus barbouri. In the first experiment, six treatments using Artemia enriched with Culture Selco Plus? (SELCO), thyroxine (T4), potassium iodide (KI), cod liver oil (CLO), cod liver oil in combination with thyroxine (CLO + T4) and potassium iodide (CLO+KI) were fed to newborn H. barbouri. Newly hatched Artemia were used as control. At the end of first experiment, treatments using CLO + T4 produced juvenile H. barbouri with the best (p < .05) wet weight (0.142 ± 0.000 g), while juvenile in treatment CLO+KI recorded the highest (p < .05) standard length (3.947 ± 0.014 cm). Subsequently, a second experiment was carried out using the two best enrichment (CLO + T4 and CLO + KI) from the first experiment, but given at different frequency (daily, twice a week, once a week, once in 2 weeks). Daily enrichment using both CLO + T4 and CLO + KI showed no significant (p > .05) difference in growth performance and survival of juvenile of H. barbouri. Interestingly, juvenile fed CLO + T4 enriched Artemia at frequency of twice a week also has no significant difference (p > .05) in survival and growth performance (except for final standard length) when compared with treatment CLO + T4 at daily frequency.  相似文献   

13.
As with many species of seahorses, Hippocampus hippocampus wild populations are being subjected to uncontrolled exploitation in their natural environment. Thus, aquaculture could contribute to satisfy the commercial demand for animals while promoting the recovery of wild stocks. The present study was conducted to compare the effect of the substituting Artemia nauplii with rotifers for first feeding seahorse juveniles. Survival, growth and biochemical composition of prey organisms and fish were studied during the feeding trial. In addition, to help the biometric study, an anaesthetic test was also carried out using clove oil. The results showed excellent survival (average 60%) in juveniles exclusively fed with Artemia, with better values than those reported previously obtained by other authors for this species. By comparison, high mortality and poor growth were observed during first feeding with seahorses fed on rotifers. This could have been related to the lower energy intake and poorer nutritional value of the rotifers. Furthermore, clove oil concentrations of 25 ppm were found to work well as an anaesthetic for seahorse juveniles. Overall, first feeding Artemia alone was found to be an efficient and simplified method for feeding young H. hippocampus fry, building the principles for their culture for ornamental or re‐stocking purposes.  相似文献   

14.
  • 1. Seahorses (Hippocampus spp.), many of which are listed as Vulnerable or Endangered on the IUCN Red List, are traded worldwide as souvenirs, aquarium fish and, primarily, for use in traditional medicines. Given concern over the sustainability of this trade, the genus was added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in May 2004.
  • 2. This paper reports findings of the first ever survey of seahorse trade in Africa, conducted in Kenya and Tanzania in May and June 2000.
  • 3. Seahorse trade in Kenya was found to be negligible, with approximately 10 live seahorses exported as aquarium fish annually. Until 1998, however, Kenya may have imported somewhere from 1 to 2.3 t of dried seahorses annually from Tanzania for re‐export to Asian medicine markets. Seahorse trade in Tanzania remained substantial, with at least 630–930 kg of dried seahorse exported directly to Asia each year.
  • 4. Accounts of declines in seahorse availability and seahorse size, although few in number, could be early warning signs that wild populations are suffering, at least locally. Close monitoring of future developments in the trade will be essential to allow for timely conservation action as and when necessary, and would contribute to our understanding of the ecological and economical implications of small‐scale, non‐food fisheries.
Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

15.
This study aims at evaluating the Patagonian seahorse, Hippocampus patagonicus, feeding behavior in captivity with regard to type and size of prey selectivity and time‐investment‐related activities for searching and capture. Experiments in aquaria were carried out under two different treatments, with and without refuge for prey. Different diets composed of amphipods (Melita palmata and Ampithoe valida), juvenile decapods (Neohelice granulata) from natural environments, and artificially cultured Artemia salina. The eaten prey’s size was analyzed and experiments with size‐controlled prey were carried out. There were neither significant differences in the prey quantity ingested between males and females nor between treatments (with or without refuge). However, significant differences were found between the quantities of each prey consumed. Amphipods and A. salina were consumed in greater quantity (P < 0.05) when compared with juvenile decapods. Experiments with A. salina of different sizes did not show significant differences on seahorses’ preference. N. granulata was highly avoided and seahorses had lower capture efficiency over this prey. Behavioral observations showed that more than 50% of the times seahorses were resting and ambushing their prey. In captivity, with optimal conditions for predation, the Patagonian seahorse modifies its opportunistic behavior, feeding selectively, and bases its food preferences on prey size and shape .  相似文献   

16.
The biochemical composition of wild and cultured seahorses Hippocampus kuda Bleeker and Hippocampus trimaculatus Leach was analysed in this study. The crude protein contents (% dry weight) of wild seahorses were high: 72.7±2.5% in H. kuda and 78.5±4.2% in H. trimaculatus . The crude lipid contents (% dry weight) of wild and cultured seahorses (1.1±0.1 vs. 1.4±0.2 for H. kuda and 1.2±0.1 vs. 1.2±0.2 for H. trimaculatus ) were low and did not differ significantly ( F 3, 12=1.461, P =0.12). The essential amino acids and flavour-enhancing amino acids in wild seahorses were higher than those in cultured seahorses, although the essential amino acid index in wild and cultured H. kuda and H. trimaculatus were generally low. The total amino acid content decreased with growth in cultured H. trimaculatus ( F 3, 12=14.927, P <0.05). The poly-unsaturated fatty acid (PUFA) contents in wild and cultured H. kuda and H. trimaculatus were 21.69%, 37.72%, 21.39% and 33.89% respectively. The fatty acid content in seahorses first decreased and then increased with growth both in wild and in cultured H. trimaculatus . The PUFA/saturated fatty acid ratio was 1.31 in cultured H. kuda and 0.87 in cultured H. trimaculatus . The trace metal concentrations in the wild seahorses were relatively low. The results presented in this study provide biochemical information necessary for understanding the medicinal value of H. kuda and H. trimaculatus and for elucidating the potential dietary requirements for their culture.  相似文献   

17.
This investigation examined the effects on growth and survival of seahorses Hippocampus abdominalis Leeson 1827 fed a 25% body weight (wet weight) daily ration of live Artemia sp. enriched with Algamac‐3050, frozen mysids Amblyops kempi or a combination of live enriched Artemia and frozen mysids. After 3 months there was no difference in seahorse length, wet weight, condition factor (CF), or food conversion ratios (FCR) between the treatments. Mean daily specific growth rate (SGR) was higher for the Artemia‐only treatment than for the mysid‐only treatment (P<0.05). FCRs ranged from 6.14 g to 8.72 g dry weight of food required to give a 1‐g dry weight increase in seahorses. There was no difference in survival between treatments. Fatty acid analysis revealed that mysids had a higher percentage composition of EPA, 20 : 5n‐3, and DHA, 22 : 6n‐3, but a lower composition of AA, 20 : 4n‐6, than enriched Artemia. Percentage n‐3 highly unsaturated fatty acids (HUFAs) in mysid levels were approximately twice that of Artemia. Proximate analysis revealed mysids to be higher than the enriched Artemia in protein and fats, and lower in water content. This experiment demonstrates that, although no growth advantage was derived from the use of frozen mysids, they can be used successfully as an alternative food to live enriched Artemia for H. abdominalis. The use of frozen mysids is highly recommended in commercial seahorse culture if the seahorses are to be sold into the live aquarium trade, as this may increase their chances of survival after sale.  相似文献   

18.
The microenvironment of bacteria associated with the gastrointestinal tract of an animal influences the host in many ways, including the metabolism of several nutrients. Isolation, molecular characterization and enzymatic activities of culturable bacteria associated with the gastrointestinal tract of hatchery‐reared oceanic yellow seahorse, Hippocampus kuda, were investigated in the present study. 16S rRNA sequencing of bacterial isolates yielded 10 different bacterial genera belonging to two major groups: proteobacteria (62.9%) and firmicutes (37.03%). The predominant microbial flora belonged to the genera Vibrio spp., Enterovibrio sp. and Bacillus spp. Burkholderia cenocepacia, hitherto unreported from the gastrointestinal tract of marine fish, was retrieved from the seahorse gut, albeit in small numbers. Enzymatic studies indicated that the bacterial isolates possess the ability to degrade lipids, cellulose, xylan, starch and proteins. Lipase activity was exhibited by a majority of the isolates (70.4%), indicating that the bacterial flora associated with the intestinal tract of seahorses is capable of digesting foods rich in lipids. The possible implications for the role of these bacteria in the digestion and physiological processes are discussed. To our knowledge, this is the first time that the characterization and enzymatic activities of bacteria associated with the intestinal tract of farmed seahorses have been reported.  相似文献   

19.
  • 1. The worldwide trade in aquarium fish is a multi‐billion dollar industry. One of the most popular and expensive species traded is the Asian arowana Scleropages formosus. As a result of over‐harvesting for the aquarium fish trade, S. formosus is now endangered and commercial international trade in the species is prohibited under CITES. Despite this, very little is known about S. formosus in the wild.
  • 2. Interviews were conducted with 62 local villagers at four sites in Koh Kong province, south‐west Cambodia, to obtain information on the reproduction, historical and current harvest and trade, and population trends of S. formosus.
  • 3. The spawning season of S. formosus in Cambodia begins towards the end of the dry season (March–April) and is approximately 3 months in duration. Each male mouth‐broods an average of 30 juveniles. Harvesters target S. formosus fry and juveniles, and typically kill or frighten brooding males into releasing their offspring in order to harvest them.
  • 4. The prices obtained by harvesters for S. formosus has been increasing since collection began, and currently averages $US11–13 per juvenile. After collection, fish are transported through a series of larger towns, most ultimately bound for Thailand. The current number of S. formosus harvested from the wild in Cambodia is almost certainly highly unsustainable, with all respondents indicating that local S. formosus population abundance had declined dramatically in recent years. It is also likely that a number of populations have already become locally extinct.
  • 5. Strengthening legislation to protect the species within Cambodia, increasing enforcement of cross‐border trade, and an investigation into alternative low‐impact income generation opportunities for local communities is vital. There is also an urgent need to gather detailed information on the distribution, population abundance and threats facing S. formosus in Cambodia, and in other countries throughout its range.
Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

20.
This study was performed to obtain information on the occurrence of multiple paternities in three species of viviparous Japanese surfperch using allelic markers of microsatellite DNA loci. Direct evidence for multiple fertilizations was established by reconstructing paternal genotypes from the progeny of gravid females. Multiple paternities were ascertained in five of 10 broods of Ditrema temmincki and in three of nine broods of Neoditrema ransonneti, but not in Ditrema viride. The number of patrilines detected in the progeny of D. temmincki and N. ransonneti females were two or three, respectively, as determined by the GERUD v2.0 algorithm for reconstructing parental genotypes from half-sib progeny arrays.  相似文献   

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