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1.
- Habitat degradation and destruction arising from rapidly increasing urbanization represents one of the most significant threats to biodiversity. Human populations are continuing to increase around coastal regions, and as marine habitats are displaced by artificial structures it is important to understand how marine species may be impacted by these changes in habitat availability. The endangered seahorse Hippocampus whitei has been observed inhabiting protective swimming nets in Sydney Harbour, Sydney, Australia, even in the presence of natural habitats.
- This study tested whether the presence of a swimming net results in increased seahorse numbers at sites around Sydney Harbour, or whether seahorses are attracted away from natural habitats. Density surveys and mark–recapture population estimates were done at sites with pre-existing swimming nets and compared to control sites where only natural habitat was present. A manipulative experiment was conducted in which panels of swimming net material were installed at two sites in Sydney Harbour, with comparisons to control sites over a period of 14 months (April 2018 to June 2019) to test whether the installation of swimming nets would affect seahorses on surrounding natural habitat or increase site abundance.
- The pre-existing and installed swimming nets were found to support greater densities of H. whitei as well as some increases in site-scale abundance, with no effects on seahorse density on natural habitats. It is likely that increased seahorse production is occurring on the nets, with no evidence that seahorses are being attracted away from natural habitat; however, effects may vary across survey occasions and sites. Furthermore, swimming nets may serve as a useful replacement habitat in locations where natural habitat has become sparse or absent.
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Tanvi Vaidyanathan Xiong Zhang Ramkumar Balakrishnan Amanda Vincent 《水产资源保护:海洋与淡水生态系统》2021,31(1):43-59
- All seahorse species (genus Hippocampus) are listed under Schedule I of India's Wild Life Protection Act, making all capture and trade of seahorses illegal. In the more than 15 years since the ban, little work has been done to assess its effects on seahorse conservation.
- Between 2015 and 2017, fisheries and trade surveys were conducted along the south-east coast of India, in the state of Tamil Nadu, historically known to be a hub for seahorse catches and trade.
- Seahorses were primarily landed as bycatch, although in greater quantities by traditional drag nets than as trawl bycatch. Total annual catches were estimated between 4.98 million and 13.64 million seahorses, 87% of which were caught by active non-selective gear.
- Generalized additive models revealed that seahorse catch per unit effort had non-linear relations with depth and latitude, and were higher in biogenic habitats, with active, bottom-used, and non-selective gears (e.g. trawls).
- The illegal nature of the trade in seahorses hampered an understanding of trade routes and trade volumes. Catch estimates indicated that 11.21–30.31 tonnes of seahorses probably entered trade, yet interviews with traders only documented trade of about 1.6 tonnes.
- Fishers reported a decreasing availability of seahorses. Since most seahorses come from bycatch in persistent fisheries that are not directly affected by the ban on seahorse capture, this decline is likely to represent a population decline.
- A fishery and trade ban for incidentally caught species, particularly in a poorly regulated fishery, appears to add little conservation value. There needs to be a shift in the management approach, moving from a ban towards spatial and temporal restrictions, and toward enforcing existing fishery regulations.
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- 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.
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B. G. Clynick 《水产资源保护:海洋与淡水生态系统》2008,18(5):483-492
- 1. Artificial structures are becoming increasingly important in conserving biodiversity in urban ecosystems, by providing habitat for endangered or rare species. Their role in providing habitat for such species has, however, been largely unexplored.
- 2. In Sydney Harbour, Australia, seahorses were observed among the netting used to keep sharks out of swimming enclosures. Over a 2‐year period, the relative densities of two species of seahorses observed on netting was measured at swimming enclosures with permanent netting and at swimming areas that were only enclosed with netting during the summer months.
- 3. The rate of colonization by seahorses to new netting was also examined over a period of 10 months.
- 4. Numbers of seahorses on permanent swimming enclosures were 10 to 100 times greater than numbers present on swimming enclosures that were only set up during the summer months.
- 5. This large difference may have been attributed to the slow rate of colonization of seahorses to new habitat. Seahorses were not observed at experimental nets that were deployed in two areas in the harbour until at least 4 months after the netting was deployed.
- 6. Swimming pool nets are a habitat for species of seahorses in Sydney Harbour and, consequently, the removal or disturbance of swimming nets may impact the survival of these fish. Management of these artificial habitats may therefore best be focused on providing a permanent habitat that may help to compensate for the loss of netting during winter months.
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- 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.
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Ying Li Zongxing Wang Fengrong Zheng Bo Wang Hongzhan Liu Peiyu Zhang Maosheng Xin 《Aquaculture Research》2020,51(3):989-999
The lined seahorse, Hippocampus erectus, is an Atlantic species, which mainly inhabits shallow sea beds or coral reefs. Seahorse has become very popular in China due to its wide use in traditional Chinese medicine (TCM). However, the aquaculture of the lined seahorse has been threatened by a variety of diseases, especially bacterial infections. Skin ulcer syndrome becomes more and more common in the culture of seahorses, leading to skin ulcer, liver erosion and minority tail rotting. These diseased seahorses die in only 72 hr, causing huge economic losses in aquaculture. Pathogen HMT‐1 was isolated from the lined seahorses with skin ulcer syndrome, which was identified as Vibrio harveyi. The median lethal dose (LD50) of HMT‐1 was 2.88 × 108 cfu/ml. The pathogenic mechanism of HMT‐1 was preliminarily studied, and the pathological changes of the diseased lined seahorses were also investigated. Moreover, the activities of ACP, complement 3, SOD and LZM at different time post injection were measured by commercial kits. Our findings can provide reliable reference for diagnosis and treatment in the future. 相似文献
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Janelle M. R. Curtis Joaquim Ribeiro Karim Erzini Amanda C. J. Vincent 《水产资源保护:海洋与淡水生态系统》2007,17(5):468-484
- 1. A 2‐year experimental seining programme and underwater visual censuses were undertaken to quantify the direct effects of active demersal fishing on the population structure and relative abundance of two sympatric seahorse species of conservation concern: the European long‐snouted seahorse, Hippocampus guttulatus Cuvier 1829 and the short‐snouted seahorse, Hippocampus hippocampus L. The influence of habitat preference on population‐level responses to changes in habitat structure following a reduction in fishing effort was also investigated.
- 2. It was predicted that the benthic habitat would be more structurally complex after fishing ceased and that seahorse densities would increase in response to reduced fishing mortality. Furthermore, it was predicted that the magnitude of the increase in density would be greater for H. guttulatus than for H. hippocampus, because the former species prefers complex vegetated habitats while the latter species uses sparsely vegetated habitats.
- 3. As predicted, the amount of habitat cover increased significantly when seining ceased, primarily through increases in the abundance of drifting macroalgae and unattached invertebrates. Despite similarities in life histories, the two seahorse species responded differently in terms of magnitude and direction to reduced fishing effort: the abundance of H. guttulatus increased significantly while H. hippocampus decreased in abundance.
- 4. Results suggest that active demersal fishing may influence the magnitude and direction of the responses of benthic marine fishes to exploitation through its impacts on habitat structure. An increase in habitat cover appeared to favour higher densities of H. guttulatus when seining effort was reduced. By contrast, repeated seining, which maintained less complex habitats, appeared to favour greater abundances of H. hippocampus.
- 5. Given differences in habitat preference among benthic marine fishes subject to incidental capture in fisheries, simultaneous attempts to manage populations of sympatric species may require complementary strategies that support the persistence of diverse habitat types.
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Growth,Survivorship, Air‐bubble Disease,and Attachment of Feeble Juvenile Seahorses,Hippocampus kuda (Bleeker, 1852) 
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下载免费PDF全文 Yanhong Zhang Geng Qin Junda Lin Qiang Lin 《Journal of the World Aquaculture Society》2015,46(3):292-300
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
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Rearing the spotted seahorse Hippocampus kuda by feeding live and frozen copepods collected from shrimp ponds 下载免费PDF全文
下载免费PDF全文 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
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Jinhui Sun Sudong Xia Shangduan Xie Yanqing Yang Pei Cui Peng Shao Yongjian Xu Lv Shuang 《Aquaculture Research》2020,51(4):1542-1550
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
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Comparison of the Intestinal Bacterial Flora in Healthy and Intestinal‐diseased Seahorses Hippocampus trimaculatus,Hippocampus erectus,and Hippocampus spinosissimus 下载免费PDF全文
下载免费PDF全文 Feng Li Kai Wang Wei Luo Liangmin Huang Qiang Lin 《Journal of the World Aquaculture Society》2015,46(3):263-272
This investigation examined the intestinal microbial flora among healthy and intestinal‐diseased seahorses Hippocampus trimaculatus, Hippocampus erectus, and Hippocampus spinosissimus by utilizing polymerase chain reaction‐denaturing gradient gel electrophoresis (DGGE) and densitometric analysis. Results demonstrated that 16 disparate DGGE bands belong to six major bacterial groups, which were Vibrionace, Enterobacteriacea, Rhodobacteraceae, Sphingomonadaceae, Flavobacteriaceae, and Alcaligenaceae. It was found that Vibrionaceae was the dominant population among the healthy and intestinal‐diseased seahorses. Vibrio ponticus strain XJ3 and Vibrio neptunius strain WT82, especially V. ponticus strain XJ3 of high abundance, were identified for the first time in seahorses and concluded to be intestinal disease pathogens because of their co‐existence in three intestinal‐diseased seahorse species and other reported fish or oyster. In comparison, uncultured bacterium clone Alcaligenaceae, Vibrio sp., uncultured bacterium clone Rhodobacteraceae, Serratia nematodiphila strain, and Serratia marcescens strain comprised the basic intestinal bacterial flora of all healthy seahorses. This study is the first to report the presence of S. nematodiphila in seahorses. 相似文献
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- Rafting has been proposed as a dispersive mechanism for some species of seahorses. Juvenile Hippocampus patagonicus rafting on the sea surface have been reported. This life stage has high mortality in nature due to ecological and environmental factors usually affecting juvenile planktonic teleosts (e.g. predation).
- In this study, 50 juvenile seahorses were captured while rafting at the beginning of the reproductive season (December). They were grown out under a standard protocol in a recirculating aquaculture system for 120 days until they reached maturity.
- During this period, only three seahorses died (6%). Mature seahorses were 65 ± 7 mm average height and showed variable coloration and pigmentation pattern (n = 47; 94%).
- The availability of juvenile seahorses during the reproductive season and their high survival performance ex situ highlight the feasibility of developing protocols in which juvenile seahorses serve as a novel source of broodstock.
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Ontogeny of digestive enzymatic capacities in juvenile seahorses Hippocampus guttulatus fed on different live diets 下载免费PDF全文
下载免费PDF全文 Differences in survival and growth rates in seahorse Hippocampus guttulatus juveniles feeding on Artemia sp. or copepods have been related to specific digestive capacities of seahorse newborn, which are capable of actively forage on available prey from the first day of live. Other seahorse species, such as H. abdominalis and H. hippocampus, show high success feeding on Artemia nauplii suggesting species-specific differences in the digestibility of prey among seahorses. In this study, the profiles of digestive enzyme activity during the initial 15 days after release (DAR) were very low for trypsin, chitinase and α-amylase. In contrast, higher activities towards any of the assayed substrates for lipase (butyrate, octanoate and oleate) were evident from 0 DAR onwards. From 15 DAR onwards, the effect of diet composition became evident in juveniles previously fed on a mixed diet (Artemia + copepods), which showed a clear increase in all the assayed enzymes when compared with juveniles fed on Artemia as a sole prey. As a practical applicability of this study, a feeding schedule ensuring an adequate digestibility of the prey is proposed based on ontogenetic enzymatic activities of seahorse juveniles fed on different prey. 相似文献
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- 1. All seahorse species (genus Hippocampus) are listed under CITES Appendix II, requiring that exports of these fishes must be regulated for sustainability. Preliminary trade surveys and anecdotal reports suggested Malaysia and Thailand represented an important source for seahorses used globally in traditional medicine, curios, and aquarium display, but few historic trade or fisheries data are available. Baseline information about pre‐CITES catch and trade is essential for managing seahorse fisheries and trade under CITES, and for understanding present‐day effects of CITES regulation on the seahorse trade.
- 2. In 1998–1999, seahorse fisheries and trade in both countries were assessed by interviewing participants at many levels of the trade and corroborating those surveys with official trade documents.
- 3. Seahorses were found to be landed primarily as trawl bycatch. Malaysia's catch of 2900 kg year?1 was less than the estimated domestic consumption (5500–6000 kg year?1), whereas Thailand's catch of 6600 kg year?1 apparently far exceeded domestic consumption (～520 kg year?1).
- 4. Both countries imported seahorses from and exported to other Asian nations. Import statistics from Hong Kong SAR and Taiwan recorded maximum annual trade from Malaysia at 1280 kg year?1. Trade surveys indicated that Thailand exported at least 5000 kg annually (similar to the estimation of catch), but national Customs records reported 10 500 kg year?1 in exports, supported by official import records from Hong Kong SAR and Taiwan which indicated that Thailand was the source of up to 11 400 kg year?1.
- 5. Fishers and traders in both countries reported decreasing availability of seahorses, raising conservation concerns. These apparent declines, in combination with substantial domestic consumption, point towards the challenges that Malaysia and Thailand face in establishing sustainable levels of exports under CITES. Copyright © 2010 John Wiley & Sons, Ltd.
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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
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Frozen mysids as an alternative to live Artemia in culturing seahorses Hippocampus abdominalis 总被引：1，自引：1，他引：1
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
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为了解灰海马的细胞遗传学特征,便于今后开展灰海马的种质评价与鉴定、规模化人工繁育、亲缘关系研究及人工选育等工作,实验以雌雄灰海马的背鳍为材料,采用秋水仙素浸泡和常规热滴片法制备染色体标本。借助Photoshop图像软件,将同源染色体配对、拼贴,做出染色体核型图。采用Image J软件的自定义曲线测量功能,以着丝粒的中心位置为起点,顺着染色体弯曲的形态,到染色体臂末端为终点,测量线段长度,得出图片中染色体的臂长,根据相同放大倍数下标尺的测量值,换算出染色体的实际臂长。根据臂比值,将染色体进行配对、分类后,得出灰海马的染色体核型公式。结果显示,灰海马的背鳍组织可作为其染色体制备的理想材料,实验选用的染色体制备方法能获得图像清晰、形态良好的细胞分裂相。此法简单、效果好,解决了海龙科鱼类染色体制备的难题;灰海马具有22对染色体,二倍体染色体数目2n=44,雄鱼的染色体核型公式为2n=2sm+20st+22t,雌鱼的染色体核型公式为2n=1m+2sm+20st+21t,雌鱼存在性染色体异型的现象,因此灰海马的性染色体为ZW/ZZ型。 相似文献