Seahorse 13 Qep - La Tene Maps
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Current Issues Life Cycle of the Seahorse Seahorses, belonging to the family Syngnathidae, are the most unusual and arguably the most interesting of fish. More than 30 species of those with the scientific name Hipppocampus are consid- ered true seahorses. Other syngnathids include pipefishes, pipehorses and sea dragons. Seahorses range in size from a few centimetres to 30 centimetres and are found in shallow waters around the world from temperate to tropical regions. However most species live in tropical or subtropical areas in waters that range in depth from 5 metres to more than 100 metres. In Europe, Hippocampus hippocampus and Hippocampus guttulatus are the most common species. They can be found in shallow seagrass beds in the coastal areas of Europe. Subtropical and tropical species are found mainly in and around coral reefs, mangroves and estuaries. Seahorse imagery has been a decorative motif from the earliest civilisations to the present day, appearing on coins, pottery, jewellery, and in books and film. They are fished commercially to meet demand from traditional medicine markets in Asia as treatments for a wide range of ailments, as well as for the souvenir and aquarium markets. Overfishing, incidental bycatch and damage to habitat are the main factors responsible for declines in seahorse populations. Seahorses are seen as a flagship species for the marine environment, meaning that the attention drawn to their con- servation should have a beneficial effect for other species and preservation of the marine environment in general. The two main conservation strategies for the seahorse may be viewed as protecting seahorse habitat and curbing the demand on wild populations. Habitat protection may be achieved through controls on fishing methods and the establishment of marine protected areas. Curbing demand on wild populations is possible through regulation of trade, improved management regimes, the introduction of alternative livelihoods for fishers, and through cultured supply. Most seahorse species are included on the IUCN – World Conservation Union’s Red List of Threatened Species, primarily classified as either Vulnerable or Data Deficient. High levels of global exploitation of seahorses have lead to the addition of all species to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. The list requires that more than 160 nations ensure their seahorse exports are sustainable. Attempts have been made to grow seahorses commercially by aquaculture methods in many countries around the world, including China, Australia, New Zealand and Ireland; some of these are beginning to show promise. La Tene Maps acknowledges the help and support received in the preparation of this poster from Project Seahorse, Canada; Tropical Marine Centre, United Kingdom; and Seahorse Ireland. Produced by La Tene Maps Copyright © AquaTT 2004. www.aquatt.ie AquaTT, P.O. Box 8989, Dublin 2, Ireland. Tel: +353 1 644 9008, Fax: +353 1 644 9009, E-mail: [email protected] COURTSHIP Seahorses mate after an elaborate courtship that involves entwined tails, colour changes and dances. Sometimes several males compete for a chance to mate with a female or vice versa. Males can inflate their pouch to entice the female to deposit her eggs in it. In many species seahorses remain faithful to one partner for at least the duration of the breeding season. JUVENILES Newly released young undergo few changes after emerging from the father. During growth, some body proportions may change while juveniles develop mature gonads, but they experience no further major body changes. Some newborns emerge with a small caudal fin (e.g. H. mohnikei), which is lost over time. EGG TRANSFER After courtship, which can last many hours, the female deposits her eggs in the male’s pouch. The number of eggs trans- ferred varies by species and female. Once safely deposited in the pouch, the eggs are fertilised by the male and the pouch is sealed. YOUNG Newborns measure 2-12 mm, depend- ing on species. The number of young released averages between 100 and 200 for most species, but can be as low as 5 for the smaller species, or more than 1,500 for larger species. Hatchlings will often grasp floating or attached objects, including artificial structures and each other, with their prehensile tails. Some species have a pelagic stage when born, which means that their movement is influenced by the prevailing tides and currents. The Seahorse BIRTH Seahorses are renowned for the fact that it is the male who gives birth. When he is ready to release the developing young, the male under- goes muscular contractions to expel the young, known as fry, from the pouch. This poster is one of a series produced by the PISCES project. PISCES was realised through the financial sup- port of the Commission of the European Communities under the LEONARDO DA VINCI PROGRAMME and industry sposors. The content of this poster does not nec- essarily represent the opinions of the Commission. PISCES is coordinated by AquaTT, the European Network for Education and Training in Aquaculture. The aims of the project relate to promoting careers in aquaculture through promoting the industry and training opportunities. The main deliverables of the project are an online multilingual aquaculture forum for European education and training and a series of educational lifecycle posters. All products are available on the project website; www.piscestt.com. This poster was supported by Project Seahorse, an interna- tional and interdisciplinary marine conservation organization. Its biologists and development specialists conduct fundamen- tal biological research, empower communities, establish marine protected areas, manage subsistence fisheries, restructure international trade, advance environmental educa- tion, promote integrated policy, and redress habitat loss. The Project Seahorse team is composed of members global- ly, working in Australia, Canada, Hong Kong, Philippines, Portugal, U.K., and U.S.A. Projects have also been managed in South Africa and Vietnam, with collaborations in many more countries. It is headquartered in Vancouver, B.C., at the University of British Columbia's Fisheries Centre. Project Seahorse has published a book: Seahorses: A Guide to the World’s Species and Their Conservation, by Lourie, Vincent and Hall 1999. Tropical Marine Centre was set up in 1970 and since that time has established itself as the leading wholesale suppli- er of marine fish to the trade in Europe and a pioneer of fil- tration and UV sterilising equipment for all sizes of ponds and aquariums both domestic and commercial. The com- pany operates three aqaurium based facilities outside London, Manchester and Bristol, which include Europe's only commercial reef fish hatchery. TMC has established an outstanding reputation for promot- ing and fostering the welfare of livestock from capture and breeding through to handling and transportation. TMC-Publishing has published a book on Seahorses: Seahorses, Pipefishes and Their Relatives: A Comprehensive Guide to Syngnathiformes by Rudie H Kulter. See www.tmc-publishing.com for further details. Tropical Marine Centre Ltd is a subsiduary of Cranswick plc. ADULT Sexual maturity in males is usually inferred by the presence of a brood pouch. Mature male seahorses are able to become pregnant any time during the breeding season, which varies with species, and is thought to be influenced by environmental conditions such as water temperature. Seahorse Trading Seahorses are highly sought after by the tradition- al medicine, live aquarium and souvenir markets. The demand has put pressure on wild populations, prompting regulations for the international trade. Captive Breeding Captive breeding may be part of a solution to help alleviate overexploitation of wild stocks. Sufficient space, the availability of the correct food and sur- roundings that resemble the natural environment contribute to successful breeding. Farming Seahorses Farming seahorses for commercial purposes is so far restricted to just a few species. Due to a simple digestive system, seahorses must consume large amounts of food and so a relatively large amount of live feed is required. Although it is possible to raise seahorses on frozen food, most only eat live animals, and farms must enrich zooplankton feed with microalgae to provide the correct nutritional balance. Habitat Loss Coastal developments near estuary channels, sea- grass beds or mangroves have an immediate effect on local seahorse numbers. Other environ- mental threats to the seahorse include turbulence and loss of vegetation that provides shelter and supports crustacean breeding, the main food source for most seahorse species. Hippocampus breviceps The Short-head Seahorse is found mainly along seagrass edges and sometimes on the sponge reefs of Australia's southern coast. Hippocampus comes The Tiger Tail Seahorse is found in S.E. Asian waters on shallow coral reefs and sponge gar- dens, kelp and other floating algae. H. comes is a potential aquaculture species. Hippocampus guttulatus The Long-snouted Seahorse can be found along Atlantic, Mediterranean and Algerian coasts, in shallow algal strands and rocky areas in winter. Hippocampus subelongatus The Western Australian Seahorse is found pri- marily along the edges of rocky areas, in muddy sea-bottoms, and is commonly asso- ciated with sponges or sea squirts. Hippocampus bargibanti The Pygmy Seahorse is found in coral reefs in the west Pacific, in the waters between Australia and Indonesia and along the south- ern coast of Japan. PREGNANCY Conditions in the pouch are controlled by the male, who also provides oxygen and nutrients through a network of capillaries in the pouch. The embryos will remain in the pouch for two to six weeks, depending on species and temperature as they develop into fully formed juveniles. The nutri- ents provided by the female influence the initial- conditions in the pouch. Decline in Wild Stocks Seahorse numbers in many exploited populations are estimated to have declined by 15–50% between 1990 and 1995. Since this period the demand for seahorses has increased substantially. Due to the drastic fall in numbers, more extensive areas are being exploited for seahorses. www.tmc-ltd.co.uk Tropical Marine Centre Ltd, Solesbridge Lane, Chorleywood, Herefordshire WD3 5SX, United Kingdom Tel: +44 (0)1923 284151, Fax: +44 (0)1923 285840, E-mail: [email protected] www.projectseahorse.org Fisheries Centre, University of British Columbia 2204 Main Mall, Vancouver BC, V6T 1Z4, Canada Tel: +1 604-827-5139 Fax: +1 604-827-5199 E-mail: [email protected] HEAD coronet eye spine nose spine snout cheek spine keel trunk ring anal fin inferior trunk ridge brood pouch (males only) first tail ring dorsal fin pectoral fin gill opening first trunk ring T R U N K T A I L Seahorse Distribution Seahorse Anatomy Credit: Paulo Machado
Transcript of Seahorse 13 Qep - La Tene Maps
Current Issues
Life Cycle of the
Seahorse
Seahorses, belonging to the family Syngnathidae, are the most unusual and arguably the most interesting of fish. More than 30 species of those with the scientific name Hipppocampus are consid-ered true seahorses. Other syngnathids include pipefishes, pipehorses and sea dragons. Seahorses range in size from a few centimetres to 30 centimetres and are found in shallow waters aroundthe world from temperate to tropical regions. However most species live in tropical or subtropical areas in waters that range in depth from 5 metres to more than 100 metres. In Europe,Hippocampus hippocampus and Hippocampus guttulatus are the most common species. They can be found in shallow seagrass beds in the coastal areas of Europe. Subtropical and tropicalspecies are found mainly in and around coral reefs, mangroves and estuaries.
Seahorse imagery has been a decorative motif from the earliest civilisations to the present day, appearing on coins, pottery, jewellery, and in books and film. They are fished commercially to meetdemand from traditional medicine markets in Asia as treatments for a wide range of ailments, as well as for the souvenir and aquarium markets. Overfishing, incidental bycatch and damage tohabitat are the main factors responsible for declines in seahorse populations. Seahorses are seen as a flagship species for the marine environment, meaning that the attention drawn to their con-servation should have a beneficial effect for other species and preservation of the marine environment in general.
The two main conservation strategies for the seahorse may be viewed as protecting seahorse habitat and curbing the demand on wild populations. Habitat protection may be achieved throughcontrols on fishing methods and the establishment of marine protected areas. Curbing demand on wild populations is possible through regulation of trade, improved management regimes, theintroduction of alternative livelihoods for fishers, and through cultured supply. Most seahorse species are included on the IUCN – World Conservation Union’s Red List of Threatened Species, primarily classified as either Vulnerable or Data Deficient. High levels of global exploitation of seahorses have lead to the addition of all species to Appendix II of the Convention on InternationalTrade in Endangered Species of Wild Fauna and Flora. The list requires that more than 160 nations ensure their seahorse exports are sustainable. Attempts have been made to grow seahorsescommercially by aquaculture methods in many countries around the world, including China, Australia, New Zealand and Ireland; some of these are beginning to show promise.
La Tene Maps acknowledges the help and support received in the preparation of this poster from Project Seahorse, Canada; Tropical Marine Centre, United Kingdom; and Seahorse Ireland. Produced by La Tene Maps Copyright © AquaTT 2004.
www.aquatt.ie
AquaTT, P.O. Box 8989, Dublin 2, Ireland. Tel: +353 1 644 9008, Fax: +353 1 644 9009,
E-mail: [email protected]
COURTSHIPSeahorses mate after an elaboratecourtship that involves entwined tails,colour changes and dances. Sometimesseveral males compete for a chance tomate with a female or vice versa. Malescan inflate their pouch to entice the femaleto deposit her eggs in it. In many speciesseahorses remain faithful to one partnerfor at least the duration of the breedingseason.
JUVENILESNewly released young undergo few changes afteremerging from the father. During growth, some bodyproportions may change while juveniles develop maturegonads, but they experience no further major bodychanges. Some newborns emerge with a small caudalfin (e.g. H. mohnikei), which is lost over time.
EGG TRANSFER After courtship, which can last manyhours, the female deposits her eggs in themale’s pouch. The number of eggs trans-ferred varies by species and female.Once safely deposited in the pouch, theeggs are fertilised by the male and thepouch is sealed.
YOUNGNewborns measure 2-12 mm, depend-ing on species. The number of youngreleased averages between 100 and200 for most species, but can be as lowas 5 for the smaller species, or morethan 1,500 for larger species.Hatchlings will often grasp floating orattached objects, including artificialstructures and each other, with theirprehensile tails. Some species have apelagic stage when born, which meansthat their movement is influenced by theprevailing tides and currents.
The Seahorse
BIRTHSeahorses are renowned for the fact that it is themale who gives birth. When he is ready torelease the developing young, the male under-goes muscular contractions to expel the young,known as fry, from the pouch.
This poster is one of a series produced by the PISCESproject. PISCES was realised through the financial sup-port of the Commission of the European Communitiesunder the LEONARDO DA VINCI PROGRAMME andindustry sposors. The content of this poster does not nec-essarily represent the opinions of the Commission.
PISCES is coordinated by AquaTT, the European Networkfor Education and Training in Aquaculture. The aims of theproject relate to promoting careers in aquaculture throughpromoting the industry and training opportunities. Themain deliverables of the project are an online multilingualaquaculture forum for European education and trainingand a series of educational lifecycle posters. All productsare available on the project website; www.piscestt.com.
This poster was supported by Project Seahorse, an interna-tional and interdisciplinary marine conservation organization.Its biologists and development specialists conduct fundamen-tal biological research, empower communities, establishmarine protected areas, manage subsistence fisheries,restructure international trade, advance environmental educa-tion, promote integrated policy, and redress habitat loss.
The Project Seahorse team is composed of members global-ly, working in Australia, Canada, Hong Kong, Philippines,Portugal, U.K., and U.S.A. Projects have also been managedin South Africa and Vietnam, with collaborations in many morecountries. It is headquartered in Vancouver, B.C., at theUniversity of British Columbia's Fisheries Centre. Project Seahorse has published a book: Seahorses: A Guideto the World’s Species and Their Conservation, by Lourie,Vincent and Hall 1999.
Tropical Marine Centre was set up in 1970 and since thattime has established itself as the leading wholesale suppli-er of marine fish to the trade in Europe and a pioneer of fil-tration and UV sterilising equipment for all sizes of pondsand aquariums both domestic and commercial. The com-pany operates three aqaurium based facilities outsideLondon, Manchester and Bristol, which include Europe'sonly commercial reef fish hatchery.
TMC has established an outstanding reputation for promot-ing and fostering the welfare of livestock from capture andbreeding through to handling and transportation.
TMC-Publishing has published a book on Seahorses:Seahorses, Pipefishes and Their Relatives: AComprehensive Guide to Syngnathiformes by Rudie HKulter. See www.tmc-publishing.com for further details.Tropical Marine Centre Ltd is a subsiduary of Cranswickplc.
ADULTSexual maturity in males is usuallyinferred by the presence of a broodpouch. Mature male seahorses are able tobecome pregnant any time during thebreeding season, which varies withspecies, and is thought to be influencedby environmental conditions such aswater temperature.
Seahorse TradingSeahorses are highly sought after by the tradition-al medicine, live aquarium and souvenir markets.The demand has put pressure on wild populations,prompting regulations for the international trade.
Captive BreedingCaptive breeding may be part of a solution to helpalleviate overexploitation of wild stocks. Sufficientspace, the availability of the correct food and sur-roundings that resemble the natural environmentcontribute to successful breeding.
Farming SeahorsesFarming seahorses for commercial purposes is sofar restricted to just a few species. Due to a simpledigestive system, seahorses must consume largeamounts of food and so a relatively large amountof live feed is required. Although it is possible toraise seahorses on frozen food, most only eat liveanimals, and farms must enrich zooplankton feedwith microalgae to provide the correct nutritionalbalance.
Habitat LossCoastal developments near estuary channels, sea-grass beds or mangroves have an immediateeffect on local seahorse numbers. Other environ-mental threats to the seahorse include turbulenceand loss of vegetation that provides shelter andsupports crustacean breeding, the main foodsource for most seahorse species.
Hippocampus brevicepsThe Short-head Seahorse is found mainlyalong seagrass edges and sometimes on thesponge reefs of Australia's southern coast.
Hippocampus comesThe Tiger Tail Seahorse is found in S.E. Asianwaters on shallow coral reefs and sponge gar-dens, kelp and other floating algae. H. comes is a potential aquaculture species.
Hippocampus guttulatusThe Long-snouted Seahorse can be foundalong Atlantic, Mediterranean and Algeriancoasts, in shallow algal strands and rockyareas in winter.
Hippocampus subelongatusThe Western Australian Seahorse is found pri-marily along the edges of rocky areas, inmuddy sea-bottoms, and is commonly asso-ciated with sponges or sea squirts.
Hippocampus bargibanti The Pygmy Seahorse is found in coral reefs inthe west Pacific, in the waters betweenAustralia and Indonesia and along the south-ern coast of Japan.
PREGNANCYConditions in the pouch are controlled by themale, who also provides oxygen and nutrientsthrough a network of capillaries in the pouch. Theembryos will remain in the pouch for two to sixweeks, depending on species and temperature asthey develop into fully formed juveniles. The nutri-ents provided by the female influence the initial-conditions in the pouch.
Decline in Wild StocksSeahorse numbers in many exploited populationsare estimated to have declined by 15–50%between 1990 and 1995. Since this period thedemand for seahorses has increased substantially.Due to the drastic fall in numbers, more extensiveareas are being exploited for seahorses.
www.tmc-ltd.co.ukTropical Marine Centre Ltd,
Solesbridge Lane, Chorleywood,Herefordshire WD3 5SX, United Kingdom
Tel: +44 (0)1923 284151, Fax: +44 (0)1923 285840, E-mail: [email protected]
www.projectseahorse.orgFisheries Centre, University of British Columbia
2204 Main Mall, Vancouver BC, V6T 1Z4, Canada
Tel: +1 604-827-5139Fax: +1 604-827-5199
E-mail: [email protected]
HEAD
coroneteye spinenose spine
snout
cheek spine
keel
trunk ring
anal fin
inferior trunk ridge
brood pouch(males only)
first tail ring
dorsal fin
pectoral fin
gill opening
first trunk ring
TRUNK
TAIL
Seahorse Distribution
Seahorse Anatomy
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dit:
Pau
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