The pygmy seahorses comprise several species of tiny
seahorse
A seahorse (also written ''sea-horse'' and ''sea horse'') is any of 46 species of small marine fish in the genus ''Hippocampus''. "Hippocampus" comes from the Ancient Greek (), itself from () meaning "horse" and () meaning "sea monster" or " ...
in the
syngnathid
The Syngnathidae is a family of fish which includes seahorses, pipefishes, and seadragons (''Phycodurus'' and ''Phyllopteryx''). The name is derived from grc, σύν (), meaning "together", and (), meaning "jaw". The fused jaw is one of the tra ...
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
or
Syngnathidae
The Syngnathidae is a family of fish which includes seahorses, pipefishes, and seadragons ('' Phycodurus'' and '' Phyllopteryx''). The name is derived from grc, σύν (), meaning "together", and (), meaning "jaw". The fused jaw is one of the ...
(seahorses and pipefish). Family Syngnathidae is part of order Syngnathiformes, which contains fishes with fused jaws that suck food into tubular mouths. They are found in Southeast Asia in the Coral Triangle area. They are some of the smallest seahorse species in the world, typically measuring less than in height.Lourie, S.A., Foster, S.J., Cooper, E.W.T. and Vincent, A.C.J. (2004) ''A Guide to the Identification of Seahorses.'' Project Seahorse and TRAFFIC North America, Washington D.C..Bargibant's seahorse Accessed 2012-11-02.
The first pygmy seahorse known to science was '' Hippocampus bargibanti''. At least six more species were named after 2000. The first species discovered lives exclusively on fan corals and matches their colour and appearance. So effective is pygmy seahorse camouflage that it was discovered only when a host gorgonian was being examined in a laboratory. In 1969 a New Caledonian scientist, Georges Bargibant, was collecting specimens of Muricella spp gorgonians for the
Nouméa
Nouméa () is the capital and largest city of the French special collectivity of New Caledonia and is also the largest francophone city in Oceania. It is situated on a peninsula in the south of New Caledonia's main island, Grande Terre, an ...
museum and whilst one of these was on his dissection table he happened to notice a pair of tiny seahorses. The next year they were officially named by Whitley as Bargibant's pygmy seahorse.Smith, Richard E Hippocampus bargibanti Other species live on soft corals or are free-ranging among seagrasses and algae.Reijnen, B.T., van der Meij, S.E.T., van Ofwegen, L.P. (2011) "Fish, fans and hydroids: host species of pygmy seahorses." ''ZooKeys'' 103: 1-26.
Description
The pygmy seahorse is both tiny and well
camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...
d. It is very difficult to spot amongst the
sea grass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families ( Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the ...
es,
soft coral
Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different f ...
s, or gorgonians (sea fans) that it inhabits. Other distinctive pygmy seahorse characteristics include a fleshy head and body, a very short snout, and a long, prehensile tail. With their short snouts, they have the appearance of baby animals. Pygmy seahorses are long from the tip of the tail to the end of the snout, so that their vertical height while swimming is still smaller.Smith, Richard E Pygmy seahorse research /ref> An adult may be as small as long.Fishes of Australia: ''H. bargibanti'' Accessed 2012-11-02.
True pygmy seahorses have distinctive morphological markers. Unlike other seahorses, they have a single gill opening on the back of the head, instead of two on the sides.
Males and females are distinguished by openings at the bottom of the trunk: females have a tiny, raised round pore for extruding eggs and males have a fore-and-aft slit for accepting them.
Similarly to the rest of seahorses, males brood their young in a pouch on their trunk.
Species
The known species are these:
* Bargibant's pygmy seahorse ('' Hippocampus bargibanti'') are always found on gorgonian corals of the genus Muricella, and live their whole adult life on a single coral. Their colour varies, seeming to match the coral that they live on: pink, yellow, lavender, or brown. They are the largest pygmy seahorse at almost 2.7 cm. They have the largest range: "from southern tropical Japan, throughout the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
,
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
, east to
Palau
Palau,, officially the Republic of Palau and historically ''Belau'', ''Palaos'' or ''Pelew'', is an island country and microstate in the western Pacific. The nation has approximately 340 islands and connects the western chain of the Ca ...
,
Papua New Guinea
Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...
,
Solomon Islands
Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its ca ...
Vanuatu
Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...
and the
Great Barrier Reef
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
in Australia."Smith, Richard E ''Hippocampus bargibanti'' Accessed 2012-10-31. They are found at 16-40m depth.Common Pygmy Seahorse Accessed 2012-10-31.
* Denise's pygmy seahorse ('' Hippocampus denise'') was described in 2003. Its range is from
Borneo
Borneo (; id, Kalimantan) is the List of islands by area, third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java Isl ...
to
New Guinea
New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...
, Solomon Islands and Palau. They must live on gorgonian corals but have been found on eight different genera: ''
Acanthogorgia
''Acanthogorgia'' is a genus of corals belonging to the family Acanthogorgiidae
Acanthogorgiidae is a family of cnidarians belonging to the order Alcyonacea.
Genera:
* '' Acanthogorgia'' Gray, 1857
* '' Anthogorgia'' Verrill, 1868
* '' Ascolepi ...
,
Annella
''Annella'' is a genus of soft corals belonging to the family Subergorgiidae.
Species
* ''Annella mollis
''Annella mollis (Subergorgia mollis)'' is a species of soft corals belonging to the family Subergorgiidae. They live in areas in the ...
,
Echinogorgia
''Echinogorgia'' is a genus of corals belonging to the family Plexauridae.
The species of this genus are found in Pacific and Indian Ocean.
Species
Species:
*''Echinogorgia abietina''
*''Echinogorgia armata''
*''Echinogorgia aurantiaca
...
Melithaea
''Melithaea'' is a genus of octocorals in the family Melithaeidae. Members of the genus are commonly known as fan corals and are found in the tropical Indo-Pacific region. The type species is ''Melithaea ochracea''.Muricella, Verrucella'' and ''
Villogorgia
''Villagorgia'' is a genus of gorgonian-type Octocorallia, octocorals in the Family (biology), family Plexauridae.
Species
The World Register of Marine Species lists these species:
References
Plexauridae
Octocorallia genera
{{octocor ...
''. Each pygmy seahorse stays on the same coral for its entire adult life. The young settle onto a host and over a few days take on its exact colour and texture, accounting for the wide variation in adults, but typically red, orange, or yellow. They grow up to 2.4 cm long.Smith, Richard E ''Hippocampus denise'' Accessed 2012-10-31. They have smooth skin with few tubercles. They have a bent, asymmetrical appearance. Females have a slender body with a small bulge at the base of the trunk, while males are rounder. They are found at depths of 13–90m. Underwater photographer Denise Tackett noticed that they were different from ''H. bargibanti'' and brought them to the attention of scientists.Denise's Pygmy Seahorse Accessed 2012-10-31.
* Pontoh's pygmy seahorse ('' Hippocampus pontohi'') was named in 2008. This species is free-living, not associated with gorgonian corals, and tends to live in shallower water (3m - 20m). They are found in the Coral Triangle area: Indonesia, Papua New Guinea, Solomon Islands and Fiji. They can be found anywhere on tropical reefs in their range. However, they are most often seen in pairs or small groups in clumps of the calcareous alga, ''
Halimeda
''Halimeda'' is a genus of green macroalgae. The algal body (thallus) is composed of calcified green segments. Calcium carbonate is deposited in its tissues, making it inedible to most herbivores. However one species, ''Halimeda tuna'', was desc ...
''Smith, Richard E ''Hippocampus pontohi'' Accessed 2012-10-31. and on the hydroid ''Aglaephenia cupressina.'' They are often found where ''Halimeda'' grows out of reef walls. Divers report them on many types of seagrass and algae, moving frequently to different hitching spots.Weedy Pygmy Seahorse Accessed 2012-10-31. They are almost identical in shape to the Severn's pygmy seahorse, but are a different colour: white with pink or yellow patches. They lack tubercules. The trunk is round but thin when viewed from behind. They are seen in high-current areas at depths of 11-25m.
* Satomi's pygmy seahorse ('' Hippocampus satomiae''), named in 2008, are the world's smallest seahorse at up to 1.4 cm. This is a free-living species that is found near coral walls with
soft corals
Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different f ...
. They are nocturnal and very active at night. They have been found in only a few places in Indonesia and northern Borneo. They can be brown to pale with specific markings such as a dark spot in front of each relatively large eye.Smith, Richard E ''Hippocampus satomiae'' Accessed 2012-10-31. Spines cover the entire body. Both males and females have a round trunk. They are found from 15 – 20 meters deep in groups of 3 to 5.Satomi's Pygmy Seahorse Accessed 2012-10-31.
* Severn's pygmy seahorse (''
Hippocampus severnsi
''Hippocampus severnsi'' (Severn's pygmy seahorse) is a synonym of ''Hippocampus pontohi
''Hippocampus pontohi'', also known as Pontoh's pygmy seahorse or the weedy pygmy seahorse, is a seahorse of the family Syngnathidae native to the central ...
'') is a free-living species described in 2008. They are almost the same shape as Pontoh's pygmy seahorse, but are a different colour: pale brown with red and orange patches. They can be found on any part of the reef, but often on hydroids and
algal turf
Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from un ...
in pairs or small group. They are no larger than 1.7 cm.Smith, Richard E ''Hippocampus severnsi'' Accessed 2012-10-31.
* Walea soft coral pygmy seahorse ('' Hippocampus waleananus'') lives on and around
soft coral
Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different f ...
. The soft coral have fat stems and this seahorse has a correspondingly long tail. They vary from pale pink to yellow. It has a very small range: it lives only in the Tomini Gulf of central Sulawesi, Indonesia, and depends on the continued existence of soft corals there.Smith, Richard E ''Hippocampus waleananus'' Accessed 2012-10-31.
* Coleman's pygmy seahorse ('' Hippocampus colemani'') is probably restricted to
Lord Howe Island
Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland ...
off the east coast of Australia. However, there are unconfirmed reports from eastern Papua New Guinea and
Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the northe ...
. This pygmy seahorse was found in the lagoon of Lord Howe Island living on seagrass, mainly ''
Zostera
''Zostera'' is a small genus of widely distributed seagrasses, commonly called marine eelgrass, or simply seagrass or eelgrass, and also known as seaweed by some fishermen and recreational boaters including yachtsmen. The genus ''Zostera'' con ...
'' and '' Halophila.'' It was described in 2003. It is white, yellow, or gold with white spots outlined in red. It has a very small snout and well-defined nose spine. Both males and females are rotund.Coleman's Pygmy Seahorse Accessed 2012-10-31.
* Japanese pygmy seahorse (''
Hippocampus japapigu
The Japanese pygmy seahorse (''Hippocampus japapigu'') is a Japanese species of seahorse in the family Syngnathidae. It is also sometimes known as the Japan pig.
Distribution and habitat
It lives in Northwestern Pacific near Japan, and lives ...
'') First described in April 2018. One of the more diminutive species of the genus, the species reaches around 16mm in length. Uniquely among seahorses, the species has a dorsal ridge of triangular bony mounds. It is native to soft coral and algal reefs around Japan. This Pygmy seahorse was founded by Dr.Graham Short and his colleagues who attend the California Academy of Sciences. They represent the fifth species of Pygmy seahorse that has been recorded in Japan.
* Sodwana pygmy seahorse ('' Hippocampus nalu'') is the second most recently described species.
Other dwarf species
Other small seahorses are sometimes called pygmy seahorses, but lack the single gill opening and trunk brooding that distinguish the true pygmy seahorse. They can be called dwarf seahorses:
* Red Sea soft coral pygmy seahorse, ''
Hippocampus debelius
''Hippocampus debelius'', commonly known as the softcoral seahorse, is a species of marine fish of the family Syngnathidae. It is known from only two specimens collected from the Gulf of Suez in the Red Sea, at depths of . Individuals were found ...
'',
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...
to the
Red Sea
The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...
* Bullneck seahorse, '' Hippocampus minotaur'', from southeast Australia
* Paradoxical seahorse, '' Hippocampus paradoxus'', from southwest Australia
* Manaia pygmy pipehorse (''
Cylix tupareomanaia
''Cylix tupareomanaia'', named the Manaia pygmy pipehorse, is a species of syngnathid, the family of seahorses and pipefish. The species is found temperate coastal waters of New Zealand, at Taitokerau Northland and the inshore islands, Pēwhaira ...
'') found in
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...
waters has been given an indigenous scientific name and the Ngātiwai iwi (tribe) listed as a naming author.