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{{Short description|Species of |
{{Short description|Species of lizard}} |
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{{Speciesbox |
{{Speciesbox |
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| image = Philippine Sailfin Dragon.jpg |
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| image_caption = Wild Philippine sailfin lizard in [[Leyte]] |
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| status = LC |
| status = LC |
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| status_system = IUCN3.1 |
| status_system = IUCN3.1 |
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| status_ref = <ref name=IUCN/> |
| status_ref = <ref name=IUCN/> |
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| ⚫ | |||
| ⚫ | |||
| genus = Hydrosaurus |
| genus = Hydrosaurus |
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| species = pustulatus |
| species = pustulatus |
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| authority = ([[Johann Friedrich von Eschscholtz|Eschscholtz]], 1829) |
| authority = ([[Johann Friedrich von Eschscholtz|Eschscholtz]], 1829) |
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| range_map = |
| range_map = |
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}} |
}} |
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'''''Hydrosaurus pustulatus''''', commonly known as the '''Philippine sailfin lizard''' or the '''Philippine sailfin dragon''', is a large [[semiaquatic]] [[agamid]] lizard [[endemic]] to all of the major island groups of the [[Philippines]], with the exception of the [[Palawan]] islands.<ref name=repdb>[http://reptile-database.reptarium.cz/species.php?genus=Hydrosaurus&species=pustulatus&search_param=%28%28genus%3D%27Hydrosaurus%27%2Cexact%29%29 ''H. pustulatus''], The Reptile Database</ref><ref name=IUCN/><ref name="Siler"/><ref name="LvlZoo">{{cite web |url=https://louisvillezoo.org/animalsandplants/lizard-philippine-sailfin/ |website=Louisville Zoo |access-date=5 November 2021 | title=Lizard, Philippine Sailfin|date=19 December 2014 }}</ref> Like other [[sailfin lizard]]s, they are characterized by large sail-like dorsal crests on their tails. They can grow to a maximum length of around {{convert|3|to|4|ft|m|abbr=on}}. They are strong swimmers, and smaller juvenile lizards can run briefly on the water surface. They inhabit areas of heavy vegetation near coastlines and low-lying rivers, particularly in [[mangrove forest]]s.<ref name="Siler">{{cite journal |last1=Siler |first1=Cameron D. |last2=Lira-Noriega |first2=Andrés |last3=Brown |first3=Rafe M. |title=Conservation genetics of Australasian sailfin lizards: Flagship species threatened by coastal development and insufficient protected area coverage |journal=Biological Conservation |date=January 2014 |volume=169 |pages=100–108 |doi=10.1016/j.biocon.2013.10.014}}</ref> They are also known locally as '''{{lang|tl|layagan}}''' or '''{{lang|tl|balubid}}''' in [[Tagalog language|Tagalog]] and '''{{lang|ceb|ibid}}''' in the [[Visayan languages]], among other names.<ref name="pp">{{cite news |title=Third Quarter Topical Issue – Philippine Endemic Lizards |url=https://archive.today/20131212134244/https://www.phlpost.gov.ph/whats-happening.php?id=1391#selection-371.0-371.56 |access-date=16 January 2024 |work=PhlPost |date=20 July 2011}}</ref><ref>{{cite news | last = Mascariñas | first = Erwin M. | title = PH sailfin lizards in Misamis Oriental: An unusual case of a community lizard | publisher = [[ABS-CBN]] | quote="We are now finalizing the steps to have this area along the lower Solana River in the town of Misamis Oriental declared as a critical habitat for the ''Hydrosaurus pustulatus'' or the Philippine Sailfin Lizard commonly known as ''ibid''." | date = 2 June 2018 | url = https://news.abs-cbn.com/focus/06/02/18/ph-sailfin-lizards-in-misamis-oriental-an-unusual-case-of-a-community-lizard | access-date = 11 February 2021}}</ref> |
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The '''Philippine sailfin lizard''' ('''''Hydrosaurus pustulatus'''''),<ref>[http://reptile-database.reptarium.cz/species.php?genus=Hydrosaurus&species=pustulatus&search_param=%28%28genus%3D%27Hydrosaurus%27%2Cexact%29%29 ''H. pustulatus''], The Reptile Database</ref> also known as '''crested lizard''', '''sail-fin lizard''', '''sailfin water lizard''', '''soa-soa water lizard'''<ref name=IUCN/> or its native name '''''ibid''''',<ref>{{cite news | last = Mascariñas | first = Erwin M. | title = PH sailfin lizards in Misamis Oriental: An unusual case of a community lizard | publisher = [[ABS-CBN]] | quote="We are now finalizing the steps to have this area along the lower Solana River in the town of Misamis Oriental declared as a critical habitat for the ''Hydrosaurus pustulatus'' or the Philippine Sailfin Lizard commonly known as ''ibid''." | date = 2 June 2018 | url = https://news.abs-cbn.com/focus/06/02/18/ph-sailfin-lizards-in-misamis-oriental-an-unusual-case-of-a-community-lizard | accessdate = 11 February 2021}}</ref> is an [[oviparous]] lizard [[endemic]] to several of the islands that make up the [[Philippines]] and is also found in New Guinea and some parts of eastern Indonesia.<ref name="LvlZoo">{{cite web |url=https://louisvillezoo.org/animalsandplants/lizard-philippine-sailfin/ |website=Louisville Zoo |access-date=5 November 2021 | title=Lizard, Philippine Sailfin|date=19 December 2014 }}</ref> The Philippine Sailfin Lizard is a protected species in its native country of the Philippines as it is a target for exotic pet collectors and sought after in the international pet trade.<ref name="Monitor">{{cite web |title=Endemic Philippine Sailfin Lizard threatened by illegal wildlife trade |url=https://mcrsociety.org/2021/06/01/endemic-philippine-sailfin-lizard-threatened-by-illegal-wildlife-trade/ |website=Monitor Conservation Research Society |date=June 2021 |publisher=Monitor |access-date=5 November 2021}}</ref> This is largely because these lizards have unique dorsal crests (otherwise known as sailfins) that give the organism a structure similar to a sail, and the Philippine sailfin lizard also has very bright coloration patterns that make them attractive to the eye.<ref name="Siler2014" /> The pustulatus species is unique within the Hydrosaurus genus because of the confusion for the past several decades of classifying these organisms amongst other lizards within their same genus in their habitat. They are also very talented swimmers, and smaller juvenile lizards can run on top of water due to their bodily structure. The genus Hydrosaurus means water dragon, which reflects the aforementioned abilities lizards have in water. The Philippine sailfin lizard usually lies close to bodies of water, stays in tree branches, and runs across the ground to get around their habitat. They utilize their sailfins/scales to do territorial displays in the presence of a competitor or a predator. In terms of their reproduction, they utilize sexual reproduction and breed one time each year, but they can produce multiple clutches of eggs with between 2 and 8 eggs. These eggs are buried into the soil for a period of two months before hatchlings are produced. Philippine sailfin lizards are heavily studied by herpetologists and other scientists, as they are unique amongst other reptile lizards with regard to their coloration and form. |
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''H. pustulatus'' is a protected species in the Philippines, as it is a target for the international exotic pet trade for their unique dorsal crests and bright coloration.<ref name="Monitor">{{cite web |title=Endemic Philippine Sailfin Lizard threatened by illegal wildlife trade |url=https://mcrsociety.org/2021/06/01/endemic-philippine-sailfin-lizard-threatened-by-illegal-wildlife-trade/ |website=Monitor Conservation Research Society |date=June 2021 |publisher=Monitor |access-date=5 November 2021}}</ref><ref name="Siler"/> The heavy deforestation of mangrove habitats in the last few decades is also a concern to their conservation.<ref name="Siler"/> |
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==History and taxonomy== |
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| ⚫ | |||
==Taxonomy== |
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==Habitat and distribution== |
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| ⚫ | ''Hydrosaurus pustulatus'' was first described as ''Istiturus pustulatus'' in 1829 by the [[Baltic German]] [[naturalist]] [[Johann Friedrich von Eschscholtz]]. The specimens were collected from [[Luzon]], Philippines, by Eschscholtz during the circumnavigational voyage of the [[Russian Empire|Imperial Russian]] expeditionary ship ''Predpriaetie'' from 1823 to 1826.<ref name=repdb/><ref>{{cite book |last1=Eschscholtz |first1=Johann Friedrich |last2=Rathke |first2=Heinrich |url=https://www.biodiversitylibrary.org/bibliography/152182 |title=Zoologischer Atlas |location=Berlin |publisher=Gedruckt und Verlegt bei G. Reimer |date=1829 |doi=10.5962/bhl.title.152182 |access-date=5 November 2021}}</ref> It is one of five species currently recognized under the genus ''[[Hydrosaurus]]'', the sailfin dragons, and the only species found in the Philippines (the other species are native to [[Indonesia]] and [[Papua New Guinea]]).<ref name="Siler"/><ref name="Zootaxa">{{cite journal |last1=DENZER |first1=WOLFGANG |last2=CAMPBELL |first2=PATRICK |last3=MANTHEY |first3=ULRICH |last4=GLÄSSER-TROBISCH |first4=ANDREA |last5=KOCH |first5=ANDRÉ |url=https://www.biotaxa.org/Zootaxa/article/view/zootaxa.4747.2.3|title=Dragons in neglect: Taxonomic revision of the Sulawesi sailfin lizards of the genus Hydrosaurus Kaup, 1828 (Squamata, Agamidae) |journal=Zootaxa |date=3 March 2020 |volume=4747 |issue=2 |pages=zootaxa.4747.2.3 |doi=10.11646/zootaxa.4747.2.3 |pmid=32230109 |s2cid=214748049 |access-date=5 November 2021}}</ref> |
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| ⚫ | The Philippine sailfin lizard is found |
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''Hydrosaurus pustulatus'' is highly variable in terms of coloration and scale patterns across geographic populations. A genetic study in 2014 has discovered that ''H. pustulatus'' is divided into six distinct genetic clusters. The most divergent of the group are the populations in [[Aurora Province|Aurora]], [[Luzon]] and the [[Polillo Islands]].<ref name="Siler"/> |
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==Distribution and habitat== |
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| ⚫ | The Philippine sailfin lizard is found throughout the Philippine islands with the exception of the [[Palawan]] islands. Populations of Philippine sailfin lizards have been documented in [[Luzon]] ([[Aurora province|Aurora]], [[Bicol Region|Bicol]]), [[Polillo Islands]], [[Samar]], [[Leyte]], [[Dinagat Islands]], [[Camiguin]], [[Bohol]], [[Negros Island|Negros]], [[Panay]], [[Romblon]] ([[Romblon Island|Romblon]], [[Tablas Island|Tablas]], [[Sibuyan Island|Sibuyan]]), [[Mindoro]], and [[Mindanao]] ([[Zamboanga Peninsula|Zamboanga]]).<ref name="Siler"/><ref name="Bion">{{cite web |last1=Neizhko |first1=I |last2=Marchevskaya |first2=E |last3=Marushchak |first3=O |last4=Troshchinkova |first4=Yu |title=SAILFIN LIZARD (HYDROSAURUS PUSTULATUS), (ESCHSCHOLTZ, 1829) |url=https://bion.com.ua/news_article/sailfin-lizard-hydrosaurus-pustulatus-eschscholtz-1829-care-sheet/ |website=BION TERRARIUM CENTER |publisher=BION TERRARIUM CENTER |access-date=5 November 2021}}</ref> The Philippine sailfin lizard lives in [[tropical]] wooded habitats near water, like [[river]]s, riverbanks, rice-fields and [[mangrove]].<ref name=IUCN/> The Philippine sailfin lizard also lives in moderately high densities in these habitats.<ref name="Siler"/> The Philippine sailfin lizard also prefers the bodies of water that they reside nearby being freshwater.<ref name="Bion" /><ref name=IUCN>{{cite iucn |author=Ledesma, M. |author2=Brown, R. |author3=Sy, E. |author4=Rico, E. |author5=Binaday, J. |author6=Lagat, R. |author7=Pitogo, K. |author8=Santos, G. |author9=dela Cruz, C. |author10=Lorenzo, A. |author11=Sarmiento, M. |author12=Maglangit, E.P. |year=2022 |title=''Hydrosaurus pustulatus'' |volume=2022 |page=e.T190349178A180276751 |doi=10.2305/IUCN.UK.2022-2.RLTS.T190349178A180276751.en |access-date=12 October 2023}}</ref> |
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==Behavior and appearance== |
==Behavior and appearance== |
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Philippine sailfin lizards are large and usually grow to a length between two and three feet, including its tail, but males are larger than females and can grow up to between 3 and 4 feet long (91–120 centimeters).<ref name="LvlZoo" /> These lizards typically weigh between 3 and 5 pounds (1.4–2.3 kg).<ref name="Care">{{cite web |last1=Corning |first1=Scott |title=Sailfin Dragon Care Sheet |url=https://reptilesmagazine.com/sailfin-dragon-care-sheet/ |website=Reptiles |date=6 December 2011 |publisher=Reptiles Magazine |access-date=5 November 2021}}</ref> Additionally, this species of lizard has a unique characteristic being its crest or sailfin, which is an upright part of its body that occurs from the base of the tail to the lower area of the back.<ref name="Faulkner">{{cite web |last1=Faulkner |first1=Tim |title=Philippine Sailfin Lizard |url=http://www.timfaulkner.com.au/wildlifefacts/philippine-sailfin-lizard/ |website=Tim Faulkner |publisher=Talk Agency |access-date=5 November 2021}}</ref> This crest or sailfin is used not only to help with its ability to swim efficiently in water, but is also thought to assist with the lizard's ability to do territorial displays and heat/cool in different environments.<ref name="Faulkner" /> The crest also makes the Philippine sailfin lizard's body look like a sail with regard to its structure. Overall, the body and tail of the Philippine sailfin lizard is largely cylindrical.<ref name="Bion" /> |
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The juvenile Philippine sailfin lizard is an excellent swimmer and has flattened toes along with smaller mass compared to adults that enable it to run across water, [[Basiliscus (genus)#Running on water|similar to the basilisks]].<ref>Jackman Bauer (2008). Global diversity of lizards in freshwater (Reptilia: Lacertilia). Hydrobiologia 595(1): 581–586.</ref> The adult Philippine sailfin lizard does not usually retain a smaller mass and loses the ability to run across water, but it uses these flattened toes to swim very effectively. The flattened toes also have scale fringes that can be used for swimming and running on top of water as mentioned before.<ref name="Oregon">{{cite web |title=Philippine sailfin lizard |url=https://www.oregonzoo.org/discover/animals/philippine-sailfin-lizard |website=Oregon Zoo |publisher=Oregon Zoo |access-date=5 November 2021}}</ref> Males have a larger crest on their back than the females. The males also have bigger heads, taller sails on their tails, and darker limbs. During mating season, the head of the Philippine sailfin lizard becomes violet while only the neck area of a female's crest can become violet.<ref name="Bion" /> In terms of coloration, Philippine sailfin lizards have dark green and brown skin, and can also have yellow patches on the back side of their body and near their heads.<ref name="Bion" /> |
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The Philippine sailfin lizard has a flattened tail that is used to propel in water more quickly, adding to its natural born ability to be agile and swift in water to evade prey.<ref name="Faulkner" /> In the presence of predators, the Philippine sailfin lizard either drops from the tree branch it is residing on, runs, or swims to the bottom of the body of water it is closest to and can hold its breath for up to 15 minutes.<ref name="Faulkner" /> Philippine sailfin lizards are also diurnal and spend most of the day time resting in vegetation out in the sun.<ref name="Bion" /> In general, the Philippine sailfin lizard utilizes running to move around its habitats and away or toward predators and competitors, and their lifespan can be anywhere between 10 and 20 years.<ref name="Care" /> The Philippine sailfin lizard also has a unique physical feature being a vestigial eye (which is also known as parietal or pineal eye) on the top of the lizard's skull that can detect differing angles of light from the sun and is thought to be used to find a sense of direction.<ref name="Oregon" /> |
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==Life cycle and reproduction== |
==Life cycle and reproduction== |
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Philippine sailfin lizards |
Philippine sailfin lizards utilize their sailfins/scales for territorial displays in the presence of competing males or threats. They only breed once every year with potentially multiple clutches of eggs.<ref name="Bion" /> For female Philippine sailfin lizards to lay their eggs after mating and birth, they dig relatively shallow holes in soil near their watery-habitats, and these eggs then incubate for approximately two months.<ref name="Faulkner" /> The eggs then eventually become hatchlings during the rainy season, which actually are born with a natural swiftness and agility that allows them to evade their predators by running across the water unlike adult lizards that swim. These female Philippine sailfin lizards are able to lay several clutches of eggs a year that each can contain anywhere between 2 and 8 eggs.<ref name="Faulkner" /> It is also important to note that these eggs are laid above the flood line.<ref name="Bion" /> |
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==Conservation== |
==Conservation== |
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Philippine sailfin lizards are classified as [[Least Concern]] by the [[IUCN]], though they are increasingly becoming vulnerable.<ref name=IUCN/><ref name=Siler/> Their main threats are [[habitat loss]], being hunted for food, and collection for the pet trade.<ref name=IUCN/> Habitat loss is particularly critical, as only an estimated 7.5% of the [[mangrove forest]]s of the Philippines are in [[List of protected areas of the Philippines|protected areas]]. Over the last 75 years, 75% of the mangrove forests of the Philippines have been lost, mainly due to the repurposing of the land for [[urban development]] and [[aquaculture]].<ref name="Siler"/> |
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Philippine sailfin lizards have now been classified as least concern by the [[IUCN]].<ref name=IUCN/> Their main threats are [[habitat loss]], being hunted for food, and collection for the pet trade. The factors contributing to this vulnerable conservation status include habitat loss, hunting by exotic meat collectors and the pet trade.<ref name="Siler2014" /> It is currently illegal according to Philippine law to export the lizard out of the country, but some exotic pet collectors claim to already be in possession of these lizards and breed them in captivity to sell them to buyers in the United States of America.<ref name="Monitor" /> In fact, the median price for these lizards is $700, which is considerably more expensive than other lizards.<ref name="Faulkner" /> Some of the most well known trading centers for the Philippine sailfin lizards are 1) Puerto Princesa City, Palawan Island, 2) Cebu City, Cebu Island, and 3) Davao City, Mindanao Island.<ref name="Siler2014" /> It’s essential that conservation efforts to create protected areas within the Philippines for the Philippine sailfin lizard are within the habitats that they normally live in and not these trading areas. In terms of the history of the pet trade, Philippine sailfin lizards were sold in higher frequency between 1980 and 1990 because the Philippines as a country was exporting them internationally, but they now do not export these lizards anymore, leaving Indonesia to be the primary source of exporting them.<ref name="Care" /> |
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Philippine sailfin lizards are a protected species in the Philippines. It is illegal to capture them from the wild or to export them out of the country.<ref name="Siler"/> Philippine sailfin lizards were sold in higher frequency between 1980 and 1990, before it became illegal.<ref name="Care" /> However, a [[black market]] for Philippine sailfin lizards still exist. Forensic examination of lizards in the exotic pets black market in [[Manila]] found that a majority of them were poached from the [[Bicol Region]]. Other major black markets for the species include [[Puerto Princesa]], [[Cebu City|Cebu]], and [[Davao City|Davao]].<ref name="Siler"/><ref name=IUCN/><ref name="Monitor" /><ref name="Faulkner" /> |
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==Diet== |
==Diet== |
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The Philippine sailfin lizards are omnivores |
The Philippine sailfin lizards are omnivores. They eat plant leaves and fruits, in addition to insects and crustaceans.<ref name="Faulkner" /> Juvenile Philippine sailfin lizards start out preferring meat more than plants, but the balance comes as they age.<ref name="CritterFacts">{{cite web |title=Sailfin Lizard |url=https://critterfacts.com/sailfinlizard/?doing_wp_cron=1635920983.9168128967285156250000 |website=CritterFacts | date=19 October 2020 |publisher=CritterFacts |access-date=5 November 2021}}</ref> Their diet is easy to replicate, which is why they are a target for exotic pet collectors, but they are less docile than other lizards.<ref name="CritterFacts" /> The Philippine sailfin lizard's omnivorous diet is also reflected by its relatively simple dental complexity, specifically with the posterior teeth of the mouth having less defined tricuspid teeth and the posterior teeth being tricuspid.<ref name="Quant">{{cite journal |last1=Christensen |first1=Kiana |last2=Melstrom |first2=Keegan M. |title=Quantitative analyses of squamate dentition demonstrate novel morphological patterns |journal=PLOS ONE |date=10 September 2021 |volume=16 |issue=9 |pages=e0257427 |pmid=34506601 | doi=10.1371/journal.pone.0257427 |pmc=8432827 |bibcode=2021PLoSO..1657427C |doi-access=free }}</ref> As a result, the lizard cannot primarily be a carnivore since its teeth were not designed to do so. |
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==In captivity== |
==In captivity== |
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In terms of keeping a Philippine sailfin lizard in captivity, they are typically kept in large enclosures with tropical-styled heating, semi-arboreal resources, access to submerging in water to mimic their natural environment. Breeding in [[captivity (animal)|captivity]] has only been done in a few cases, but this explanation has also been used as a method of smuggling the Philippine sailfin lizards out of their native habitats for sale. Since it is common in many parts of the Philippines, the pet trade in many regions still continues and some are even unrecognized by the government. |
In terms of keeping a Philippine sailfin lizard in captivity, they are typically kept in large enclosures with tropical-styled heating, semi-arboreal resources, access to submerging in water to mimic their natural environment. Breeding in [[captivity (animal)|captivity]] has only been done in a few cases, but this explanation has also been used as a method of smuggling the Philippine sailfin lizards out of their native habitats for sale. Since it is common in many parts of the Philippines, the pet trade in many regions still continues and some are even unrecognized by the government. It is also important to note that the Philippine sailfin lizards are to be approached with caution when held captive as they are extremely nervous and can scratch people, but studies have shown that hand-feeding these lizards helps them become less nervous and gain trust. |
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==Gallery== |
==Gallery== |
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|alt1=Philippine sailfin lizard at Bristol Zoo |
|alt1=Philippine sailfin lizard at Bristol Zoo |
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|Philippine sailfin lizard at [[Bristol Zoo]] |
|Philippine sailfin lizard at [[Bristol Zoo]] |
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|File:KIRKAMON Philippine Sailfin Lizard.jpg |
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|alt2= |
|alt2= |
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|File:Taxidermied_Philippine_Sailfin_Lizard_displayed_at_Philippine_National_Museum.jpg |
|File:Taxidermied_Philippine_Sailfin_Lizard_displayed_at_Philippine_National_Museum.jpg |
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|alt3=Taxidermied [[Philippine Sailfin Lizard]] displayed at [[National Museum of the Philippines|Philippine National Museum]] |
|alt3=Taxidermied [[Philippine Sailfin Lizard]] displayed at [[National Museum of the Philippines|Philippine National Museum]] |
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Latest revision as of 11:22, 16 November 2024
| Philippine sailfin lizard | |
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| Wild Philippine sailfin lizard in Leyte | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Iguania |
| Family: | Agamidae |
| Genus: | Hydrosaurus |
| Species: | H. pustulatus
|
| Binomial name | |
| Hydrosaurus pustulatus (Eschscholtz, 1829)
| |
Hydrosaurus pustulatus, commonly known as the Philippine sailfin lizard or the Philippine sailfin dragon, is a large semiaquatic agamid lizard endemic to all of the major island groups of the Philippines, with the exception of the Palawan islands.[2][1][3][4] Like other sailfin lizards, they are characterized by large sail-like dorsal crests on their tails. They can grow to a maximum length of around 3 to 4 ft (0.91 to 1.22 m). They are strong swimmers, and smaller juvenile lizards can run briefly on the water surface. They inhabit areas of heavy vegetation near coastlines and low-lying rivers, particularly in mangrove forests.[3] They are also known locally as layagan or balubid in Tagalog and ibid in the Visayan languages, among other names.[5][6]
H. pustulatus is a protected species in the Philippines, as it is a target for the international exotic pet trade for their unique dorsal crests and bright coloration.[7][3] The heavy deforestation of mangrove habitats in the last few decades is also a concern to their conservation.[3]
Taxonomy
[edit]Hydrosaurus pustulatus was first described as Istiturus pustulatus in 1829 by the Baltic German naturalist Johann Friedrich von Eschscholtz. The specimens were collected from Luzon, Philippines, by Eschscholtz during the circumnavigational voyage of the Imperial Russian expeditionary ship Predpriaetie from 1823 to 1826.[2][8] It is one of five species currently recognized under the genus Hydrosaurus, the sailfin dragons, and the only species found in the Philippines (the other species are native to Indonesia and Papua New Guinea).[3][9]
Hydrosaurus pustulatus is highly variable in terms of coloration and scale patterns across geographic populations. A genetic study in 2014 has discovered that H. pustulatus is divided into six distinct genetic clusters. The most divergent of the group are the populations in Aurora, Luzon and the Polillo Islands.[3]
Distribution and habitat
[edit]The Philippine sailfin lizard is found throughout the Philippine islands with the exception of the Palawan islands. Populations of Philippine sailfin lizards have been documented in Luzon (Aurora, Bicol), Polillo Islands, Samar, Leyte, Dinagat Islands, Camiguin, Bohol, Negros, Panay, Romblon (Romblon, Tablas, Sibuyan), Mindoro, and Mindanao (Zamboanga).[3][10] The Philippine sailfin lizard lives in tropical wooded habitats near water, like rivers, riverbanks, rice-fields and mangrove.[1] The Philippine sailfin lizard also lives in moderately high densities in these habitats.[3] The Philippine sailfin lizard also prefers the bodies of water that they reside nearby being freshwater.[10][1]
Behavior and appearance
[edit]Philippine sailfin lizards are large and usually grow to a length between two and three feet, including its tail, but males are larger than females and can grow up to between 3 and 4 feet long (91–120 centimeters).[4] These lizards typically weigh between 3 and 5 pounds (1.4–2.3 kg).[11] Additionally, this species of lizard has a unique characteristic being its crest or sailfin, which is an upright part of its body that occurs from the base of the tail to the lower area of the back.[12] This crest or sailfin is used not only to help with its ability to swim efficiently in water, but is also thought to assist with the lizard's ability to do territorial displays and heat/cool in different environments.[12] The crest also makes the Philippine sailfin lizard's body look like a sail with regard to its structure. Overall, the body and tail of the Philippine sailfin lizard is largely cylindrical.[10]
The juvenile Philippine sailfin lizard is an excellent swimmer and has flattened toes along with smaller mass compared to adults that enable it to run across water, similar to the basilisks.[13] The adult Philippine sailfin lizard does not usually retain a smaller mass and loses the ability to run across water, but it uses these flattened toes to swim very effectively. The flattened toes also have scale fringes that can be used for swimming and running on top of water as mentioned before.[14] Males have a larger crest on their back than the females. The males also have bigger heads, taller sails on their tails, and darker limbs. During mating season, the head of the Philippine sailfin lizard becomes violet while only the neck area of a female's crest can become violet.[10] In terms of coloration, Philippine sailfin lizards have dark green and brown skin, and can also have yellow patches on the back side of their body and near their heads.[10]
The Philippine sailfin lizard has a flattened tail that is used to propel in water more quickly, adding to its natural born ability to be agile and swift in water to evade prey.[12] In the presence of predators, the Philippine sailfin lizard either drops from the tree branch it is residing on, runs, or swims to the bottom of the body of water it is closest to and can hold its breath for up to 15 minutes.[12] Philippine sailfin lizards are also diurnal and spend most of the day time resting in vegetation out in the sun.[10] In general, the Philippine sailfin lizard utilizes running to move around its habitats and away or toward predators and competitors, and their lifespan can be anywhere between 10 and 20 years.[11] The Philippine sailfin lizard also has a unique physical feature being a vestigial eye (which is also known as parietal or pineal eye) on the top of the lizard's skull that can detect differing angles of light from the sun and is thought to be used to find a sense of direction.[14]
Life cycle and reproduction
[edit]Philippine sailfin lizards utilize their sailfins/scales for territorial displays in the presence of competing males or threats. They only breed once every year with potentially multiple clutches of eggs.[10] For female Philippine sailfin lizards to lay their eggs after mating and birth, they dig relatively shallow holes in soil near their watery-habitats, and these eggs then incubate for approximately two months.[12] The eggs then eventually become hatchlings during the rainy season, which actually are born with a natural swiftness and agility that allows them to evade their predators by running across the water unlike adult lizards that swim. These female Philippine sailfin lizards are able to lay several clutches of eggs a year that each can contain anywhere between 2 and 8 eggs.[12] It is also important to note that these eggs are laid above the flood line.[10]
Conservation
[edit]Philippine sailfin lizards are classified as Least Concern by the IUCN, though they are increasingly becoming vulnerable.[1][3] Their main threats are habitat loss, being hunted for food, and collection for the pet trade.[1] Habitat loss is particularly critical, as only an estimated 7.5% of the mangrove forests of the Philippines are in protected areas. Over the last 75 years, 75% of the mangrove forests of the Philippines have been lost, mainly due to the repurposing of the land for urban development and aquaculture.[3]
Philippine sailfin lizards are a protected species in the Philippines. It is illegal to capture them from the wild or to export them out of the country.[3] Philippine sailfin lizards were sold in higher frequency between 1980 and 1990, before it became illegal.[11] However, a black market for Philippine sailfin lizards still exist. Forensic examination of lizards in the exotic pets black market in Manila found that a majority of them were poached from the Bicol Region. Other major black markets for the species include Puerto Princesa, Cebu, and Davao.[3][1][7][12]
Diet
[edit]The Philippine sailfin lizards are omnivores. They eat plant leaves and fruits, in addition to insects and crustaceans.[12] Juvenile Philippine sailfin lizards start out preferring meat more than plants, but the balance comes as they age.[15] Their diet is easy to replicate, which is why they are a target for exotic pet collectors, but they are less docile than other lizards.[15] The Philippine sailfin lizard's omnivorous diet is also reflected by its relatively simple dental complexity, specifically with the posterior teeth of the mouth having less defined tricuspid teeth and the posterior teeth being tricuspid.[16] As a result, the lizard cannot primarily be a carnivore since its teeth were not designed to do so.
In captivity
[edit]In terms of keeping a Philippine sailfin lizard in captivity, they are typically kept in large enclosures with tropical-styled heating, semi-arboreal resources, access to submerging in water to mimic their natural environment. Breeding in captivity has only been done in a few cases, but this explanation has also been used as a method of smuggling the Philippine sailfin lizards out of their native habitats for sale. Since it is common in many parts of the Philippines, the pet trade in many regions still continues and some are even unrecognized by the government. It is also important to note that the Philippine sailfin lizards are to be approached with caution when held captive as they are extremely nervous and can scratch people, but studies have shown that hand-feeding these lizards helps them become less nervous and gain trust.
Gallery
[edit]Philippine Sailfin Lizard
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Philippine sailfin lizard at Bristol Zoo -
Philippine sailfin lizard in Tropicario in Helsinki, Finland -
Taxidermied Philippine Sailfin Lizard displayed at Philippine National Museum -
Living specimen at the San Diego Zoo
References
[edit]- ^ a b c d e f g Ledesma, M.; Brown, R.; Sy, E.; Rico, E.; Binaday, J.; Lagat, R.; Pitogo, K.; Santos, G.; dela Cruz, C.; Lorenzo, A.; Sarmiento, M.; Maglangit, E.P. (2022). "Hydrosaurus pustulatus". IUCN Red List of Threatened Species. 2022: e.T190349178A180276751. doi:10.2305/IUCN.UK.2022-2.RLTS.T190349178A180276751.en. Retrieved 12 October 2023.
- ^ a b H. pustulatus, The Reptile Database
- ^ a b c d e f g h i j k l Siler, Cameron D.; Lira-Noriega, Andrés; Brown, Rafe M. (January 2014). "Conservation genetics of Australasian sailfin lizards: Flagship species threatened by coastal development and insufficient protected area coverage". Biological Conservation. 169: 100–108. doi:10.1016/j.biocon.2013.10.014.
- ^ a b "Lizard, Philippine Sailfin". Louisville Zoo. 19 December 2014. Retrieved 5 November 2021.
- ^ "Third Quarter Topical Issue – Philippine Endemic Lizards". PhlPost. 20 July 2011. Retrieved 16 January 2024.
- ^ Mascariñas, Erwin M. (2 June 2018). "PH sailfin lizards in Misamis Oriental: An unusual case of a community lizard". ABS-CBN. Retrieved 11 February 2021.
We are now finalizing the steps to have this area along the lower Solana River in the town of Misamis Oriental declared as a critical habitat for the Hydrosaurus pustulatus or the Philippine Sailfin Lizard commonly known as ibid.
- ^ a b "Endemic Philippine Sailfin Lizard threatened by illegal wildlife trade". Monitor Conservation Research Society. Monitor. June 2021. Retrieved 5 November 2021.
- ^ Eschscholtz, Johann Friedrich; Rathke, Heinrich (1829). Zoologischer Atlas. Berlin: Gedruckt und Verlegt bei G. Reimer. doi:10.5962/bhl.title.152182. Retrieved 5 November 2021.
- ^ DENZER, WOLFGANG; CAMPBELL, PATRICK; MANTHEY, ULRICH; GLÄSSER-TROBISCH, ANDREA; KOCH, ANDRÉ (3 March 2020). "Dragons in neglect: Taxonomic revision of the Sulawesi sailfin lizards of the genus Hydrosaurus Kaup, 1828 (Squamata, Agamidae)". Zootaxa. 4747 (2): zootaxa.4747.2.3. doi:10.11646/zootaxa.4747.2.3. PMID 32230109. S2CID 214748049. Retrieved 5 November 2021.
- ^ a b c d e f g h Neizhko, I; Marchevskaya, E; Marushchak, O; Troshchinkova, Yu. "SAILFIN LIZARD (HYDROSAURUS PUSTULATUS), (ESCHSCHOLTZ, 1829)". BION TERRARIUM CENTER. BION TERRARIUM CENTER. Retrieved 5 November 2021.
- ^ a b c Corning, Scott (6 December 2011). "Sailfin Dragon Care Sheet". Reptiles. Reptiles Magazine. Retrieved 5 November 2021.
- ^ a b c d e f g h Faulkner, Tim. "Philippine Sailfin Lizard". Tim Faulkner. Talk Agency. Retrieved 5 November 2021.
- ^ Jackman Bauer (2008). Global diversity of lizards in freshwater (Reptilia: Lacertilia). Hydrobiologia 595(1): 581–586.
- ^ a b "Philippine sailfin lizard". Oregon Zoo. Oregon Zoo. Retrieved 5 November 2021.
- ^ a b "Sailfin Lizard". CritterFacts. CritterFacts. 19 October 2020. Retrieved 5 November 2021.
- ^ Christensen, Kiana; Melstrom, Keegan M. (10 September 2021). "Quantitative analyses of squamate dentition demonstrate novel morphological patterns". PLOS ONE. 16 (9): e0257427. Bibcode:2021PLoSO..1657427C. doi:10.1371/journal.pone.0257427. PMC 8432827. PMID 34506601.
External links
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Wikimedia Commons has media related to Hydrosaurus pustulatus.