Poecilia vandepolli, or Vandepoll's molly, is a poeciliid fish native to the Lesser Antilles. A euryhaline species, it is one of the most common fish in its range, inhabiting fresh, brackish, salt, and hypersaline waters. The fish vary significantly in size and color.
| Vandepoll's molly | |
|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Cyprinodontiformes |
| Family: | Poeciliidae |
| Genus: | Poecilia |
| Species: | P. vandepolli
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| Binomial name | |
| Poecilia vandepolli Van Lidth de Jeude, 1887
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Taxonomy
editPoecilia vandepolli was originally described by Van Lidth de Jeude in 1887.[2] He simultaneously described the subspecies P. vandepolli arubensis,[3] but it has not been recognized by others.[2] Hubbs considered P. vandepolli a subspecies of P. sphenops. In 1963, Rosen and Bailey challenged the validity of this and other short-fin molly species and made them synonyms for P. sphenops. Poeser resurrected P. vandepolli as a separate species in 1992, and considers it to have common ancestry with P. vivipara.[2] The ancestral form of P. vandepolli diverged approximately 150,000 years ago when the Lesser Antilles, which the species inhabits today, were connected to mainland Venezuela.[4]
Description
editP. vandepolli is variable in many respects.[3] Sexually mature females normally reach 30–45 mm in standard length, while males grow to 25–35 mm SL. Though these measurements place them among the smaller mollies, large specimens are sometimes encountered as well: a 72.7 mm SL female and a 51.9 SL male have been reported.[2] These size variations pertain to distinct populations.[3] The fish vary in color as well,[2] even within the same population.[3] Some males have prominent vertical bars and a humeral blotch, dark spots on the dorsal and caudal fins, and orange coloration on the abdomen; others have only spots on the fins and faint bars, if any. The same color pattern, only paler, is found in females.[2]
P. vandepolli is polymorphic, with physical differences between populations being the result of varying ecological conditions, especially salinity. The specimens living in marine habitats have larger bodies, longer dorsal fins, and stronger coloration.[2]
Distribution and habitats
editP. vandepolli is native to the Caribbean islands of Aruba, Bonaire, and Curaçao[2] where it inhabits freshwater, brackish, saltwater, and hypersaline coastal habitats.[3] It is also found in the freshwater habitats of the island of Saint Martin,[1] but was probably introduced there by Dutch settlers.[2] P. vandepolli is one of the most common fish species found in the coastal habitats across the Lesser Antilles and is found in nearly all freshwater localities.[1] Occurrences have been reported from mainland Venezuela, including the Lake Maracaibo river estuary, but the validity of these collection records remains unconfirmed.[1]
The molly is widespread in rivulets and freshwater ponds on the Lesser Antilles, reaching them from the sea during torrential rain floodings. It is likewise common in sheltered lagoons and inner bays, particularly in localities with mangroves. The sea population is small, likely due to high predation, but crucial because of its stability. Populations in the inland waters are vulnerable to mass mortalities and occasionally extinctions, after which the habitats must be repopulated from the sea.[3]
Ecology
editP. vandepolli prefers to feed on unicellular and other small algae. When food becomes scarce, Vandepoll's mollies may take plankton and Artemia. Stomach content analyses show that cannibalistic adults eat fry when food is lacking.[3]
The pupfish Cyprinodon dearborni, which can also live in all salinities, shares the molly's dietary habits and is a major competitor. They may only coexist if their habitat has a connection to the sea; if the habitat is cut off, one of the species vanishes. In confined water bodies population density is kept down by a lack of food: most offspring starve or fall prey to adults. In sea the molly is heavily predated on by other fish. Freshwater and supersaline habitats are generally free of predators, but on Curaçao birds and trematodes prey on the mollies.[3]
Reproduction
editP. vandepolli is a ovoviparous livebearer. Small females produce about 10 live fry per litter; the particularly large ones may produce over 100. Newborn fry measure 8-9 mm. Their growth is faster in the sea than in fresh or supersaline waters.[3] Adults readily predate on their own offspring.[3][5] The females usually outnumber the males 2:1, sometimes less.[3]
Fishkeeping
editP. vandepolli is easy to care for in a home aquarium and will breed readily. It demands plenty of space on account of its activity as well as warm water.[5]
References
edit- ^ a b c d Lyons, T.J. (2021). "Poecilia vandepolli". IUCN Red List of Threatened Species. 2021: e.T125989461A125989537. doi:10.2305/IUCN.UK.2021-1.RLTS.T125989461A125989537.en. Retrieved 28 August 2024.
- ^ a b c d e f g h i Poeser, Fred N. (1992). "Re-establishment and redescription of Poecilia vandepolli Van Lidth de Jeude, 1887 (Pisces: Poeciliinae), with comments on related species" (PDF). Studies on the Natural History of the Caribbean Region. 71 (1): 79–98.
- ^ a b c d e f g h i j k Feltkamp, Constance A.; Kristensen, Ingvar. "Ecology and morphological characters of different populations of Poecilia sphenops vandepolli (Cyprinidontidae)" (PDF). Studies on the Fauna of Curaçao and other Caribbean Islands. 32 (1): 102–130.
- ^ Ho, A.L.F.C.; Pruett, C.L.; Lin, J. (2016). "Phylogeny and biogeography of Poecilia (Cyprinodontiformes: Poeciliinae) across Central and South America based on mitochondrial and nuclear DNA markers". Molecular Phylogenetics and Evolution. 101: 32–45.
- ^ a b Lundkvist, Ronny. "Some Experiences Keeping a Rare Wild Poeciliid". Tropical Fish Hobbyist.