Poecilia velifera

Last updated

Yucatan molly
PoeciliaVelifera (cropped).jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cyprinodontiformes
Family: Poeciliidae
Genus: Poecilia
Species:
P. velifera
Binomial name
Poecilia velifera
(Regan, 1914)
Synonyms [2]

Mollienesia veliferaRegan, 1914

Poecilia velifera, known as the Yucatan molly, is a poeciliid fish that lives in coastal waters of the Yucatan Peninsula in Mexico. The species is best known for the enlarged dorsal fin and ornamentation of some of its males as well as its social behaviors.

Contents

Poecilia velifera reaches up to 15 cm in total length. It belongs to sailfin mollies and is most closely related to P. latipinna , though larger overall and with a higher and longer dorsal fin in males. Large males display their dorsal fin for females in an elaborate courtship and flare it when challenging other males. Smaller males are not ornamented; instead, they hide among females and mate sneakily.

The Yucatán molly's preferred habitats are salt and brackish waters, especially salt marshes and mangrove forests, but it also occurs in freshwater cenotes. It is primarily herbivorous, feeding by browsing submerged surfaces, and is in turn preyed upon by other fish, birds, and crocodiles. While classified as a vulnerable species because of threats in its native habitat, the Yucatán molly has also been introduced to various South American and Asian countries.

Taxonomy

Phylogenetic relationships based on combined D-loop and ND2 genetic data [3]

The Yucatán molly was scientifically described by Charles Tate Regan in 1914 from specimens collected at Progreso, Yucatán. The original material included two males and one female, all deposited in the British Museum. Regan placed the species in the genus Mollienesia , [4] which was subsumed under the genus Poecilia in a major taxonomic revision of poeciliid fish by Donn E. Rosen and Reeve M. Bailey in 1963. [5]

Poecilia velifera belongs to the sailfin molly species complex, a monophyletic group containing three other Poecilia species: P. latipinna , P. kykesis , and P. latipunctata . Of these, P. velifera is most closely related to P. latipinna, with which it shares its preference for saltwater. [6] In contrast to shortfin mollies, sailfin mollies show a particularly pronounced difference between males and females, with males having a large, colorful dorsal fin that they display to females during courtship and in competitive interactions. [7] These traits likely evolved in the common ancestor of the sailfin mollies. [8]

The specific epithet velifera means "sail carrier". [9] The species is commonly known as the Yucatán molly or sailfin molly and, in its native range, as topote de aleta grande in Spanish. [10]

Description

Poecilia velifera grows up to 15 cm in total length. [11] It has a noticeably deep body and a relatively large head with moderately sized eyes set widely apart. Along each side of the body runs a single row of 27 scales. [4] The species is highly sexually dimorphic. [12] Its most striking feature is the dorsal fin, which has 18 to 19 rays and, in males, rises exceptionally high, making it taller than the head and proportionally larger than in any other molly. The base of the dorsal fin is long, extending over much of the back. The anal fin contains 10 rays. The pectoral fins are about as long as the head, while the pelvic fins reach the front of the anal fin; in males, one pelvic ray is elongated and matches the length of the gonopodium. The tail fin is usually rounded, though in some individuals the lower corner is slightly extended. [4] Males are polymorphic with respect to size and color and may be broadly divided into three groups: ornamented large males, ornamented intermediate males, and cryptic intermediate males (so called because they hide among females). [7]

The Yucatan molly has a relatively large head. Poecilia velifera - Alicia Christman - 474416055.jpeg
The Yucatán molly has a relatively large head.

The overall body color is olive-green. Near the front of the body are three or four dark vertical bars, though these are mostly hidden by the pectoral fins. Along the back and sides, dark brown stripes run lengthwise, with broader stripes following the rows of scales and narrower ones in between. Between these stripes are pearl-like white spots, two on each scale, creating a distinctive shimmering pattern. These markings are especially vivid in males. The dorsal fin is dark and covered with many pale spots; in males, a row of larger dark spots is often visible near the outer edge of the fin. The tail fin is usually almost plain, though some individuals show spots on the upper part while the lower part remains unmarked and edged in black. [4]

P. velifera is closely related to P. kykesis but can be distinguished by its larger head, lower scale count, distinctive coloration, and above all by its unusually large dorsal fin. [4]

Distribution and habitat

Poecilia velifera is native to coastal waters of the northern Yucatán Peninsula in Mexico. Its natural range extends along the Atlantic slope, including coastal habitats of the states of Yucatán, Quintana Roo, and Campeche, as well as the islands of Mujeres and Cozumel. On the Gulf of Mexico slope, the species occurs southward to a tidal stream roughly 50 km southwest of San Francisco de Campeche, north of latitude 19°30′ N. Records from inland waters of Yucatan may all represent introduced populations. [10] The species has also been recorded in the marine park at Contoy Island. [13] It is known from a total of nine locations, all up to roughly 20 m above sea level. [14] [12]

Yucatan mollies prefer still or slowly moving salt or brackish waters. Their habitats are often structured by roots. Poecilia velifera - bemma - 104751438.jpeg
Yucatán mollies prefer still or slowly moving salt or brackish waters. Their habitats are often structured by roots.

The Yucatán molly occupies a wide variety of coastal and near-coastal habitats, primarily in marine and brackish environments. It is commonly found in lagoons, estuaries such as Ria Lagartos, tidal streams, salt marshes, mangrove channels, and coastal cenotes (sinkholes in the karst) and freshwater pools. [1] [10] It also occurs in freshwater cenotes in the interior of the peninsula; these populations may the result of human introduction [10] or recent colonization following hurricane flooding. [10] Water clarity ranges from clear to turbid, including green and dark, tea-stained waters colored by decaying vegetation. Currents are typically absent or weak. [10] This species' habitat preference separates it from Yucatán's other sailfin molly, P. kykesis , which prefers freshwater rivers and reservoirs in the interior of the peninsula, [12] but may be found together with a shortfin molly, P. orri , in freshwater cenotes. [6]

A group of females feeding off rocks. Algae and plants are a usual feature of their habitats usually.

P. velifera occurs over diverse substrates, including sand, mud, fine loose silt, shell debris, accumulations of decaying plant material, gravel, and rock. Plant growth may be absent in some habitats, but is more often present. Where vegetation occurs, it commonly consists of algae (such as Chara ), mangroves, Typha , and Potamogeton . In freshwater cenotes, plant communities may also include water lilies, Myriophyllum , and Utricularia . Individuals are usually found in shallow water, typically less than 1 m deep. In some inland cenotes, however, adults have been recorded at greater depths, reaching about 3 m. [10]

Habitat loss and degradation pose a potential threat to Poecilia velifera. These impacts include changes to water flow, channel modification, pollution, and sediment accumulation within its range. Its population is declining; over roughly 20 years, urbanization and highway construction have wiped out two of the approximately 28 known sub-populations. [14] [15] The International Union for Conservation of Nature consequently lists P. velifera as a vulnerable species. [1] As a result of fish farm escapes or intentional releases from home aquariums, introduced populations of the Yucatán molly have been recorded in Libya, [16] Singapore, [17] Colombia, [18] Taiwan, [19] [20] Israel, [21] Minas Gerais, [22] Thailand, [23] [24] and Peru. [25] In 1987, Thailand imported more mollies from Taiwan to help manage algae in shrimp farms near the mouth of the Chao Phraya River, [24] and by 2002 a robust wild population had become established in a brackish section of the river. [23]

Ecology and behavior

Social encounters

Males flare their dorsal fin at rivals before striking or biting them. Poecilia velifera 46761207.jpg
Males flare their dorsal fin at rivals before striking or biting them.

In Poecilia velifera, interactions between males are often marked by territorial and aggressive displays. A male may confront another by swimming directly toward it while fully extending the dorsal fin and opening the mouth. Such encounters can escalate into physical combat, during which both individuals flare their dorsal fins, curve their bodies into pronounced S-shaped postures, and strike one another with their flanks, tails, or bites. These aggressive exchanges are frequently initiated by earlier harassment. Conversely, subordinate or threatened males may abruptly flee by sharply changing direction and swimming rapidly away from the aggressor. [7]

Smaller or subordinate individuals may trail a larger male at a close but consistent distance, matching its swimming speed while remaining 10-30 cm behind. Males may also be harassed by P. mexicana males. Females have been observed to freely move between open water and mangrove margins, whereas male space use appears more constrained by size: larger males travel alone across wider areas, smaller ornamented males tend to be limited to particular sections, while cryptic males remain within female groups. [7]

Non-social behaviors

A mixed-sex group feeding. Invertebrates are occasionally taken, but Yucatan mollies prefer algae. Poecilia velifera 40658318.jpg
A mixed-sex group feeding. Invertebrates are occasionally taken, but Yucatán mollies prefer algae.

Yucatán mollies spend considerable time engaged in routine maintenance activities. Fish often seek shelter among mangrove roots, beneath submerged logs, or in other protected locations, where they remain still for extended periods. Body maintenance includes rubbing the sides of the body against hard surfaces such as rocks or wood. Feeding behavior consists of browsing along substrates, stones, or submerged objects in search of food. [7] Filamentous algae and diatoms are preferred food items, but fish also take crustaceans and insects. [14]

When engaged in surface respiration, individuals congregate near the water surface, swimming slowly or remaining nearly stationary while rhythmically opening and closing the mouth and gill covers. Additional surface-related behaviors include brief upward lunges in which the fish reaches the surface and forcefully raises the dorsal fin, producing a splash; this action may be repeated several times in succession. Unusual postural behaviors are also observed, including brief pauses in swimming during which the fish adopts a vertical orientation with the head directed upward toward the surface. [7]

Yucatán mollies fall prey to various species of cichlids and marine fish, including Lutjanus , Arius , Strongylura , Gobiomorus dormitor , and Megalops atlanticus . They are also preyed upon by wading birds, such as herons, egrets, and storks; and by crocodiles, including Crocodylus moreletii and C. acutus . [12] Antipredator responses are rapid and stereotyped: when startled, particularly by the shadow of a bird passing overhead, individuals dart away from the surface and seek refuge in submerged cover. [7]

Reproduction

A male courting a female in a cenote. He tilts towards her while extending his fin and curving his body.
While smaller males merely sneak up on females, larger males woo them with their large dorsal fin. CenoteAzul.jpg
While smaller males merely sneak up on females, larger males woo them with their large dorsal fin.

Reproductive behavior in Poecilia velifera involves a combination of active pursuit, courtship displays, and both consensual and opportunistic mating attempts. [7] Smaller males typically rely on sneak copulations, attempting rapid, forced inseminations without courtship, whereas larger males combine these thrusting attempts with conspicuous courtship. [26] Males frequently initiate interactions by rapidly chasing females, sometimes singly and sometimes in groups. This vigorous pursuit is often competitive and may precede mating attempts directed at females already being courted by other males. [7]

During close interactions, males may make brief physical contact with the female's genital opening, a behavior described as gonoporal nibbling. [7] Courtship displays are elaborate and visually conspicuous: a male positions himself in front of or beside a female, fully extends his dorsal fin, and often curves the body into a pronounced S-shaped posture while tilting toward her. [7] [6] Such displays are primarily performed by large ornamented males; intermediate ornamented males tend to display only when larger competitors are absent. Mating attempts involve the male positioning himself behind the female and swinging the gonopodium forward while swimming alongside or slightly beneath her, attempting to insert its tip into the female's gonopore to transfer sperm. [7]

Males also employ opportunistic tactics. A male may rush toward a female that is already being courted by another male and attempt a rapid gonopodial thrust from behind, effectively attempting to mate without prior display. Similar thrusting attempts are also directed at females that are not being courted. Conversely, courting males may themselves be disrupted when rivals exploit these moments to attempt sneak inseminations while the primary male is engaged in display behavior. Associating with shoals of females rather than fighting rivals allow cryptic males to attempt to copulate more often than large males. [7] Females prefer large males. [6] Breeding appears to extend from late February to late July, and in certain cenotes, reproductive activity may occur almost throughout the year. [10] Females give birth to 20-50 live fry at intervals of three to five weeks. [27]

Poecilia velifera and the shortfin molly P. mexicana –which occur together in one site in Campeche–have long been known to produce viable and fertile hybrid offspring in laboratory settings, but no such hybrids were collected in the wild in over three decades of intense efforts. That the two species do hybridize in nature, however rarely, was only confirmed in 2004, when two hybrid specimens were caught: an early-generation hybrid, determined to be the offspring of a male P. velifera and a female P. mexicana, and a later generation hybrid. Laboratory tests have shown that female shortfin mollies prefer sailfin males to shortfin males, the former being larger than the latter, which may lead to the occasional breakdown in the behavioral barriers that normally prevent crossbreeding. [28]

Fishkeeping

High-finned fancy mollies are derived from P. velifera. Poecilia velifera.jpg
High-finned fancy mollies are derived from P. velifera.

Poecilia velifera is popular in the ornamental fish trade. [29] It is peaceful and lively. [27] Because of its size and activity, it is not suitable for small aquariums: a 110-litre aquarium may house a pair or a trio. [9] It may be kept in both freshwater and marine setups, [30] but hard and alkaline water is essential. It requires plenty of vegetal matter in its diet. [31] [27] Most fish traded as P. velifera are P. latipinna x P. velifera hybrids. [27] The development of high-finned fancy mollies is attributed to genetic contributions from P. velifera. [32]

References

  1. 1 2 3 Schmitter-Soto, J.; Matamoros, W.A.; Valdes Gonzales, A. (2019). "Poecilia velifera". IUCN Red List of Threatened Species . 2019 e.T191755A2002448. doi: 10.2305/IUCN.UK.2019-2.RLTS.T191755A2002448.en . Retrieved 19 November 2021.
  2. ↑ Froese, Rainer; Pauly, Daniel (eds.). "Poecilia velifera". FishBase . August 2019 version.
  3. ↑ Ptacek, M. B.; Breden†, F. (1998). "Phylogenetic relationships among the mollies (Poeciliidae: Poecilia: Mollienesia group) based on mitochondrial DNA sequences". Journal of Fish Biology. 53 (sA). Wiley: 64–81. doi:10.1111/j.1095-8649.1998.tb01018.x. ISSN   0022-1112.
  4. 1 2 3 4 5 Regan, C. Tate (1914). "Description of a new cyprinodont fish of the genus Mollienesia from Yucatan". Annals and Magazine of Natural History. 8. 13 (75): 338.
  5. ↑ Rosen, Donn E.; Bailey, Reeve M. (1963). "The poeciliid fishes (Cyprinodontiformes), their structure, zoogeography and systematics". Bulletin of the American Museum of Natural History. 126 (1): 55.
  6. 1 2 3 4 Kozak, Heather L.; Cirino, Lauren A.; Ptacek, M. (2008). "Female mating preferences for male morphological traits used in species and mate recognition in the Mexican sailfin mollies, Poecilia velifera and Poecilia petenensis". Behavioral Ecology. Retrieved 2026-01-08.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 13 Domínguez–Castanedo, Omar; Schlupp, Ingo (2023-10-16). "Intra- and interspecific behavioural ecology within and between Mollienesia males (sailfin molly Poecilia velifera and shortfin molly P. mexicana) in mangroves of the Yucatán peninsula". Behaviour. 160 (15). Walter de Gruyter GmbH: 1359–1391. doi:10.1163/1568539x-bja10243. ISSN   0005-7959.
  8. ↑ Breden, Felix; Ptacek, Margaret B.; Rashed, Michael; Taphorn, Donald; Figueiredo, Carlos Augusto (1999). "Molecular Phylogeny of the Live-Bearing Fish Genus Poecilia (Cyprinodontiformes: Poeciliidae)". Molecular Phylogenetics and Evolution. 12 (2). Elsevier BV: 95–104. doi:10.1006/mpev.1998.0600. ISSN   1055-7903.
  9. 1 2 Stoye, Frederick Hans (1932). Tropical Fish for the Home: Their Care and Propagation. Empire Tropical Fish Import Company. p. 39. Retrieved 2026-01-12.
  10. 1 2 3 4 5 6 7 8 Miller, Robert Rush (2005). Freshwater fishes of México. Chicago, Illinois, United States: University of Chicago Press. pp. 236–7. ISBN   978-0-226-52604-1.
  11. ↑ Reis, Roberto E. (2003). Check List of the Freshwater Fishes of South and Central America. EDIPUCRS. ISBN   978-85-7430-361-1 . Retrieved 2026-01-10.
  12. 1 2 3 4 Hankison, S. J.; Childress, M. J.; Schmitter‐Soto, J. J.; Ptacek, M. B. (2006). "Morphological divergence within and between the Mexican sailfin mollies, Poecilia velifera and Poecilia petenensis". Journal of Fish Biology. 68 (5): 1610–1630. doi:10.1111/j.0022-1112.2006.001051.x. ISSN   0022-1112 . Retrieved 2026-01-07.
  13. ↑ Vega-Cendejas, Ma. Eugenia; Hernández-de-Santillana, Mirella (1990-01-06). "Ichthyofauna that inhabits coastal systems of the Contoy Island marine park". CienciaUAT (in Latin). 9 (1): 44–59. ISSN   2007-7858 . Retrieved 2026-01-04.
  14. 1 2 3 Schmitter-Soto, J. J. (1998). Catálogo de los peces continentales de Quintana Roo. San Cristóbal de Las Casas: ECOSU.
  15. ↑ Schmitter-Soto, J.J.; Rodiles-Hernández, R.; Valdez-Moreno, M.E.; Hendrickson, D.A. (2006). Evaluación del riesgo de extinción de los cíclidos mexicanos y de los peces de la frontera sur incluidos en la NOM-059 (Report). Chetumal, Mexico: El Colegio de la Frontera Sur and Comisión Nacional para el Conocimiento y Uso de la Biodiversidad.
  16. ↑ Elbaraasi, Houssein; Mohamed, Mohamed; Elsilini, Osama; Jenjan, Hussein; Corinaldesi, Cinzia; Buschi, Emanuela; Azzurro, Ernesto (2022). "The Yucatan molly Poecilia velifera (Regan, 1914) (Cyprinodontiformes: Poeciliidae): an invasive species in the Mediterranean lagoon of Ayn Zayanah (Benghazi, Libya)". BioInvasions Records. 11 (2). Regional Euro-Asian Biological Invasions Centre Oy (REABIC): 537–546. doi:10.3391/bir.2022.11.2.26. ISSN   2242-1300.
  17. ↑ Ng, Peter K.L.; Chou, L.M.; Lam, T.J. (1993). "The status and impact of introduced freshwater animals in Singapore". Biological Conservation. 64 (1). Elsevier BV: 19–24. doi:10.1016/0006-3207(93)90379-f. ISSN   0006-3207.
  18. ↑ Welcomme, R. L. (1988). International introductions of inland aquatic species. Rome, Italy: FAO. p. 318.
  19. ↑ Shen, S. C. (1993). Fishes of Taiwan. National Taiwan University.
  20. ↑ Kuo, S.; Lin, Hsing‐Juh; Shao, K. (1999). "Fish assemblages in the mangrove creeks of northern and southern Taiwan". Estuaries. Retrieved 2026-01-06.
  21. ↑ Golani, Dan (2000). "Introduction of fishes to the freshwater system of Israel". The Israeli Journal of Aquaculture. 52: 47–60.
  22. ↑ Magalhães, A. L. B.; Amaral, I. B.; Ratton, T. F.; Brito, M. F. G. (2002). "Ornamental exotic fishes in the Gloria Reservoir and Boa Vista Stream, Paraíba do Sul River Basin, state of Minas Gerais, southeastern Brazil". Comunicações do Museu de Ciências e Tecnologia da PUCRS – Série Zoologia. 15 (2): 265–278.
  23. 1 2 Vidthayanon, C.; Premcharoen, S. (2002). "The status of estuarine fish diversity in Thailand". Marine and Freshwater Research. 53: 471–478. doi:10.1071/MF01122.
  24. 1 2 Welcomme, R. L.; Vidthayanon, C. (2003). The impacts of introductions and stocking of exotic species in the Mekong Basin and policies for their control (MRC Technical Paper No 9). Mekong River Commission (MRC). p. 35.
  25. ↑ Ortega, H.; Guerra, H.; Ramírez, R. (2007). "The introduction of nonnative fishes into freshwater systems of Peru". In Bert, T. M. (ed.). Ecological and Genetic Implications of Aquaculture Activities. Dordrecht, The Netherlands: Springer Netherlands. pp. 247–277. doi:10.1007/978-1-4020-6148-6_14.
  26. ↑ Hankison, Shala J.; Ptacek, Margaret B. (2007). "Within and Between Species Variation in Male Mating Behaviors in the Mexican Sailfin Mollies Poecilia velifera and P. petenensis". Ethology. 113 (8): 802–812. doi:10.1111/j.1439-0310.2007.01388.x. ISSN   0179-1613 . Retrieved 2026-01-09.
  27. 1 2 3 4 Riehl, Rüdiger; Baensch, Hans A. (1987). Aquarium Atlas. Baensch. p. 604. ISBN   978-3-88244-050-8 . Retrieved 2026-01-12.
  28. ↑ Kittell, Michele M.; Harvey, Megan N.; Contreras-Balderas, Salvador; Ptacek, Margaret B. (1990-01-06). "Wild-caught Hybrids Between Sailfin and Shortfin Mollies (Poeciliidae, Poecilia): Morphological and Molecular Verification". Hidrobiológica. 15 (2). Universidad Autónoma Metropolitana, División de Ciencias Biológicas y de la Salud: 131–137. ISSN   0188-8897 . Retrieved 2026-01-09.
  29. ↑
  30. ↑ Hiscock, Peter (2000-08-07). Creating a Natural Aquarium. Wiley. ISBN   978-0-7645-6141-2 . Retrieved 2026-01-12.
  31. ↑ Axelrod, Herbert R. (1983). Exotic Tropical Fishes. T.F.H. Publications. p. 1005. ISBN   978-0-87666-543-5 . Retrieved 2026-01-12.
  32. ↑ Balon, Eugene K. (1 April 2006). "The oldest domesticated fishes, and the consequences of an epigenetic dichotomy in fish culture". Aqua: Journal of Ichthyology & Aquatic Biology. 11 (2). Aquapress Publisher: 47–87. ISSN   0945-9871 . Retrieved 7 January 2025.

Commons-logo.svg Media related to Poecilia velifera at Wikimedia Commons

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.