''Phallichthys'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

poeciliid Poeciliidae are a family of freshwater ray-finned fishes of the order Cyprinodontiformes, the tooth-carps, and include well-known live-bearing aquarium fish, such as the guppy, molly, platy, and swordtail. The original distribution of the fam ...

s native to

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

. They are hardy fish which inhabit stagnant and slow-flowing waters, making them well-suited to

fishkeeping Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. It is a practice that encompasses the art of maintaining one's own aquatic ecosystem, featuring a lot of variety with various w ...

Etymology

The genus name literally means "

phallus A phallus (: phalli or phalluses) is a penis (especially when erect), an object that resembles a penis, or a mimetic image of an erect penis. In art history, a figure with an erect penis is described as ''ithyphallic''. Any object that symbo ...

(penis) fish", from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

''phallos'' meaning "penis" and ''ichthys'' meaning "fish", referring to the "comparatively huge"

gonopodium Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

, the modified

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

used for

copulation Sexual intercourse (also coitus or copulation) is a sexual activity typically involving the insertion of the erect male penis inside the female vagina and followed by thrusting motions for sexual pleasure, reproduction, or both.Sexual inte ...

. The common name for '' P. amates'', the merry widow, is sometimes applied to other species in the genus as well.

Taxonomy

There are currently four recognized species in the genus ''Phallichthys'': * '' P. amates'' ( N. Miller, 1907) (merry widow livebearer) * '' P. fairweatheri'' D. E. Rosen & R. M. Bailey, 1959 (Picotee livebearer) * '' P. quadripunctatus'' W. A. Bussing, 1979 * '' P. tico'' W. A. Bussing, 1963 Phallichthys amates female.png, '' P. amates'' female Phallichthys tico - José Fabricio Vargas Murillo.jpg, '' P. tico'' male and female Phallichthys fairweatheri.jpg, '' P. fairweatheri'' The

sister clade In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to the genus includes genera ''

Neoheterandria ''Neoheterandria'' is a genus of poeciliids native to Panama and Colombia. Species There are currently three recognized species in this genus: * '' Neoheterandria cana'' ( Meek & Hildebrand, 1913) * '' Neoheterandria elegans'' Henn Henn is a ...

'' and ''

Poeciliopsis ''Poeciliopsis'' is a genus of poeciliid fishes that primarily are native to Mexico and Central America. The only exceptions are ''P. turrubarensis'' where the range extends into Colombia, and ''P. occidentalis'' where the range extends into Ari ...

''.

Ecology

''Phallichthys'' species are found primarily on the

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

slope of Central America. They prefer shallow, stagnant or slow-flowing waters and muddy substrate.

Aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

s are often present in their habitat. Their diet consists mainly of algae and aufwuchs but small aquatic invertebrates are occasionally taken as well.

Reproduction

''Phallichthys'' males are not known to display any

courtship behavior A courtship display is a set of display behaviors in which an animal, usually a male, attempts to attract a mate; the mate exercises choice, so sexual selection acts on the display. These behaviors often include ritualized movement ("dances"), ...

, but the female's cooperation is nevertheless necessary for

reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: Asexual reproduction, asexual and Sexual ...

. When mating, the male approaches the female from below and behind. The gonopodium, then extended in front of the male's head, delivers

spermatophore A spermatophore, from Ancient Greek σπέρμα (''spérma''), meaning "seed", and -φόρος (''-phóros''), meaning "bearing", or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especiall ...

s into the female's genital pore. ''Phallichthys'' species are

livebearers Livebearers are fish that retain their eggs inside the body and give birth to live, free-swimming young. They are especially prized by aquarium owners. Among aquarium fish, livebearers are nearly all members of the family Poeciliidae and include: ...

: the female gives birth to live fry after a gestation of about four weeks or as short as just over three weeks in high temperatures. The number of the fry produced depends on the size of the female. Superfoetation has not been recorded; all species produce a single brood before developing another. Superfoetation existed in the ancestral species but has been subsequently lost. The offspring do not obtain nutrients from the mother during gestation. The fry receive no

parental care Parental care is a behavioural and evolutionary strategy adopted by some animals, involving a parental investment being made to the evolutionary fitness of offspring. Patterns of parental care are widespread and highly diverse across the animal k ...

and are able to fend for themselves from birth. The adults do not normally prey on the fry, which are born looking like miniature versions of their parents. They feed ravenously and grow quickly. Males start developing gonopodia at about 7 weeks of age, while females start reproducing at 10 to 12 weeks.

Aquarium husbandry

Though not commonly sold, ''Phallichthys'' are easy to care for in the home

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

due to their hardiness, peacefulness, and outgoing disposition. Other than

hardness In materials science, hardness (antonym: softness) is a measure of the resistance to plastic deformation, such as an indentation (over an area) or a scratch (linear), induced mechanically either by Pressing (metalworking), pressing or abrasion ...

, water parameters are not important. The fish are reportedly able to distinguish their caregiver from other humans. It is possible to keep them with other species, but their fry are vulnerable to predation. The fish do particularly well in planted aquariums and accept a variety of food. A

heater Heating, ventilation, and air conditioning (HVAC ) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. ...

is not required.

References

{{Taxonbar, from=Q140986 * Freshwater fish of Central America Freshwater fish genera Taxa named by Carl Leavitt Hubbs Ray-finned fish genera