Eastern Mosquitofish (Gambusia holbrooki )
- Gambusia affinis holbrocki
- Gambusia affinis holbrooki
- Gambusia holbrookii
- Gambusia patruelis holbrooki
- Heterandria holbrooki
- Heterandria uninotata
- Schizophallus holbrooki
- Zygonectes atrilatus
- English: mosquito
- Spanish: gambusino
- Albania: barkaleci
- Australia: eastern
- Iran: gambusia
- Italy: gambusia
- Portugal: peixe-mosquito
- Romania: gambuzie
- Sweden: östlig
- USA: eastern
Eastern mosquitofish is a small, light-colored fish with semitransparent fins.
The females usually have a black stripe near their eye area and light spots can
be seen on the caudal and dorsal fins of both sexes. Due to its similar
size, shape, and reproductive habits, it can easily be mistaken for a guppy. Generally,
males reach 1.5 in and females 2.5 in. These fish are a livebearer
species, and as such, the females are larger and more rounded than the males.
Pregnant females are also easily recognizable by their gravid spot; a darker
area on their bellies where they hold the fry.
may have a melanistic color pattern with black spots, resembling a dalmatian.
This could result in its being misidentified as another species.
Gambusia is an
opportunistic omnivore that feeds on a diverse range of terrestrial insects
such as ants and flies that fall on the water surface as well as aquatic
invertebrates including bugs, beetles, fly larvae, zooplankton, filamentous
algae and fragments of fruit and other plant tissues. Gambusia select their
prey according to size, color, movement and position in water column G.
holbrooki is also a planktivorous species which consumes algae
and detritus. Feeding habits seem to change based on maturity and mating season.
Gambusia holbrooki will, if need arises, switch food sources to survive.
With an increase of competition, this species will switch from a diet rich in
plankton, algae, and detritus to one consisting of zooplankton, other
invertebrates, the larvae of many species, and plant-associated animals. The
main source of competition for G. holbrooki seems to be an increase of its own species and other
planktivorous species. The main problem with this is, as mentioned before, it
will change its diet; this is common even among the juveniles and both sexes of
its own species. The females tend to not specialize on one prey, and consume
all evenly, whereas the males and juveniles specialize on one prey type.
However. males, females, and juveniles all consume detritus at the same rate.
Mosquitofish are found in waters from 0.5°C to 39°C, with a
preference for warm waters of about 25°C, though mosquitofish prefer water temperatures between 31-35°C. Juvenile mosquitofish are more thermally tolerant than adults, allowing them to colonise
and exploit warm patches of the environment with increasing growth, survival,
and maturation rate.
The broad salinity tolerance of mosquitofish
allows them to colonise environments, such as salt lakes, estuaries, near
coastal marine environments.