Green terror

The green terror (Andinoacara rivulatus, syn. Aequidens rivulatus) is a colorful freshwater fish in the cichlid family.<ref name=fishbase>{{#invoke:Cite taxon|main|fishbase|genus=|species=|subspecies=}}</ref> The fish originates from the Pacific side of South America from the Tumbes River in Peru to the Esmeraldas River in Ecuador.<ref name=fishbase/> It is polymorphic and can have white or gold-orange edging to the tail and dorsal fins. It has historically been confused with two other species that always have narrow, clearly defined white edging, the more southerly distributed A. stalsbergi (often considered the "true" green terror) and the more northerly A. blombergi.<ref name=Musilova2009>Musilova, Rican, and Novak (2009). Phylogeny of the Neotropical cichlid fish tribe Cichlasomatini (Teleostei: Cichlidae) based on morphological and molecular data, with the description of a new genus. Journal of Zoological Systematics and Evolutionary Research 47(3): 209—304.</ref><ref name=Wijmark2012>Wijkmark, Kullander, and Barriga (2012). Andinoacara blombergi, a new species from the río Esmeraldas basin in Ecuador and a review of A. rivulatus (Teleostei: Cichlidae). Ichthyological Exploration of Freshwaters 23(2): 117—137.</ref>

Species

Males of A. rivulatus grow larger than females and may reach lengths of up to Template:Convert.<ref name=seriouslyfish>SeriouslyFish: Andinoacara rivulatus. Retrieved 7 May 2017.</ref> Females are sexually mature at around Template:Convert.

As the name implies, late juvenile-phase and adult-phase specimens can be very aggressive. This is not guaranteed, however, and peaceful individuals can be observed. Juveniles of A. rivulatus are often sold in aquarium stores. This species is not to be confused with the blue acara (A. pulcher) which is similar in appearance; the blue acara is not as aggressive and does not grow as large as the gold saum.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

The fish is somewhat deep-bodied, possessing a prominent forehead. Adult males develop a pronounced forehead hump, composed of fatty tissue. Juveniles are tan colored with silver-blue flecks and lack the bright iridescent blue, green, and orange coloration and long, flowing fins of adult specimens.

In nature, A. rivulatus lives in a tropical climate and prefers water with a 6.5–8.0 pH, a water hardness of 25.0 dGH, and a temperature range of Template:Convert.

In the aquarium

Template:More citations needed A. rivulatus is a popular fish in the aquarium trade and is noted for its hardiness, as well as its aesthetic appeal.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The fish may grow up to Template:Convert in length, though Template:Convert lengths are more typical, fish do not grow based on the size of their habitat.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

A. rivulatus is an inherently aggressive fish. With the exception of fully mature P. dovii (wolf cichlid) and P. managuense (jaguar cichlid), which rarely cohabit peacefully, A. rivulatus is cunning enough to survive—and even thrive—with larger cichlids. However, as a rule, a preying cichlid is capable of consuming any animal whose dimensions are inferior to that of the cichlid's fully expanded jaw. A. rivulatus of an appropriate size can often be assimilated with R. octofasciata (Jack Dempsey cichlid), A. citrinellus (midas cichlid), T. meeki (firemouth cichlid), flowerhorns (no scientific designation), smaller P. managuense (jaquar cichlid) and P. dovii (wolf cichlid), and other similarly aggressive cichlids.Template:Citation needed

Role in hormone research

A. rivulatus has also been used as a model for the effects of testosterone on lateralization.<ref name=SchaafsmaGroothuis2011>Template:Cite journal</ref><ref name=SchaafsmaGroothuis2012>Template:Cite journal</ref>

See also

• List of freshwater aquarium fish species

References

General

• {{#if:169839

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