A successful case of biological invasion: the fish Cichla piquiti, an Amazonian species introduced into the Pantanal, Brazil

Abstract

The "tucunaré", Cichla piquiti, an exotic Amazonian fish has become established along the left bank of the Paraguay River in the Pantanal. It was introduced by escaping from culture ponds in the Upper Piquiri River and spread downstream, along the lateral flooded areas of that river, continuing through the clear waters of the left bank of the Paraguay River and reaching south as far as the Paraguai Mirim and Negrinho rivers. Adult spawners have been found in the region, meaning that it is a self-sustained population. Reproduction occurs in the period of low waters. They were found feeding on fishes of lentic environments belonging to the families Characidae, Cichlidae and Loricariidae. Until the end of 2004, its distribution was restricted to the left bank of the Paraguay River, but in March 2005, some specimens were found on the right bank, raising a question for the future: what will be the distribution area of the tucunaré in the Pantanal? Information about its dispersion is increasing: it is known to be in the Tuiuiú Lake, Pantanal National Park and in the Bolivian Pantanal, all of them on the right bank of the Paraguay River. The hypothesis that the "tucunaré" could not cross turbid waters, such as in the Paraguay River, was refuted by these recent findings. Possibly, the tucunaré's capacity to lay more than one batch of eggs in a reproductive period, as well as its care of eggs and young, lead them to establish themselves successfully in new environments, as has been observed in the Pantanal and other localities.Keywords: invasion, dispersion, reproduction, feeding. Um caso de sucesso de invasão biológica: o tucunaré

Growth and mortality of Cichla spp. (Perciformes, Cichlidae) introduced in Volta Grande Reservoir (Grande River) and in a small artificial lake in Southeastern Brazil

“…Espinola (2005) found that Cichla monoculus Spix and Agassiz, 1831 (= C. kelberi) had a greater frequency of juveniles in the rainy seasons, with several reproductive strategies and tactics depending on the sites, showing a high degree of phenotypic plasticity, allowing it to adapt to highly variable environments. Seasonal reproduction occurs both for the peacock bass in natural environments and for those in the environments of introductions (Zaret, 1980;Ruffino and Isaac, 1995;Jepsen et al, 1999;Resende et al, 2008;Souza et al, 2008).…”

Assemblage of fish species associated with aquatic macrophytes in Porto Murtinho Pantanal, Mato Grosso do Sul, Brazil

“…In relation to introduced specie tucunaré Cichla piquiti, Resende et al (2008) defines as a well-established species in the Pantanal, and reported its occurrence from the Piquiri River (northern Pantanal) to the region of Corumbá (central Pantanal). Our data revealed that it occurs approximately 400 km southward, at the limit of the Pantanal (Upper Paraguay River).…”

Analysis of propagule pressure and genetic diversity in the invasibility of a freshwater apex predator: the peacock bass (genus Cichla)

“…Likewise, we found that propagule pressure appears unimportant in the peacock bass establishment, even in pristine sites where greater resilience to invasions would be expected (i.e., Doce River and Marginal Lake). Is interesting to note that in the Pantanal (the world's largest wetland ecosystem), where more than 260 fish species occur (Britski et al, 1997) evidence suggest that a co-existence among CP and native fishes will be reached in the long term (Resende et al, 2008). Other examples of biotic resistance have been reported in marine (Stachowicz et al, 1999;Hunt & Yamada, 2003), freshwater (Harvey et al, 2004;Yonekura et al, 2004) and terrestrial (Lake & O'Dowd, 1991;Parker et al, 2006) ecosystems.…”

“…Moreover, the biological characteristics of Cichla species have made their populations capable of expanding rapidly in the invasive range, especially in modified ecosystems such as hydroelectric reservoirs, pristine floodplains and lagoons (Espinola et al, 2010;Zaret & Paine, 1973). These include reproductive activity during almost the entire year (Vieira et al, 2009), bi-parental care of eggs and capability to rear young in oxygen-depleted lakes (Zaret, 1980), opportunistic feeding behavior -it preys on whatever it can swallow (Resende et al, 2008), cannibalism (Gomiero & Braga, 2004), and phenotypic plasticity that allowed adaptation to harsh ecological conditions (Chellappa et al, 2003). While Cichla species were apparently introduced into northeastern Brazil in the late 1940s by government agencies for establishing fish breeding farms, no information was available regarding their origin.…”