The Arapaima Fish

            The introduction and establishment of arapaima (Arapaima gigas) in southeastern Peru and northwestern Bolivia is an example of a fish species that appears to be increasingly common and widespread in non-native portions of its range, but whose populations are on the decline within its native range. The arapaima is overfished and considered threatened throughout its native range in the Central Amazon. We gathered and examined data on the distribution of fish and wildlife in the Takana II Indigenous Territory in Bolivia, near the arapaima’s reported initial invasion zone in Peru. Results confirmed the presence of arapaima in several water bodies where local people have also reported a strong decline in native fish populations. Further south in the Takana I Indigenous Territory, monitoring of fisheries by local communities (2002-2008), including observations on arapaima catches, indicate that until 2008 arapaima had not been reported in the area. However in 2009, there were reports of arapaima in the Undumo stream. Our results demonstrate that since the first presence of arapaima in Bolivia at the beginning of the 1980s, it has steadily expanded its distribution. We propose actions to mitigate this situation by managing and controlling populations of this invasive and endangered species, as well as improving income for indigenous communities.

        Arapaima [Arapaima gigas (Schinz, 1822)], known as paiche in Bolivia and Peru and as pirarucú in Brazil, is one of the most emblematic species of the Amazon and the focus of numerous studies (Migdalaski 1957; Hrbek et al. 2005; Castello et al. 2009). This giant fish is native to the Central Amazon where it has long been over-exploited by humans as a source of food (Figure 1) (Hrbek et al. 2007). The arapaima was introduced into lagoons in the Madre de Dios region of Peru for aquaculture and during the late 1970s these fish or their progeny escaped into nearby streams during flood events (Wust 2001; Farrel and Azurduy 2006). Local people report that the introduction of arapaima has caused serious environmental impacts. In northern Bolivia, it may be causing a reduction of native fish populations, including many fish of high commercial value

The Bull Shark Fish

          The earliest collection of Mongolian fi shes was made by the German naturalist Peter Simon Pallas in the late 1700s, who described the taimen (Hucho taimen) and the lenok (Brachymystax lenok). Continued exploration in the 1800s led to the description of further fi sh species, notably by B. Dybowski, S. Basilewsky and K. Kessler, and the early 1900s saw the fi rst of numerous studies on the fi shes of Mongolia and Russia by Leo Berg. A number of joint Soviet-Mongolian, Czechoslovakian-Mongolian and German-Mongolian expeditions were carried out in the latter half of the twentieth century, but while providing new collections of fi sh for analysis, they tended to be broad multi-disciplinary studies. However, several specifi c fi sh studies were carried out during the tenure of Prof. A. Dashdorj, the fi rst Mongolian to hold the Chair of Zoology at the Mongolian State University in 1947, as he had a particular interest in ichthyology. The publication of ‘The Fishes of Mongolia’ by G. Baasanjav and Y. Tsendayush in 2001 (published in Mongolian) provided an important taxonomic review of Mongolian fi shes. It also consolidated much of the existing regional biological and fi sheries data. Prior to this, Leo Berg’s ‘Freshwater Fishes of the U.S.S.R. and Adjacent Countries’ (published in Russian, 1949 and English, 1962) was the standard reference to the fi shes of Mongolia.
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The Fish Taimen

         The earliest collection of Mongolian fi shes was made by the German naturalist Peter Simon Pallas in the late 1700s, who described the taimen (Hucho taimen) and the lenok (Brachymystax lenok). Continued exploration in the 1800s led to the description of further fi sh species, notably by B. Dybowski, S. Basilewsky and K. Kessler, and the early 1900s saw the fi rst of numerous studies on the fi shes of Mongolia and Russia by Leo Berg. A number of joint Soviet-Mongolian, Czechoslovakian-Mongolian and German-Mongolian expeditions were carried out in the latter half of the twentieth century, but while providing new collections of fi sh for analysis, they tended to be broad multi-disciplinary studies. However, several specifi c fi sh studies were carried out during the tenure of Prof. A. Dashdorj, the fi rst Mongolian to hold the Chair of Zoology at the Mongolian State University in 1947, as he had a particular interest in ichthyology. The publication of ‘The Fishes of Mongolia’ by G. Baasanjav and Y. Tsendayush in 2001 (published in Mongolian) provided an important taxonomic review of Mongolian fi shes. It also consolidated much of the existing regional biological and fi sheries data. Prior to this, Leo Berg’s ‘Freshwater Fishes of the U.S.S.R. and Adjacent Countries’ (published in Russian, 1949 and English, 1962) was the standard reference to the fi shes of Mongolia.

The Nile Perch

: Evolutionary histories of aquatic species are often characterized by distinct patterns of genetic variation, which in part reflect drainage evolution. In the present study, the consequences of paleo-environmental changes on patterns of genetic variation of the mitochondrial DNA control region in Nile perch Lates sp. sampled from seven water bodies across the African continent were investigated.

These lineages may have developed in geographical isolation during the Pleistocene and have remained largely allopatric without gene flow (Nm = 0.0) since that time. There was also evidence that both of these genetic lineages have undergone recent population expansions. We interpret these results in light of the recent evolution of Africa's modern drainage network.