REPORT ON Amphilophus trimaculatum AT CHENNAI FRESHWATER LAKE

Globally, fish biodiversity is being exhausted by the introduction of invasive alien species because of its potential to destroy the natural habitat that depletes the indigenous fish diversity. Invasive species would cause several issues to the native fish biodiversity viz. (i) resource exploitation (outcompete for food and space which decline the native populations, (ii) alter the surroundings that favourable to them (Ecological facilitation), (iii) entry of new pathogens result in the outbreak of new diseases, that consequently have an effect on fish eaters, and (iv) killing large numbers of endemic species via damaging the egg and predate the larvae and adults of native fishes. It has been reported that the invasive species are the second largest cause of species extinctions in the certain countries. It has also been reported that alien fish hybridize with the native fishes and transfer their genetic information through introgression of genes which ends to dilute the wild genetic stock.

A survey carried out at Madambakkam Freshwater Lake, Chennai, Tamil Nadu, India (12°56'54.0672''N; 79°55' 17.1012''E), revealed the infestation of an exotic Cichlid, Amphilophus trimaculatum native to South America. This species is a predacious invasive fish that eats smaller fish. Although there are previous records available for this species from Rettai Eri Lake at Chennai, it is surprising to note that a huge population of this species existing in the natural waters of Madambakkam Lake which is located in the distant part of the region from Rettai Eri Lake. This survey recorded the distribution of A. trimaculatum in the natural waters of Madambakkam Lake, Chennai.