Ecophenotypic Variation of Midas Cichlid, Amphilophus citrinellus (Gunther, 1864), in Lake Batur, Bali, Indonesia.

Cichlid fishes exhibit rapid adaptive radiations with significant diversification rates in response to ecological variability, i.e., ecological opportunity or geographical isolation. The discovery of a Midas cichlid species in Lake Batur, Indonesia's largest volcanic lake, first reported in 2013, could represent such adaptations. Midas cichlids can now be found in a range of habitats in Lake Batur and dominate the lake's fish population by up to 60%. This study aimed to identify the interaction between habitat, water quality, and Midas cichlid in Lake Batur, facilitating morphometric variances in the fish populations. The fish were captured at five locations in Lake Batur using fishing rods, community nets with mesh sizes of 2-3 inches, experimental gillnets with mesh sizes of 1 inch, and fish scoops in floating net cages during August and November 2022. There were 46 fish samples caught from the five stations, all photographed using a digital camera and later measured using the ZEN 2012 software. The fish measurement employed a truss morphometric method using 21 distinct morphometric body features. Canonical analysis was used to determine the distribution of characteristics, while discriminant analysis was used to examine the closeness of association. The measured water quality parameters included pH, DO, temperature, conductivity, and TDS for in-situ and TSS, TP, TN, and chlorophyll A for ex-situ. The findings revealed morphometric changes among Midas cichlid species in Lake Batur caused by habitat and water quality differences. The distinction can be detected in the anterior and posterior bodies (C1, B1, C3, C6, C5, B3 and B4). Temperature and aquatic plants, Azolla pinnata, may detect the station and shape of fish in Lake Batur. Body shape cannot be identified by chlorophyll A, TN, DO, and TDS. Future genetic research could answer why fish groups with varied body types coexist in the same location.

Domestication of Mahseer (Tor soro) in Indonesia.

Mahseer is an economically important fish in the world with a distribution from the Himalayan Mountains up to Southeast Asia. One species of Masheer is Tor soro in the Indonesian Archipelago. For a long time, T. soro has been collected from the wild and now is becoming rare. In addition, the degradation of its habitat is another problem. Hence, it is urgent that this species is saved from extinction. Domestication of T. soro from North Sumatra has been conducted since 1996. This paper reports the results of domestication of T. soro starting from collecting live specimens, genetic and morphometric characterizations, evaluation to breeding, and growing out. In 2010, domestication was successful to produce a second generation of young broodstocks and now the breeding technology is being shared with several provinces where T. soro exist.