Sex ratio and reproduction of invasive red devil, (Amphilophus labiatus: Cichlidae) in Lake Sentani, Indonesia

Abstract

The Red Devil Cichlid Amphilophus labiatus (Günther 1864), native to Lake Nicaragua and Lake Managua in Central America, is widely cultivated as an attractive, yet aggressive, aquarium fish that has been introduced to several freshwater locations around the world. It was recently introduced into Lake Sentani in Indonesian New Guinea, a naturally rich aquatic habitat home exhibiting a diverse fauna with high endemism. To better understand the invasive potential and impacts of A. labiatus, the present study was undertaken to describe the sex ratio and reproductive potential of A. labiatus in Lake Sentani through determination of its gonad maturation stages, gonado‐somatic index and fecundity. The fish were collected using floating gill nets at six locations around the lake between June and August 2019. Sex identification, gonads type, gonad stage and weight, fecundity were observed in the laboratory. Of the total 542 of A. labiatus collected during the survey, 345 individuals were sampled for sex ratio and reproduction. The overall male:female ratio was skewed towards males in a ratio of 3.28:1. The males were generally found to be in the gonad maturation stage I, while the females were commonly found in gonad maturation stages III and IV for all sampling locations during the study period. The highest male mean GSI value was found for the Yakonde site (0.24 ± 0.21) and at the Ayapo site (1.11 ± 1.01) for the females, with a fecundity of 191–2,720 eggs. The fish have spread to most parts of the lake, being conditioned to potentially spawn at any location, thereby providing an explanation for the observed rapid increase of the A. labiatus population over the last ten years. The results of the present study suggest a high invasive potential for this species in this and other similar lake habitats, warning that their careful management should be undertaken to restrict their further spread in Indonesia and elsewhere.

Length-Weight Relationship and Condition Factor of Introduced Red Devil Cichlid Amphilophus labiatus, in Lake Sentani, Indonesia

“…To our knowledge, this is the first determination of length-weight relationships and condition factors for A. labiatus in Lake Sentani. Despite the rapid increase in the population of this fish in the lake, there has not been much work describing the population dynamics and ecology of A. labiatus in Lake Sentani except for a recent study of sex ratio and reproduction (Ohee, et al, 2020). Further studies of the length-frequency of A. labiatus throughout the year may better elucidate the tremendous spawning potential periods that we preliminarily conclude to be in late July or early August.…”

A biological perspective for the fishery management of a small urban lake in Indonesia: a case study on the reproductive stage of the red devil (Amphilopus citrinellus) in Situ Cilodong, West Java, Indonesia

“…There has been various research on the reproductive biology of the red devil in Indonesia; for examples: Jatiluhur reservoir (Purnamaningtyas & Tjahjo, 2010), Situ Panjalu (Warsa & Purnomo, 2013), Kedung Ombo Reservoir (Adjie & Fatah, 2015), Lake Sentani (Ohee et al, 2020), Sangiran Reservoir (Santoso, 2019), and Sermo Reservoir (Hedianto, 2023). Nevertheless, those studies did not provide a histological assessment of the fish's gonad development.…”