AGE STRUCTURE, GROWTH RATE AND MORTALITY OF MANGGABAI FISH (Glossogobius Giuris) IN LAKE LIMBOTO

Abstract

Manggabai fish, scientifically known as Glossogobius giuris, is an economically important fish that is often found in Lake Limboto and is very popular among the majority of the population of Gorontalo Province. Currently there is a decline in the Mangabai fish population, causing the market price to increase. This decline is caused by the shrinking and narrowing of Lake Limboto, which is the natural habitat of this species. This research took place at Lake Limboto, Gorontalo Regency, from February to July 2023. Data collection in this research took the form of observations and reviews of existing literature to categorize fish according to age and growth rate. Data were analyzed using descriptive methods, presented in the form of tables and illustrations. Mangabai fish sampling was carried out twice a week for three months. Research findings reveal that Mangabai fish caught from Lake Limboto have body lengths ranging from 49.00 mm to 149.50 mm. These fish were classified into four different age groups: the first group (L1) had an average length of 81.96 mm, the second group (L2) measured approximately 90.31 mm, the third group (L3) had an average length of 98.48 mm, and the fourth group (L3) had an average length of 98.48 mm. L4) reached an average length of 125.01 mm. Mangabai fish show a relatively fast growth rate, indicated by a growth coefficient value of 0.76. Total mortality rate (Z) = 0.28 per year; natural mortality (M) = 0.05 per year and fishing mortality (F) = 0.33 per year.