Amran Ronny Syam

Climbing perch, Anabas testudineus , is an economically important freshwater fish in Indonesia. The climbing perch, also known as betok, has emerged as a prominent species in aquaculture due to its air‐breathing ability, which allows the climbing perch to thrive in low dissolved oxygen environments. However, there is a lack of information on the genetic diversity of climbing perch from potential sources of populations as candidates for sustainable culture development. This study aimed to analyze the similarity, genetic distance, and diversity of climbing perch from Java, Sumatra, and Kalimantan Islands. We examined 21 truss morphometric characters to determine the intrapopulation variation. In addition, to assess genetic diversity and phylogenetic relationship between populations of climbing perch, we used random amplified polymorphic DNA (RAPD) with primers OPA 07, OPC 02, and OPC 05. The result showed that the population of climbing perch from Kalimantan shows higher similarity with the population from Sumatera (49.97%) than the population from Java (24.96%). Climbing perch from Kalimantan showed the highest polymorphism and heterozygosity of 39.29% and 0.16%, respectively. The interpopulation genetic distance between Kalimantan, Sumatera, and Java ranged from 0.17 to 0.39. The result suggests that the climbing perch from Kalimantan has potential as a candidate for the culture development of the climbing perch.

This research examines the function changes around the coral reef ecosystem caused by coral disease in Paraja Bay. The research aims to identify coral disease and the correlation between diseases and reef coral species. These identifications of coral diseases can be used to assess corals’ growth process, reproduction, and structural changes. The in-situ data was collected in February 2022 at 16 stations on each side of four small islands. The closeness relationship analysis was performed using PCA and XLstat. The results show that the disease prevalences in four small islands are varied, namely Badul Island (17.2%), Mangir Island (6.96%), Oar Island (2.66%), and Umang Island (4.86%) with an average of 7.91%. The coral diseases found in all stations were Trematodiasis and White Syndrome. Corals with Trematodiasis symptoms were Favia sp., Favites sp., and Platygyra sp., while ones with White Syndrome were Acropora sp., Favites sp., and Pavona sp. The existence of the diseases indicates the need for ecosystem restoration to include environmental aspects and community activities. This restoration action can accelerate the process of habitat and associated biota recovery.

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.

Fisheries and Aquatic Sciences

Ajamaru Rainbowfish (Melanotaenia ajamaruensis) is an endemic species of Lake Ajamaru, Papua, Indonesia, and inhabits water at a pH of 6.5 – 8.5. However, the reproductive rate of the Ajamaru rainbowfish and what factors influence it are not widely known. This study aimed to determine the reproductive capacity of the Ajamaru Rainbowfish. A pair of male and female fish with a ratio of 1:1 were used during the study. The pH of the water was increased by adding different amounts of Perna viridis green mussel shells. The dosages used for the treatments were 0, 2, 4, 6, and 8 g/l, with three replications for 30 days in the Jakarta Technical University of Fisheries Laboratory. Fish spawned naturally every two days for 30 days. Fish fed blood worms 5% of their weight. The parameters observed were the calcium content of mussel shells and water media, water quality (pH, alkalinity, temperature, and oxygen), spawning frequency, number of eggs, fertilization rate, and hatching rate. The results showed that 2 g/l green mussel shells gave the highest value at 15 spawning times, fertilization rate/FR was 97.16%, hatching rate/HR (%) was 97.93, and 537.67 ± 89.37 larvae. Increase in pH 7.42-7.7 from 6.45-6.47.

Due to rapid urban development in the coastal area of the East Aceh Regency, water quality degradation and marine pollution issues become the primary concern in this region. Moreover, seasonal observation of water quality and phytoplankton has yet to be assessed. This study aimed to determine the...

Ir H Djuanda Reservoir (Jatiluhur Reservoir) is the largest dam in West Java, with an area of 8,300 ha. This dam was built in 1957 by a French contractor, with a maximum depth of 90 meters and is the first multipurpose reservoir in Indonesia. The reservoir functions as hydropower, irrigation, marine cage, raw water and tourism. The number of anthropogenic activities encourages changes in the trophic status of the waters. The explosion of phytoplankton and floating aquatic plants is an indication of eutrophication in this lake. The purpose of this study was to determine the fertility conditions of the waters of the Ir. H. Juanda through the approach of nutrient values (nitrate and phosphate) and chlorophyll-a with TSI and TRIX analysis. This research was conducted in October 2019 at the Research Center for Fish Resource Recovery (BRPSDI) Purwakarta, West Java Province. Chemical parameters such as nitrate, phosphate and chlorophyll-a were analyzed in the laboratory using the spectrophotometric method. In addition, in-situ measurements were made of several physical and chemical parameters (temperature, brightness, depth and pH). The results showed that the reservoir waters of Ir. H. Djuanda is classified as eutrophic based on TSI with a value of 62.0337, to hypereutrophic based on TRIX with a value of 7.4581.KEYWORDS: Nitrate, Phospate, Chlorophyll-a, Eutrophication