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Abstract. Serdiati N, Arfiati D, Widodo MS, Lelono TJ, Ndobe S, Saranga R. 2020. Morphological variations and phylogenetic analysis of Oryzias nigrimas Kottelat, 1990 (Rice fish) from Lake Poso, Central Sulawesi, Indonesia. Biodiversitas 21: 882-888. Rice fish (Oryzias nigrimas Kottelat, 1990) is a well-studied species endemic to Lake Poso, Sulawesi and identified as scarce. This study aims to identify the Rice fish of Lake Poso, Central Sulawesi based on morphological characters (15 morphometric characters and 5 meristic counts) and phylogenetic analysis using maximum-likelihood (ML) method based on mtDNA, CO1 gene. Based on the morphological analysis, it was showed that the meristic counts show significantly different only on the lateral line scale. However, the morphometric measurements show significantly different characteristics on postorbital distance, body depth, and length of jaw. Our phylogenetic analysis also showed that our samples are indeed a species of O. nigrimas. We suggest that the endemicity of this Rice fish on Lake Poso is greatly influenced by the well-maintained genetic structure of the population.

The climbing perch, Anabas testudineus Bloch 1972, is a valued freshwater fish with a wide distribution in South and Southeast Asia. This study examined the meristic counts and length-weight relation of climbing perch from Sigi District, Central Sulawesi, Indonesia, close to the eastern extremity of the species distribution. Specimens collected from wetlands in Sigi District were weighed and measured (total length) to derive length–weight relation (n = 265) and meristic counts (n = 140). Length (L, in mm) – weight (W, in g) relation (W = a·Lb) parameter b = 2.98 overall; for females b = 3.06 while for males b = 2.88. Maximum length Lmax was 163 mm. The meristic formula using median values was D, XVII+8; A, X+9; P, 13; V, I+5; C, 16. Mean scale counts for both male and female climbing perch were: longitudinal 31 and vertical 15. There was no significant between-sex difference in meristic characters. Although the average growth pattern was isometric, males exhibited a slight allometric negative tendency. Low maximum size is consonant with other indications of a population under pressure, reinforcing the need for sustainable, holistic wetland management. In the context of domestication, high variability in meristic characters may indicate high genetic diversity and/or plasticity, which could provide scope for selective breeding.

The striped snakehead Channa striata is a freshwater fish with potential for aquaculture for consumption and as a source of nutraceutical products. A domestication program using seed (wild fry) from Sigi District in Central Sulawesi Province was initiated in 2013 to promote snakehead culture (grow-out and full-cycle) in this province. During the first two stages (fry to fingerling, fingerling to juvenile), cannibalism was the only observed cause of mortality. The main aim of the third stage was to evaluate locally available natural feeds for juvenile snakeheads over 180 mm in total length. Juvenile snakeheads were reared for 8 weeks in individual compartments in a concrete tank with 3 natural feed treatments (A: Golden apple snail, Pomacea canaliculata; B: Blue panchax, Aplocheilus panchax; C: Earth worms, Lumbricus rubellus) and 5 replicates per treatment. Feeding (11% of body weight) was twice daily. All juveniles remained in good health, however results showed that treatment B produced the highest relative growth in wet weight (21.8%), significantly different from A (11.8%) and C (9.5%). Over the 3-stage study period the length-weight relationship W = aLb was isometric (b=3), with considerable variation in individual growth patterns.

Demand for tropical eel seed has been increased and many tropical eel populations are under pressure. To conserve eel biodiversity and manage eel populations sustainably, it is necessary to identify eel species and their recruitment patterns at regional and watershed scales. The research objective was to determine the species composition and temporal recruit-ment patterns of glass eels recruiting to Palu River in Central Sulawesi. Glass eels sampling were conducted in January-April 2009, May-November 2010 and April-December 2011. Identification under anaesthetic (15-17.5 ppm clove oil solution) was based mainly on the number of ano-dorsal vertebrae (ADV). Species composition was dominated by two commercially species, Anguilla marmorata and A. bicolor pacifica with substantial variation and no clear temporal patterns. Specimens of other species that important from conservation and biodiversity aspects were present at each month but cannot be accurately identified using the ADV method. DNA analysis method is required to identify these specimens.

The Banggai cardinalfish Pterapogon kauderni is the Indonesian national marine ornamental fish mascot, and an object of national and international conservation concern. The endemic population of this species is limited to the Banggai Archipelago in Central Sulawesi, Indonesia and a few nearby islands in North Maluku. In addition, introduced populations have become established, mainly along ornamental fish trade routes. The National Action Plan for Banggai Cardinalfish Conservation (NAP-BCFC) calls for monitoring and management of all P. kauderni populations. A survey of the Luwuk introduced P. kauderni population was carried out in October 2021.   Data were collected at three sites with established P. kauderni populations: the ferry harbour, public harbour (Teluk Lalong) and a recreational area on the nearby coast (Kilo 5). P. kauderni were recorded by microhabitat association and size class (recruits, juveniles, adults). Data collected were compared with data from previous surveys where available. With the exception of one group in a sea anemone at Kilo 5, all P. kauderni were associated with Diadema sea urchins (D. setosum at all sites; D. savignyi at Kilo 5). At Kilo 5 P. kauderni the population structure indicates the possible capture of market-sized juveniles. Overall abundance was also lower compared to the polluted but unfished harbours. The proportion of recruits was significantly negatively correlated with the ratio of adult P. kauderni to Diadema urchins. The results will inform regional legislation currently in preparation to support sustainable management of P. kauderni populations, habitat and microhabitat in Central Sulawesi, as well as contributing to NAP-BCFC targets.Keywords:Banggai cardinalfishEndangered speciesDiademaMicrohabitat,MonitoringOrnamental fisheryLocal regulation

Pertumbuhan ikan nila jantan cenderung lebih cepat dibandingkan dengan ikan nila betina. Salah satu upaya untuk mempercepat pertumbuhan ikan nila yaitu dengan sex reversal. Sex reversal melalui maskulinisasi memungkinkan ikan betina berdiferensiasi menjadi ikan jantan. Air kelapa mengandung kalium (312 mg/100 g) berfungsi sebagai alternatif bahan alami pengganti hormon sintetis 17α- Methyltestosterone. Tujuan penelitian ini untuk mengetahui pengaruh konsentrasi air kelapa yang berbeda terhadap persentase kelamin jantan ikan nila yang dihasilkan melalui perendaman. Penelitian menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 5 ulangan yaitu Perlakuan A (kontrol), B (konsentrasi air kelapa 25%), C (konsentrasi air kelapa 35%) dan D (konsentrasi air kelapa 45%). Data dianalisis ragam (ANOVA) pada taraf kepercayaan 95% dengan uji lanjut Duncan. Hasil penelitian menunjukkan perendaman larva ikan nila dalam air kelapa berpengaruh nyata (α<0,05) terhadap persentase kelamin jantan denga persentase tertinggi pada konsentrasi 35% (86,87%).

Plastic is a material that cannot naturally be decomposed. The increase in the amount of marine litter is influenced by currents, winds, tides and tsunamis at certain locations. The purpose of this study was to study marine litter on the Baiya beach, Palu Bay using a rapid beach survey from the pre and post tsunami time of Palu Bay on September 28 2018. The results of monitoring the amount of marine litter before the tsunami at Baiya Beach in 2017 contained 4 meso litter materials with 10 litter types. There were 6 materials of macro litter, found 24 litter types. After the Palu Bay Tsunami in 2018, monitoring in 2019 found 9 materials of meso and macro with 31 litter types. Monitoring in 2020 found 9 meso litter materials with 19 litter types. There were 9 materials of macro, found 29 litter types. The plastic increase in marine litter on Baiya beach during monitoring was dominated by PL24 (other plastics) and the tsunami incident increased the litter type of plastic.