Correct identification of fish larvae from East Plawangan is very difficult to be done due to undefined of their morphology, while correct name is an important information for management of that area as spawning and nersery ground. Therefore, so far no scientific report on what species that utilize East Plawangan as their spawning and nursery ground. Cytochrome c oxidase 1 gene provide a precise tool for correct larvae identification. This study aims to test the accuracy of the cytochrome c oxidase 1 gene on fish larvae identification. The COI gene were amplified and sequenced. The homology of sequences were checked using Basic Local Alignment Search Tool (BLAST). Genetic distances were calculated with the help of MEGA 6 software. Taxonomic tree was reconstructed using neighbor-joining and maximum parsimony methods with 1000 bootstraps repeats. A sum of 24 morphotypes were identified, indicating high diversity of fish that utilize East Plawangan as their spawning and nursery ground. BLAST result showed that seven morphotypes were convincingly identified into species level, while three remaining morphotypes could only be identified at generic level. Taxonomic tree shows clear discrimination among morphotypes. This proved that cytochrome c oxidase 1 gene showed high accuracy on larval species discrimination.

Segara Anakan Cilacap waters consist of lagoon and riverine areas with mangrove forests. The mixing of inland and marine waters affects the plankton community. The research objectives were to describe plankton species richness and abundance, water quality during tides, and to analyze the relationship among them. The research method was a survey with a purposive sampling technique. Sampling was taken from five stations, four times in a dry season, on a spring tide when the maximum tidal range occurs. The water quality parameters consisted of temperature, current velocity, light penetration, pH, dissolved oxygen, free carbon dioxide, and salinity. The results showed that plankton species richness was the highest during the new moon at Station 3 near Motean and dominated by sea waters from Divisio Chrysophyta, such as Chaetoceros decipiens. The next taxa were Phylum Arthropoda, Divisio Cyanophyta, Divisio Chlorophyta, Phylum Euglenozoa, and Phylum Cnidaria. The plankton abundance was the highest during the new moon at Station 1 and dominated by sea waters from Divisio Chrysophyta, such as Chaetoceros. Water quality during the maximum tidal range in the new moon was better than the full moon at Station 1. In general, the highest plankton abundance was related to better water quality at Station 1.

The taxonomic status of Anguilla species' in river watershed that empties into Segara Anakan Cilacap is uncertain, thereby making it difficult for further studies to be carried out to determine its genetic in that area. Therefore, this study evaluates Anguilla's taxonomic status and population genetic in Cibeureum and Sapuregel River watersheds. Data were obtained from molecular characterization study using cytochrome c oxidase 1, with fourteen Anguilla specimens collected from two sequenced watersheds. Taxonomic status was determined based on homology and divergence values and monophyly of the samples to the reference species. Meanwhile, genetic divergences among samples to the reference species were calculated based on the Juke-Cantor substitution model in DnaSP6. A homology test was performed using a basic local alignment search tool, with monophyly inferred from the cladogram, which was developed using neighbor-joining and maximum likelihood algorithms in MEGAX with 1000 pseudoreplicates and out-group comparison. Furthermore, population genetic was analyzed through polymorphism, haplotype, nucleotide diversity within the population, divergence, and genetic differences. All calculations conducted in Arlequin 3.5 had Anguilla samples comprising of high (99.23% to 99.84%) to low genetic divergences (0.224% to 1.127%). The result shows that cladogram with all Anguilla samples formed a monophyletic clade with A. bicolor, separated from their taxa. Furthermore, Anguilla samples from both watersheds have low genetic polymorphisms with medium to high haplotype and nucleotide diversity. The population's comparison proved that both populations have low genetic divergence, and no genetic difference based on variance analysis (p=0761). Therefore, Anguilla resources in river watersheds that empty into Segara Anakan are a single genetic conservation unit.

Abstract. Mahmoud HHA, Sastranegara MH, Kusmintarsih ES. 2020. Short Communication: The lifecycle of Neocaridina denticulata and N. palmata in aquariums. Biodiversitas 21: 2396-2402. The study on the life cycle of Neocaridina spp. is important because it plays a major role in the economy and trade between countries. However, there is a lack of sufficient studies on this particular topic. One of the factors that influence Neocaridina spp. life production is its life cycle and the associated water parameters. The objectives of this study were to conduct, observe, and record the life cycle of Neocaridina denticulata and N. palmata and the associated with water parameters (temperature, pH, ammonia, nitrite, and oxygen) in the aquarium. The results showed that there was no difference in the life cycle stages between the two shrimp species. Both species reached the first sexual maturity stage of the life cycle at 75 days, with the maximum body length of the mature shrimp ranging from 2.30-3.00 cm. The eggs became larvae in 15 days, larvae reached the juvenile stage after 60 days, and the juvenile became mature in 15 days. The number of eggs was influenced by the body size of the female shrimps; smaller females produced fewer eggs. Optimal water quality varies by species and must be monitored to ensure growth and survival. The temperature range in this study was 25-28°C and the pH was 6.5-8.0. The ammonia level was in the range between 1.21 and1.72 mg/L, the nitrate was between 0.06 and 7.91 mg/L, and the oxygen was around 5.5-7.9 mg/L. All of the water quality parameters in this study are within the acceptable range for Neocardina cultivation.

There was a unique brackish water ecosystem and affected a chance in the plankton composition at lagoon and riverside in Segara Anakan Cilacap. This study aimed to map phytoplankton and zooplankton composition consisting of freshwater and marine plankton from the lagoon to the marine entrance in the west part of Segara Anakan Cilacap. The survey method was taken with purposive random sampling in fourteen stations and four replicates with new and full moon conditions from March to April 2018 in a wet season. The result showed 52 species of plankton. All species belonged to phylum Cyanophyta (9 species), Chlorophyta (13 species), Chrysophyta (19 species), Euglenozoa (2 species), Rotifera (2 species) and Arthropoda (7 species). Of the 52 species collected in all stations and replicates, phytoplankton has a greater species richness (41 species) than zooplankton (11 species). And also, freshwater plankton (47 species) has a higher species richness than marine plankton (5 species) due to the wet season condition causing freshwater enters brackish water. The largest freshwater of River Citanduy enters the brackish water of Segara Anakan mangrove ecosystem in Cilacap and causing the freshwater phytoplankton abundance, especially Staurastrum sp. in inland waters of Segara Anakan Cilacap.