The increased of organic substance pollutans in waters as one of stimulate factors for phytoplankton growth. The input of organic matter from antrophogenic  activity tend to influence the trophic state of reservoir. The aims of this research are to examine the influence of organic waste to Panglima Soedirman reservoir concerning the trophic state, Redfield ratio N and P, also the relation with abundance of phytoplankton. This research used survey methods with purposive sampling technique on 7 obsevation stations with 3 repeating conducted on May-July 2013. The result of the research showed that the input of organic matter increased in BOD5, COD and ammonia in reservoir and trophic state. Redfield ratio was shown 19,13-65,82 which means P as a limiting factor. Relationship between N/P with the abundance of phytoplankton with degree was strong correlated with chlorophyta and chrysophyta.

Segara Anakan is an estuarine ecosystem located on the southern coast of Central Java Province which is very fertile with high biodiversity. However, the current condition is thought to have experienced a decline in biodiversity caused by sedimentation, overexploitation and water pollution problems so that it is feared that it will disrupt the preservation of organisms including fish. The purpose of this study was to determine the diversity of fish found in Segara Anakan Cilacap, and to know the conservation status of each species of fish caught in Segara Anakan in eastern Cilacap. This research was conducted using a survey method with cluster random sampling technique at 6 stations (3 stations on the Sapuregel River and 3 stations on the Kembangkuning River) with 3 replications each during highest tide. Fish collection is done by using a net and gillnet or gillnet that is installed during low tide and carried out during high tide. The diversity of fish in the waters of Segara Anakan is 36 species from 25 families. There are 16 species from 15 families in the Donan River and 34 species from 25 families in the Sapuregel River. The diversity of fish in the Sapuregel River is higher than in the Donan River. The status of fish in the eastern Segara Anakan waters management area is mostly in the LR (Least Concern) or low risk status and 1 NT (Near Threatened) species or threatened with extinction namely Sidat Fish (Anguilla bicolof)

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<p>The fish’s reproduction status is affected by both fed compositions and vitamins intake lead to determine improvement of eggs quality as well as fish production. The presence of Ascorbic Acid (AA) in the cultivation ponds, might accelerate female’s gonad maturation and so rematuration. The research  aimed to determine: (1) Level gonad maturity of supplementation Ascorbic Acid; (2) Oocyts diameter; (3) Larvae survival rate. The research used experimental methods.The method was a completely randomized design (CRD) of 4 treatments and 4 replications.  Treatments were supplementation of AA at different dosages of 0, 600, 1200 and 1800 mg/kg fish-fed ration.The gonad maturity level was analysed descriptively and oocyte diameter and larvae survival rate data were analysed  by  ANOVA. The result showed that supplementation of AA at a dosage of 1200 mg / kg fish-fed ration accelerated the process of gonad maturity, development of oocyt diameter and larvae survival rate as well as the viability of <em>O. vittatus</em> larvae at 90 rearing days.<em>  </em>In this case, level IV gonad maturity was reached at 90 days which characterized by completed vitelogenesis process and oocyte diameter of 1.1 mm.  Thus, this study useful for aquaculture science by provide information on utilization of ascobic acid as food supplement in fish culture and also for fish farmer who wish to accelerate <em>O. vittatus</em> reproduction.</p>

Channa striata are one of the essential catches in freshwater, including Sempor Reservoir. This study aimed to investigate the spatial distribution and abundance of Channa striata and the correlation between the abundance of snakehead and water quality parameters. The study was undertaken in Sempor Reservoir Central Java from March to October 2020. The method included a survey with five Stations of sampling. Distribution data were tabulated using the Microsft Excel program. Data of abundance and water quality were subjected to ANOVA. The correlation between the abundance and water quality was analyzed with the Principle Component Analysis (PCA). The result showed that the distribution of snakehead fish in Sempor Reservoir covered a wide range across the inlets, middle, outlets, and beyond the dam. The catch fish was 110-390 mm long and weighed 12-588g. The male and female fish percentage was 55.68% vs 44.32%, so the female to male ratio was 0.8:1. The highest abundance of snakehead fish was in the KW station (33%). The distribution of C.striata was more affected by the fish behaviour in selecting their habitat than the water temperature, depth, and transparency. The significance of this study expects to lay the foundation for snakehead fisheries management in Sempor Reservoir.

River Sapuregel empties into the eastern region of Segara Anakan Cilacap. It is one of the major rivers surrounded by mangrove forests and has a variety of biological resources, including fish. The research aimed to study the fish diversity and composition Sapuregel river mouth of Segara Anakan Eastern Area Cilacap. Research on fish diversity was carried out from April to September 2018. The method was purposive random sampling at the Sapuregel estuary. The results showed that 1.446 individuals representing 23 families and 34 species were dominated by Engraulidae families in the rainy season (42.57%) and dry season (57.41%) followed by Gobidae (16.82%) in the rainy season and Mugilidae (19, 44%) in the dry season. Small fish within the range of 2.7–22.9 cm dominated the caught fish. Fish Diversity Index ranges from 1.71 to 1.843 in the rainy and dry seasons between 1.352-1.56. These results indicated that fish diversity in the rainy season was higher than the dry season. Evenness Index ranges from 0.1907 to 0.2178 in the rainy season, between 0.2274 and 0.28 in the dry season, the species similarity in the dry season was higher than the rainy season. The size of the fish obtained varied from juvenile to adult size. It was dominated by small fish so that it was suspected that the waters of the River Sapuregel were used as spawning grounds and enlargement of several types of fish.

The reproduction potential fish is bacic information from the phenomenon a review gonad maturation. Fish reproduction procces can see to the gonad maturation until the fish spawn and baby fish product. The research aimed to determine: (1) Fecundity, (2) Oocyts diameter; (3) Gonado Somato Index (GSI); (4) Larvae survival rate. The research materials were Cyprinus carpio, Barbonymus gonionatus, Osteochillus vittatus, Oreochromis niloticus and Clarias gariepinus. Measure parameters are fish weight, gonad weight, partial gonad weight, partial egg, oocyt diameter and life larvae. The research used experiment design, the method was a complete-ly randomized design (CRD) with 5 treatments fish species and 3 replications. The oocyt diameters was analysed descriptively and fecundity, GSI, larva survival rate were analysed by ANOVA. The result showed that fecundity and GSI accelerated at a 5 species fish (P <0.05), B. gonionotus had the highest fecundity on range 120. AbstrakInformasi dasar mengenai potensi reproduksi ikan dapat diperoleh dari tinjauan fenomena perkembangan gonad. Fenomena ini untuk memprediksi proses reproduksi ikan mulai dari perkembangan gonad sampai ikan memijah dan menghasilkan benih sebagai baby fish. Tujuan penelitian adalah mengetahui fekunditas, diameter telur, gonado somato index (GSI) dan kelangsungan hidup larva untuk menghasilkan baby fish. Materi penelitian adalah induk Cyprinus carpio, Barbonymus gonionatus, Osteochillus vittatus, Oreochromis niloticus dan Clarias gariepinus. Variabel adalah fekunditas, diameter telur, gonado somato index (GSI) dan kelangsungan hidup larva. Parameter yang diukur berat ikan, berat gonad,berat gonad sebagian, jumlah telur sebagian, ukuran telur dan jumlah larva hidup. Metode yang digunakan eksperimental, menggunakan metode rancangan acak lengkap (RAL) dengan perlakuan 5 spesies ikan, dengan 3 kali ulangan. Data Diameter telur dianalisis secara deskriptif dan data fekunditas, GSI, kelangsungan hidup larva dianalisis menggunakan Anova. Hasil penelitian diperoleh bahwa fekunditas dan GSI pada 5 species ikan menunjukkan perbedaan (P<0,05), B. gonionotus memiliki fekunditas tertinggi kisaran 120.400-217.150 butir (rata-rata 182.320 ±sd 53763,7) dan O. vittatus memiliki nilai GSI tertinggi 35,13%. Diameter telur berbeda-beda pada semua spesies, B. Gonionotus memiliki diameter terkecil yaitu kisaran 0,486 -0,729 mm (rata-rata 0,604 mm ±sd 0,045), sedangkan diameter terbesar pada ikan C. carpio kisaran 1,126 -1,248 (rata-rata 1,170 mm ±sd 0,067

Over exploitation of consumed fishes causes declining of  targeted fish populations that will lead to a cascade effect to the guild compositions. The change of carnivorous, omnivorous and herbivorous fish populations drives to the food chain destructions and unstable ecosystems. The objective of this study was to build fish community modelling based on guild compositions. This study was conducted on fish communities in the Banjaran River. The data collected were species richness, the abundance of fish and the guild composition among carnivore, herbivore, and omnivore. Survey and purposive random sampling technique were applied and Banjaran River was divided into five sites based on the physical characteristics of the environment and fishing activities. Species richness data were analyzed by ANOVA, the composition of the carnivorous, omnivorous and herbivorous fish was analyzed descriptively based on the guild pyramides.  About 115 individuals consist of 17 species belong to 5 families were found. The species richness in the five sites in was relatively similar (P > 0.05 (P = 0.269)). The fish community in site 3 had the balanced composition which was composed by 3% carnivores, 21.2% omnivores and 75.8% of herbivores.  This fish community modelling could be an an alternative way to manage fish community.  By controlling the carnivorous fish population, the natural resource especially fish as food resource will sustain and the species loss will be prevent.