Judul: Kelangsungan Hidup Udang Vaname (Litopenaeus vannamei) PL12 yang Terpapar Ammonia pada Berbagai Salinitas
Abstrak: Ammonia berasal dari sisa metabolisme organisme (feses), bahan organik, sisa pakan, dan bangkai organisme maupun mikroorganisme dalam perairan. Total ammonia nitrogen (TAN) terdiri atas ammonia terionisasi (NH4+) dan ammonia tidak terionisasi (NH3). Senyawa ammonia yang toksik bagi organisme perairan yaitu NH3. Penelitian ini dilakukan untuk mengukur kelangsungan hidup udang vaname PL 12 yang terpapar ammonia pada berbagai salinitas. Penelitian dilakukan selama tujuh hari dengan konsentrasi TAN perlakuan sebesar 29 mg L-1 pada salinitas 5 g L-1, 15 g L-1 dan 25 g L-1. NH4Cl digunakan sebagai bahan pembuatan larutan stok TAN dengan konsentrasi 10.000 mg L-1 yang disimpan pada botol gelap dengan suhu rendah. Tingkat kelangsungan hidup (TKH), pertumbuhan bobot mutlak (PBM), pertumbuhan panjang mutlak (PPM), Total Haemocite Count (THC), glukosa tubuh, dan aktivitas lisozim diukur pada akhir penelitian untuk melihat pengaruh konsentrasi salinitas terhadap toksisitas ammonia. Perbedaan konsentrasi salinitas terbukti berpengaruh nyata terhadap TKH dan pertumbuhan panjang mutlak udang yang dikultur pada lingkungan dengan konsentrasi ammonia yang tinggi, namun tidak berpengaruh nyata terhadap pertumbuhan bobot mutlak. Tingkat kelangsungan hidup yang dihasilkan pada konsentrasi salinitas 5 g L-1, 15 g L-1 dan 25 g L-1 adalah sebesar 41,67%; 46,67% dan 31,67%. Pertumbuhan panjang mutlak udang sebesar 0,76 cm; 0,44 cm dan 0,35 cm sedangkan pertumbuhan bobot mutlak berturut-turut sebesar 0,012 g; 0,014 g dan 0,010 g. Terdapat peningkatan respons fisiologis berupa aktivitas lisozim pada postlarvae 12 udang vaname yang diberi perlakuan penambahan TAN 29 mg L-1. Hasil penelitian ini menunjukkan bahwa TAN memiliki peran penting dalam peningkatan toksisitas yang menyebabkan kematian pada postlarvae 12 udang vaname dan toleransi udang vaname terhadap TAN tergantung salinitas pada habitat stadia udang., Ammonia comes from the remains of organism metabolism (faeces), organic matter, leftover feed, and dead organisms and microorganisms in the waters. Total ammonia nitrogen (TAN) consists of ionized ammonia (NH4+) and non-ionized ammonia (NH3). Ammonia compound that is toxic to aquatic organisms is NH3. This research was conducted to measure the survival of vaname PL 12 shrimp exposed to ammonia at various salinities. The study was conducted for seven days with a TAN concentration of 29 mg L-1 at a salinity of 5 g L-1, 15 g L-1 and 25 g L-1. NH4Cl was used as an ingredient for making TAN stock solution with a concentration of 10000 mg L-1 which was stored in dark bottles at low temperature. Survival rates (TKH), absolute weight growth (PBM), absolute length growth (PPM), Total Haemocite Count (THC), body glucose, and lysozyme activity were measured at the end of the study to see the effect of salinity concentration on ammonia toxicity. The difference in salinity concentration was proven to have a significant effect on TKH and absolute length growth of shrimp cultured in an environment with high ammonia concentration, but had no significant effect on absolute weight growth. The resulting survival rates at salinity concentrations of 5 g L-1, 15 g L-1 and 25 g L-1 were 41.67%; 46.67% and 31.67%. The absolute length growth of shrimp was 0.76 cm; 0.44 cm and 0.35 cm while the absolute weight growth was 0.012 g, respectively; 0.014 g and 0.010
Keyword: salinity, total ammonia nitrogen, vaname shrimp

Judul: Toxicity of Total Ammonia Nitrogen (TAN) Exposure to Productivity and Physiological Responses of Day of Culture 30 Litopenaeus vannamei
Abstrak: Total Ammonia Nitrogen (TAN) berasal dari sisa metabolisme organisme (feses), bahan organik, sisa pakan, dan bangkai organisme maupun mikroorganisme dalam perairan. TAN merupakan suatu senyawa anorganik yang terdiri dari amonia terionisasi (NH4+) dan amonia tidak terionisasi (NH3). Senyawa amonia yang toksik bagi organisme perairan yaitu NH3. Tujuan dari penelitian yaitu untuk menentukan konsentrasi akut amonia yang diekspresikan oleh nilai LC50 dan menganalisis pengaruh toksisitas amonia terhadap produktivitas serta respons fisiologis udang vaname pada salinitas 15 g L-1. Penelitian dilakukan dengan menggunakan tiga uji diantaranya uji pendahuluan, uji letal dan uji subletal. Kadar TAN sebesar 103,05 mengandung NH3 sebesar 4,37 mg L-1 dalam perairan bersalinitas 15 g L-1 dapat membunuh 50% dari populasi udang vaname dalam jangka waktu 96 jam serta adanya amonia sebesar 10 sampai 52 mg L-1 dapat menurunkan tingkat produktivitas (SR, Pertumbuhan Bobot Mutlak dan Pertumbuhan Panjang Mutlak) dan meningkatkan respons fisiologis (THC, Glukosa dan Kolesterol) dari udang vaname DOC 30, Total Ammonia Nitrogen (TAN) is formed by the metabolic waste of organism (feces), organic matter, feed waste, and cardaver of organism or microorganism in the media of aquaculture. TAN is an inorganic compounds consists of ionized ammonia (NH4+) and unionized ammonia (NH3). TAN compounds that are toxic to aquatic organisms are NH3. The aim of this research was to specify the acute concentration of ammonia expressed by the value of LC50 and observe the impact of TAN toxicity in productivity and physiological responses of vannamei shrimp Litopenaeus vannamei in salinity 15 g L-1. This research was done with compeletely randomized design with 3 test which were preliminary, lethal, and sub lethal test. TAN levels of 103,05 containing NH3 of 4,37 mg L-1 in water with a salinity of 15 g L-1 killed 50% of the vaname shrimp population within 96 hours and the presence of ammonia of 10 to 52 mg L-1 reduced the productivity levels (SR, Growth of Absolute Weight and Growth of Absolute Length) and increased the physiological responses (THC, glucose and cholesterol) of DOC 30 vaname shrimp
Keyword: ammonia, LC50, stress, toxicity, vanname shrimp

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology