Judul: Optimasi Salinitas untuk Kelangsungan Hidup dan Pertumbuhan Benih Ikan Tengadak Barbonymus schwanenfeldii
Abstrak: Environmental manipulation techniques are required to increase survival rate and growth of fishes, salinity manipulation is one of them. Salinity directly affects the living organisms life especially in survival rate and growth rate because it is strongly related with their osmoregulation process. The purpose of this research was to determine the optimum salinity for survival rate, growth, and economic profit for nursery activities of tinfoil barb (Barbonymus schwanenfeldii). This research consisted of four treatments of media salinity: 0 ppt (A), 2 ppt (B), 4 ppt (C), and 6 ppt (D). The rearing of tinfoil barb in different salinities showed significant effects on survival rate. Different salinity treatments also showed significant difference on specific growth rate of tinfoil barb.The optimum salinity for tinfoil barb was 4 ppt showed by the highest survival rate at 90%, highest specific growth rate at 1,65%, and highest profit achieved for nursery activities at Rp 139.002 with R/C ratio at 1,12.
Keyword: salinity., specific growth rate, survival rate, tinfoil barb

Judul: Different Photoperiod and Light Intensity on Growth and Survival of Juvenile Tinfoil Barb Barbonymus schwanenfeldii
Abstrak: Tinfoil barb Barbonymus schwanenfeldii is one of the endemic fish species from Borneo and Sumatera. Tinfoil barb as one of the ornamental fish commodities, but has the potential to be aquaculture as a consumption fish. To support the much needed aquaculture juvenile mass production technologies and sustainable. Problems Tinfoil barb is overfishing, endangered, aquaculture has not grown, relatively slow growth, and low survival rate. Environmental manipulation such as photoperiod and light intensity could be expected to be applied to increase fish production. This study aimed to determine the best of photoperiod and light intensity on growth and survival of juvenile Tinfoil barb. Tinfoil barb with the initial average of body weight and length of 0.12±0.04 g and 2.01±0.22 cm were used. Fish were reared in the plastic tank with water volume of 50 l and stocked of 50 fish each tank. Fish was fed commercial food three times a day. White fluorescent lamp was used in order to adjust to light intensity and provided with automatic timer. Factorial completely randomized design with two factors was performed. The treatments of this experiment were as followed: (L6I250) photoperiod of 6 hours and 250 lux, (L6I400) photoperiod of 6 hours and 400 lux, (L6I550) photoperiod of 6 hours and 550 lux, (L12I250) photoperiod of 12 hours and 250 lux, (L12I400) photoperiod of 12 hours and 400 lux, (L12I550) photoperiod of 12 hours and 550 lux, (L18I250) photoperiod of 18 hours and 250 lux, (L18I400) photoperiod of 18 hours and 400 lux, (L18I550) photoperiod of 18 hours and 550 lux. Each treatment consisted of three replicates. Parameter study are survival rate, specific growth rate, absolute length, total feed intake, feed efficiency, and vitality of juvenile Tinfoil barb to water flow were analyzed using analysis of variance followed by Duncan's test post hoc to determine differences between treatments with 95% confidence interval. Data distribution of the weight and length of the fish, water quality were analyzed descriptively. The results showed the existence of interaction photoperiod and light intensity on juvenile Tinfoil barb that significantly affect the specific growth rate, absolute length, total feed intake, and vitality level of juvenile Tinfoil barb. But no significantly effect on survival and efficiency feed. In addition, photoperiod and light intensity also affects the distribution of weight and length of juvenile Tinfoil barb. Growth and survival Tinfoil barb the best performances at photoperiod of 12 hours and 550 lux was found.
Keyword: Barbonymus schwanenfeldii, growth, light intensity, photoperiod, survival

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