The spotted halibut is species that has a high potential market value in Korea, but the supply of seed is unstable because of the limited milt production of males. The objective of this research was to explore different aspects, such as CPAs, diluents, dilution ratio, and freezing rates, to develop an optimal sperm cryopreservation. The parameters assessed were movable sperm ratio, sperm activity index, survival rate, and DNA damage. The CPAs tested in this research were propylene glycol, dimethyl sulfoxide (DMSO), methanol, ethylene glycol, and glycerol. Different diluents, including 300 mM sucrose, 300 mM glucose, Stain’s solution, and Ringer’s solution, were investigated. The previous experiment showed that the optimal CPA for cryopreservation was DMSO with a concentration of 15% with 300 mM as diluent. To determine the effect of the dilution ratio, sperm was diluted to 1:1, 1:2, 1:10, 1:100, and 1:1000 with 300 mM sucrose containing DMSO at a final concentration of 15%. Lastly, the optimal freezing rate of the sperm was evaluated with four different freezing rates (−1, −5, −10, and −20 °C/min). Post-thaw sperm motility was higher with a dilution ratio lower than 1:2, and the freezing rate was less than −5 °C/min. In conclusion, these findings represent the development of a cryopreservation protocol for spotted halibut.

Organic material produced from domestic food waste can be functionalized as useful product such as fish feed by fermentation process. The fermentation process changed several properties such as nutrition content and particle size. Here, we reported the effect of fermentation process on physical properties of organic material from domestic food waste. In this study, fermented product will be conducted to become fish feed. The fermentation was performed by using commercial probiotic BIOM-S with various levels of probiotic from 0 to 10% using solid substrate fermentation method. The physical properties including nutritional content, particle size, distance between particles, and functional group of fermented organic material from domestic food waste were investigated. After fermentation, it is found that the best level of probiotic use is 8%, which are crude protein increased from 15.58% to 26.16% and crude fiber content decreased from 4.88% to 3.71%. The average particle sizes and distance between particles of fermented domestic food waste fermented by 8% probiotic were 147.723 µm and 1708.802 µm, respectively, while the functional group did not change after fermentation. The present result indicated that fermentation process effected to improve the quality of organic material from domestic food waste.

Andriani Y, Irawan B, Iskandar, Zidni I, Partasasmita R. 2019. Diversity of duckweed (Araceae-Lemnoideae), morphological characteristics and its potentials as food sources for herbivorous fishes in West Java, Indonesia. Biodiversitas 20: 1617-1623. Duckweed is aquatic plant potential as a source of protein to feed herbivorous fish. The purpose of this study was to explore the diversity of duckweed species occurred in several areas in West Java. The exploration was done by collecting duckweed (Araceae) from water bodies such as lakes and ponds located in the fishery center in Garut, Bandung, Sumedang and Tasikmalaya Districts. The sample was identified using stereomicroscope to know the morphological characteristic. Characteristics being observed included root tip and sheath as well as the morphological frond characteristics. The result of study showed there were three species of duckweed recorded at the studied areas in West Java, namely Spirodela polyrhiza (L.) Schleid, Lemna perpusilla Torr. and Lemna gibba L. The three duckweed species can be distinguished based on its morphological characteristics, such as the number of roots, types of root tip, root sheath, symmetric-frond, gibbous-frond, and nerve-frond. In the studied areas, duckweed plants were found in ponds, stagnant water, and rice fields. Duckweeds can be used as a source of protein in fish feed as they have high protein content and complete amino acids.

The purpose of this study was to determine the selectivity and level of environmental friendliness of mini bottom trawl in Pangandaran District. This research conducted on May-October 2017. Primary data obtained from purposive sampling either by interview or observation Selectivity indicator used was selectivity of catch species and size. Environmental friendly fishing was evaluated based on the FAO criteria. The result showed that catch rate of mini bottom trawl was 26.45 kg/hour. The main catch of mini bottom trawl in Pangandaran District was Trachypenaeus asper amount of 39,5% while by catch was Acetes sp¸ Oiolithes ruber, Trichiurus lepturus, and others catch with amount 60,40%. Catch size of mini bottom trawl main catch was ranged 4 cm - 9.90 cm. The main catch was 39,00% was more than size capture and under size capture was 61.00%. Catch utilization of this fishing gear was 93%. The result evaluation of environmental friendliness based on catch selectivity was 6 point which mean ‘less environmentally’ friendly while FAO criteria showed 18 point which mean ‘not environmentally’ friendly fishing. The purpose of this study was to determine the selectivity and level of environmental friendliness of mini bottom trawl in Pangandaran District. This research conducted on May-October 2017. Primary data obtained from purposive sampling either by interview or observation Selectivity indicator used was selectivity of catch species and size. Environmental friendly fishing was evaluated based on the FAO criteria. The result showed that catch rate of mini bottom trawl was 26.45 kg/hour. The main catch of mini bottom trawl in Pangandaran District was Trachypenaeus asper amount of 39,5% while by catch was Acetes sp¸ Oiolithes ruber, Trichiurus lepturus, and others catch with amount 60,40%. Catch size of mini bottom trawl main catch was ranged 4 cm - 9.90 cm. The main catch was 39,00% was more than size capture and under size capture was 61.00%. Catch utilization of this fishing gear was 93%. The result evaluation of environmental friendliness based on catch selectivity was 6 point which mean ‘less environmentally’ friendly while FAO criteria showed 18 point which mean ‘not environmentally’ friendly fishing.

The roughscale sole, Clidoderma asperrimum is categorized as an endangered species. Sperm freezing is essential for preserving gametes. This study examined the CPA concentration, diluent, dilution ratio, and thawing temperature to design a sperm cryopreservation protocol for roughscale sole. The variables examined included sperm motility and kinematics, cell survival, fertilization, and DNA fragmentation. Sperm motility parameters were assessed via computer-assisted sperm analysis using a CEROS II instrument. Cell survival rate and DNA damage were assessed using the Cell Counting Kit-8 and single-cell gel electrophoresis assay, respectively. Sperm preservation was tested using several CPAs, including ethylene glycol, dimethyl sulfoxide (DMSO), glycerol, propylene glycol, and methanol. The diluents tested were 300 mM sucrose, 300 mM glucose, Stein’s solution, Ringer’s solution, and Hank’s solution. The optimal conditions for sperm cryopreservation were 10% DMSO + Stein’s solution. After thawing, sperm motility was highest with a 1:1 dilution ratio (sperm to CPA + diluent), at 69.20 ± 0.32%; thawing at 10 °C was optimal for post-thaw motility (72.03 ± 0.95%). The highest fertilization rate (40.00 ± 1.22%) was obtained using DMSO. The fresh sperm had the lowest tail DNA, followed by 10% DMSO + Stein’s solution. The developed cryopreservation methods can be used in roughscale sole hatcheries.