• Animal Systematics, Evolution and Diversity
• /
• v.40 no.3
• /
• pp.211-220
• /
• 2024

During the surveys of ciliates from hypoxic habitats, three marine anaerobic species were found: Metopus spiculatus, M. vestitus, and Muranothrix felix. These species have not been previously recorded in South Korea and belong to the taxonomic classes Armophorea and Muranotrichea. The morphology of these species was examined by both microscopic observations of live specimens, and stained cells using protargol impregnations. Metopus spiculatus has the following characteristics: body size 80-110×25-35 ㎛ in vivo, beak-like structure at the end of preoral dome, ectosymbiotic bacteria covering cell surface, intracytoplasmic needle-shaped structures and the conspicuous tail end. Metopus vestitus has the following distinguishing characteristics: body size 95-130×25-45 ㎛ in vivo, a cone-shaped body, a covering of ectosymbiotic bacteria on its cell surface, intracytoplasmic needleshaped structures, somatic kineties arranged in 26-28 longitudinal rows, and a posterior part tapered into a tail. Muranothrix felix has the following characteristics: body size 100-130×20-30 ㎛ in vivo, elongated body with twisted neck region, bristle-like cilia protruding perpendicular to the cell margin, ectosymbiotic bacteria covering the cell surface, about 10 macronuclear nodules, and a long, stiffened caudal cilium.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.1
• /
• pp.69-76
• /
• 2014

This study was carried out to evaluate the relationship between threonine (Thr) efficiency and Thr dehydrogenase (TDG) activity as an indicator of Thr oxidation on chicks fed with levels of diets (CP [17.5% and 21.5%] and Thr [3.8 and 4.7 g/100 g CP]; glycine [Gly][0.64% and 0.98%] and true digestible Thr [dThr] [0.45% and 0.60%]). Calculation of the Thr efficiency was based on N-balance data and an exponential N-utilization model, and TDG activity was determined as accumulation of aminoacetone and Gly during incubation of hepatic mitochondria. This study found that in the liver of chicks who received a diet containing up to 0.79% Thr (4.7 g Thr/100 g of CP) in the 17.5% CP diet, no significant (p>0.05) effect on TDG activity was observed. However, significantly (p = 0.014) increased TDG activity was observed with a diet containing 21.5% CP (4.7 g Thr/100 g of CP) and the efficiency of Thr utilization showed a significant (p = 0.001) decrease, indicating the end of the Thr limiting range. No significant (p>0.05) effect on the total TDG activity and accumulation of Gly was observed with addition of Gly to a diet containing 0.45% dThr. In addition, addition of Gly to a diet containing 0.60% dThr also did not result in a change in accumulation of Gly. Due to an increase in accumulation of aminoacetone, an elevated effect on total TDG activity was also observed. No significant (p>0.05) reduction in the efficiency of Thr utilization was observed after addition of Gly at the level of 0.45% dThr. However, significantly (p<0.001) reduced efficiency of Thr utilization was observed after addition of Gly at the level of 0.60% dThr. Collectively, we found that TDG was stimulated not only by addition of Thr and protein to the diet, but also by addition of Gly, and efficiency of Thr utilization was favorably affected by addition of Gly at the level near to the optimal Thr concentration. In addition, no metabolic requirement of Gly through the TDG pathway was observed with almost the same accumulation of Gly and a slight increase in TDG activity by addition of Gly. Thus, our findings suggest that determination of TDG activity and parameter of efficiency of Thr utilization may be useful for evaluation of dietary Thr level.

• Journal of fish pathology
• /
• v.23 no.1
• /
• pp.85-98
• /
• 2010

Ministry of Agriculture, Fisheries and Food (MAFF) and National Fisheries Research and Development Institute (NFRDI) have inspected the hatchery-reared seeds of 22 marine species and 11 freshwater species for aquatic animal diseases in stock enhancement program in 2009. Results showed that total 12 local selfgovernments have been restocking the sea with cultured juveniles. Gyeongsangnam-do, Jeollanam-do, Jejudo and Chungcheongnam-do have a preference for marine species seeds to freshwater species. On the contrary, freshwater species were released mostly in Gyeonggi-do, Jeollabuk-do and Chungcheongbuk-do. In the marine species group, abalone was the most abundant as 24.5%, and then sea cucumber (15.2%), olive flounder (11.5%), swimming crab (5.6%), black sea bream and rockfish (6.8%), rock bream (5.1%), black rockfish (4.6%) and scorpionfish (4.5%) were followed. Crucian carp was the most abundant as 19.4%, and then eel (17.0%), Korean bullhead (12.3%), melanian snail (12.0%), catfish (8.4%) were followed in the freshwater species group. The total number of inspection cases in this study were 1,080 and disqualification cases were 19 by detection of aquatic animals pathogens such as red sea bream iridovirus (RSIV), koi herpesvirus (KHV) or white spot syndrome virus (WSSV).

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.1
• /
• pp.98-103
• /
• 2012

This study was conducted to re-evaluate the dietary vitamin C requirement in juvenile eel, Anguilla japonica by using L-ascorbyl-2-monophosphate (AMP) as the vitamin C source. Five semi-purified experimental diets were formulated to contain 0 ($AMP_0$), 30 ($AMP_{24}$), 60 ($AMP_{52}$), 120 ($AMP_{108}$) and 1,200 ($AMP_{1137}$) mg AMP $kg^{-1}$ diet on a dry matter basis. Casein and defatted fish meal were used as the main protein sources in the semi-purified experimental diets. After a 4-week conditioning period, fish initially averaging $15{\pm}0.3$ g (mean${\pm}$SD) were randomly distributed to each aquarium as triplicate groups of 20 fish each. One of five experimental diets was fed on a DM basis to fish in three randomly selected aquaria, at a rate of 3% of total body weight, twice a day. At the end of the feeding trial, weight gain (WG) and specific growth rate (SGR) for fish fed $AMP_{52}$ and $AMP_{108}$ were significantly higher than those recorded for fish fed the control diet (p<0.05). Similarly, feed efficiency (FE) and protein efficiency ratio (PER) for fish fed $AMP_{52}$ were significantly higher than those for fish fed the control diet (p<0.05). Broken-line regression analysis on the basis of WG, SGR, FE and PER showed dietary vitamin C requirements of juvenile eel to be 41.1, 41.2, 43.9 and 43.1 (mg $kg^{-1}$ diet), respectively. These results indicated that the dietary vitamin C requirement could range from 41.1 to 43.9 mg $kg^{-1}$ diet in juvenile eel when L-ascorbyl-2-monophosphate was used as the dietary source of vitamin C.

• ALGAE
• /
• v.30 no.1
• /
• pp.59-66
• /
• 2015

The growth and hole formation of Ulva australis were examined at seven coastal areas of Korea between July and August, 2013. Animal species and weight growing on the Ulva fronds were estimated at Haseom, Pohang, and Woedo. The effects of wave exposure on the morphological features and residential animals of Ulva fronds were investigated at wave-exposed and sheltered sites of Seongsan on October 19, 2013. U. australis had different frond areas ($82-665cm^2$), hole areas ($2.5-6.3cm^2$), and hole numbers (9.8-41.3 holes) at the seven sites. Within $0.1m^2$ of Ulva frond, hole areas ranged from 0.37 to $5.94cm^2$, and between 4.9 and 36.2 holes were observed. Fourteen residential animal species were observed at the three evaluated sites, 75.0 (Haseom) to 408.7 individuals $100g^{-1}$ Ulva (Pohang) per site. The dominant residential species at each site differed with Amphithoe sp. at Haseom, Monodonta spp. at Pohang, and Pagurus sp. at Woedo. The growth (frond area, wet weight) and hole number of Ulva fronds, and the number of residential animals were significantly greater in samples collected from the sheltered shore than the wave-exposed shore of Seongsan. The present results showed U. australis grew well at sheltered shores and had more holes on the fronds due to abundance of residential animals. The dominant residential animals (crabs, gammaridea, and snails) were similar in the Ulva populations of sheltered and wave-exposed shores, but greater species diversity was observed at the exposed shore (18 species ver. 11 species). In conclusion, U. australis is a keystone species providing habitat to various invertebrates and frond holes are positively correlated to the number of residential animals.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.6
• /
• pp.724-732
• /
• 2010

Two feeding experiments were conducted to investigate the effects of dietary paprika (DP) and lipid (DL) levels on growth performance and skin pigmentation of pale chub, Zacco platypus. Six diets (designated as $P_0L_8,\;P_0L_{17},\;P_8L_8,\;P_8L_{17},\;P_{16}L_8\;and\;P_{16}L_{17}$) were formulated to contain 0%, 8% and 16% paprika with 8% and 17% lipid, respectively. For the growth experiment (Exp I), three replicate groups of fish (average weight 2.6${\pm}$0.2 g) were fed one of the six experimental diets for 8 weeks. At the end of the feeding period, survival was above 94% and not significantly different among dietary treatments. Weight gain, feed efficiency and protein efficiency ratio of fish fed the $P_{16}L_8$ diet were lower than for fish fed the $P_0L_8$ diet. The highest total carotenoid (TC) content was observed in fish fed the $P_{16}L_8$ diet. For the pigmentation experiment (Exp II), each experimental diet was fed to two replicate groups of fish (average weight 9.0${\pm}$0.5 g) for 8 weeks. At the end of the feeding period, TC content of the skin was significantly affected by DP (p<0.05). The highest TC content of the skin was observed after 6 weeks of feeding at all dietary treatments. Astaxanthin content of the skin was not affected by DP and DL (p>0.05). The capxanthin and zeaxanthin contents of skin increased significantly with increasing DP, whereas the opposite trend was observed for lutein and ${\beta}$-cryptoxanthin contents. The skin lightness ($L^*$ values) significantly decreased whereas the values of $a^*$ and $b^*$ were significantly increased in fish fed the diets containing paprika (p<0.05). The present results suggest that feeding a diet containing 8% paprika and 8% lipid for 6 weeks could improve skin pigmentation of pale chub without any adverse effects on growth performance.

• Korean Journal of Animal Reproduction
• /
• v.25 no.4
• /
• pp.359-369
• /
• 2001

Polymerase chain reaction (PCR) amplification of DNA as 30 different arbitrary primers and random amplified polymorphic DNAs (RAPD) analysis were performed on genomic DNA extracted from the blood of the marine rockfish (Sebastes schlegeli) from the Yellow Sea and the Southern Sea. The unique properties of the genomic DNA were used to investigate the features of the population dynamics and origins of the species. Out of 30 primers, seven generated 207 highly reproducible RAPD polymorphic products, producing approximately 2.7 polymorphic bands per primer. About 67.4% of total amplified products (307) were either polymorphic (207) to rockfish. The degree of similarity varied from 0.22 to 0.63 as calculated by bandsharing analysis. Also, the average level of bandsharing was 0.39$\pm$0.02 within the rockfish strains. The electrophoretic analysis of RAPD-PCR products showed the relatively high levels if variation between different individuals in rockfish from the Yellow Sea. However, the RAPD outlines obtained with DNA of different rockfish strains from the Yellow Sea and the Southern Sea in Korea were very similar. Also, a small number of polymorphic bands were identified. Even if further analyses or more rockfish populations are required, this result implies RAPD analysis reflects genetic differences between the geographical strains of the rockfish.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.12
• /
• pp.1777-1781
• /
• 2003

The lysine requirements of juvenile yellowtail flounder (Pleuronectes ferrugineus) having 19.5 g initial body weight were estimated by feeding six practical-type diets containing graded levels of lysine (1.21 to 2.69% of dry diet). Dietary amino acid profile simulated that of whole body of yellowtail flounder. Most of amino acids in the diets were provided by corn gluten meal, herring meal and gelatin. Protein efficiency ratio (PER) improved significantly until lysine level increased up to 2.1% (4.3% of protein). Same trend was observed in feed:gain ratio (FGR) which maintained constant in fish groups fed diets containing lysine above 2.1%. The highest nitrogen gain (0.34 g/fish) in whole body was found in fish fed 2.1% lysine, though the value was not different from those of fish fed above the level of lysine. Fish fed 2.1% lysine also showed the best nitrogen retention efficiency of 24.6%. The broken-line analysis of protein efficiency ratio and body nitrogen gain against dietary lysine level yielded an estimated lysine requirement of 2.2% (4.5% of protein) and 2.3% (4.7% of protein), respectively.

• ALGAE
• /
• v.21 no.3
• /
• pp.333-341
• /
• 2006

The productivities of Chlorella ovalis and Dunaliella parva were influenced by the rates of medium compositions obtained from the fermented animal wastewater (BM: bacteria mineral water) including a natural substitute chelator for EDTA (etylenediaminetetraacetic acid). The most favorable medium was -E+50 adding 50% BM in f/2 medium instead of EDTA, a chemical chelator, which increased more 19-fold of cell density in C. ovalis and 7-fold in D. parva than cells cultured on f/2 medium as well as the enhancements of chlorophyll a (f/2-E: 0.26 g L–1, -E+50: 1.5 g L–1 in C. ovalis; f/2-E: 2.7 g L–1, -E+50: 15 g L–1 in D. parva) and the increase of maximal PSII quantum yields. These results were verified that the BM could play an important part as a natural chelator substituted for EDTA. In the fields of biotechnology, food organisms in fishery and eco-industries of CO2 sequestration in air and nutrient removal in water, the natural chelator of BM could be applied to enhance the biomass of the other microalgae.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.3
• /
• pp.394-399
• /
• 2011

The effect of intermittent feeding on growth, feed utilization and body composition of subadult olive flounder fed extruded pellet (EP) in suboptimal temperature ($13.5{\pm}2.10^{\circ}C$) was determined. Two hundred twenty five subadult fish averaging 272 g were randomly distributed into fifteen of 300 L circular flow-through tanks (fifteen fish per tank). Five treatments with different days of feeding a week were prepared in triplicate: fish were hand-fed with EP to apparent satiation once a day, seven days a week (7DF), which was used as the control group or consecutive six, five, four and three days a week, for 12 weeks, referred to as 6DF, 5DF, 4DF and 3DF treatments, respectively. Weight gains and specific growth rates of fish in 6DF treatment were higher than those of fish in 7DF, 4DF and 3DF treatments, but not different from those of fish in 5DF treatment. Daily feed intake of fish in 6DF and 7DF treatments was higher than that of fish in 5DF, 4DF and 3DF treatments. Feed efficiency and protein efficiency ratio of fish were not different among treatments. There was no difference in the chemical composition of fish between treatments. Results of this study demonstrated that feeding five days per week could be recommended for subadult olive flounder fed extruded pellet in suboptimal temperature.