This study was conducted to investigate the attractant substances of different solvent fractions of mackerel and tuna viscera. Mackerel and tuna viscera were extracted with methanol and the resultant were fractionated with n-hexane, chloroform, ethyl acetate, n-butanol and water. The chemical compounds such as free amino acid, fatty acid, nucleotide related compounds contents were estimated for mackerel, tuna viscera and various fractions. These fractions were also subjected to attracting experiments in water tank to estimate attracting effects. The aqueous fractions of mackerel and tuna viscera showed the highest attraction effect on swimming crab. The major chemical compounds of the aqueous fractions were histidine, taurine, cysteine, glutamic acid, inosine monophosphate (IMP) and inosine (HxR) for mackerel and arginine, glutamic acid, aspartic aid, alanine, IMP and hypoxanthin (Hx). Results indicated that higher polarity compounds, such as amino acid and nucleotide related compounds have higher attraction activities than nonpolar substances such as neutral lipid.
To investigate the catching efficiency of a biodegradable round trap for a swimming crab (Portunus trituberculatus), four types of material (two types of biodegradable net, one type of biodegradable plus polyethylene net and one type of polyethylene net) for traps were used in the field test, and the field tests were carried out 11 times in the Boryeong fishing ground of Korea, 2012∼2013. The catching efficiency of four type traps was analyzed by catch per trap, weight per trap and mean weight per individual of small and large size swimming crab. Statistical Kruskal-Wallis test was carried out to verify the significant difference for the efficiency between types of material. The catch in number of swimming crab was 9,015 and formed about 94.3% of total catch. In the results of catching efficiency of traps, there was a little difference in catch per trap, weight per trap and mean weight per individual of swimming crab in-situ data. But there was no significant difference in catching efficiency between the biodegradable traps and the PE trap (P>0.05), so it’s needed to use widely a biodegradable trap for the conservation and sustainable management of swimming crab resources.
To study the catching efficiency of biodegradable trammel net for swimming crab (Portunus trituberculatus), three types (biodegradable, monofilament and multifilament) of trammel nets were used in the field test, and the tests were carried out 16 times with two different mesh sizes (105mm and 160mm) in the Yeonpyeong fishing ground of Korea, 2009~2011. The catching efficiency of three type nets was analyzed by catch in number, catch in weight and average weight per individual of small and large size swimming crab by net types and mesh sizes. Statistical T-test was also carried out to verify the efficiency between the three types of nets. The results are as follows. The catch in number of swimming crab was 24,667 and formed about 81.0% of total catch. Of all swimming crab catch, small swimming crabs with less than 64mm in carapace length which is a prohibited landing size by law formed 48.1%, larger swimming crabs with more than 64mm in carapace length which is a landing size formed 51.9%. In 105mm mesh size trammel net test, the catch share in number of small size swimming crab by biodegradable trammel net was 47.5% in comparison with multifilament trammel net and 74.2% in comparison with monofilament trammel net, so biodegradable trammel net has more protective effects on small size swimming crab than other types of trammel nets. The protective effects for small size swimming crab by biodegradable trammel net was 25.8~52.5% in comparison with other types of trammel nets. The catch share in weight of large size swimming crab by biodegradable trammel net was 98.3% in comparison with multifilament trammel net and 92.3% in comparison with monofilament trammel net, so biodegradable trammel net has a similar catch efficiency to multifilament trammel net. The results of 160mm mesh size trammel net test have shown similar results of 105mm mesh size trammel net test. This study shows that biodegradable trammel net is a more useful fishing gear than multifilament and monofilament trammel net because biodegradable trammel net has lower catch rate than other types of nets in small size swimming crab and similar catch rate than multifilament trammel net which is a well used net by fishermen.
영광 주변해역에서 꽃게의 갑폭조성, 상대성장, 성비와 외포란량을 조사하였다. 조사해역에서 출현한 꽃게는 총 658개체(수컷:305, 암컷:353)로 나타났다. 조사기간 동안 수온과 염분의 변화 양상은 수온은 5.9-27.3℃의 범위를 나타내었으며, 염분 농도의 경우 28.1-31.6 psu의 범위를 각각 나타내었다. 두흉갑폭(CW)과 갑장(CL)의 관계와 두흉갑폭(CW)과 전중량(TW)의 관계식의 경우 암컷의 경우 CL = 1.3073 CW + 25.684(R2=0.791), TW=0.0061CW2.4231(R2=0.801)로 나타났고, 수컷의 경우 CL = 1.3652 CW + 22.495(R2= 0.741), TW=0.0068CW2.400(R2=0.749)로 나타났다. 꽃게의 성비의 경우 수컷과 암컷의 출현비율이 평균 0.86 : 1로 나타났다. 외포란량의 경우 암컷의 크기가 증가함에 따라 포란량은 증가함을 알 수 있었다.
Swimming crabs, Portunus trituberculatus(Miers) are commercially important off the coasts of Korea, Japan and China. Harvest of swimming crabs has been fluctuated along their distribution ranges. Fluctuations in the interannual harvest of swimming crabs may be correlated with the survival rate during the larval period. The survival rates, intermolt periods, and growth of larval swimming crabs were investigated in the laboratory. Larval swimming crabs are released and undergo development from April to August off the western coast of Korea in the Yellow Sea. Sea surface temperatures off the western coast of Korea during the larval season were used for the laboratory experiments, and ranged from 22 to 26℃. Larvae were individually cultured at four different temperatures, 22℃, 24℃, 26℃, and 28℃. Zoea molted to megalopa at all temperatures and developed to the first crab stage at 24℃, 26℃, and 28℃. Survival rates from zoea I to the first crab stage increased with increasing temperatures. Intermolt period and the growth rate of the mean carapace length were inversely correlated with temperature. Our research helps understand the changes in survival rate and growth of larval swimming crabs resulting from changing oceanic temperatures. Further, our study suggests that the fluctuations in fishery harvest of swimming crabs off the coast of Korea may be related to changes in larval survival affected by changing ocean conditions.
In order to develop the substitutive materials for natural baits of swimming crab pots, the attracting effects of swimming crab such as the preference of baits which were made of the by-products of marine and stock raising through the water tank experiments and fishing experiments. On the investigation of mean entrapped catch number to the pot by the baits after putting the 4 kinds of baits, mackerel(M), mackerel with grinded mackerel s internals(MMI), mackerel with tuna s internalsMMI) and makerel with grinded krill(MK) each in one pot by turns, MMI and MK were entrapped mean 3.9(13.0%) and they were a little more comparing to M, and MTI is least with mean 2.1(7.0%)(F=12.913, P 〈 0.05). Otherwise, on the preference investigation of swimming crabs by the baits after putting the 4 kinds of baits in the 4 pots each, M was entrapped mean 3.0(10%), but MMI, MTI and MK were mean 1.2(4.0%), 1.0(3.3%) and 1.5(5.0%) each and they were only 30-50% of M(F=13.398, P 〈 0.05). On the preference investigation of swimming crabs by the 5 kinds of baits, mackerel(M), and krill(K), manila clam(MC), pig s fat(PF) and chicken s head(CH) which were used in substitutive baits, M was entrapped mean 3.2(10.7%), but K was about 50% of catch of M with mean 1.6(5.3%), and MC, PF and CH were very few with mean 0.1-0.2(0.3-0.7%)(F=89.186, P 〈 0.05). On the preference investigation of swimming crabs by the pots which were put each the 3 kinds of baits, original krill(K), grinded krill with gluten and soybean oil cake(KGGS) and grinded krill with gluten, soybean oil cake and glycine(KGGSGL) in the blue fluorescent hexahedral plastic bait cages(BF), and which were put the mackerel(M) in the non-fluorescent hexahedral red plastic bait cage(RFN), it was entrapped mean 3.0(10.0%) in the pot which was put the mackerel in the RFN, and the same level in the pots which were put the K and KGGSGL in the BF, but it was mean 2.0(6.7%) in the pots which was put the KGGS in BF and it was decreased by 30% of catch comparing to RFN(F=3.750, P 〈 0.05). On the preference investigation of swimming crab by the pots which was put grinded tuna with gluten, soybean oil cake and glycine(TIGSGL) in the blue fluorescent hexahedral plastic bait cage(BF), and which was put mackerel(M) in the nonfluorescent hexahedral red plastic bait cage(RFN), it was entrapped mean 3.3(11.0%) in the pot which was put mackerel in RFN, and mean 2.7(9.0%) in the pot which was put TIGSGL in BF and it was about 15% less comparing to use bait M(t=1.387, P 〈 0.05). As a results of fishing experiments, a plan for enhancing catching efficiency of TIGSGL will be required because catching efficiency of TIGSGL, alternative bait, was half of fish catching efficiency of natural bait using mackerel. Fishing experiments were conducted 3 times using reinforced substitutive artificial bait that is reinforced attractive effect of TIGSGL and composed of tuna intestine, grinded mackerel, gluten, soybean cake, glycine and alanine(TIMGGSGLA). Catching efficiency of TIMGGSGLA was about 80% of that of natural bait made of mackerel.
In order to develop the substitutive materials for natural baits of swimming crab pots, the fluorescent characteristics of the baits were analyzed, and the preference of fluorescent dyes were investigated by the mean entrapped catch number to the pots through the water tank experiments and fishing experiments. On the investigation of fluorescent characteristics by the 5 kinds of baits, mackerel, krill, manila clam, pig's fat and chicken's head which were used in substitutive baits for test in the UV long wave(365nm) area, it showed clear blue fluorescence in the skin of mackerel, shell of krill, manila clam and bill of chicken's head, and green fluorescence in the mackerel s muscle and internals, and yellow fluorescence in the pig's fat and chicken's head. On the investigation of fluorescent characteristics by the bait cages in the UV short wave(254nm) and long wave(365nm) area, it showed each green, red and blue fluorescence in the cylinderical or hexahedral red plastic bait cages which were painted each green, red and blue fluorescence dyes, but it showed yellowish green flourescence in the cylinderical or hexahedral red plastic bait cage which was painted yellow fluorescent dye. On the preference investigation of the fluorescent dyes of swimming crabs by the 5 kinds of the bait cages which were put the mackerel in the non-fluorescent red plastic cage(RFN), red, yellow, green and blue fluorescent plastic cages(RF, YF, GF, BF) each, nonfluorescent red plastic cage(RFN) was entrapped mean 2.0(6.7%), but blue fluorescent plastic cage(BF) was mean 5.0(16.7%) and it was more 2.5 times comparing to RFN, and red fluorescent cage(RF) was same level and green fluorescent cage(GF) was 50% of catch number comparing to RFN, and yellow fluorescent cage(YF) was entrapped nothing(F 46.324, P 〈 0.05). On the investigation of the entrapped catch number to the pots which were put the mackerel in the blue fluorescent hexahedral plastic cage(HP) and blue fluorescent silicon mackerel model cage(SM), HP was mean 3.4(11.3%) and it was a little more comparing to SM which was entrapped mean 3.2(10.7%)(t 0.775, P 〉 0.05). Fishing experiments on the preference investigation of swimming crabs by the pots which were put in the non-fluorescent red plastic cage(RFN) and blue fluorescent plastic cage(BF) were conducted 3 times. Mean catching number and weight of RFN were 71.7 ind.(18.3%) and 16.9kg(64.3%), and those of BF were 93.0 ind.(23.1%) and 19.8kg(64.5%), respectively.
The purpose of this study was to investigate the effects of fertilizer application on the content of functional materials, such as fatty acids and organic acids in perilla leaves. (1) As compared to the controlled with Ammonium sulfate fertilizer, the yield of Perilla frutescens leaves increased by 7.3% and 12.8% of biomass at 2000 and 1000 times liquid respectively, but decreased by 7.6% at 500 times. The lipid and protein contents of perilla leaves were higher than those of Portunus trituberculatus liquid at 1000 times. The average contents of minerals (mg/100g) were as follows; K (638.4) > Ca (561.6) > P (145.4) > Mg (133.5) > Fe (36.2) > Zn (1.9) > Mn (1.6) > Na (1.4 mg). However, the correlation between the controlled with P. trituberculatus liquid was relatively low. (2) The fat-soluble vitamin E content of P. frutescens leaves was 3.4, 3.9, 3.3, and 3.9 mg in the controlled with liquid by 500, and 1000, 2000 times respectively; Vitamin A contents were 6.4, 8.9, 10.9, and 8.5 mg respectively, which was more than twice as much as the corresponding vitamin E content. The water soluble vitamin C contents were 177.9, 172.6, 195.2, and 163.5 mg respectively. (3) Amino acid contents of P. frutescens leaves in 100 g of fresh weight were 3821.7 mg in the controlled with Ammonium sulfate fertilizer and 3918.8, 4054.0, and 4005.4 mg in the controlled with P. trituberculatus liquid at 2,000, 1000, 500 times respectively. Amino acid contents of each controlled group with P. trituberculatus liquid above were as small as 2.5~6.1%, and these contents of amino acid were as follows: Glutaminic acid > Aspartic acid > Leucine > Arginine > Phenylalanine. In further study, it is necessary to develop an effective microorganism and a variety of amino acid fertilizer to supplement the study on new manufacturing.
참게(Eriocheir sinensis)와 꽃게(Portunus trituberculatus)의 2종으로부터 genomic DNA를 분리 추출하였다. 선택된 7개의 OPA-05, OPA-13, OPA-16, OPB-06, OPB-15, OPB-17 and OPD-10의 RAPD primer를 이용하여 identical, polymorphic 그리고 specific fragment를 얻어냈다. 본 연구에서 부안산 참게 집단에서는 505개의 fragment