To study the lipid adsorption characteristic of chitosans with different molecular weights and the degrees of deacetylation, in vitro test and near-infrared (NIR) spectroscopic analysis have been performed for the measurement of lipid adsorption characteristics of chitosan. The degrees of deacetylation in chitosans were $70{\%},\;85{\%}\;and\;92{\%}$ at different deacetylation times (1 hr, 2 hrs, 3 hrs), respectively. The molecular weight of each chitosan was controlled by enzymatic hydrolysis, and then the molecular weight of the chitosan was 4 kDa. The bulk density, water holding capacity and fat binding capacity of each chitosan powder were $96.2-504.0{\%},\;374.4-1217.9{\%},\;and\;307.0-659.3{\%}$, respectively. The higher molecular weight of chitosan was exhibited the lower bulk density and the higher water and fat binding capacities. Bindinf capacities of chitosan powders to bile salts, cholesterol and linoleic acid were $41.2-63.3{\%},\;40.8-67.4{\%},\;42.6-72.6{\%}$, respectively. In NIR spectrum of lipid adsorbed chitosan the occurrence static eletronical binding between chitosan and lipid was identified by NIR spectrum peak induced from combination of carboxylic group in lipid and amino group in chitosan. In conclusion, the higher degree of deacetylation and molecular weight of chitosan showed the higher lipid binding capacity and the lipid adsorption of chitosan were occurred by combination of carboxylic group in lipids and amino group in chitosan.

Powder and liquid products of the seasoned and smoked fish were manufactured with small-sized skipjack tuna (Euthynus pelamis) captured in the East Sea, Korea. The property changes of nucleotides and their related compounds, amino acid, and sensory attribute during storage were analyzed. IMP content was the highest among the nucleotides and their related compounds followed by inosine in both powder and liquid products. Nucleotides and their related compounds of the powder product increased slightly as storage period increased, while those of liquid product were constant. Glutamic acid $(15.6{\%})$, aspartic acid $(10.7{\%})$, and lysine $(9.3{\%})$ were major amino acids of the power product, while histidine $(36.2{\%})$ and taurine $(10.6{\%})$ were high in the liquid product. Free amino acid contents of liquid product increased during storage periods. There was no significant difference In the concentration of nucleotides and their related compounds, and composition of free amino acid between the products with/without liquid smoke. Aroma and acceptance were good in both products, while bitterness and sweetness were poor.

This study evaluated polymanuronates on the differentiation of 3T3-L1 adipocytes. Polymannuronates increased glucose utilization and reduced the accumulation of triglycerides in the cells. The differentiation showed the same results as Oil red O staining. Also, the polymannuronates inhibited GPDH activity as a result of the restrained adipogenesis promotion process in 3T3-L1 adipocytes. The addition of the differentiation promotion factor to 3T3-L1 promoted the differentiation of adipocytes and increased the expression of the leptin level. However the addition of polymannuronates inhibited differentiation of adipocytes and the leptin secretion level in cells by checking the leptin protein level in the culture media. As well as this, it also inhibited the transcriptional mechanism and leptin mRNA expression. These results suggest that the addition of polymannuronates improves the physiological function of 3T3-L1 cells by reducing the accumulation of triglyceride and GPDH activity, and the repressing expression of leptin at a molecular level.

The toxic impact of parathion on bagrid catfish (Pseudobagrus fulvidraco) juvenile was examined 96 hr $LC_{50}$ value of parathion estimated as 1 90 mg/L. Chronically, bagrid catfish were exposed for 30 days to concentrations of parathion, i.e. 63, 95, 190 and $380\;{\mu}g/L$, representing 3.3, 5.0, 10.0 and $20.0{\%}$ of the 96 hr $LC_{50}$. Survival rate was significantly affected by the concentration over $63\;{\mu}g/L$ after 10 days. Growth rate, specific growth rate (SGR) and feed efficiency were reduced in time as concentration dependent manner. Growth rates of the exposed groups were significantly reduced as $28.06-60.63{\%}$ to the control fish, SGR was decresed as $1.50-4.72{\%}$ and feed efficiency was declined as $6.10-11.90{\%}$. It can be concluded that if p. lulvidraco is chronically exposed to parathion over $63\;{\mu}g/L$ concentration, the physiological damages might affect growth factors of the fish.

Gonadal development, gametogenesis, reproductive cycle, gonad index, and flesh weight rate of the murex shell (Ocenebra japonica) collected from the rocky intertidal zone of Buan-gun, Jeollabuk-do, Korea were investigated by means of histological method from January to December 2002. O. japonica had separate sexes, and was oviparous. The gonad was widely situated on the surface of the digestive gland located in the rear of the spiral flesh part in the shell. The male penis was located near the two tentacles. The ovary was composed of a number of oogenic follicles, and the testis was composed of several spermatogenic tubules. The size of ripe oocyte was approximately $140{\mu}m$ in diameter. The gonad index (GI) began to increase in March $(33.24{\pm}2.33)$ and reached the maximum in June $(47.77{\pm}1.90)$ Thereafter, the values decreased from July $(45.12{\pm}3.60)$ to October $(19.32{\pm}2.91)$. The flesh weight rate (FWR) began to increase in January $(25.93{\pm}1.32)$ and reached the maxium in May $(31.78{\pm}1.09)$ Thereafter, the values decreased from June $(31.50{\pm}0.66)$ to October $(24.09{\pm}1.60)$. The reproductive cycle could be classified into five successive stages: early active (October to April), late active (January to June), ripe (May to September), spawning (July to September) and recovery (September to February). The reproductive cycle was closely related to the seawater temperature.

Annual reproductive cycle of Siganus canaliculatus was studied based on monthly variation of gonadosomatic index (GSI) and histological changes of gonads. Samples were monthly collected by a set net along the southern coast of Jeju Island, Korea from January to December, 1996. Variation of the monthly mean GSI values showed similar trends in female and male. The GSI values increased from June and reached a peak in the spawning season in July $(9.65{\pm}1.96\;in\;females,\;10.00{\pm}4.27\;in\;males)$, and decreased rapidly thereafter. Female hepatosomatic index (HSI) values ranged from $1.26{\pm}0.22\;(in\;April)\;to\;2.34{\pm}0.39$ (in July), and male HSI values ranged from $1.27{\pm}0.21\;(in\;April)\;to\;1.87{\pm}0.30$ (in October). Annual reproductive cycle was classified into the following successive stages: in female, growing stage (from February to June), mature stage (from June to July), ripe and spawning stage (from July to August), recovery stage (from August to March); and in male, growing stage (from January to June), mature stage (from June to July), ripe and spent stage (from July to August), and recovery stage (from August to April). Based on these data, this species has a group-synchronous oocyte development and one spawning season a year.

Growth performances of the selected and the non-selected red sea bream (Pagrus major) lines were evaluated up to marketable size. The offspring were mass-produced either from the selected line (the fourth generation of broods from mass selection) or the non-selected line (the second generation of wild broods). Early (59 to 103 days old, trial I) and late growth performances (4 to 24 months old, trial II) were evaluated based on communal rearing in land-based tanks and sea cages, respectively. In trial I, the selected line exhibited significantly higher values in both weight gain (WG) and specific growth rate (SGR) when compared to those observed in the non-selected line (P<0.05). In trial II comprising of three growth phases (4-9, 9-16 and 16-24 months old), selected line showed only slightly improved in WG and SGR at the beginning two growth phases (4-9 and 9-16 months old) (P>0.05), however, displayed significantly higher values at the last growth phase (16-24 months old) (P<0.05). Overall WG and SGR throughout the experiment (4-24 months) were also significantly higher in the selected line than the non-selected line (P<0.05). Consequently, mean body weight of the selected line at 24 months old was 1.4-fold (40.8{\%}\;increased) as compared to that of the non-selected line. This present result indicates that mass selection of this species against the growth traits might be quite effective, and the present advance has important Implication in the productivity enhancement of red sea bream aquaculture.

The previous morphology-based taxonomic frameworks within the family Syngnathidae had emphasized the significance of the male brood pouch and reproductive biology in defining the group. However, several different hypotheses had been proposed by different investigators. This study has been carried out to determine the phylogenetic relationships among 19 species belonging to the order Syngnathiformes with three Gasterosteiformes species as outgroup taxa by using the mitochondrial cytochrome b DNA sequences. Phylogenetic analyses based on neighbor-joining distance, maximum parsimony, minimum evolution and maximum likelihood method strongly supported that the family Syngnathidae, the suborder Syngnathoidei and the order Syngnathiformes were all monophyletic group. Although much of previous morphological analyses were supported by our molecular data, there were some significant discrepancies between molecular and morphological work. Such an interesting result was that the weedy seadragon (Phyllopteryx taeniolatus) strongly grouped together with the New Zealand pot-belly seahorse (Hippocampus abdominalis). Considering the markedly different brooding structure between them, this unexpected result might be explained whether by multiple independent origins of brooding structure or by hybridization between the female Hippocampus and other syngnathid species having individual membranous egg compartment. In addition, the suborder Aulostomoidei was paraphyletic group because the shrimpfish (Aeliscus strigatus), belonging to the family Centriscidae, always grouped together with the family Syngnathidae as a sister taxon.

To infer phylogenetic relationships among Epinephelus species inhabiting coastal regions of Korean peninsula, mitochondrial cytochrome b genes from 9 species belonging to the subfamily Epinephelinae were PCR-amplified, cloned and sequenced. Aligned cytochrome b sequences of 10 species containing one additional sequence from GenBank were 1,140 base pairs in length, including 439 variable and 330 parsimony informative sites. The cytochrome b genes of 10 species, as other vertebrates studied to date, exhibit unequal base compositions: an entirely low G content ($15.2{\pm}0.3{\%}$on average) and almost equal T, C and A contents ($29.3{\pm}0.8{\%},\;30.7{\pm}1.0{\%},\;and\;24.8{\pm}0.5{\%}$ on average, respectively).In third codon positions, transitional substitutions especially between Epinephelus species and outgroup species are almost certainly saturated or near saturation. Phylogenetic analyses were performed with sequence data from 8 Epinephelus species and 2 outgroup species (Cephalopholis urodela and Vaviola louti) by using distance-based (neighbor-joining and minimum evolution) and parsimony-based (maximum parsimony) methods. The results showed that the monophyly of the genus Epinephelus was supported by relatively high bootstrap values. However, phylogenetic relationships among E. areolatus, E. moara, E. septemfasciatus, and Epinephelus sp were poorly resolved. Within the genus Epinephelus, three resolved monophyletic groups were found: clade 1 included E. akaara and E. awoara;, clade 2 included E. fasciatus and E. merra; and clade 3 included E. akaara, E. awoara, E. fasciatus, E. merra, E. areolatus, E. moara, E. septemfasciatus and Epinephelus Sp.

In coastal area of Inchon, dredging and the disposal of dredged material for sea-wall construction and reclamation have increased in recent years. These activities may impact the benthic environment and result in changes in benthic communities, but little information is available on the extent and direction of these changes. We investigated whether there have been changes in the dominant macrobenthic species and benthic community over the last decade, and explored the relationship between environmental variables and spatial patterns of macrobenthic community structure. We sampled macrobenthos and recorded environmental variables in the coastal habitats of Inchon in March and June 2004. In total, 212 macrobenthic species were recorded during this study, predominately crustaceans $(34{\%})$, mollusks $(32{\%})$ and polychaetes $(21{\%})$. The mean density of macrobenthos was $1,393\;ind./m^{2}$.The most abundant species was Amphioplus japonicus $(20.5{\%})$, followed by Heteromastus filiformis $(14.4{\%})$, Theora fragilis $(8.2{\%})$ and Ampharete sp. $(4.0{\%})$. Over the past decade the dominant macrobenthic species in this area shifted. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among three regions: the middle part of the sampling area (B), site 8 (C) and other sites (A). Mean density varied significantly among the three regions, but no differences in the number of species and diversity (H') were observed. The distribution of the macrobenthic community was affected by environmental variables such as percentage sand content and sediment kurtosis. Species that were important in different areas included A. japonicus in region A, Raeta puchella in region B and T. fragilis in region C. The important species in regions B and C were filter-feeding bivalves, and the abundance of these species may be related to the increase in percentage sand content. We suggest that the sediment composition (percentage sand content) may be an important factor in determining the dominant species and structure of the macrobenthic communities in coastal Inchon. Long-term monitoring programs are necessary to understand ongoing changes in the benthic communities of this area.

The movement range and diurnal behavior of red seabream (Chrysophrys major) tagged by the ultrasonic pinger externally were measured by acoustic telemetry techniques in the marine ranch of Tongyeong on 20 March to 30 October, 2003. The movement of fishes was monitored with the radio-acoustic linked positioning (RAP) buoy system and VR2 receivers. The test fishes showed behavior. pattern going to deep waters and returning to shallow waters. They moved gradually to deep waters as time goes by. They had a tendency to move wider range in night-time than day-time. It was found that the test fishes rarely showed a significant response to the artificial reefs.