• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.28-34
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• 2016

The anatomy and histology of the olfactory organ in Favonigobius gymnauchen was investigated using a stereo microscopy, light microscopy and scanning electron microscopy. The paired olfactory organs in the dorsal snout are set in between the upper lip and the eyes. These organs are composed of two openings (anterior nostril with a tubular structure and posterior nostril), a single olfactory cavity, two nasal sac (ethmoidal and lacrimal sacs), olfactory nerve and olfactory bulb. The distributional pattern of the sensory epithelium is a only one type (continuous type). This epithelium is made up of the receptor cell, supporting cell and basal cell. The receptor cell has a only one type (ciliated receptor cell with 3~4 cilia). The non-sensory epithelium is built of the stratified epithelial cells and has mucous openings on the surface. Such an olfactory organ in F. gymnauchen may be considered to reflect its ecological habitat as a shallow water or tidal pool in the coastal zone.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.117-119
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• 1970

A goby Synechogobius hasta (TEMMINCK et SCHLEGEL) was studied on the length-weight relation-ship, and the fish were sampled from the closed tributary and the lower part of the Naktong River, near Pusan, during the period from November of 1967 to December of 1968. The data for this study were taken from 1,050 fish. The relationships between the body length (X) and body weight (Y) are indicated as follows: 7.5cm to 32.5cm: $Y=0.09863X^{2.17926}$ 7.5cm to 19.5cm: $Y=0.04995X^{2.472l6}$ 28.5Cm to 32.5Cm: $Y=0.0004127X^{3.67265}$ The normal relative growth was not found in fish between 20.5cm and 27.5cm in body length, because of the maturity of gonads and spawning.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.982-987
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• 2015

During the study period, a total of 158 individuals of Synechogobius hasta were collected. The range of body length (BL) was 15.4-44.5 cm. The stomachs of 26.6% of the individuals were empty. The most abundant prey was shrimp. Among shrimp, Exopalaemon orientis was the most abundant species, being present in 27% in %IRI (index of relative importance). Fishes and crabs were also abundant prey. Analysis of ontogenetic changes, suggested that shrimp were the main prey of S. hasta of two size classes (<20 and 20-25 cm). The proportion of shrimp decreased, but that of fishes and crabs increased, with increasing body length, beginning at the 25-30 cm size class. In spring, fishes were the dominant prey, while shrimps, and crabs and fishes dominated in autumn and winter, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.1
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• pp.41-47
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• 2017

Perhaps the most common type of reproductive dysfunction in captive fish is failure of females to undergo final oocyte maturation and thus to ovulate and spawn. The success of aquaculture could therefore be improved by developing techniques to enhance natural spawning, artificial maturation, and/or to induce ovulation in farmed fish. This study aimed to investigate the effects of prostaglandin $E_2$ ($PGE_2$) and prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$) on in vitro oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation in the marine fish Chasmichthys dolichognathus. Post-vitellogenic follicles (0.80-0.94 mm diameter oocytes) were incubated with $PGE_2$ or $PGF_{2{\alpha}}$ at concentrations of 5, 50, or 500 ng/mL for 24 hours. A significant increase in GVBD was seen in 0.84 mm and 0.94 mm oocytes incubated with 50 ng/mL $PGE_2$ compared with the control. There was no significant increase in GVBD in any of the other experimental conditions (5 or 500 ng/mL $PGE_2$ or 5, 50, or 500 ng/mL $PGF_{2{\alpha}}$). Neither of the prostaglandins induced ovulation at the concentrations tested.These results suggest that GVBD was induced by incubation with 50 ng/mL $PGE_2$.

• Analytical Science and Technology
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• v.23 no.5
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• pp.492-497
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• 2010

In this study, mercury concentrations in freshwater fish from Lake An-dong basin were investigated and were compared with the results of the national freshwater fish monitoring survey. The mercury concentrations of fish from Lake An-dong were in the range of 37~611 ng/g and Korean piscivorous chub, the top predator showed the highest average mercury concentrations, $198{\pm}97\;ng/g$. Most of fish caught from upstream of Lake An-dong were herbivorous and omnivorous, and goby minnow and pale chub showed relatively lower mercury concentrations of $21{\pm}16\;ng/g$ and $33{\pm}24\;ng/g$, respectively. Especially, mercury concentrations of long nosed barbel and largemouth bass caught from Lake An-dong were found to be higher than those of the average of the national survey monitoring data.

• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.333-337
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• 2012

We encountered an indigenous case of intestinal capillariasis with protein-losing enteropathy in the Republic of Korea. A 37-year-old man, residing in Sacheon-si, Gyeongsangnam-do, admitted to the Gyeongsang National University Hospital (GNUH) due to long-lasting diarrhea, abdominal pain, anasarca, and weight loss. He recalled that he frequently ate raw fish, especially the common blackish goby (Acanthogobius flavimanus) and has never been abroad. Under the suspicion of protein-losing enteropathy, he received various kinds of medical examinations, and was diagnosed as intestinal capillariasis based on characteristic sectional findings of nematode worms in the biopsied small intestine. Adults, juvenile worms, and eggs were also detected in the diarrheic stools collected before and after medication. The clinical symptoms became much better after treatment with albendazole 400 mg daily for 3 days, and all findings were in normal range in laboratory examinations performed after 1 month. The present study is the 6th Korean case of intestinal capillariasis and the 3rd indigenous one in the Republic of Korea.

• Parasites, Hosts and Diseases
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• v.44 no.1 s.137
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• pp.7-13
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• 2006

Heterophyid metacercarial infections in brackish water fishes, i.e., perch, shad, mullet, redlip mullet, and goby, of Jinju-man (Bay), Kyongsangnam-do, Korea, were investigated using a digestion technique. Among 45 perch (Lateolabrax japonicus), the metacercariae of Heterophyopsis continua were found in $55.6\%$ (18.5 metacercariae per fish), Stictodora spp. in $28.9\%$ (3.6), and Metagonimus takahashii in $6.7\%$ (17.0). The metacercariae of H. continua were detected in 23 $(65.7\%)$ of 35 shad (Konosirus punctatus). Among 15 mullet (Mugil cephalus), the metacercariae of Pygidiopsis summa were found in $100\%$ (105.9 metacercariae per fish), Heterophyes nocens in $40.0\%$ (8.5), H. continua in $13.3\%$, and Stictodora spp. in $6.7\%$. Among 12 redlip mullet (Chelon haematocheilus), the metacercariae of P. summa were detected in $91.7\%$ (1,299 metacercariae per fish), H. nocens in $16.7\%$, and Stictodora spp. in $16.7\%$. Among 35 gobies (Acanthogobius flavimanus), the metacercariae of Stictodora spp. were found in $82.9\%$ (44.5 metacercariae per fish), and H. continua in $25.7\%$ (2.8). The adult flukes recovered from a cat experimentally infected with metacercariae from perches were compatible with M. takarashii. The results confirm that the estuarine fish in Jinju-man (Bay) are heavily infected with heterophyid metacercariae. Furthermore, it was found for the first time that the perch acts as a second intermediate host for M. takahashii.

• Korean Journal of Ichthyology
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• v.25 no.4
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• pp.227-233
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• 2013

Speceis composition and distribution by altitude of fish in the rock tide pools in Taean were determined using montly samples collected in the 9 tide pools from January to December 2010. Among 16 species collected, a forktongue goby Chaenogobius annularis was dominant accounting for 34.6% in the total number of individuals, and followed by Dictysoma burgeri (22.0%), Sebastes schlegelii (6.9%) and Tridentiger trigonocephalus (6.8%). A resident fish Dictyosoma burger occurred at all tide pools, and Chasmichthys dolichognathus was dominant in the upper tide pools and was collected throughout the study period. The resident fish is more abundant than the transient fish and occasional fish accounted for 61.4%, 14.2% and 24.4% in biomass, respectively.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.267-272
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• 2016

The feeding habits of Chaenogobius annularis were studied based on gut contents analysis of 315 individuals, collected from September 2014 to August 2015 in the tidepools at the intertidal zone of Tongyeong, Korea. The size of C. annularis ranged from 17.0 to 54.0 mm in standard length (SL). C. annularis mainly consumed copepods (especially Tigriopus japonicus). Its diets included seaweeds, cirripeds, mysids and amphipods. C. annularis showed ontogenetic changes in feeding habits. Small individuals fed mainly on copepods. As body size increased, the portion of seaweed increased, whereas the consumption of copepods decreased.

• Animal Systematics, Evolution and Diversity
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• v.12 no.4
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• pp.331-347
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• 1996

The geographic distribution and variation for Rhinogobius brunneus were surveyed by means of allozymic and morphological analyses and it was revealed that the Korean populations of R. brunneus comprise three distinct types, Type-A, Type-B, and Type-C, which show considerable differentiation to a degree of interspecific level(Rogers' S(1972): $S_{A-B}$=0.631, $S_{A-C}$=0.628, $S_{B-C}$=0.661). In addition, no evidence of gene flow among the types was found at sympatric area and it is assumed that reproductive isolation is completed. Moreover there is microhabitat segregation according to the distance from river mouth among each types and which segregation was regarded as a factor to facilitate reproductive isolating mechanism. Therefore, based on the evidence presented above, these three types of R. brunneus are considered as typical discrete species.