• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.122-123
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• 2005

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1996.06a
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• pp.355-357
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• 1996

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.1
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• pp.28-36
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• 1974

For the development of acoustic fishing method, we had been researched a fundamental study which concerned on the sound production and behaviour of crabs was conducted. For specimen crabs such as Portunus trituberculatus and Charybdis japonica were selected. Croaking noise were recorded by the Cassette-recorder (Sony model CF-1600) through the under water monitor microphone, and analyzed in frequencies by Octave band analyzer, Rion SA-55, and sound pressure level of source by sound level meter, SM-5844. The following are the results obtained from the present investigations : When sound production of crabs (Portunus trituberculatus( female ) : carapace width $12.6\~15$cm) were attracted to another crabs in the water of anechoic aquarium, efficacy of phonotaxis was $84\~100\%$ and velocity by phonotaxis was $6.5\~7.2cm/sec$. The time required for copulation ranged from 90 minute to 95 minutes by Charybdis japonica, at that time there was no sound production with their copulation.

• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.121-121
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• 2005

• The Korean Journal of Zoology
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• v.1 no.1
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• pp.9-16
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• 1958

In this paper the author reports on 4 species of crabs qhich were collected during August 20th-26th 1957 in the Island Quelpart. Among them Philyra kanckoi Sakai, Charybdis japonica A. Milne Edwards, Macrophthalmus dilatatus de Haan are unrecorded species on the Island Quelpart and phynchoplax messor Stimpson is unrecored one in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.535-544
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• 1998

Seasonal variation of the crab community in the eelgrass (Zostera marina) bed in Kwangyang Bay was studied based on the monthly collections through a year of 1994. The crab community in the eelgrass bed was composed of 21 species representing 12 families. The community was dominated by Charybdis Japonica, Telmessus acutidens, Hemigrapsus penicillatus, and Pugettia quadridens. Crabs collected in the study area were primarily small-sized species or early juveniles of large crab species. Most individuals had carapace width smaller than 25 mm except C. japonica and T. acutidens which had maximum carapace width over 85 mm. More than 5 species were collected every month except January and February (4 and 3 species, respectively). The peak abundance occurred in August and low abundances in autumn and winter. Species diversity indices showed that more diverse crabs were collected In spring and summer, and lesser ones in autumn and winter. The crabs in the study area can be grouped into three groups on the basis of their occurrence patterns: resident species, seasonal species, and temporary species. More abundant and more diverse crabs were collected during nighttime than daytime.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.20-28
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• 2005

Species composition and seasonal variation of decapod crustacean assemblage in Hampyeong Bay, Korea were examined. Sampling was monthly made by a shrimp trawl between March 2003 to February 2004. A total of 39 species of 20 families were collected. Of these, Latreutes planirostris, Palaemon gravieri, Parapenaeopsis tenella, Exopalaemon carinicauda, Charybdis japonica, Trachysalambria curvirostris and Palaemon macrodactylus were dominant species comprising $84.3\%$ of the total number of individuals. Charybdis japonica, P. gravieri, Oratosquilla oratoria, E. carinicauda, T curvirostris, Metapenaeus joyneri and P. tenella represented $90.6\%$ of the total biomass. While total abundance (number of individuals) was high in spring, total biomass and species richness (number of species) and diversity were high in summer. Cluster analysis, based on monthly abundance data of the 14 most common species, showed that the species were separated into three different groups. Group A composed of Leptochela gracilis, Alpheus japonicus, Crangon uritai, P. macrodactylus, E. carinicauda, P. gravieri, O. oratoria, C. japonica, which were year round residents, group B M. joyneri, T. curvirostris and P. tenella, which were abundant in summer, and group C Crangon hakodatei, Latreutes anoplonyx and L. planirostris, which were abundant in winter. Principal component analysis revealed that seasonal variation in the decapod crustacean assemblage was attributed to the abundance of temporal species such as penaeid shrimps, which were abundant in summer, due to seasonal variation of water temperature and reproductive pattern.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.348-354
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• 1987

The behavior of crab, Charybdis japonica h. Milne EDWARDS, to the net pots with baits was investigated alternately in the experimental tanks. One of the pots being dropped on the tank bottom, the crabs touched it to obtain the bait probably reacted by their senses of smell and sight, and increased gradually in the number of touch to show a maximum within 30 min. The crabs, if touched circular pots, were guided more easily to the pot entrances than the case of touching square ones, but the guidance from the vicinity of the entrances into the pots was easier in the square. When the crabs entered the pots, they always showed a sharp precaution. However, most of enterings were made mainly within 30 minutes and easier in pots with lower entrances. If 30 min. elapsed, the entering was little made by the decrease in the number of touch and the getting-out was remarkable, especially in pots with low entrances. But, in all the pots the getting-out was hampered by the drawing of the entrance tips into the pots. In case in which flappers were attached to the entrance tips, the entering was very hampered, hut the getting-out was not shown.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.310-314
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• 1990

In order to find out the most favorable shape and structure of pot for crab, Charybdis japonica Edwards, the common box type and cylinder type of net pots with two entrances, and the modified cone type and box type of net ones with four were prepared respectively. Then, the ability of the above pots attracting the crab into them and their catches were investigated through tank and field experiments. The attracting ability was higher in pots with four entrances than those with two. In case of two entrance pots, the ability was a little higher in the cylinder type than in the box type. But in four entrance pots, the box type yielded a little higher ability than the cone type. The catches were also arranged by the pots in almost same order with the attracting ability. But, it was only added to the arrangement that the cone type with four entrances had no significant difference of catch with the cylinder type with two entrances. Thus, the most favorable pot for the crab was concluded to be the box type with four entrances.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.14 no.1
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• pp.15-36
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• 1978

Underwater sounds of some fishes and crabs were analyzed in the laboratory. The behavioral responses to the playback sounds of their feeding and croaking sound were investigated. The samples used in the experiment were as follows: Nibea albiflora, seriola quinqueradiata, Navodon modestus, Fugu xanthopterus, chrysophrys major, Scylla serrata, Telmessus acutidens, Charybdis japonica, and Portunus trituberculatus. The feeding and croaking sounds of the samples were recorded by a tape recorder through a hydrophone in an anechoic aquarium. The sound intensity level was measured by means of a sound level meter at an anechoic chamber. The frequency, intensity and wave form of various sounds were analyzed with an analyzing system consisting of a 1/3 octave filter set, a high speed level recorder, an amplifier, an octave band analyzer and an oscilloscope. The most successful recording was edited into a sequence of sound track which repeats sound emitting for 5 to 7 seconds after pausing for 5 to 7 seconds. The sequence was then reproduced into an anechoic aquarium through the under water speaker. The experimental anechoic aquarium used for the sample fishes was divided into the four sections with any three screens selected from 40$\times$40mm, 60$\times$60mm, 80$\times$80mm and 100$\times$100mm mushes according to the species of the fishes, besides that for crabs were not sectioned. The results of the investigation are as follows: 1. Of the feeding sound of fish, the frequency of wave from of the sound produced by Nibea albiflora and seriola quinqucradiata was 125～250Hz, that by Navodon modestus 63～125Hz, and that by Fugu xanthopterus 400～500Hz. The pressure level of the feeding sound produced by Nibea albiflora and Seriola quinqueradiata was 56～62db, that by Navodon modestus 57～59db, and that by Fugu xanthopterus 60～64db. 2. Of the croaking sound of Nibea albiflora, the frequency of the sound was 125～250Hz almost equivalent to that of feeding sound, and the pressure level was 62～63db, slightly higher than that of feeding sound. 3. Of the croaking sounds of crabs, the frequency of the sound produced by scylla serrata was 125～250Hz, that by Charybdis japonica and Telmessus acutidens 500～1,000Hz, and that by Portunus trituberculatus 250～500Hz. The pressure level of the croaking sound by Scylla serrata was 68～70db, and that by Charybdis japonica, Telmessus acutidens and Portuens trituberculatus 50～62db. 4. Phonotactic responses of Nibea albiflora and Seriola quinqueradiata to the feeding sounds produced by their own species, the same body length were conspicuous with the phonotactic index of 56～87%, but that of Navodon modestus, Chrysophrys major and Fugu xanthopterus were hardly recognized. 5. Phonotactic responses of the sample fishes to the sinusoidal sound with the frequency range of 50 to 9,000 Hz were observed not conspicuous. 6. Phonotactic responses of Portunus trituberculatus to the croaking sounds produced by their own species was varied in the range of 40～100%, according to the carapace length and the sex.