• Korean Journal of Ichthyology
• /
• v.34 no.1
• /
• pp.34-43
• /
• 2022

A distribution survey was conducted from March to August 2021 to evaluate the distribution status, habitat characteristics, and threat of extinction of the Korean cold-water fish Ladislabia taczanowskii Dybowski (Cypriniformes, Cyprinidae). Historical distribution reports were divided into 1997~2005, 2006~2012, 2013~2019, and distribution surveyed 169 sampling sites, and 1,040 individuals were collected from 72 sites. Areas where the habitat was confirmed were Namhan River (27 stations), Han River (17 stations), Bukhan River (16 stations), Samcheok Osipcheon (4 stations), Yeongokcheon (3 stations), Gangneung Namdaecheon (2 stations), Jeoncheon (1 station), Chucheon (2 stations). The main habitat of L. taczanowskii was upstream of the river with a high altitude of more than 300 m, 2~30 m water flow width, 0.3~1.5 m water depth, and high ratio (50~90%) boulder bottoms. The main reasons for the decline in population size were assumed as river works, construction of reservoirs and bridges, discharge of contaminated water into the river, the inflow of summer vacationers, and weir. Compared to our results there exists evidence that states a 36.1% reduction in occupancy within 10 years, in a small appearance range (7,820 km²) and occupancy area (288 km²), number of disconnected locations (19 locations), and a decline in habitat quality. Therefore, L. taczanowskii is now considered as Vulnerable (VU) based on the results (VU A2ac, Near meets B1b (i, ii, iii)+B2b (i, ii, iii)) of IUCN Red List categories and criteria. Lastly, the conservation plan of Ladislabia taczanowskii was discussed.

• Korean Journal of Environment and Ecology
• /
• v.34 no.6
• /
• pp.551-557
• /
• 2020

This study surveyed the ecological characteristics of Ladislabia taczanowskii at Songcheon Stream from March to November 2019. The species inhabited upstream, where the riverbed structure was mostly covered with boulders and cobbles. The water depth was 31-148 cm, and the stream velocity was fast at 0.94±0.23 (0.51-1.39) m/sec. The gender ratio of females to males was 1 : 0.89. The age according to the total length frequency distribution indicated that the group with 38-70 mm below in total length was one year old, the group with 70-100 mm was two years old, the group with 100-120 mm was three years old, and the group over 120-128 mm was over four years old. The total length of sexually mature fishes was 70 mm for females and 75 mm or more for males. The spawning season was from May to August, and the water temperature was 15.5-20.1℃ during the period. The prosperous spawning season was from June to July, and the water temperature was 15.8-17.2℃ during the period. The spawning ground was where the riffle began in the pool, and its bottom was formed of sand and gravel. The width was about 150 cm, and the water depth was 20 to 50 cm. The average number of eggs in the ovaries was 821 (401-1,314) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 1.62±0.02 (1.43-2.01) mm. The live foods of L. taczanowskii Cyanophyta, Chlorophyta, Bacillariophyta, Ephemeroptera, and Diptera. The feeding habit of L. taczanowskii is omnivorous, but more than 90% of the stomach content was attached algae.

• Korean Journal of Ichthyology
• /
• v.18 no.3
• /
• pp.244-250
• /
• 2006

The ichthyofauna and fish community structure were investigated at five stations in Yeongok stream, Gangneung, during April and December 2005 monthly. During the surveyed period twenty nine species belonging to ten families were collected. Dominant species in number was Zacco platypus (relative abundance : 29.0%) and subdominant was Rhynchocypris steindachneri (12.1%). There were six Korean endemic species including Rhynchocypris kumgangensis. Koreocobitis rotundicaudata and Luciogobius guttatus that were not reported in near streams were collected in Yeongok stream only. Ladislabia taczanowskii was considered as a geographically important species. There were stabilized fish community structure with species diversity index of the community 2.521 in Yeongok stream ichthyofauna.

• Korean Journal of Environment and Ecology
• /
• v.29 no.5
• /
• pp.718-728
• /
• 2015

The fish community and inhabiting status of introduced fish were surveyed at nine stations of Gangeungnamdae stream from September 2013 to May 2014. A total of 36 species of fourteen families were collected from the survey stations and among them, Pungitius sinensis was identified as endangered species. There were nine Korean endemic species (25%) including Coreoleuciscus splendidus. Dominant species were Rhynchocypris steindachneri (St. 1), Zacco koreanus (St. 2, 4, 5, 6), Ladislabia taczanowskii (St. 3)), Zacco platypus (St. 7, 8) and Tribolodon hakonensis (St. 9). Of the 11 introduced species fishes in Gangeungnamdae stream, L. taczanowskii, Pungtungia herzi, Coreoleuciscus splendidus, Squalidus gracilis majimae, Pseudogobio esocinus, Rhynchocypris kumgangensis, Z. platypus, Z. koreanus, Koreocobitis rotundicaudata, Liobagrus andersoni and Coreoperca herzi were released from Han river water zone in Korean. Rapidly expanded population and distribution of introduces fishes were Z. platypus, Z. koreanus, P. herzi and S. gracilis majimae, but L. taczanowskii, C. splendidus, R. kumgangensis were not rapidly expanded population. Settlement but very small population fishes were C. herzi and L. andersoni. When reduced 3% fishes of relative abundance with previous data (1973), R. steindachneri, Orthrias toni, Iksookimia pacifica, Plecoglossus altivelis, P. sinensis and Gymnogobius urotaenia, and R. steindachneri was most reduced from 56.1% to 12.9%.

• Parasites, Hosts and Diseases
• /
• v.52 no.4
• /
• pp.399-412
• /
• 2014

The infection status of zoonotic trematode metacercariae was investigated in a total of 2,293 freshwater fish collected from 11 rivers or streams in 9 administrative regions of Gangwon-do, Korea for 5 years (2009-2013). All fish were collected by netting methods and examined using the artificial digestion methods. Clonorchis sinensis metacercariae were detected in 4 fish species, i.e., Pungtungia herzi, Squalidus japonicus coreanus, Acheilognathus rhombeus, and Ladislabia taczanowskii, from only Hantangang in Cheorwon-gun. Metagonimus spp. metacercariae were found in 1,154 (50.3%) fish and their average number per infected fish was 55.8. Among the positive fish species, especially Tribolodon hakonensis from Namdaecheon in Yangyang-gun and Plecoglossus altivelis from Osipcheon in Samcheok-si were most heavily infected. Centrocestus armatus metacercariae were detected in 611 (26.7%) fish and the average metacercarial burden per infected fish was 1,032. Two chub species, Zacco platypus and Zacco temminckii were highly and heavily infected with C. armatus metacercariae in almost all regions surveyed. Echinostoma spp. metacercariae were also found in 24 fish from a few localities, but their numbers per fish infected were very low. From the above results, it is confirmed that the metacercariae of intestinal flukes, especially Metagonimus spp. and C. armatus, were heavily infected, while C. sinensis metacercariae were rarely found in fish from Gangwon-do, Korea.