• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.24-27
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• 2001

The barbel structure of the spined loach Iksookimia longicorpa were investigated histologically. Their barbels consist of epidermis, dermis, and a central rod. The epidermis contains mucous cells, terminal buds, granular cells, and epidermal cells. The mucous cells are thin rims of basophilic cytoplasm and are located at the surface of the epidermis. The terminal bud is basophilic and is situated at the distal portion of the epidermis. The dermis consists of loose connective tissue containing blood vessels, pigment cells, and nerve cells. The central region of cartilage is the innermost region and is enclosed within muscle layers.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.239-248
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• 2016

The habitat, age and spawning characteristics of the Korean eastern spined loach, Iksookimia yongdokensis, were investigated to obtain baseline data for its ecological characteristics in the Chuksancheon (stream), Yeongdeok-gun, Gyeongsangbuk-do, Korea. The difference between the habitats of juveniles (0+) and 1~4 year old loaches was that juveniles mainly inhabited sandy bottoms (substratum particle size $0.6{\pm}1.44\;cm$) with very slow velocities of water current ($2.4{\pm}2.09\;cm/sec$) and low depths ($29.2{\pm}7.57\;cm$), whereas 1~4 year old loaches inhabited pebble and cobble bottoms (substratum particle size 5.5~6.1 cm) with relatively fast velocities of water current (3.8~4.6 cm/sec) and deep depths (50~70 cm). The age groups for I. yongdokensis (female) estimated by the frequency distribution of total length in the spawning season (July) indicated that the 35~64 mm is 1-year old, the 65~94 mm group is 2-year old, the 95~119 mm is 3-year old, and the 120~145 mm is more than 4-year old. The sex ratio (♂/♀) was 0.69, and females were 10~30 mm larger than males. The lamina circularis at the base of the pectoral fins in males, a secondary sexual characteristic, formed at the 13th month after hatching. The spawning season according to the gonadosomatic index (GSI) was June to July with water temperatures of $20{\sim}25^{\circ}C$. The average number of eggs was $2,292{\pm}618$, with a diameter of $1.46{\pm}0.02\;mm$ for mature eggs.

• The Korean Journal of Zoology
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• v.36 no.4
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• pp.535-544
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• 1993

Sinca early 1930' Colitis taenia striate were introduced to the Donsgjin in Chollabukdo, where it hybridized with an endemic subspecies C. tiutheri. Protein electrophoresis revealed high levels of hybridization with intensive backcrossing occupied approximately 20 kilometers of the river. This is roughly one-half of tech historic range of the endemic species. The average frequency of introduced alleles of three diagnostic loci ranged 0.03-0.46 among 11 sites in tech svrnpatric area. Clinal patterns in allele frequencies suggest C. tiutheri were introduced in an upper reaches of the Dongjin and downstream dispersal of the introduced alleles followed. There is little linkasedisequilibrium between the diagnostic loci, suggesting the nuclear genomes of tech two subspecies are randomly associated. The evidence presented here and previously supports recognition of C. t. striata and C. t. lutheri as the typical subspecies.

• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.27-35
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• 2018

The activity period and feeding ecology of the Iksookimia yongdokensis were investigated to obtain baseline data for its ecological characteristics in the Chuksan Stream and Gokgang Stream, Gyeongsangbuk-do, Korea from 2015 to 2016. I. yongdokensis were active on cobble, pebble and sand bottom from March to November when the water temperature exceeded $10^{\circ}C$, but tended to overwinter in cobble and pebble during the winter months (December~February) when the water temperature was lower than $10^{\circ}C$. During the day from 9 am to 15 pm, individuals of I. yongdokensis were highly active with a high rate of food consumption. I. yongdokensis activley fed on the surface of stone, pebble and sand as a filter feeder. Their main food sources analyzed with an index of relative importance (IRI) include Chironomidae (54.7%), Branchiopoda (10.1%), Rotatoria (8.7%), Arcellidae (8.6%), Chlorophyceae (6.5%) and Bacillariophyceae (5.1%). Juveniles of I. yongdokensis (total length 20~39 mm) fed on small-sized preys such as Rotatoria, Branchiopoda and Arcellidae, but they exhibited a transition in their prey-size markedly dominated by large-sized preys such as Chironomidae and Ephemeroptera as they grow.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.93-101
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• 2012

In the present study, egg development and early life history of Korean spined loach, $Iksookimia$ $koreensis$, were observed. Adult fish were sampled using spoon nets in Okgye-ri, Hoengseong-gun, Gangwon-do, Korea in July 2010. Eggs were obtained after injecting females with Ovarprim. Eggs were then artificially fertilized in the laboratory using the dry method. Mature eggs were slightly adhesive and transparent with a light yellowish color, and measured $1.40{\pm}0.04mm$ (mean${\pm}$SD) in diameter. Hatching of the embryo occurred approximately 50 h after fertilization in the water at $23^{\circ}C$, and newly hatched larvae were averaged $4.7{\pm}0.21mm$ in total length. 5 days after hatching, the averaged total length of larvae was $7.1{\pm}0.25mm$ and their yolk sacs had been completely absorbed. 17 days after hatching, fish started to enter the juvenile stage and reached $12.2{\pm}1.10mm$ in total length. 80 days after hatching, the band patterns and external form of juvenile fish were similar to those of adults, and they averaged $31.0{\pm}3.98mm$ in total length.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.172-176
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• 1999

Chromosome of cobitid fishes, Iksookimia yongdokensis collected from the 4 streams flowing to the eastsouthern coast of Korea was studied using chromosome of gill and kidney cells prepared by flame drying technique. The results obtained were as follows: the chromosome number was 100 composed of 44 meta-submetacentric and 56 subtelo-telocentric chromosomes, and the fundamental number (FN) was 144. It was remarked that Iksookimia yongdogensis was distinguishable from its congeners in the karyotype. The above evidences may suggest that Iksookimia yongdokensis was one of the tetraploid species of cobitid fishes.

• Korean Journal of Ichthyology
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• v.12 no.1
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• pp.25-32
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• 2000

The structure of skin was studied in Iksookimia longicorpus based on the micro-anatomical investigation of skin fragments taken from four regions. The epidermis was distinguished by two types of skin glands, a small mucous cell and a large club cell. The mucous cell was acid sulfomucins (some sialomueins) but the club cell did not give any histochemical tests for mucosubstances. The presence of a well defined lymphatic system with small lymphocytes was established in the stratum germinativum layer of the epidermis. A large number of blood capillaries run very close to each other just below the basement membrane, and a definite area giving AB and PAS positive was present between the basement membrane and scale.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.233-235
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• 2008

A 123.2 mm TL female of Iksookimia longicorpa with a laminar circularis at the base of its pectoral fin was collected in the Hoeya River, Korea, on May 5, 2008. The specimen had full-grown ovaries like those of normal females. Its pectoral fins were larger than those of normal females, but was smaller than those of males. The laminar circularis of the pectoral fin base was more similar to normal males in its shape but was less developed. The ovaries in the individual had about 3,148 mature eggs, with egg sizes approximately $1.26{\pm}0.11mm$.

• Korean Journal of Ichthyology
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• v.2 no.2
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• pp.203-210
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• 1990

The cobitid hybrid complex of C. sinensis and C. longicorpus occurs commonly in the upper streams of the Nakdong River, Korea where it is sympatric with the bisexual species, C. sinensis and C. longicorpus.The specimens of hybrid complex which are all females accounted for approximately 40% of all cobitid fish observed. These cobitid complex having the unique cloudy specks on body sides appeared to be morphologically intermediate between C. sinesis and C. longicorpusus. The chromosomes of hybrid complex were composed of both diploid form of 49 and triploid form of 73. This forms are tentatively presumed to be a unisexual complex originating from hybrid between C. sinensis and C. longcorpus.

• Korean Journal of Ichthyology
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• v.17 no.4
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• pp.241-247
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• 2005

To observe the respiratory system in relation to the air-breathing organ in Iksookimia longicorpa, micro-anatomical investigation was performed on the epidermis and on intestinal tract fragments. The epidermis was distinguished by two types of skin glands, a small mucous cell and a large club cell. The mucous cell was acid sulfomucins (some sialomucins), but the club cell did not give any histochemical tests for mucosubstances. The presence of a well defined lymphatic system with small lymphocytes was established in the stratum germinativum layer of the epidermis. A large number of blood capillaries run very close to each other just below the basement membrane. The straight intestinal tract is divided into an intestine and rectum, which consisted of a mucosa (epithelial layer), lamina propria-submucosa, muscularis, and serosa. The intestine and rectum have shorter mucosal folds and a thinner wall. The majority of the epithelial mucous cells contain acid sulfomucines. Based on the above results, I. longicorpa adapts to poor dissolved oxygen conditions by using an additional respiratory system using air through the epidermis, not the intestines.