• The Korean Journal of Ecology
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• v.19 no.5
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• pp.477-486
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• 1996

The freshwater goby, Micropercops swinhonis ($G\"{u}nther$) was studied on the spawning behavior and egg develeopment at the two areas of Chollabukdo, Korea from March to May 1995. Egg mass attached to a layer under stones and the inner wall of waterplant, Cyperus. Spawning behavior was divided in to 1) premating stage: selecting spawning sites and formation of territory by male, 2) mating stage: enticement with zigzag-like dance and intermittant shaking of head by male and fertilization, 3) postmating stage: fanning, guarding and cleaning the nest by male. The eggs were transparent and spherical in shape, measuring $0.9\times1.4mm$ with yellowish yolk sac and many oil globules. Hatching began in about ten days after fertilization at water temperature $16~20^{\circ}C$. The newly hatched larvae were 3.8~4.0 mm in total length with 30 myomeres and their mouths and anuses were opened. Melanophores appeared at the air-bladder and the ventral side of caudal region.gion.

• Korean Journal of Ichthyology
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• v.12 no.3
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• pp.157-165
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• 2000

The skeletal system of freshwater goby Micropercops swinhonis from Korea is figured and described in detail. The osteological characteristics of the species are as follows: infraorbital bearing a subocular shelf present; mesopterygoid present and separated from metapterygoid; scapula forked and dorsal postcleithrum present; and caudal skeleton and first dorsal pterygiophore formula highly variable.

• Animal cells and systems
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• v.2 no.4
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• pp.501-506
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• 1998

In the goby Micropercops swinhonis, the development of its egg's enveloping layers could be divided into 4 stages. In the earliest developmental period, stage I, there is a simple oocyte surrounded by a layer of squamous follicular cells. Stage II corresponds to the yolk vesicle stage of vitellogenesis. Here the initial follicular layer has become bilaminar with the retention of its outer squamous cell layer and the acquisition of an inner cuboidal cell layer just over the zona radiata. The number and size of the cuboidal cells increases throughout this stage. Stage III corresponds to the yolk granule stage of true vitellogenesis. Here the cuboidal cells begin to be replaced by columnar cells. As the oocyte grows, the columnar cells increase in size. The columnar cells produce cytoplasmic neutral mucins and by the end of this stage their cytoplasm has been filled with this mucin. In stage IV a single layer of squamous cells still remained as the outer follicular layer of the oocyte. The secretory activity of the inner follicular layers' columnar cells has ceased and they had lost their cell wall integrity and ended as a series of bullet-shaped, neutral mucin deposits.

• Korean Journal of Ichthyology
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• v.13 no.4
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• pp.254-260
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• 2001

In the goby Micropercops swinhonis, the follicular layer of full-grown oocytes consists of an outer layer (theca cell) and an inner layer (granulosa cell). As the oocyte grows, columnar cells of inner granulosa layer secrete mucin to their cytoplasm and then surround the oocyte. Such granulosa cells appear to be cuboidal cells in the early vitellogenesis, yolk vesicle stage, to be replaced by columnar cell secreting mucins (adhesive materials) in the middle vitellogenesis, yolk granule stage. The enveloping layer of the oocyte has a muco- follicle layer filled with mucins. The mucins are an amorphous and electron-dense substance. Interestingly, the oocyte enveloping layer becomes thickened towards the animal pole as vitelogenesis proceeds. A zona radiata of about $7.8{\sim}11.5\;{\mu}m$ thick is present below the muco-follicle layer. The zona radiata is composed of an one-layered electron-dense externa and a three to five-layered electron-less interna.

• Korean Journal of Ichthyology
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• v.35 no.3
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• pp.151-159
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• 2023

This study investigated the early life history of the Micropercops swinhonis in Botongcheon stream Hangang River and compared the relationship between the related species and flexibility. The fertilized egg of the ovoid type, and the average egg diameter was 1.23 mm in long diameter and 0.85 mm in short diameter. At a water temperature of 20.6℃, the hatching time took 179 hours. The newly hatched larvae measured 3.82~4.08 mm in total length (TL), and their mouth and anus were not yet open. At 18 days after hatching, the postflexion larvae reached 7.97~8.43 mm in TL, with the tip of the caudal fin bent at 45°. At 29 days after hatching, the juveniles reached 9.83~10.8 mm in TL and were differentiated by their constant number of fins (7~10 first dorsal, 10~11 second dorsal, 7~10 anal fins). As a result of the study, there was a difference from the related species in the egg diameter, the newly hatched larva size. The postflexion larvae period and the development period of the first dorsal fin were the slowest among the comparable simila species, and the size was characterized by a large number, indicating a difference from similar species in the early life history process.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.178-186
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• 2006

Community structures of fish in six small eutrophied lakes, located in Gyeonggi province, Korea were investigated from September 2003 to August 2004. Total number of fish species was 33 species of 13 families in which five Korean endemic species such as Rhodeus uyekii, Squalidus gracilis majimae, Abbottina springeri, Iksookimia koreensis, and Odontobutis interrupta were found. Dominant species in the lakes was Hemiculter leucisculus. Both Zacco platypus and Pseudorasbora parva were numberous as subdominant species. In particlilar, Micropercops swinhonis known as partly distributed in the Jeonlabukdo was first recorded in Lake Wangsong and Heungbu which are located in the Gyeonggi province. In lake Myukwoo, Wangsong, and Heungbu, the proportion of Pelagic and omnivorous fish were high, reflecting that fish habitat is poor. A CPUE based fish production was the lowest in Lake Geumgwang of which lake is relatively favorable, whereas it was higher in eutriphied lakes suchs as Dukwoo, Myukwoo and Heungbu lakes.

• Korean Journal of Ichthyology
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• v.23 no.4
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• pp.288-299
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• 2011

Freshwater fish fauna and community structure were surveyed through 21 lakes in the Yeungnam area including Gyeongsangbukdo and Gyeongsangnamdo provinces, Korean Peninsula from April 2008 to October 2009. Among 21 lakes, 16 lakes belong to the Nakdong River and 5 are independent drainages. From the present study, 61 species (44 genera, 15 families) were collected including 32 cyprinid species (52.5%), 6 cobitid species (9.8%) and so on. The dominant and subdominant species in aspect of the number of individuals were Hypomesus nipponensis (26.6%) and Squalidus gracilis majimae (14.8%), respectively. On the other hand, in aspect of in biomass, dominant and subdominant species were Lepomis macrochirus (19.8%) and Cyprinus carpio (14.7%), respectively. Among 61 examined species, there were found 20 Korean endemic species and 2 Korean endangered species (Pseudobagrus brevicorpus and Pungitius kaibarae). P. brevicorpus was found in Yongyeonji and Yeongcheonho, and P. kaibarae in Yongyeonji. In addition, 5 exotic species were identified such as Cyprinus carpio nudus (leather carp), Carassius cuvieri, Hypophthalmichthys molitrix, Lepomis macrochirus and Micropterus salmoides. Interestingly, a bluegill L. machrochirus appeared dominant or subdominant species in 5 of 21 examined lakes. Five species introduced from the other rivers in Korean Peninsula were additionally described. In the present study, it was first reported that Micropercops swinhonis inhabits in the Nakdong river basin. The fish species diversity, evenness and dominant indices were examined, and a dendrogram based on similarity indices of inhabiting species among the 21 examined lakes was constructed and discussed.