• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.151-159
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• 2012

Cross and reciprocal hybrids from intrageneric crosses between Rhodeus uyekii and R. notatus were analyzed morphometrically using truss and classical dimensions, erythrocyte size using blood smears, and cytogenetically using flowcytometry, then compared with the parental species. Although the morphometric assessment based on body proportions indicated that the hybrids were generally intermediate between the maternal and paternal species, the morphometric characters of cross and reciprocal hybrids included at least 14 paternal-like and 7 maternal-like, and 13 paternal-like and 5 maternal-like characters, respectively (P<0.05). The pigmentation of the hybrids was intermediate in some respects, and resembled that of the parental species. The DNA content of the cross and reciprocal hybrids, based on flow cytometry analysis, was significantly different from the parental species. The characterization of morphometric traits and the cytogenetic analysis of hybrids of R. uyekii and R. notatus used in this study may be useful for distinguishing genotypes in commercial Acheilognathinae aquaculture.

• Journal of Aquaculture
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• v.10 no.1
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• pp.49-54
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• 1997

Characteristics of sex ratio and morphometric traits of induced allotriploid between female rainbow trout, Oncorhynchus mykiss and male cherry salmon, O. masou were performed. Sex ratios in both rainbow trout and cherry salmon were equally 1:1, while hybrid and allotriploid revealed higher proportion of male offspring (p<0.01). Body trait measurements of allotriploid in head hight/head length, length of dorsal fin base/body length and length of pectoral fin/body length were intermediate to their parental species, while in length of upper jaw/head length, allotriploid much more resembled that of rainbow trout. These facts proved that allotriploidization improved characters in sex ratio and morphometric traits compared to those o their parental species.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.507-517
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• 2020

Several methods including morphometric analysis were used to distinguish small yellow croaker (Larimichthys polyactis) from yellow croaker (Larimichthys crocea), which have very similar external shapes. Morphometric analysis showed four considerable differences (p<0.05) among the total 48 morphometric dimensions, but no differences were seen in the classical dimensions (p>0.05). Rather, significant differences were seen in two truss dimensions: Insertion of dorsal fin base - origin of pectoral fin base and origin of anal fin base - origin of pectoral fin base, and two head part dimension: most anterior extension of the head - above of eye and above of eye - posterior aspect of operculum(p<0.05). However, the yellow croaker had higher values than the small yellow croaker in the other three morphometric dimensions except for the head part dimension of above of eye - posterior aspect of operculum of the four morphometric dimensions (p<0.05). The X-ray photographs indicated that the small yellow croaker (45.1±2.34°) had 8.4% more curved vertebral column than the yellow croaker(38.4±1.82°). A diamond-shaped cranium was found when the skin was peeled off from both fish but the commonly held fact that only the small yellow croaker has a diamond-shaped cranium is not accurate. Our results confirmed that the two fish could be definitely distinguished by their external body shape.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.209-215
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• 2006

A closely associated set of characteristics was analyzed using both classical and truss dimensions to discriminate the morphometric traits of three species of torrent catfish (Amblycipitidae) in Korea. After arcsine square root transformation, 18 measurements relative to the standard length and three measurements relative to the head length of each species of torrent catfish were compared statistically. Classical and truss dimensions of each of four morphometric traits showed higher values in the bullhead torrent catfish, Liobagrus obesus, than the Korean and south torrent catfish (L. andersoni and L. mediadiposalisa, respectively; P<0.05). Truss dimensions of three morphometric traits were higher in the bullhead and Korean torrent catfish than in the south torrent catfish (P<0.05). There were no significant differences in six morphometric traits among these Amblycipitidae. The dimensions used in this study may be useful as taxonomic indicators to discriminate species of Liobagrus in Korea.

• Journal of Aquaculture
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• v.17 no.3
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• pp.197-208
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• 2004

Five commercially valuable Korean Veneroid, Protothaca jedoensis, Ruditapes philippinarum, Saxidomus purpuratus, Cyclina sinensis and Meretrix lusoria were recognized by comparing internal and external morphological characters. As length of the primary tooth was directly grown proportional to shell size but all other characters were not measured according to size of shell. Hence, the morphological characters of these Veneroids may be estimated from the size of the unique primary tooth and it might be enough to be a good criterion for identification of species among Veneriods. Numerical index of hinge plate length of these species was assessed systematically, irrespective of measuring the length, height and width of the shell. The highest internal and external morphological similarity was observed between P. jedoensis and R. philippinarum and the lowest similarity was observed between P. jedoensis and M. lusoria. These similarities may be affected by multiple environmental factors as well as genetic characters. For artificial seed production of P. jedoensis, R. philppinarum, a closest relative among the five species, must be focussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.404-408
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• 1999

To analyze the possibility for the genetic improvement at the early period at 60 days of age in tilapia, Oreochromis niloticus. Genetic parameters on eight traits, total length (TL), standrad length (SL), head length (HL), body depth (BD), body height at the origin of dorsal fin (BH1), length from the origin of dorsal fin to the origin of dorsal fin (BH2), snout length (SNL), and body weight (BW), were estimated by sib analysis. Heritabilities estimated from sire, dam and full-sib components were moderately high in all metric traits, ranged 0.08$\~$0.70, 0.22$\~$0.41 and 0.18$\~$0.55, respectively. Those of SL from sire, dam, and full-sib component were estimated as 0.13, 0.22, and 0.18, respectively, Besides BH1, BH2 also showed high heritabilities, $h^2_s$ (0.08), $h^2_d$ (0.38) and $h^2_{s+d}$ (0.23), indicating that it would be a new production-related metric trait for selection. Among the metric traits, phenotypic and genetic correlation coefficients were ranged from 0,86 to 0.97 and from 0.90 to 0.99, respectively. Thus, genetic improvement would be possible at the early growth rate by the individual selection in tilapia.

• Korean Journal of Ichthyology
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• v.7 no.2
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• pp.128-134
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• 1995

In order to study the taxonomic status of Cottus species from Korea, 19 morphological characters, egg number and size and hatched juvenile form in C. poecilopus and C. hangionsis were compared. The two species of C. poecilopus and C. hangionsis overlap each other in morphometric characters mostly, but snout length, caudal peduncle length and pectoral fin ray number were distinguished between them. Moreover the C. poecilopus and C. hangionsis specimens were differ from each other in the number of egg and size. The newly hatched juvenile form of C. hangiongensis produced many small eggs from which pelagic larvae were formed. In contrast, C. poecilopus produced well - developed juveniles. Two species have distinctly different life - cycles ; amphidromous for C. hangionsis and fluvial land - locked for C. poecilopus.

• Korean Journal of Ichthyology
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• v.29 no.3
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• pp.176-189
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• 2017

Age estimation and sexual dimorphism of Coreoleuciscus splendidus were estimated using otolith, length-frequency distribution and 23 morphological measurements, from 245 individuals collected from September 2016, February and April 2017 in the Gapyeong stream, Han River, Korea. Result of age estimation of C. splendidus, we most examined were 2, 3 and 4-age, and the maximum observed ages were 5-age. Nine out of twenty-three morphometric measurements were significantly different between the genders. Anal fin have showing major sexual dimorphism in particular between adult individuals. This sexual dimorphism was based on extension of anal fin soft rays of male individuals. Therefore anal fin of males is always longer and wider than females. During spawning season male individuals possess nuptial tubercles on anal fin rays. However, another measurements and morphological characters does not exhibit sexual dimorphism in the between male and female individuals. The sexual dimorphism was observed to only over 2-years old individuals with sexual maturity. But juvenile and 1-years old individuals do not have sexual dimorphism with sexual maturity. Peak season of spawning was April to May and they start first spawning at 2-age. The ages at major spawning groups were most 3-age, and they maximum GSI index was 14.91 (female), 8.96 (male) at 5-age, respectively.

• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.42-47
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• 1991

A suspected intergeneric hybrid cross between Pungtungia herzi and Pseudopungtungia nigra was collected at the Ungcheon River. Overall hybrid index did not show the hybrid connection clearly, but the most striking key character between two genus, pigmentation on the all fins except pectoral, the shape and position of the mouth part appeared to show the intermediary. So this specimen was thought to be an intergeneric natural hybrid which merits further study.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.351-368
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• 2004

Following the previous experiments, a starvation experiment was conducted to determine the influence of feeding and starvation on the histological and biochemical changes, the morphormetric changes in the sectioned body and the morphometric changes in Rhynchocypris oxycephalus (Sauvage and Dabry). The influence of starvation on nutritional conditions of the histological changes of hepatocyte and intestinal epithelium as hepatosmatic index (HSI), protein, RNA and DNA concentrations of liver in R. oxycephalus was tested. Although the starved group showed higher concentrations of protein, DNA and RNA than the fed group, food deprivation resulted in a decrease in the HSI, hepatocyte nucleus size and nuclear height of the intestinal epithelium. The RNA - DNA ratio appears to be a useful index of nutritional status in R. oxycephalus and may be useful for determining if R. oxycephalus is in a period of rapid or slow growth at the time of sampling. Additionally, the data have been interpreted in detail and some biologically important relationships discussed. The effects of starvation on the morphometrical changes in sectioned body traits, condition factor, viscera index and dressing percentage were determined for evaluating nutritional conditions of R. oxycephalus. Starvation for nine weeks resulted in a decrease in most sectioned traits as well as in condition factor and viscera index (P<0.05). These findings suggest that nutritional parameters used in this study appear to be a useful index for nutritional status in this species. The data has been interpreted in detail and some important body sectioned values of interest to commercial growers discussed. A 75-day study was conducted to determine the effect of starvation on classical and truss parameters in R. oxycephalus. Truss dimensions of almost the entire head and trunk region as well as the abdomen were increased significantly through feeding or starvation (P<0.05). Truss dimensions of the caudal region generally decreased through feeding or starvation, particularly those dimensions at the hind part of the trunk. There were some significant decreases in classical dimensions of the head region during feeding, in relation to body depth characteristics in the trunk and caudal region during starvation, whereas there was only one decreasing classical dimension in the caudal region during feeding. The results of this study indicate that application of the truss network as a character set enforces classical coverage across the body form, discrimination among experimental groups thus being enhanced. Considering that the dimension of the lower part of the head and some truss and classical dimensions were least affected by feeding and starvation, these dimensions may then be useful as a taxonomical indicator to discriminate the species of Rhynchocypris sp. The value of trunk region dimensions with a large component of body depth in R. oxycephalus is most likely to be compromised by variability related to differences in feeding regimes of fish in different habitats.