• Animal Systematics, Evolution and Diversity
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• v.39 no.1
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• pp.47-52
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• 2023

Thermopolynoe Miura, 1994 is a monotypic genus in Lepidonotopodinae that comprises species endemic to chemosynthesis-based ecosystems. Here, we examined T. branchiata collected from the hydrothermal vents in the North Fiji Basin. For the first time in Thermopolynoe, we report sexual dimorphism detecting nephridial papillae on segments 11-13 in males, additionally describe the morphology on elytra with round to conical microtubercles on the surface, and distinguish presence of small neuropodial lobes on segments 3-26. We also revised couple of errors and ambiguities in the original description: incongruence between the description and figure and existence of individual variation in ratio of tentacular cirri and palps. In addition, three COI sequences of T. branchiata specimens from the North Fiji Basin were newly obtained and sequences divergence with other Lepidonotopodinae species were determined. These results would contribute to the taxonomy of polynoids in a chemosynthesis-based ecosystem.

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.117-122
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• 2001

Three species, Gymnogobius urotaenia, G. sp. 1 and G. sp. 2, collected at Hosan-river, Hosan-ri, Samcheock-si, Gangwon-do, Korea, were examined for the study of sexual dimorphism. The three species have peculiar nuptial pigmentation during the breeding season: all females of the three species showed an intense black coloration on the ventral part of the head, the pelvic fin, the anal fin and the margin of the first dorsal fin. There was a difference between G. sp. 1 and the other two species in 1/3 from margin of first dorsal fin. Namely, G. sp. 1 showed an intense black coloration, whereas the other two species had an intense yellow coloration. All females of the three species showed the same, intensely yellow coloration in the ventral part of the body. Males of G. urotaenia and G. sp. 2 had almost the same nuptial pigmentation, however the former showed diffuse black coloration in the anal fin, whereas the latter had an intensely black anal fin. Males of G. sp. 1 differed from those of the other two species in their yellow color on the ventral part of the head, the pelvic f ins, the anal fin, in contrast to the diffuse black coloration in those parts in the other species. The genital papilla of males was triangle-shaped, but that of females was heart-shaped. Significant differences between sexes include: G. urotaenia, 7 characters (body depth, head length, snout length, upper jaw length, head depth, pectoral fin ray length, eye diameter); G. sp. 1, 11 characters (body depth, head length, caudal peduncle length, caudal peduncle depth, snout length, upper jaw length, head width, head depth, anal fin ray length, pectoral fin ray length and caudal fin ray length); G. sp. 2, 10 characters (body depth, head length, caudal peduncle depth, snout length, upper jaw length, head width, anal fin ray length, pectoral f in ray length, caudal fin ray length and eye diameter). Of the 5 characters which showed differences in all three species (body depth, head length, snout length, upper jaw length and pectoral fin ray length), females had higher values than males only in body depth, whereas males values in all other characters. The upper jaw length was the most distinctive sexually dimorphic feature, the upper jaw extended beyond the posterior margin of the eyes (p<0.001) in males but not in females.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.389-397
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• 2017

The purpose of this study was to investigate the characteristics of species by comparing the external shape traits and skull size of Tscherskia triton in Jeju Island from May 2014 to November 2016. Body weight, head-body length, ear length, and hind-foot length were not statistically significant (p>0.05), but tail length was statistically significant in females compared to males (p=0.003). To examine the secondary sexual dimorphism characteristics of the collected T. triton, B_HR, T_HR, E_HR, and H_HR were calculated based on the head-body length, and only T_HR was statistically significant (p=0.003). Because of comparing male and female averages, among the 21 traits, the greatest length of skull (GLS; p=0.020) and occipitonasal length (ONL; p=0.014) were statistically significant and length of incisive foramen (LIF) was statistically significant, when the significance level was 90%. However, the other 18 traits did not show statistically significant differences between males and females (p>0.05). Other than GLS, ONL, interorbital breadth (IB), and breadth of occipital foramen (BOF), there was female-biased SSD. The results of this study are the analysis of external morphology and skull characteristics of T. triton in Jeju Island and will be used as basic data to understand the morphological characteristics of T. triton. In addition, the data can be used as a basic information to compare characteristics of T. triton, which is known as a single species, inhabited in China and Russia. The data will play an important role in biogeography and ecology research of T. triton, based on geographical conditions, climate effects, and habitat environment.

• Animal Systematics, Evolution and Diversity
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• v.9 no.2
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• pp.151-170
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• 1993

Morphometric, band-pattern and electrophoretic analysis on Cobitis taenia complex were performed to investigate the morphological and genetic differentiation and to clarify their taxonomic status. Intermediate types of band-pattern (C and D type) were more frequently expressed than that of types of C. t. taenia(type A) and C. t. lutheri (type B). Sexual dimorphism of band-pattern was observed not only in C. t. taenia(type A) and C. t. lutheri(type B). Sexual dimorphism of band-pattern was observed not only in C. t. lutheri but also in C. t. taenia and C. t. striata as well. Discriminant function analysis based on 19 morphological characters shows no significant differences among C. taenia complex. The degree of genic variation of C. t. striata was higher ( =1.48, P=31.2%, HD=0.009) than those of C. t. striata was higher( =1.48, P=31.2%, HD=0.082 and HG=0.009) than those of C. t. lutheri ( =1.37, P=2.7%, HD=0.058 and HG=0.065). The average genetic similarities between C. t. lutheri and C. t. taenia-C. t. striata were S=0.62 and S=0.66 respectively and these values indicate that C. t. tanenia has evolved specific level of differentiation. C. t. striata and C. t. lutheri show subspecifc level of close genetic similarity (S=0.82). Based on the divergent time estimate (Nei, 1975) it is assumed that C. t. tanenia was branched off from the other subspecies about two million years before present (MYBP) and C. t. striata and C. t. lutheri were differentiated about 0.6 MYBP. The use of C. sinesis an the scientific name for the Korean C. t. taenia, proposed by Kim and Lee (1988) seems incorrect since they are quite different in the structure of lamina circularis (Vladycov, 1935), the external morphology and distribution (Cheng and Zheng, 1987) and the chromosome number(Yu et al., 1989). Kim and Lee(1988) also argued that C.t. striata and C. t. lutheri should be treated as distinct species but the present study and other reports (Kim and Lee, 1984; Kim and Yang, 1993) do not support it. We conclude that C. t. taenia is a good species and C. t. striata and C. t. lutheri are subspecific status. Their scientific names should be revised in the future.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.668-674
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• 2012

This study was conducted to find the sexual size dimorphism(SSD) in morphometric characters of three species, Eremias argus, Takydromus amurensis and T. wolteri in lacertid lizard from Korea. Six external traits, snout-vent length, tail length, head length, head width, forelimb length and hind-limb length were focused to compare two sexes among the each three lizards. Student's t-test was used to compare the adult SVL between the sexes for each species. For the other parts of the body, a one-way analysis of covariance(ANCOVA) with SVL as the covariate was used. In all these species, males have longer tail and head than females like general lacertid lizard. In addition, male E. arugus have broader head and longer forelimbs and hind-limbs than conspecific females. Likewise, male T. wolteri have broader head than females. In the three lacertid lizards from Korea, snout-vent length did not significantly differ between the sexes. To understand the causes for SSD in SVL, ecological information, such as the presence/absence of male-male combat and the correlation between the SVL of female and litter size, is required. Therefore, further ecological study on the three species of lacertid lizard from Korea will make it possible to explain the reason SSD is not found in SVL.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.49-54
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• 2020

The morphometry and morphology of the olfactory organ of the southern king spine loach Iksookimia hugowolfeldi were investigated by stereo microscopy and statistical analysis. Its external morphology consists of two holes, the anterior and posterior nostrils. The anterior nostril (0.35~0.53 mm in diameter) forms tubular process protruding vertically from each side of the snout. The posterior nostril (0.32~0.68 mm in major diameter) is a eye-like hole parallel to the skin. Internally, the rosette structure is set with 14 to 21 lamellae and medium raphe on the inner floor. In morphometry, its lamellar number (male vs. female; 18±1.8 vs. 17±1.6, P<0.05) and lamellar number to standard length ratio (24.2±1.3% vs. 21.7±2.5%, P<0.05) was larger in male than female. The lamellar number and standard length have high correlation in male (P<0.001) but not in female (P=0.170). It seems that such characteristics of the olfactory organ of I. hugowolfeldi are related to its bottom-dwelling life which digs and takes a rest under sand and sexual dimorphism by a distinct degree in olfactory dependence for reproduction of each sex.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.35-40
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• 2003

In this study we investigated the effect of gametocides on the number of larger-sized pollen in anther, and also induced callus from the anther culture of Zoysia japonica Steud. Before culturing, we have observed pollens in anther through fluorescence and electron microscopes to know pollen dimorphism. There were two types of pollens observed. One type (30-36 ${\mu}{\textrm}{m}$ in diameter) consisted of vacuolated, larger-sized pollens and the other (15-20 ${\mu}{\textrm}{m}$ in diameter) smaller-sized ones with dense cytoplasm and plenty of amyloplasts. Within few hours, all the smaller-sized pollens were dead, while larger-sized ones were viable for one or two days. To induct larger-sized pollens, various gametocides were leaf-sprayed on three booting stages cultured under 4$0^{\circ}C$ /15$^{\circ}C$ (day/night) before anther culturing. Number of these larger pollens were few (less than 1%) in anther without spraying gametocides. GA$_3$increased the number of larger-sized pollens when applied at mid-booting stage. GA$_3$ with 50 mg/L treatment caused the highest percentage (25.4%) of the larger-sized pollen. Anthers with GA$_3$ treatment were only produced calli on AA medium (modified B$_{5}$+8.0 mg/L 2,4-D ＋0.2 mg/L kinetin), but callus formation was quite low (less than 1%).).

• Anatomy & Biological Anthropology
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• v.27 no.3
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• pp.155-163
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• 2014

This study aimed to investigate the cusp size and morphological characteristics of permanent mandibular molars in Koreans with reference to the hypoconulid, and to analyze the differences and correlations between both sexes as well as between first and second mandibular molars. We obtained data from dental casts of 110 adults (78 males and 32 females). Mesiodistal and buccolingual diameters of first and second mandibular molars, the area of five cusps (protoconid, metaconid, hypoconid, entoconid, and hypoconulid), as well as the total cusp area and occlusal table area were measured. Paired t-test was performed to analyze the morphological differences between first and second mandibular molars and the sex differences between both sexes using SPSS program. Crown diameters and cusp areas of mandibular first molars were larger than those of mandibular second molars in both sexes. The hypoconulid was the most variable in size and morphological pattern among the five cusps, and the first molars showed a higher incidence of hypoconulid than the second molars. Except for the entoconid area of the first molar (p=0.06) and the hypoconulid area of the second molar (p=0.24), all other mean values were larger in males than in females, demonstrating a significant sexual dimorphism. These data suggest that the teeth which develop late in ontogeny tend to be smaller in size and more variable in morphological characteristics.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.69-76
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• 2018

Sexual dimorphism in birds refers to male-female differences in body size, plumage, color and/or behavior. In general, many seabirds, including the family of Laridae, are monomorphic in plumage-color, which makes the determination of sex difficult in the field because both parents also tend to share a great portion of parental care. The development of an inexpensive sexing tool facilitates understanding the degree of sex-specific parental care in the evolution of the life history. Here, we developed a non-invasive method for the determination of sex using the bill-head morphometric of known captive pairs and applied this tool to wild pairs to document factors underlying male-female parental care during the incubation period of Saunders's gulls (Saundersilarus saundersi). Males exhibited relatively larger bill-head ratios than their mates within naturally formed pairs in captivity, resulting in the determination of sex in12 wild pairs at the nest during the incubation period. Males and females equally shared the incubation role during the daytime, attending the nest at a high rate of 95%. However, the male's proportion of nest attentiveness greatly increased with time towards sunset, presumably reflecting the male duty for nighttime incubation. The present study provides a non-invasive method for the determination of sex in a monomorphic seagull species and highlights how male-female incubation behavior is associated with time of the day, rather than other ecological conditions.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.178-185
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• 2023

This study was described the microscopic anatomy of male reproductive organs and spermatophore necessary for understanding the reproductive ecology of the long arm octopus Octopus minor. The long arm octopus was a species that has sexual dimorphism that can distinguish between sex based on the presence of hectocotylus. Male reproductive organs consisted of testis, primary spermatic duct, spermatic gland, secondary spermatic duct, spermatophoric gland and spermatophoric sac. Histologically, the testis was testicular tubule type and male germ cells showed a layered arrangement. The primary spermatic duct was a tube connecting the testis and spermatic gland, and consisted with epithelial layer and connective tissue. The spermatic gland was located between the primary and secondary spermatic duct, and the epithelial layer was composed of epithelial cells and mucous cells. Mucous cells reacted blue in the AB-PAS (pH 2.5) reaction and purple in the AF-AB (pH 2.5) reaction. The secondary spermatic duct was a short tube connecting spermatic gland and spermatophoric gland, and folds were developed in lumen. The spermatophoric gland consisted of numerous tubular glands and secretory cells had eosinophilic granules. The spermatophoric sac was shape of pouch, folds were developed in lumen, and vacuolar secretory cells were present in the epithelial layer. The spermatophore was 83.5 mm long and consisted of cap thread in anterior portion, ejaculatory apparatus and cement body in medial portion, sperm mass in posterior portion.