Background: Hybridization between closely related fish species can generate novel phenotypes that influence aquaculture performance. This study aimed to evaluate the morphological characteristics of hybrids between the two aquaculture-relevant flounder species Kareius bicoloratus and Platichthys stellatus using a hybrid index and a newly proposed resemblance p-value-based morphometric analysis, providing insights into hybrid resemblance patterns relative to their parental species. Methods: One-year-old individuals from the three genotype groups (K. bicoloratus, P. stellatus , and hybrid) were analyzed using a combination of traditional and trussbased morphometrics. From the full dataset, 77 morphological indices were extracted, including proportions, ratios, and angular measurements. The hybrid index was computed to quantify parental resemblance, while the delta resemblance value (ΔRV) was derived from Kruskal-Wallis test to assess statistical resemblance trends. One-way ANOVA and multiple comparison tests were used to determine statistical significance among groups. Results: Hybrid flounders exhibited a complex blend of parental and hybrid-specific traits, with morphological resemblance varying by trait category. Among the 77 morphological indices, 44 (57.1%) fell within the parental range, while 33 (42.9%) exceeded parental values, demonstrating transgressive segregation or heterosis in hybrid morphology. Morphometric resemblance patterns were trait-dependent: indices relative to total length or head length tended to resemble maternal species, whereas depth-related ratios and angular traits were more similar to father. Conclusions: The integration of H-index and ΔRV analysis provided a systematic and quantitative framework for assessing hybrid morphology, offering valuable insights into phenotypic expression of hybrids, with potential relevance to aquaculture.

강도다리 대상 수인성 카드뮴 독성 영향을 확인하기 위해 96시간 동안 0, 2.5, 5, 10, 20, 40 mg Cd2+/L 에 노출시켰으며, 96시간 반수치사농도(LC50)는 21.42 mg Cd2+/L로 나타났다. 혈액학적 성상분석에서 Hematocrit와 Hemoglobin은 20 mg Cd2+/L에서 유의하게 증가하였다. 혈장 무기성분에서 calcium은 20 mg Cd2+/L에서 유의적으로 감소한 반면 magnesium은 유의적 변화가 없었다. 혈장 유기성분인 glucose는 카드뮴 노출에 의해 유의적으로 증가하였다. 혈장 효소 성분인 AST, ALT 및 ALP는 수인성 카드뮴 노출에 의해 20 mg Cd2+/L에서 유의적으로 증가하였다. 본 연구를 통해 수인성 카드뮴 급성 노출이 강도다리 혈액학적 성상 및 혈장성분 내 독성을 유발함을 확인하였으며, 이로 인한 사망률 유발 가능성을 예상할 수 있다.

수산 양식 산업에서 발생하는 다제내성균에 의한 질병을 통제하기 위해 기존에 사용하던 수산 용 의약품 대신 어류에 사용이 금지된 동물용 의약품 사용이 증가하고 있다. 그 중, 티아물린 은 그람 양성균에 효과적인 항균성을 나타내기 때문에 일부 양식 어가에서 불법적으로 사용 되고 있다. 불법적 사용을 막기 위해서는 티아물린의 수산동물에 대한 연구를 통해 수의사나 수산질병관리사의 처방전에 따라 수산생물의 치료행위가 수반되어야 한다. 연쇄구균에 감염된 강도다리에 대해 티아물린을 5, 10, 15 mg kg-1의 농도로 근육주사 하였으나 치료 효과가 나타 나지 않았고 15, 30 mg kg-1의 농도로 경구투여 하였으나 마찬가지로 치료 효과가 미비하였다. 안전성 확인을 위해 30, 60 mg kg-1의 농도로 근육주사와 경구투여한 경우 항생제의 독성에 의한 폐사가 발생하였고 따라서 연쇄구균에 감염된 강도다리에 티아물린으로 항생제 처리를 하는 것은 부적절하다고 할 수 있다.

This study was evaluated individual growth and hematological changes of young starry flounder, using hyperpigmentation marks on the blind side of body after feeding extruded pellet (EP) and moisture pellet (MP) for 45 days. As a result, the fish grew up to 220.1±47.8 g in the EP treatment and 224.7±42.4 g in the MP treatment, so the weight gain was significantly higher in the MP treatment (74.6±17.3%) than in the EP treatment (63.7±16.9%) (P<0.05). Osmolalities of flounder after 45 days culture were similar between the treatments (P>0.05), showing values of 359.8±4.2 mOsm kg-1 in the EP treatment and 358.5±6.2 mOsm kg-1 in the MP treatment. Similarly, other blood chemistry indicators such as sodium, chloride, total protein, albumin, glucose, total cholesterol, BUN, creatinine, ammonia, triglyceride, cortisol, GOT, GPT and hematocrit showed no differences between the treatments. However, the free fatty acid concentration was significantly higher in the MP treatment than in the EP treatment (P<0.05).

This study was performed to estimate biomass and provide management guidance through population ecological characteristics, including growth parameters, instantaneous coefficients of natural and fishing mortalities, and age at first capture of the starry flounder, Platichthys stellatus and olive flounder, Paralichthys olivaceus of Korea. For describing growth of this species, a von Bertalanffy growth model was adopted. The von Bertalanffy growth parameters estimated from a non-linear regression for starry flounder were L∞=48.25 cm, K=0.16/yr, and t0=-1.48, respectively and those for olive flounder were L∞=86.46 cm, K=0.26/yr, and t0=-0.29, respectively. Biomass of Platichthys stellatus was estimated by direct biomass estimation method was 2.6 M/T, that was estimated by indirect method was 13.4 M/Tt. Those of Paralichthys olivaceus were estimated as 10.1 M/T, 19.3 M/T, respectively. An yield per recruit analysis showed that the current yield per recruit on Platichthys stellatus was about 48.2 g with F=0.646/yr and the age at first capture (tc) 1.35yr, that on Paralichthys olivaceus was about 167.6 g with F=1.121/yr and the age at first capture (tc) 1yr.

본 연구는 밀폐식 순환여과 시스템의 호흡측정실내에서 해수 및 담수사육 강도다리의 산소소비에 미치는 수온 영향을 조사하였다. 실험에 사용한 어류는 해수 및 담수에 각각 순화시킨 해수사육 강도다리(9마리, 평균체중 263.0±40.4 g)와 담수사육 강도다리(9마리, 평균체중 265.8±34.8 g)를 사용하였다. 수온 15, 20, 25℃에서 해수사육 강도다리의 산소소비량은 각각 74.4±17.0, 85.