earticle

영어

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.