The global surge in seafood demand has led to significant overexploitation of wild fish stocks, intensifying the need for sustainable seafood alternatives. Both plant-based and cell-based seafood analogs have emerged as promising solutions, aiming to meet consumers’ needs while addressing environmental and food security challenges. Texture, a critical sensory attribute for seafood, plays a pivotal role in consumer acceptance of these alternatives. However, replicating the diverse textures of commercial fish species remains a significant obstacle due to limited baseline knowledge of fish muscle architecture and its relationship to texture. This study provides a comprehensive, species-specific analysis of the structural and textural properties of four commercially significant fish species: salmon (Salmo salar), tilapia (Oreochromis niloticus), tuna (Thunnus spp.), and grouper (Epinephelus spp.). Using Texture Profile Analyzer (TPA), colorimetry, collagen assays, and collagen imaging, this study established critical baselines for muscle fiber size, collagen density, and their correlations to textural attributes which are hardness, adhesiveness, springiness, gumminess, cohesiveness, and chewiness. Notably, hydroxyproline content, a proxy for collagen levels, varied significantly across species, with tilapia exhibiting the highest levels, followed by grouper, salmon, and tuna. Collagen content positively correlated with hardness springiness, gumminess, and chewiness (p<0.05), while muscle fiber size was inversely correlated with hardness (p<0.05). These findings offer valuable insights into the structural underpinnings of fish texture, informing material selection, scaffold design, and muscle alignment considerations for both scaffold-based and scaffold-free seafood analog production. By bridging this critical knowledge gap, this study supports the development of alternative seafood products that align with consumer expectations and advance sustainability goals in cellular and plant-based aquaculture.