日出時在寧靜非洲河流中打哈欠的河馬

create a photorealistic picture of a hippopotamus standing partially submerged in a wide, calm African river, its enormous mouth opened wide, clearly showing its large teeth and powerful jaws. Dawn, sun just rising, lush green vegetation along the riverbanks, realistic water reflections and splashes, dramatic wildlife-photography composition, detailed skin texture, cinematic lighting, high resolution, natural colors.