All four statements are correct and reflect the diversity of feeding and reproductive strategies in different animal groups. Turtles, such as the green sea turtle, exhibit herbivorous diets, while many fish species, like parrotfish, also primarily consume plant matter. Marine mammals, including manatees and some whale species, are known for their herbivorous feeding habits in marine ecosystems. Additionally, certain snake species, such as some boa constrictors, can give birth to live young, highlighting the reproductive adaptation of viviparity in reptiles. Recognizing these biological traits is crucial in understanding ecological interactions and species adaptations, which are key topics in the UPSC syllabus.