Fishes of the sea and dating
Many smaller wrasses follow the feeding trails of larger fish, picking up invertebrates disturbed by their passing.Most wrasses inhabit the tropical and subtropical waters of the Atlantic, Indian, and Pacific Oceans, though some species live in temperate waters: the Ballan wrasse is found as far north as Norway. Juveniles are a mix of males and females (known as initial phase individuals), but the largest adults become territory-holding (terminal phase) males.It does not include the land vertebrates or tetrapods, which descended from fish. Some kinds of fish, such as sharks and rays, do not have real bones (their skeletons are made of cartilage) they are known as cartilaginous fish.Though often used interchangeably, these words have different meanings. All fish are covered with overlapping scales, and each major group of fish has its own special type of scale.Wrasses are usually found in shallow-water habitats such as coral reefs and rocky shores, where they live close to the substrate. The dorsal fin has eight to 21 spines and six to 21 soft rays, usually running most of the length of the back. The wrasses have become a primary study species in fish-feeding biomechanics due to their jaw structures.The nasal and mandibular bones are connected at their posterior ends to the rigid neurocranium, and the superior and inferior articulations of the maxilla are joined to the anterior tips of these two bones, respectively, creating a loop of four rigid bones connected by moving joints.Adults can maintain a body temperature up to 15 degrees C warmer than the surrounding water.
Four species are found in Pacific waters from North America to South America. The pectoral fins located on either side of the head are used for maneuvering. Their prehensile tail can only be unlocked in the most extreme conditions.The white shark is the Earth's largest predatory fish.This species has successfully thrived for more than 11 million years, with its immediate ancestors dating back more than 60 million years.Seahorses swim very poorly, rapidly fluttering a dorsal fin and using pectoral fins (located behind their eyes) to steer. zosterae (the dwarf seahorse), with a top speed of about 5 ft (1.5 m) per hour.Since they are poor swimmers, they are most likely to be found resting with their prehensile tails wound around a stationary object.