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The bony fish lineage shows more derived anatomical traits, often with major evolutionary changes from the features of ancient fish. They have a bony skeleton, are generally laterally flattened, have five pairs of gills protected by an operculum, and a mouth at or near the tip of the snout. The dermis is covered with overlapping scales. Bony ...
Guiyu oneiros, the earliest known bony fish, lived during the Late Silurian, 425 million years ago. [1] It has a combination of both ray-finned and lobe-finned features. Bony fish are characterized by a relatively stable pattern of cranial bones, rooted, medial insertion of mandibular muscle in the lower jaw.
They are often the largest bony components of the gill system, as well as the most essential and abundant components. Small connecting bones known as Hypophyals or Hypobranchials may link the basi- and cerato- components, and hypobranchials in particular are common among all types of fish. Paired hypophyals are characteristic of living ...
The small intestine is the part of the digestive tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In fish, the divisions of the small intestine are not clear, and the terms anterior or proximal intestine may be used instead of duodenum. [21]
Thelodonti ('feeble-teeth') are a group of small, extinct jawless fishes with distinctive scales instead of large plates of armour. There is much debate over whether the group of Palaeozoic fish known as the Thelodonti (formerly coelolepids [11]) represent a monophyletic grouping, or disparate stem groups to the major lines of jawless and jawed ...
A seahorse (also written sea-horse and sea horse) is any of 46 species of small marine bony fish in the genus Hippocampus. "Hippocampus" comes from the Ancient Greek hippókampos (ἱππόκαμπος), itself from híppos (ἵππος) meaning "horse" and kámpos (κάμπος) meaning "sea monster" [4] [5] or "sea animal". [6]
Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including mollusks, crustaceans, insects, fish, and amphibians. Semiterrestrial marine animals such as crabs and mudskippers have gill chambers in which they store water, enabling them to use the dissolved oxygen when they are on land.
In fish, barbels can take the form of small, fleshy protrusions or long, cylindrical shaped extensions of the head of a fish. The cylindrical barbel shapes are built on an internal support system that can be made from ossified tissue or from cartilaginous connective tissue that provides a base for blood vessels and myelinated nerves to wrap ...