Ichthyological terms, not general ones.
Gas-filled sac with 1-3 chambers, situated just below the vertebral column in most ray-finned fishes. Its primary function is to aid in buoyancy by offsetting the weight of heavier structures such as bone, but is also used for respiration or sound production in some species. Often reduced in benthic fishes and sometimes absent altogether. Also known as the air or swim bladder.
Used in 104 profiles
Genus of freshwater cnidarian existing only in sessile, solitary polyp form attached to the substrate at one end and with a mouth surrounded by up to 12 tentacles at the other. Members are predatory, feeding mostly on small invertebrates, and regarded as pests in aquaria due to their appearance as whitish spots on submerged surfaces and tendency to prey on fish fry.
Used in 1 profile
The lower jaw bone of a vertebrate organism.
Used in 2 profiles
Interval of geological time covering the period from around 250 million years ago to 65 million years ago. Often referred to as the 'Age of Reptiles' because dinosaurs were the dominant terrestrial and marine vertebrates.
Any member of the invertebrate phylum Mollusca.
Used in 27 profiles
Large, highly diverse invertebrate phylum. Members are difficult to define but generally possess a soft, unsegmented body, and often a shell or shell-like structure secreted by a mantle. Includes all bivalves, cephalopods, and gastropods.
Muscular tube through which food passes from mouth to stomach in vertebrates; the gullet. Also spelled 'esophagus'.
Small bone, especially any of the three small bones in the inner ear of vertebrates.
Used in 4 profiles
Elongate bone located in the base of the skull in many vertebrate organisms.
Used in 7 profiles
Bony or cartilaginous structure supporting the forelimbs or anterior fins in vertebrates.
Used in 26 profiles
Anterior, paired fin attached to the pectoral girdle of fishes, usually just behind the opercle and corresponding to the forelimbs of higher vertebrates. Assists in controlling direction of movement and swimming speed. Frequently abbreviated to 'P' or 'P1' in scientific papers.
Used in 508 profiles
Either of the pair of fins, also known as pelvic fins, attached to the pelvic girdle in fishes that help control the direction of movement. Correspond to the hind legs in higher vertebrates and vary in position depending on taxon. Sometimes absent entirely.
Used in 431 profiles
Tooth-shaped scale-type found in certain fishes, e.g., sharks, rays. Structurally homologous with vertebrate teeth.
In vertebrates, the internal structure composed of bone and/or cartilage that supports the soft tissues and protects the internal organs.
Used in 15 profiles
In vertebrates, the thin, membranous layer of external tissue forming the protective covering of the body.
Used in 399 profiles
Taxonomic rank into which a genus is divided, but otherwise difficult to delineate precisely with a single definition satisfying all eventualities still lacking to date. There exist a number of concepts of which the most popular in vertebrate taxonomy include the biological species concept and phylogenetic species concept.
Used in 1,790 profiles
See fin spine; also a hard, pointed, protective outgrowth or process elsewhere on the body, e.g., a preopercular spine; the spinal column of a vertebrate.
Used in 414 profiles
Either of the pair of fins, also known as pelvic fins, attached to the pelvic girdle in fishes that help control the direction of movement. Correspond to the hind legs in higher vertebrates and vary in position depending on taxon. Sometimes absent entirely.
Used in 74 profiles
In biology, a minute, hairlike process present on certain membranes, such as the mucous membrane in the small intestine of many vertebrates. Typically has a sensory or absorptive function.
Thin, anterior, flattened bone dividing the nostrils in most vertebrates. Sometimes bears teeth.
Used in 4 profiles