anal-fin
A median, unpaired, ventral fin located between the anus and caudal fin, usually in the posterior portion of the body. Used to maintain equilibrium and stability.
Used in 764 profiles
Results for “anal-fin”
Ichthyological terms, not general ones.
anal-fin origin
Anteriormost point at which the anal fin base is attached to the body.
Used in 108 profiles
unpaired fins
The dorsal, caudal, anal and, if present, adipose fins.
Used in 61 profiles
vertical fin
Unpaired, median fin, i.e., dorsal, caudal, adipose and anal fins.
Used in 1 profile
body depth
The vertical distance between the dorsal and ventral margins of the body measured at the base of the pectoral fin where it joins the body. In most icthyological works the greatest dimension, normally anterior to the dorsal fin, is taken but in some cases body depth is measured at the origin of pectoral, pelvic and first anal. Fins or fin bases are not included in the measurement, however.
Used in 85 profiles
caudal peduncle
The typically narrow section of the body located between the posterior of the dorsal and anal fins and caudal fin origin. Its depth is measured vertically at the narrowest point.
Used in 394 profiles
andropodium
Modified, flexible anal fin rays present in males of some fish species (families Hemirhamphidae and Goodeidae) giving the fin a 'notched' appearance. Not used for insemination like the gonopodium in members of the family Poecillidae but to clasp the female during mating.
Used in 5 profiles
gonopodium
Modified anal fin used in copulation for the transfer of male gametes to a female. In many cases only the anterior part of the fin is modified.
Used in 24 profiles
transverse scale row
Number of scales in the diagonal row between the orgins of dorsal and anal fins in a fish specimen, excluding the lateral line scales.
Used in 10 profiles
paired fins
The pectoral and pelvic/ventral fins, both of which occur in pairs and are analogous to the fore and hind limbs in higher animals.
Used in 58 profiles
humeral spot
A marking on the body in the area analogous to the humerus, or shoulder. In fishes it's normally located above the pectoral-fin and behind the opercle. There may be more than a single such spot in some species.
Used in 42 profiles
head and lateral line erosion
Severe physical condition relatively common to certain fishes in captivity and also known as hole-in-the-head. Sometimes attributed to protozoan parasites of the genus Hexamita or an autoimmune disorder though these theories remains unconfirmed. Certainly associated with and exacerbated by poor water quality and/or nutrition, however. Initially manifests itself as small lesions, normally on the head of an affected individual, but may also extend along the lateral line and into the unpaired fins. If left unchecked these lesions can develop into larger, whitish pits and the condition may prove fatal. Often abbreviated to HLLE and similar to, but not analagous with, neuromastic pitting. Does not appear to occur in nature.
Used in 35 profiles