The zebrafish is named for the five uniform, pigmented, horizontal, blue stripes on the side of the body, which are reminiscent of a zebra's stripes, and which extend to the end of the caudal fin.

The main features of the fish, the fins, are bony fin rays and, except the caudal fin, have no direct connection with the spine.

The caudal peduncle is absent and the caudal fin is reduced to a stiff rudder-like structure.

Sexual dimorphism is slight, the male's caudal fin being more pointed.

An additional caudal fin covers the post-anal tail.

alt = Drawing of a shark labeling major anatomical features, including mouth, snout, nostril, eye, spiracle, dorsal fin spine, caudal keel, clasper, labial furrows, gill openings, precaudal pit and fins: first and second dorsal, anal, pectoral, caudal and pelvic

Sharks possess a heterocercal caudal fin in which the dorsal portion is usually noticeably larger than the ventral portion.

By contrast, most bony fish possess a homocercal caudal fin.

Coelacanths (, adaptation of Modern Latin Cœlacanthus " hollow spine ", from Greek κοῖλ-ος koilos " hollow " + ἄκανθ-α akantha " spine ", referring to the hollow caudal fin rays of the first fossil specimen described and named by Louis Agassiz in 1839 ) are members of an order of fish that includes the oldest known living lineage of Sarcopterygii ( lobe-finned fish and tetrapods ).

They possess a three-lobed caudal fin, also called a trilobate fin.

Coelacanths have 8 fins – 2 dorsal fins, 2 pectoral fins, 2 pelvic fins, 1 anal fin, and 1 caudal fin.

The tail is very nearly equally proportioned and is split by a terminal tuft of fin rays that make up the caudal lobe of the tail.

There is also an anal fin, which is also considered spiny, and a caudal fin.

The lobes of the caudal ( tail ) fin in muskellunge come to a sharper point, while those of northern pike are more generally rounded.

Walleyes are distinguished from their close cousin the sauger by the white colouration on the lower lobe of the caudal fin which is absent on the sauger.

In addition, the two dorsals and the caudal fin of the sauger are marked with distinctive rows of black dots which are absent from or indistinct on the same fins of walleyes.

Drums are somberly colored, usually in shades of brown, with a lateral line that extends to the tip of the caudal fin.

Most species have a rounded or pointed caudal fin.

The telson is flanked by a pair of long, thin caudal rami.

In rodents, the EC is located at the caudal end of the temporal lobe.

The vaginal opening is at the caudal end of the vulva, behind the opening of the urethra.

The gills of other insects are tracheal, and also include both thin plates and tufted structures, and, in the larval dragon fly, the wall of the caudal end of the alimentary tract ( rectum ) is richly supplied with tracheae as a rectal gill.

At the posterior end, a hardened caudal shield is sometimes present in Aspidosiphon.

The hypopharynx or laryngopharynx or ( Latin: pars laryngea pharyngis ) is the caudal part of the pharynx ; it is the part of the throat that connects to the esophagus.

Expression of this hairy-like bHLH transcription factor, which represses Neurogenin but is required for Ascl1, is progressively lost from the caudal thalamus but maintained in the prethalamus and in the stripe of rostral thalamic cells.

In terms of development, the human nervous system is often classified based on the original 3 primitive vesicles from which it develops: These primary vesicles form in the normal development of the neural tube of the human fetus and initially include prosencephalon, mesencephalon, and rhombencephalon, in rostral to caudal ( from head to toe ) orientation.

It is suspended by the caudal part of the mesentery ( mesoileum ) and is attached, in addition, to the cecum by the ileocecal fold.

* a projecting, modified ( rough and strongly ridged ) scale, usually associated with the lateral line, or on the caudal peduncle forming caudal keels, or along the ventral profile.

The NTS is divided into a rostral gustatory nucleus and caudal region of neurons.

Scale arrangement includes 23 scale rows at mid body ( rarely 19 or 21 ), 211-250 ventral scales, a divided anal scale and 60-91 paired caudal scales ( Schultz 1996 ; Arnold 2002 ).

* Ostraciiform: the body remains rigid and the stiff caudal fin is swept in a pendulum-like oscillation.

The wild-caught forms of the species are typically darkly coloured with orange-ringed spots or ocelli on the caudal peduncle and on the dorsal fin.

Serotonin transmission from both the caudal raphe nuclei and rostral raphe nuclei is reduced in patients with depression compared with non-depressed controls.

Males display to each other by positioning themselves parallel to each other, head to tail, with dorsal and caudal fins erect and cheek odontode spines everted.

The caudal fin is rounded, the pectoral fins are fan-shaped, and pelvic fins are narrow with an elongate second fin ray.

Their body cilia are mostly uniform, sometimes with a few long caudal cilia, and arise from monokinetids or from dikinetids at the anterior.

Mosquitofish are small, dull grey, with a large abdomen, and have rounded dorsal and caudal fins and an upturned mouth towards the surface.

Hominoids have more mobile shoulder joints and arms due to the dorsal position of the scapula, broad ribcages that are flatter front-to-back, and a shorter, less mobile spine compared to Old World monkeys, with caudal ( tail ) vertebrae greatly reduced, resulting in complete tail loss in living species.

Modern lungfish all have an elongate body with fleshy, paired pectoral and pelvic fins and a single unpaired caudal fin replacing the dorsal, caudal and anal fins of most fishes.

Milkfish have a generally symmetrical and streamlined appearance, with a sizable forked caudal fin.

Its dorsal and anal fins confluent with the rudimentary caudal fin.

They have long dorsal fins, and an anal fin that is typically united with the caudal fin.

Their caudal fins are very small, and except for Guentherus it is merged with the long anal fin ( which has 70 fin rays or more ).

As the common name suggests, they are somewhat eel-like in appearance, with elongated bodies and the dorsal and anal fins continuous with the caudal fin.

The tail was bi-lobed, with the lower lobe being supported by the caudal vertebral column, which was " kinked " ventrally to follow the contours of the ventral lobe.

They are solitary animals, and maintain well-defined territories, which they scent mark with their caudal glands.

Neither the dorsal nor anal fins have spines, and in Nagaichthys and Pillaia they have fused with the caudal fin ; in the other genera the caudal is small but separate.