In some primitive cartilaginous fishes, such as the spiny dogfish or mud shark ( Squalus acanthias ), there is a terminal nerve numbered zero, since it exits the brain before the traditionally designated first cranial nerve.

The indirect pathway consists of three links, first a projection from striatal medium spiny cells to the external part of the globus pallidus ( GPe ); second a GABAergic projection from GPe to the subthalamic nucleus ( STN ); third a glutamatergic projection from STN to SNr.

There are two dorsal fins, the first one spiny and the second soft.

The spiny first dorsal fin is normally folded back in a groove, as are its pectoral fins.

Spiny lobsters can be easily distinguished from true lobsters by their very long, thick, spiny antennae, by the lack of chelae ( claws ) on the first four pairs of walking legs, although the females of most species have a small claw on the fifth pair, and by a particularly specialized larval phase called phyllosoma.

The first book deals with the parts of plants ; the second book with the reproduction of plants and the times and manner of sowing ; the third, fourth, and fifth books are devoted to trees, their types, their locations, and their practical applications ; the sixth book deals with shrubs and spiny plants ; the seventh book deals with herbs ; the eighth book deals with plants that produce edible seeds ; and the ninth book deals with plants that produce useful juices, gums, resins, etc.

The first sarcopterygians, found in the uppermost Silurian ( ca 418 Ma ), closely resembled the Acanthodians ( the " spiny fish ", a taxon that went extinct at the end of the Paleozoic ).

However, after this first week, filopodia are replaced by spiny dendrites but also small, stubby spines that protrude from spiny dendrites.

Cotton Thistle is a biennial plant, producing a large rosette of spiny leaves the first year.

In its first year the plant grows as a dense rosette, at first with narrow, entire leaves with spiny, dark purple edges ; later, larger leaves are lobed.

The first ( spiny ) dorsal fin is entirely colorless and is normally folded back into a body groove, as are the pelvic fins.

The first ( spiny ) dorsal fin on Atlantic Spanish mackerel and cero has a prominent black patch.

But the first bony fishes were already showing their potential to dominate the waters of the world, and their competition proved too much for the spiny sharks, which died out in Permian times ( approximately 250 MYA ).

The origins of the teleostomes are obscure, but their first known fossils are Acanthodians (" spiny sharks ") from the Late Ordovician Period.

The California Department of Fish and Game estimates that recreational fishers caught more than 200, 000 spiny lobsters in the first half of the 2008 / 2009 season, amounting to around, compared to commercial fishermen, who caught a total of in the same time.

# Open season for California spiny lobster runs from the Saturday before the first Wednesday in October until the first Wednesday after March 15.

Acanthostega ( meaning spiny roof ) is an extinct labyrinthodont genus, among the first vertebrate animals to have recognizable limbs.

However, this fails to explain why the lichid trilobites, especially those of the family Odontopleuridae, first began evolving large spines ( and in some cases, spiny spines ) during the start of the Ordovician period, long before the advent of jawed vertebrates.

The first ( spiny ) dorsal fin is black at the front.

The first ( spiny ) dorsal on Spanish and Cero mackerel has a prominent black patch.

Saugers obtain two dorsal fins, the first is spiny and the posterior dorsal fin is a soft-rayed fin.

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

The first dorsal and anal fins are spinous, as is the operculum.

Gigantactis is a deep-sea fish with a dorsal fin whose first filament has become very long and is tipped with a bioluminescent photophore lure.

At first observation, the day after the operation, the back of Head's hand and the dorsal surface of his thumb were seen to be " completely insensitive to stimulation with cotton wool, to pricking with a pin, and to all degrees of heat and cold.

This jack can be distinguished from the pilot fish by the presence of a first dorsal fin.

Masked triggerfish ( Sufflamen fraenatum ) with its first dorsal spine partially raised.

As a protection against predators, triggerfish can erect the first two dorsal spines: The first, ( anterior ) spine is locked in place by erection of the short second spine, and can be unlocked only by depressing the second, “ trigger ” spine, hence the family name “ triggerfish ”.

This, the amniotic fold, first makes its appearance at the cephalic extremity, and subsequently at the caudal end and sides of the embryo, and gradually rising more and more, its different parts meet and fuse over the dorsal aspect of the embryo, and enclose a cavity, the amniotic cavity.

Burbot have two soft dorsal fins: the first being low and short, the second being much longer.

In some highly derived species the first five abdominal segments are fused into a dorsal shield called the scutum, which in most such species is fused with the carapace.

The " easiest " way to distinguish the two species is the fact that A. percula has 10 spines in the first dorsal fin and A. ocellaris has 11, which is a more reliable distinction than color patterns.

They grow to 30 – 90 cm long ( 1 – 3 ft ), and their distinctive first dorsal fins take the form of a modified oval sucker-like organ with slat-like structures that open and close to create suction and take a firm hold against the skin of larger marine animals.

They are frequently found basking at the surface, airing their first dorsal fin.

The GSV originates from where the dorsal vein of the first digit ( the large toe ) merges with the dorsal venous arch of the foot.

A saddle-like marking may be apparent between first and second dorsal fins.

Surgery ( in which the sheath of the first dorsal compartment is opened longitudinally ) is documented to provide relief in most patients.

* DeQuervain's Syndrome ( affecting the first dorsal compartment of the wrist )

The second dorsal fin is smaller than the first.

The suboccipital nerve is the dorsal primary ramus of the first cervical nerve ( C1 ).

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 ).

The first signs of modern " proto-hippies " emerged in fin de siècle Europe.

For 1936, there was the new Airflow-inspired 302 ( which ran until 1938 ) and a 402-based large model, designed by Andrean, which featured a vertical fin and bumper, with the first high-mounted taillight.

Uniquely, the Tatra T603 featured three headlights, and the first prototypes had a central rear stabilising fin, though this was lost for production.

In the first movement of Quatuor pour la fin du temps the piano and cello together provide an early example.

In literature, the Decadent movement — late nineteenth century fin de siècle writers who were associated with Symbolism or the Aesthetic movement — was first given its name by hostile critics, and then the name was triumphantly adopted by some writers themselves.

The fin was introduced in 1936 by Woody " Spider " Brown ", later inventor of the modern catamaran, when he built America's first modern surfboard ( i. e., capable of being surfed standing up ) using principles learned during his decade of aeronautical experience.

Later, Fresh Water also came out with the first wakeskate specific fin.

The first and original fin material to wakeskating is plastic.

( 1872 ); and especially the learned work of Leopold Hervieux, Les Fabulistes latins depuis le siècle d ' Auguste jusqu ' a la fin du Moyen Âge ( Paris, 1884 ), who gives the Latin texts of all the medieval imitators ( direct and indirect ) of Phaedrus, some of them being published for the first time.

The first volume was expanded into three volumes, La Gaule romaine ( 1891 ), L ' Invasion germanique et la fin de l ' empire ( 1891 ) and La Monarchie franque ( 1888 ), followed by three other volumes, L ' Alleu et le domaine rural pendant l ' époque mérovingienne ( 1889 ), Les Origines du système féodal: le bénéfice et le patronat ... ( 1890 ) and Les Transformations de la royauté pendant l ' époque carolingienne ( 1892 ).

The first type of British naval swimming fin had a short blade which was even shorter at the big toe side: this made walking on land easier for such purposes as creeping up on a sentry from behind on land, but reduced swimming speed.

In its first two years, in what Japan called its " feasibility study ", 850 Antarctic minkes, as well as 10 fin whales, were to be taken each season ( 2005 – 06 and 2006 – 07 ).

This species can be distinguished from similar species by the plain or white-tipped first dorsal fin, the dark tips on the other fins, the broad, black rear margin on the tail fin, and the lack of a ridge between the dorsal fins.

It was originally distinguished from the grey reef shark by a white tip on the first dorsal fin, a shorter snout, and one fewer upper tooth row on each side.

Identifying features of the grey reef shark include dark edges on all fins except for the first dorsal fin.