The dorsal and anal fins are divided into anterior spiny and posterior soft-rayed portions, which may be partially or completely separated.

The most notable feature of the acanthocephala is the presence of an anterior, protrudible proboscis that is usually covered with spiny hooks ( hence the common name: thorny headed worm ).

The anterior spines are much longer, giving a concave outline to the spiny part of the dorsal fin.

If both are present, the spiny rays are always anterior.

* Ctenoid scales have a toothed outer edge, and are usually found on fish with spiny fin rays, such as bass and crappie.

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

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

The first ( spiny ) dorsal fin and the pelvic fins are normally retracted into body grooves.

* The spiny and soft ray portions of the dorsal fin are continuous, so there is only one long fin instead of two short separate ones as for the wreckfish Polyprion americanus, scup Stenotomus chrysops, rose fish Sebastes marinus, cunner Tautogolabrus adspersus, striped bass Morone saxatilis.

* Compared to a tautog or cunner, its mouth is much larger, also the caudal fin, pectoral fin, and soft portion ( 11 rays ) of dorsal fin as long as spiny portion.

A fin may contain only spiny rays, only soft rays, or a combination of both.

In eastern freshwater cod the spiny dorsal fin is moderate in height and is partially separated by a notch from the high, rounded soft dorsal fin.

This silvery minnow gets its name from the sharp spiny rays in its dorsal fin.

The ruffe also has a large, spiny dorsal fin likely distasteful to its predators.

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.

All feature a sloped profile, medium-to-large scales, a spiny dorsal fin and a laterally compressed body.

All feature a sloped profile, medium-to-large scales, a spiny dorsal fin and a laterally compressed body.

Zander are often called pike-perch as they resemble the pike with their elongated body and head, and the perch with their spiny dorsal fin.

The spiny dogfish has dorsal spines, no anal fin, and white spot along its back.

The silvery John dory ( Zenopsis conchifera ) is typical of the Zeidae, with its scute-covered belly and filamentous spiny dorsal fin.

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

The spiny dogfish has the longest lifespan at more than 100 years.

Lake Huron has suffered recently due the introduction of a variety of new invasive species, including zebra and quagga mussels, the spiny water flea, and round gobies.

A 2006 study by Canadian scientists has found five species of deep-sea fish – blue hake, spiny eel – to be on the verge of extinction due to the shift of commercial fishing from continental shelves to the slopes of the continental shelves, down to depths of 1600 meters.

Species more or less completely parasitic include the leafless quintral, Tristerix aphyllus, which lives deep inside the sugar-transporting tissue of a spiny cactus, appearing only to show its tubular red flowers, and the genus Arceuthobium ( dwarf mistletoe ; Santalaceae ) which has reduced photosynthesis ; as an adult, it manufactures only a small proportion of the sugars it needs from its own photosythesis but as a seedling it actively photosynthesizes until a connection to the host is established.

The fossil record of spiny lobsters has been extended by the discovery in 1995 of a 110 million year-old fossil near El Espiñal in Chiapas, Mexico.

These forests contain several impressive trees, among them the banyan fig, which can be recognised by its large, spreading aerial roots, and the kapok tree, which has a spiny trunk, large, waxy red flowers and pods full of cotton-like material.

For example, the spiny egg laying anteater ( echidna ) has a highly developed brain, yet is not widely considered to be very intelligent.

The species has been described based on three specimens found in 2001 ; its only known habitat – stands of spiny guadua and ripidocladus spp.

Serving as a claim in establishing its provenance, it has been suggested that this spiny plant was used for the " crown of thorns " worn by Jesus, though others have suggested Christ's thorn jujube ( Ziziphus spina-christi ).

It has a spreading rosette ( about wide ) of gray-green leaves up to long, each with a spiny margin and a heavy spike at the tip that can pierce to the bone.

In common with all spiny lobsters, the California spiny lobster has two large, spiny antennae, but no large claws on its legs.

The principal type of neuron found in the subthalamic nucleus has rather long sparsely spiny dendrites.

The link rat, Deomys ferugineus, has been traditionally placed in this subfamily, but molecular phylogenetic studies have shown that it is more related to the spiny mice, genus Acomys.

In the recent past the European market for spiny dogfish has increased dramatically, which led to the overfishing and decline of the species.

This marsupial has a thick harsh coat but is not spiny.

This engine has special cast-iron cylinder liners cast into the block, which are a spiny type to improve adhesion between the liner and cylinder block.

This building has a large variety of animals including primates, reptiles, birds, and fish Some endangered animals on display are the spiny turtle, Pan's box turtle ( Cuora pani ), Black-breasted Hill Turtle, radiated tortoise, Flat-backed Spider Tortoise, Fiji iguana, Grand Cayman Island Blue Iguana, Bali Myna birds, Black and White Ruffed Lemurs, and Thick-billed parrots.

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

The short-beaked echidna was commonly called the spiny anteater in older books, though this term has fallen out of fashion since the echidna bears no relation to the true anteaters.