Cnidarians - coelenterates

Acropora Pulchra

Acropora pulchra, è una specie di corallo appartenente alla famiglia degli Acroporidi (Cnidaria). Vive in acque poco profonde nelle barriere coralline dell’Oceano Indo-Pacifico occidentale. ...

Coral loaf - Cladocora caespitosa

Cladocora caespitosa, commonly known as Coral loaf or "cushion coral", is a stony coral of the subclass Hexacorallia, phylum Cnidarian. This species forms the only true coral reef in the Mediterranean Sea. ...

Corallo di Staghorn - Acropora cervicornis

Il corallo di staghorn (Acropora cervicornis) è un corallo sassoso ramificato con rami cilindrici che vanno da pochi centimetri a oltre due metri di lunghezza e altezza. ...

Corallo Tubastraea micranthus

Tubastraea micranthus è un corallo appartenente al phylum Cnidaria, al genere Tubastraea ed alla famiglia Dendrophylliidae. E’ un corallo coloniale dalla forma arborea appartenente al gruppo di coralli pietrosi a polipo grande che pur producendo uno sc...

Dendronephthya hemprichi

Dendronephthya hemprichi è un corallo molle comune che troviamo dal Mar Rosso al Pacifico Occidentale. Di solito è rosa o arancione con tronco trasparente e cresce fino a 70 cm. Questa particolare specie del Dendronephthya ...

False black coral - Savalia savaglia

Savalia savaglia is a colonial antozoo whose appearance resembles that of the common sea fans, but the polyps that constitute it differ greatly from those of the latter is for the structure to the size. Savalia savaglia falso corallo nero antozoo coloniale...

Gorgonia Bianca - Eunicella verrucosa

Eunicella verrucosa, Gorgonia Bianca, ampia gorgonia, gorgonia rosa o gorgonia verrucosa, è una specie di "corallo molle" coloniale gorgoniano della famiglia Gorgoniidae, phylum Cnidari. ...

Gorgonia leptogorgia - Leptogorgia sarmentosa

La Leptogorgia  appartiene al philum dei Cnidari, alla classe degli Antozoi, alla sottoclasse degli Ottocoralli e all’ordine degli Gorgoniacei. Il nome cnidari giustifica la presenza di cnidocisti o meglio cellule urticanti ...

Gorgonia Ventaglio Gigante - Subergorgia hiksoni

Gorgonia a Ventaglio gigante - Sea Whip coral - Subergorgia hiksoni - intotheblue.it - Gorgonia Ventaglio gigante Subergorgia hiksoni intotheblue.it ...

Madrepora Solitaria - Balanophyllia Europea

La Balanophyllia europea, conosciuta comunemente come madrepora solitaria, è una madrepora della famiglia Dendrophylliidae. Madrepora Solitaria Balanophyllia europea intotheblue.it ...

Madreporaria - Scleractinia

La Scleractinia, chiamata anche corallo sassoso o corallo duro, è un animale marino nel Cnyidaria che si costruisce uno scheletro duro. I singoli animali sono noti come polipi ...

Medusa

La medusa è un animale planctonico, in prevalenza marino, appartenente al phylum degli Cnidari, che assieme agli Ctenofori formavano quelli che erano una volta i Celenterati. ...

Aequorea forskalea

Aequorea forskalea (Péron & Lesueur, 1810) è una medusa della famiglia Aequoreidae. Aequorea forskalea medusa della famiglia Aequoreidae ...

Australian spotted jellyfish - Phyllorhiza punctata

This young punctate jellyfish missing its tentacles is an Australian spotted jellyfish - Phyllorhiza punctata. Surely the tentacles have been eaten by natural predators. The presence of this jellyfish in the southern Mediterranean is more and more frequented ...

Barrel Jellyfish - Rhizostoma pulmo

The Barrel Jellyfish (Rhizostoma pulmo Macri, 1778) is one of the scifomedusa Rhizostomatidae family. Polmone di mare Rhizostoma pulmo scifomedusa intotheblue.it Polmone di mare Rhizostoma pulmo scifomedusa Rhizostomatidae intotheblue.it ...

Cigar jellyfish - Olindias phosphorica

Olindias phosphorica is a species of jellyfish originating from the central Atlantic, and from the Mediterranean Sea, including Malta. Olindias phosphorica Medusa Cigar jellyfish intotheblue.it ...

Glowing jellyfish - Pelagia noctiluca

Pelagia noctiluca, commonly known as glowing jellyfish, jellyfish is one of pelagiidae family. Pelagia noctiluca medusa luminosa famiglia Pelagiidae ...

Mediterranean Cassiopeia or Fried Egg jellyfish - Cotylorhiza tuberculata

The Mediterranean Cassiopeia or Fried Egg jellyfish (Cotylorhiza tuberculata Macri, 1778) is one of scifomedusa cepheidae family, common in the Mediterranean Sea. Cassiopea mediterranea Cotylorhiza tuberculata scifomedusa Cepheidae ...

Sea Raft - Velella Velella

Velella Velella is a monospecific genus of hydrozoa in the Porpitidae family. Its only known species is Velella velella, a cosmopolitan free-floating hydrozoan that lives on the surface of the open ocean. ...

Penna di mare Pennatula bianca - Pteroeides spinosum

In questo articolo parliamo della "Penna di mare" Pennatula bianca Pteroeides spinosum, o "Piuma di mare", un raro corallo molle del Mediterraneo che appartiene al philum dei Cnidari, alla classe degli Antozoi, alla sottoclasse degli Ottocoralli ...

Red coral or precious coral - Corallium Rubrum

Red coral, precious coral (Linnaeus, 1758), is a octocorallo of Coralliidae family, common in the Mediterranean and eastern Atlantic. Corallo Rosso Red Coral Corallium Rubrum Cnidari Cnidarians ...

Red gorgonian - Paramuricea clavata

IUCN Red List classifies Paramuricea clavata as a vulnerable species. In the past, red gorgonian colonies were very numerous, today we are witnessing their decline throughout the Mediterranean, especially in surface waters as a result of water heating. Other...

Sea anemone - Actinaria

Sea anemones are a group of marine, predatory animals of the order Actiniaria. They are named after the anemone, a terrestrial flowering plant, because of the colourful appearance ...

Anemone - Anemonia sulcata

Anemonia sulcata (Pennant, 1777), nota come capelli di Venere, è un celenterato antozoo della famiglia Actiniidae. Anemone Anemonia sulcata Celenterato antozoo cnidari cnidarians ...

Anemone grosso - Cribrinopsis crassa

L' Anemone grosso, Cribrinopsis crassa (Andrès, 1881) è un anemone di mare della famiglia Actiniidae, endemico del mar Mediterraneo. Cribrinopsis crassa Fat anemone Anemone grosso Actiniaria intotheblue.it ...

Anemone magnifica - Heteractis magnifica

Heteractis magnifica , noto anche come anemone magnifica o anemone Ritteri , è un anemone di mare appartenente alla famiglia Stichodactylidae originario dell’area Indo-Pacifica. ...

Beadlet Anemone - Actinia Equina

The beadlet anemone, Actinia equina, is a common sea anemone found on rocky shores around all coasts  of theUnited Kingdom and Ireland. ...

Cylindrical anemone - Cerianthus Membranaceus

Cerianthus membranaceus, the cylindrical anemone or colored tubular anemone, is a species of large, tubiform anemone of the Cerianthidae family. It originates from the Mediterranean Sea and adjacent parts of the northeastern Atlantic Ocean. Cerianthus...

Golden anemone - Condylactis aurantiaca

This anemone, Golden anemone or in a bad translation the sand actinia or sand anemone, is a species of anemone rather widespread in the Mediterranean Sea but difficult to meet since it populates almost exclusively sandy and gnarly ...

Hermit Crab Anemone - Calliactis parasitica

Calliactis parasitica is a species of sea anemone associated with hermit crabs. It lives in the eastern Atlantic Ocean and the Mediterranean Sea at depths between the intertidal zone and 60 m (200 ft). It is up to 10 cm × 8 cm (3.9 in × 3.1 in) large, w...

Trumpet anemone - Aiptasia mutabilis

Trumpet anemone (Aiptasia mutabilis Gravenhorst, 1831) is an antozoo belonging to the Aiptasiidae phylum cnidarians in the Mediterranean Sea ...

Sea pen - Pennatula phosphorea

Pennatula phosphorea  is a octocoral in the family Pennatulidae.  Pennatula is a genus of sea pens in the family Pennatulidae. The genus contains several bioluminescent species, including Pennatula rubra, Pennatula phosphorea and Pennatula aculeata. Sea pe...

Venus fan - Gorgonia Flabellum

Gorgonia flabellum, also known as the Venus fan, Venus sea fan, common sea fan, West Indian sea fan, and purple gorgonian seafan, is a species of sea fan, a sessile colonial soft coral. ...

White gorgonian - Eunicella singularis

White gorgonian Eunicella singularis, is a gorgonian typical of the Mediterranean Sea, grows on rocky, muddy and detrital bottoms and often colonizes bottoms that have undergone stress caused by the change in water temperatures or damage caused by trawling,...

Yellow cluster anemone - Parazoanthus axinellae

Yellow cluster anemone (Parazoanthus axinellae Schmidt, 1862) is a zoanthid coral found on the southern Atlantic coasts of Europe and in the Mediterranean Sea. ...

Yellow gorgonian or Yellow sea whip - Eunicella Cavolinii

Eunicella cavolini, commonly known as the yellow gorgonian or yellow sea whip, is a species of colonial soft coral in the family Gorgoniidae. It is native to parts of the eastern Atlantic Ocean and most of the Mediterranean Sea, where it is a common ...

Cnidari Celenterati Cnidarians coelenterates celenteron

Cnidarians, or coelenterates, are a phylum of animals radially symmetrical, diblasteri and water.

Anatomy and Physiology

Their body can be schematically shown as a lot, with a single opening, surrounded by tentacles, which acts as a mouth but also serves to expel carbon dioxide and waste substances. The tentacles are used to grab prey. The internal cavity, said celenteron, is a true gastrovascular cavity, which extends in part also in the tentacles.

The celenteron performs two functions:

1. digestive, as there are poured digestive juices produced by the cells which cover it.
2. vascular, since the water that fills it comes close enough to all tissues of the body, providing nutrients and oxygen and removing carbon dioxide and waste substances.

The structural model of Coelenterates is expressed in two forms: polyp and Jellyfish.

Polyps are normally sessile, or fixed to a solid support, and then benthic, with the mouth opening upwardly.

Jellyfish are floating, with the mouth opening downwards. The body of the jellyfish, because of its shape, is said umbel; the aboral part of the umbrella (normally facing upward), convex, is said esombrella, whereas the oral part (normally facing downwards), concave, is said subombrella; This extends to the center in a tubuliforme structure more or less elongated said handlebars, ending with the mouth. The tentacles usually radiate from the umbrella margin (that is, the border between esombrella and subombrella). They are part of the plankton, since it does not actively swimming in the horizontal direction, although they can contract the umbrella to move vertically. In the outer layer of the body (epidermis) are differentiated cells. Muscle cells, able to contract and ensure the movement and body tone. The nerve cells, able to transmit stimuli. Polyps in the nervous system is a network, not a particular organization. In jellyfish there is some hierarchy, with main nerve rays that depart from umbrella top. Between the outer layer and the inner which lines the celenteron (gastrodermis) there is a gelatinous layer, the mesoglea, acellular least in the most primitive forms.

Polyps in the only ways these are the tact and sensitivity to substances dissolved in the water.

In the jellyfish we find two real sense organs. The statocisti, a vesicle internally covered with hair cells and containing one statolito, a mineral body secreted by the animal. It allows the jellyfish to react to the changes in position relative to the vertical, because in that case the statolito pressed on different parts of the wall. A eyespot, sensitive to the light intensity, which allows the animal to adjust its depth according to the intensity of the light.

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Biology

Supply The diet of cnidarians is carnivorous: they feed on copepods and small fish, more juveniles feed on fitoflagellati and rotifers. The abundance of food is important for the development of cnidarians as it is the main element that the strobilazione of hydroids and scyphozoans take place.

The prey is captured with poison inoculation through cnidocysts, including all species of the phylum are provided and subsequently introduced into the internal cavity to be digested. The digestion is partly extracellular and intracellular part. The extracellular digestion occurs because of digestive enzymes produced in celenteron. Intracellular digestion is obtained from the same cells that engulf and digest internally small food particles. The digestion residues are then expelled from the external environment mouth.

Reproduction Sexual reproduction is present in all species; that asexual, mostly by budding, it generally has in polyps.

There are species in which it has alternation of generations between polyps and jellyfish. In these cases, the jellyfish reproduce sexually by producing gametes are expelled from the mouth. Fertilization takes place in the water; from the fertilized egg develops ciliated larva, called planula, that at some point lies in a prime area and begins to grow giving the embryo. The latter reproduces asexually for strobilazione giving rise to jellyfish.

Systematic The phylum Cnidaria is generally divided into 6 classes, each of which comprising a wide diversity of organisms share a similar life cycle and by the same elements of internal symmetry. According to Petersen (and later Bouillon), the cnidarians are divided into two sub-phylum: the Anthozoaria who only phase polypoid and the Medusozoa who is the phase of jellyfish.

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• Classe Anthozoa (Antozoi)
  • Sottoclasse Hexacorallia (Esacoralli)
    • Ordine Actiniaria
    • Ordine Antipatharia
    • Ordine Ceriantharia
    • Ordine Corallimorpharia
    • Ordine Rugosa †
    • Ordine Scleractinia
    • Ordine Zoantharia
  • Sottoclasse Octocorallia (octocoralli)
    • Ordine Alcyonacea
    • Ordine Helioporacea
    • Ordine Pennatulacea
• Classe Hydrozoa (Idrozoi)
  • Sottoclasse Hydroidolina o Hydroida
    • Ordine Anthoathecata
    • Ordine Leptothecata
    • Ordine Siphonophora
  • Sottoclasse Trachylinae o Automedusae
    • Ordine Actinulida
    • Ordine Limnomedusae
    • Ordine Narcomedusae
    • Ordine Trachymedusae
• Classe Scyphozoa (Scifozoi)
  • Sottoclasse Discomedusae
    • Ordine Semaeostomea
    • Ordine Rhizostomea
  • Ordine Coronatae
• Classe Cubozoa (Cubozoi)
  • Ordine Carybdeida o Cubomedusae
  • Ordine Chirodropida
• Classe Staurozoa
  • Ordine Conulatae 
  • Ordine Stauromedusae
• Classe incertae sedis
  • Famiglia Tesseranthidae
• Classe Polypodiozoa (filogenetica incerta nel 2014)
  • Ordine Polypodiidea

(Wikipedia)