Sea pens are colonial marine cnidarians belonging to the order Pennatulacea. There are 16 families within the order; they are thought to have a cosmopolitan distribution in tropical and temperate waters worldwide. Sea pens are grouped with the octocorals ("soft corals"), together with sea whips or gorgonians.
Although named after their feather-like appearance reminiscent of antique quill pens, only sea pen species belonging to the suborder Subselliflorae live up to the comparison. Those belonging to the much larger suborder Sessiliflorae lack feathery structures and grow in club-like or radiating forms. The latter suborder includes what are commonly known as sea pansies. (Wikipedia)
Common seadragon or weedy seadragon (Phyllopteryx taeniolatus) is a marine fish related to the seahorse. Adult common seadragons are a reddish colour, with yellow and purple markings; they have small leaf-like appendages that resemble kelp fronds providing camouflage and a number of short spines for protection. Males have narrower bodies and are darker than females. Seadragons have a long dorsal fin along the back and small pectoral fins on either side of the neck, which provide balance. Common seadragons can reach 45 cm in length.
The leafy seadragon or Glauert's seadragon, Phycodurus eques, is a marine fish in the family Syngnathidae, which includes seadragons, pipefish, and seahorses. It is the only member of the genus Phycodurus.
It is found along the southern and western coasts of Australia. The name is derived from the appearance, with long leaf-like protrusions coming from all over the body. These protrusions are not used for propulsion; they serve only as camouflage. The leafy seadragon propels itself by means of a pectoral fin on the ridge of its neck and a dorsal fin on its back closer to the tail end. These small fins are almost completely transparent and difficult to see as they undulate minutely to move the creature sedately through the water, completing the illusion of floating seaweed.
The Ruby seadragon (Phyllopteryx dewysea) is a marine fish in the family Syngnathidae, which also includes seahorses. It inhabits the coast of Western Australia. The species was first described in 2015, making it only the third known species of seadragon, and the first to be discovered in 150 years.
The team that discovered this species named the marine fish after its color and they believe it is so red because it inhabits the deeper waters, where red hues are absorbed more efficiently and being red colored can help camouflage.
Ruby seadragon (Phyllopteryx dewysea) in the wild
First glimpse of ruby seadragons in the wild
To determine if Ruby seadragons truly lacked appendages, or if the museum specimens had lost them prior to or during the collection process, the researchers needed to observe them in the wild.
This latest discovery of the fish in the wild confirmed that Ruby Seadragons lack ornate leaf-like appendages, a feature that scientists had long considered to be distinguishing characteristics of all seadragons based upon the two known species—Common and Leafy seadragons. Both species use their leaf-like appendages as camouflage in the lush seaweed and kelp meadows where they prefer to live.
Sea urchins or urchins, archaically called sea hedgehogs, are small, spiny, globular animals that, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. About 950 species of echinoids inhabit all oceans from the intertidal to 5,000 metres (16,000 ft; 2,700 fathoms) deep. The shell, or "test", of sea urchins is round and spiny, typically from 3 to 10 cm (1.2 to 3.9 in) across. Common colors include black and dull shades of green, olive, brown, purple, blue, and red. Sea urchins move slowly, feeding primarily on algae. Sea otters, starfish, wolf eels, triggerfish, and other predators hunt and feed on sea urchins. Their roe is a delicacy in many cuisines. The name "urchin" is an old word for hedgehog, which sea urchins resemble.
Sea urchins are members of the phylum Echinodermata, which also includes sea stars, sea cucumbers, brittle stars, and crinoids. Like other echinoderms, they have five-fold symmetry (called pentamerism) and move by means of hundreds of tiny, transparent, adhesive "tube feet". The symmetry is not obvious in the living animal, but is easily visible in the dried test.
Specifically, the term "sea urchin" refers to the "regular echinoids", which are symmetrical and globular, and includes several different taxonomic groups, including two subclasses : Euechinoidea ("modern" sea urchins, including irregular ones) and Cidaroidea or "slate-pencil urchins", which have very thick, blunt spines, with algae and sponges growing on it. The irregular sea urchins are an infra-class inside the Euechinoidea, called Irregularia, and include Atelostomata and Neognathostomata. "Irregular" echinoids include: flattened sand dollars, sea biscuits, and heart urchins.
Fivefold symmetry:
Like other echinoderms, sea urchin early larvae have bilateral symmetry, but they develop five-fold symmetry as they mature. This is most apparent in the "regular" sea urchins, which have roughly spherical bodies with five equally sized parts radiating out from their central axes. Several sea urchins, however, including the sand dollars, are oval in shape, with distinct front and rear ends, giving them a degree of bilateral symmetry. In these urchins, the upper surface of the body is slightly domed, but the underside is flat, while the sides are devoid of tube feet. This "irregular" body form has evolved to allow the animals to burrow through sand or other soft materials.
(Wikipedia)
Left: Paracentrotus lividus
Right: Paracentrotus lividus in Sala Maremagnum of Aquarium Finisterrae (House of the Fishes), in Corunna, Galicia, Spain.
Paracentrotus lividus is a species of sea urchin in the family Parechinidae commonly known as the purple sea urchin. It is the type species of the genus and occurs in the Mediterranean Sea and eastern Atlantic Ocean.
Toxopneustidae is a family of globular sea urchins in the class Echinoidea.
Tripneustes ventricosus, commonly called the West Indian sea egg or white sea urchin, is a species of sea urchin. It is common in the Caribbean Sea, the Bahamas and Florida and may be found at depths of less than 10 metres (33 ft).
Toxopneustes pileolus Flower urchin from Tasitolu, East Timor (note the visible purple zigzag in one of the ambulacral segments)
Toxopneustes is a genus of sea urchins from the tropical Indo-Pacific. It contains four species (oxopneustes elegans, Toxopneustes maculatus, Toxopneustes pileolus, Toxopneustes roseus). They are known to possess medically significant venom to humans on their pedicellariae (tiny claw-like structures). They are sometimes collectively known as flower urchins, after the most widespread and most commonly encountered species in the genus, the flower urchin (Toxopneustes pileolus).
Odontodactylus scyllarus, known as the peacock mantis shrimp, harlequin mantis shrimp, painted mantis shrimp, or clown mantis shrimp, is a large mantis shrimp native to the Indo-Pacific from Guam to East Africa.
In the saltwater aquarium trade, it is both prized for its attractiveness and considered by others to be a dangerous pest.
O. scyllarus is one of the larger, more colourful mantis shrimps commonly seen, ranging in size from 3 to 18 centimetres (1.2 to 7.1 in). They are primarily green in colour, with orange legs and leopard-like spots on the anterior carapace. (Wikipedia)
The mantis shrimp, or stomatopod, is a type of marine crustacean of the order Stomatopoda. The majority of Stomaopoda species grow to around 10 centimetres (3.9 in) in length. A few can reach up to 38 cm (15 in). The largest mantis shrimp ever caught had a length of 46 cm (18 in) and was caught in the Indian River near Fort Pierce, Florida of USA. A mantis shrimp's carapace (the bony, thick shell that covers crustaceans and some other species) covers only the rear part of the head and the first four segments of the thorax. Varieties range from shades of brown to vivid colours, as there are more than 450 species of mantis shrimp. They are among the most important predators in many shallow, tropical and sub-tropical marine habitats. However, despite being common, they are poorly understood as many species spend most of their life tucked away in burrows and holes.
Called "sea locusts" by ancient Assyrians, "prawn killers" in Australia[5] and now sometimes referred to as "thumb splitters" – because of the animal's ability to inflict painful gashes if handled incautiously[6] – mantis shrimps sport powerful claws that are used to attack and kill prey by spearing, stunning, or dismemberment. In captivity, some larger species are capable of breaking through aquarium glass with a single strike.
(Wikipedia)
Mantis shrimp or stomatopods are an ancient group of marine predators that are only distantly related to other more familiar crustaceans, such as crabs, shrimp and lobsters. While most occur in shallow tropical marine waters, a few species are found in more temperate seas. Although they are called mantis shrimp, they are neither shrimp nor mantid (a species of insect), but received their name due to their resemblance to both praying mantis and shrimp. Mantis shrimp appear in a variety of colors, from shades of browns to bright neon colors. (Wikipedia)
Mantis shrimp from frontMantis shrimp A predatory marine crustacean with a pair of large spined front legs that resemble those of a mantis and are used for capturing prey.
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