CRUSTACEANS

Phylum: Arthropodia

Order: Decapods

These aquatic animals are invertebrates with a hard exoskeleton. They have two pairs of antennae and their bodies are divided into three parts; the head, thorax and abdomen. The fused head and thorax is covered by a carapace or dorsal shell. There order is derived from the five pairs of legs they have in which the front three pairs function as a mouth part. Most are scavengers.

Included in this group:

LOBSTERS: Lobsters are bottom dwellers with long cone-like antennae. In order to grow they have to go through a moulting stage which leaves them vulnerable to predation. They generally crawl along the surface floor but they can swim backwards by repeatedly curling their abdomen and using their wide flat tails if endangered. The presence of Hemocyanin in their blood makes it a blue colour. Lobsters are normally omnivores eating fish, small custaeceans, molluscs and plant matter. They prefer to live in self dug burrows however will take refuge in cracks and crevices. The clawed Lobsters are the ones known for culinary dishes however the Spiny and Slipper Lobsters lack large front claws

The sculptures "Anthropocene" and "La Jardinera" were designed with an internal tunnel system specifically for lobsters and shrimps to inhabit.

CRABS: Crabs make up nearly half of the 15,000 species within this order. They have evolved to have a reduced abdomen, four pairs of legs and a front pair of claws which are used for moving objects and for protection. Due to the articulations of their legs they move swiftly sideways along the surface floor and are generally very discrete and hard to locate. Crabs are often aggressive towards each other and communicate by waving or drumming their pinchers. They are omnivores and feed on algae, crustaceans, detritus and small molluscs.

HERMIT CRABS: These are not true crabs, they have soft curved abdomens unlike most crustaceans. They use discarded shells as a home and when they outgrow one they move onto a larger one, often in gastropod shells.

SHRIMPS: Shrimps are Decapods with long legs, very thin antennae and its thin exoskeleton makes it lightweight for swimming. They tend to hide in dark recesses, within anemones or near sponge openings. Many species clean the area by feeding on bacteria residue and parasites from fish and a high tolerance to toxins. Examples in this group include: Coral banded shrimp (such as that living in the VW Beetle), Red snapping shrimp, Golden coral shrimp. They are distinguished from the true prawn by the differences in their gill structure.

MANTIS SHRIMP: These are not true shrimps and receive their name by resembling the praying mantis. They have very strong claws to capture prey an elongated body and feather-like gills on the lower abdomen. Typically they are aggressive and very fast predators that use their limbs as spears or smashing their prey. They are solitary animals that inhabit reefs and burrow in sand.

"Snorkelling guide to Marine Life" Paul Humann, Ned DeLoach

en.wikipedia.org/wiki/Decapoda

en.wikipedia.org/wiki/Crab

animals.nationalgeographic.com/animals/invertebrates/lobster/

en.wikipedia.org/wiki/Shrimps

www.bbc.co.uk/nature/blueplanet/factfiles/crustaceans/mantis_shrimp_bg.shtml

en.wikipedia.org/wiki/Calappa_(crab)

ECHINODERMS

Phylum: Echinodermata

These are ocean dwelling creatures which are found at every depth from shallow to the abyss. They have five body sections equally proportioned arranged around a central axis, this fivefold symmetry is called Pentermerism. Many move by adhesive tube feet which work to move the animal across the ocean floor and are vivid colours due to pigments the skin which can change colour with light intensities. They are important biologically to the reef system because they are so abundant and their ossified skeletons contribute to calcium carbonate formation.

SEA STARS OR STAR FISH

Class: Asteroidae

Most species have five arms with a central mouth located on the underneath surface with their anus dorsally forming pentaradial symmetry as an adult. When an arm is broken they can normally regenerate and occasional species have the ability to form a new animal from a severed member. Their bodies are composed of calcium carbonate ossicles or plates which form the endoskeleton and are externally expressed as spines or granules. Internally they have a hydraulic internal water-vascular system which is used for feeding and aid in its movement by projecting many tube feet along each arm for locomotion. They can live at a broad range of depth of water from intertidal to over 60,000 meters deep. They are opportunistic feeders, feeding on molluscs or sometimes coral and not all species are pure carnivores but can supplement their diet on algae and detritus. Some species have specialised feeding mechanisms such as suspension feeding and specific prey feeding. They have become known as a keystone species in ecology because they are very vulnerable to water pollution due to the simple gut and water vascular pump they posses. Sea stars can live up to 34 years.

The Silent Evolution Collection has become home to many Sea star families in a short space of time.

BRITTLE STARS:

Class: Ophiuroidea

Similar in shape to a Sea star but with a small central axis containing all the internal organs and five slender arms containing several rows of spines. The mouth is a five toothed jaw system which serves as an anus as well as for ingestion. They move only laterally due to the formation of the calcareous plates along the dorsal surface of their arms and do not rely on their tube feet for locomotion. Severed arms can regenerate. They hide under rocks and in crevices but can be seen on sponges and soft corals.

SEA URCHINS:

Class: Echinoidea

Urchins are Spherical or globular creatures with long spines projecting from their bodies and tube feet and a mouth underneath usning the same water vascular system as sea stars. Their internal organs are enclosed in a hard shell composed of fused plates of calcium carbonate however the symmetry is not as obvious unless the shell is dried. The long spines can penetrate skin easily and are difficult to remove. They live off algae and organic food which they scrape off of rocks using a mouth with a five tooth arrangement. Common colours range from Black to dull green, brown and red and can differ in size from 6-36cm. They are closely related to the Sand Dollar and their roe is a delicacy is some cuisines. The West Indian Sea Egg a large example of an urchin which devours algae and often found under the camouflage of snails and in crabs.

HEART URCHINS: Oval dome shaped urchins distinguished by a mouth and anus at different ends of the body forming a "heart" shape. Their bodies are covered with closely arranged short spines adapted for burrowing under the sand or mud. They feed on organic material underneath the ocean substrate by extending long tentacles.

SEA CUCUMBERS

Class: Holothuroidea

Sea cucumbers have elongated rounded bodies which obscure the five segment separation. They have a mouth and an anus at opposite ends of the body. Their endoskeletal ossicles are buried beneath a leathery skin and body wall. Some species have very reduced or absent tube feet. A variety of fish, worms and crabs have developed a symbiotic relationship with sea cucumbers by living under their anus for protection. Sea cucumbers contain both a water vascular system and haemal system making them more complex to the rest of the phylum. They crawl very slowly along the surface and communicate by sending hormone signals through the water. They are scavengers gathering up plankton and organic debris

"Snorkelling Guide to Marine Life" by Paul Humann, Ned DeLoach

www.britannica.com/EBchecked/topic/258504/heart-urchin

animals.nationalgeographic.com/animals/invertebrates/starfish/

en.wikipedia.org/wiki/Echinoderm

en.wikipedia.org/wiki/Sea_urchin

reefcleaners.org/index.php?page=shop.product_details&flypage=flypage-ask.tpl&product_id=150&category_id=4&option=com_virtuemart&Itemid=34

SEGMENTED WORMS

Phylum: Annelida

Oceanic worms or annelids, can be hard to distinguish disguised against the reef or they are easily seen like the free moving

FIREWORMS: Their long segmented bodies are divided externally by ring-like constrictions called annuli and internally by septa. Most segments contain the same sets of organs although they share a common gut, nervous system and circulatory system. Most annelids have a closed circulatory system and the blood is circulated entirely in blood vessels. The body is covered by a cuticle make form strong flexible collagen that is secreted by the skin beneath. They bury their bodies below rock or coral attached to the reef and the visible section are called "radioles" which are featherlike projections. These radioles function as gills for oxygen and waste exchange and also as a method for capturing prey, plankton in the water. Marine worms count for over one third of bottom dwelling animals around reefs and in the tidal zones. The burrowing species increase the penetration of oxygen and water into the sea bed and therefore in turn encourage the growth of bacteria and small animals alongside their habitat.

BEARDED FIREWORM: These flattened segmented worms are very colourful and can reach up to 35cm in length. Each body segment has a pair of lobe-like pedicles called 'parapodia' which are used for swimming, burrowing and feeding. They have a group of poisonous white bristles on either side of their body which are extended if threatened. The neurotoxin they release can easily penetrate skin through the bristles and cause intense irritation. They are found living on reefs or rocky habitats and can be seen up to 150 meters below the surface. Fireworms are voracious predators on hard and soft corals, anemones and small crustaceans.

CHRISTMAS TREE WORM: Tube building worms with twin spíral plumes of tenticles forming a Serpulid shaped like a Christmas tree, used for feeding and respiration. They retract their plumes into the burrow in coral when disturbed. Typically they are relatively small , 3.6cm, come in a variety of bright colours and white and are sedentary worms living on plankton in the water.

FEATHER DUSTER: Normally live in colonies all with the same characteristics. The small worm lives inside the central tube with a single circular ring of radioles protruding. The radioles act like gills for gas exchange and also trap tiny particles in the water. These animals live in the reef where there us a current and can be found in depths of 5-50m.

STAR HORSESHOE WORM: Another variety of Tube worm with a double fold of radioles forming a U-shaped crown. The entry into the tube as a small covering made from calcareous discs. Most are shades of red, brown, orange and white. The entire animal is around 10cm and the crown protrudes about 4cm. They are very common in the Caribbean and are found at depth up to 30m.

"Snorkelling Guide to Marine Life" by Paul Humann, Ned DeLoach