Marine Invertebrates: Porifera, Cnidaria, and Mollusca

Pillar coral  is a hard coral. It is a digitate coral, i.e. it resembles fingers or a cluster of cigars, growing up from the sea floor without any secondary branching. It is large and can grow on both flat and sloping surfaces at depths.

Corals are marine invertebrates in the class Anthozoa of phylum Cnidaria. They typically live in compact colonies of many identical individual polyps.

Bamboo coral  is a commonly recognised inhabitant of the deep sea, due to the clearly articulated skeletons of the species. These organisms may be an important environmental indicator in the study of long term climate change, as some specimens of bamboo coral have been discovered that are 4,000 years old.

Cerianthids look very similar to sea anemones. They are solitary, living buried in soft sediments. Tube anemones live and can withdraw into tubesthat are made of a fibrous material, which in turn is made from secreted mucus and threads of nematocyst-like organelles known as ptychocysts.

Kinorhynchans are segmented, limbless animals with a body consisting of a head, neck and a trunk of eleven segments. Unlike some similar invertebrates they do not have external cilia, but instead have a number of spines along the body, plus up to seven circles of spines around the head. These spines are used for locomotion.

The reef surface is the shallowest part of the reef. It is subject to the surge and the rise and fall of tides.

Atoll reef is a  more or less circular or continuous barrier reef extending all the way around a lagoon without a central island.

V. shiloi is infectious only during warm periods. Elevated temperature increases the virulence of V. shiloi, which then become able to adhere to a beta-galactoside-containing receptor in the surface mucus of the host coral.

Lophocytes are amoeba-like cells that move slowly through the mesohyl and secrete collagen fibres.

S. officinalis is a hermaphrodite having both ova and sperm. When ripe, their sperm escape from the body through vents and float around in the sea until they are sucked into the pores of another sponge by a water current. This sponge is dark grey or purplish when alive. When dry they can either be yellow or brown.

 Pinacocytes are flattened cells containing many granules; capable of contracting. They are involved in the maintenance of the size and structure of sponge. They can expand and contract and slightly alter the size of the sponge. It can also produce collagen.

Yellow-band disease is a disease that attacks colonies of coral at a time when coral is already under stress from pollution, overfishing, and climate change. It is characterised by large blotches or patches of bleached, yellowed tissue on Caribbean scleractinian corals.

These sponges are rounded masses or repent thick branches, often with volcano-shaped oscular elevations though the oscules may also be flush. Their surface is smooth. The consistency is fairly soft and easy to tear.

Caudofoveata are small (1-30 mm), mainly deep sea molluscs. They are worm-like, lacking shells or distinct muscular feet; they instead have scales and calcareous spines called sclerites for movement.

Body is monomeric and highly variable in form, may possess a dorsal or lateral shells of protein and calcareous spicules.

Squid are cephalopods.They have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles. Squid are strong swimmers and certain species can "fly" for short distances out of the water.

Hemiarthrum setulosum is a species of chiton in the family Hanleyidae, the only member of the genus Hemiarthrum.

Octopuses have a relatively short life expectancy and some species live for as little as six months.

A nudibranch is a member of Nudibranchia, a group of soft-bodied, marine gastropod mollusks, which shed their shell after their larval stage. They are noted for their often extraordinary colours and striking forms.

Limpet is a common name applied to aquatic snails with shells broadly conical in shape. Limpets are easily  found on rocky shores that are rich in algae. 

Cephalopods are the only mollusks with a closed circulatory system. Coleoids have two gill hearts (also known as branchial hearts) that move blood through the capillaries of the gills. A single systemic heart then pumps the oxygenated blood through the rest of the body.

Pinctada maxima is the only species that produces South Sea pearls. Currently south sea pearls are cultured primarily in Australia and Tahiti. Because these pearl oysters are so large, a much larger nucleus than usual can be used in culturing.

Nacre is known as mother of pearl. It is an organic-inorganic composite material produced by some mollusc, as an inner shell layer. It is strong, resilient and iridescent.

Otala lactea  is a large, edible species of air-breathing land snail. Archaeological recovery at the Volubilis illustrates prehistoric exploitation of O. lactea by humans. This snail creates and uses love darts as part of its courtship behaviour, prior to mating.

Shell gorgets are a Native American art form of polished, carved shell pendants worn around the neck. The gorgets are frequently engraved and are sometimes highlighted with pigments, or fenestrated (pierced with openings).

Geoducks are the longest-living organisms in the animal kingdom. The oldest recorded specimen was 168 years old but individuals over 100 years old are rare. Scientists speculate that the geoduck's longevity is the result of low wear and tear. A geoduck sucks water containing plankton down through its long siphon, filters this for food and ejects its refuse out through a separate hole in the siphon.

Helix texta  is a species of large, edible, air-breathing land snail. This species is endemic to Israel. It lives in the high northern part of Israel, typically in the Hermon ridge area.

Pinna is a genus of pen shells. It is a cosmopolitan genus of bivalve molluscs characterised by elongated and wedge-shaped shells, which most commonly stand point-first in the sea bottom in which they live, anchored by a net of byssus threads.

Cultured pearls are the response of the shell to a tissue implant. A tiny piece of mantle tissue from a donor shell is transplanted into a recipient shell.

The California two-spot octopus (Octopus bimaculoides) is an octopus species found off the coast of California. One can identify the species by the circular blue eyespots on each side of its head. Due to their friendly temperament and relative hardiness, they are considered by most experts to make the best pet octopus.