Gray's Reef National Marine Sanctuary, about 17 miles off Sapelo Island, Georgia, is home to a variety of strange creatures. The Glyceridae, or bloodworms, are ferocious epi- and infaunal polychaetes that prey upon small invertebrates. They are errant burrowers that build galleries of interconnected tubes to aid in catching their prey.
Photis pugnator is another tube-building amphipod that can be found at sediment depths of 26 cm. On the surface of the seafloor it is often found in association with algae, and a closely related species even uses discarded gastropod shells as its home.
This isopod is an epifaunal resident of Gray's Reef. Generally, it is found on the surface of sponges, rocks, and tunicates, with reproduction even taking place in these areas. For example, a related species sets up breeding territories inside of sponges (where it's difficult for predators to get to), and the female travels to the male's territory to lay her eggs.
Brachiopods, also referred to as lamp shells, are filter feeders found in the surface layers of the sediment (upper 2 cm). They bury themselves in the sand using a stalked portion of their body called a pedicle, and use their lophophore to extract small organic material from the water column.
Brittlestars, like urchins may be epi- or infaunal. They are important bioturbators, burrowing up to 12 cm, and as deposit feeders have important effects on sediment characteristics and the cycling of nutrients and chemical within the sediment.
Paramphinome sp. B is an undescribed fireworm from Gray's Reef that typically is found in rocky areas above the sediment, while only rarely below. Fireworms have acquired their name from the notosetae (bristle-like appendages on their bodies) that break off when touched, subsequently causing a painful skin reaction in the unsuspecting victim.
This mysid shrimp generally resides a soft burrow in the upper few centimeters of sediment. It is a nocturnal filter and suspension feeder that may have a large impact on the structure of zooplankton communities from its selective feeding habits.
Renilla reniformis, or the sea pansy, is typically found on the surface of the seafloor, but can also occur up to 4 cm below the surface. It has bioluminescent properties as a result of some symbiotic zooxanthelle (it can glow in the dark!), and uses a mucus net to catch prey.
Cirratulid polychaetes live either on the surface of the seafloor among rocks and crevices, or within tubes and burrows beneath the seafloor. They are brightly colored and have tentacle-like gills that are used for respiration.
This species of sipunculid can found in a soft mucus burrow deep within the sediment, in discarded mollusc shells, and in rock crevices. It is typically a deposit feeder and a detritivore, using a feeding apparatus called an introvert to capture its prey.
Sea stars may lead an epi- or infaunal lifestyle. Whichever, they are important ecosystem-level predators that have significant tropic effects within their community.
Sand dollars, like this one, may be found in sediment depths of 30 cm or more. Members of the genus Encope, typically have commensal relationships with Dissodactylus crabs. In this association the crab receives food, shelter, and means of transportation and the sand dollar receives no harm or benefit.
Cumaceans, like this one, generally reside at the sediment-water interface, and as a result, are an important component of the diets of benthic-dwelling fishes.
Relatively little is known about Cirrophorus ilvana. This species is a deposit feeder that resides solely within the sediment, either actively burrowing, or living within the interconnected tubes it builds out of its own mucus.
Sipunculids, or peanut worms, may be epi- or infaunal. Above the sediment they may bore into rock, or are found in mollusc shells, foraminiferan tests, crevices, or in polychaete tubes. Below the sediment, they occupy soft mucus burrows that may extend 50 cm into the sediment.
This sipunculid genus is found in hard mucus burrows deep within the sediment, in rock crevices, and attached to tunicates. It is a predatory carnivore and scavenger that uses a feeding apparatus called an introvert to capture its prey.
Nephtys simoni is an errant, predatory worm that can burrow up to 10 cm beneath the sediment. It is a popular food of numerous benthic fishes, and humans even use it as "bait" on their fishing hooks.
Little is known about the two species of Bhawania that live at Gray's Reef. They have an epi- or infaunal lifestyle, are carnivorous, have no obvious symbiotic relationships, and have typical polychaete reproductive habits.
Sigalion arenicola, also referred to as a "scaleworm," is an epi- and infaunal errant polychaete, typically associated with rocky areas. It is a predatory carnivore that uses its eversible proboscis to capture small invertebrate prey.
Acteocina species are deep-dwelling, carnivorous and deposit feeding gastropods. They feed on small invertebrates, and are an important food item for benthic fishes.