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This guide is being developed to enable paint chemists,
formulators, and other industry scientists to identify fouling
organisms normally found at the various test sites studied by
Poseidon. By comparing the digital photographic records submitted by
Poseidon from each of the test sites, one can identify the specific
organisms that attach or are prevented from attaching to the test
panels. This guide is an ongoing project, and not limited to our test
sites. Those who may wish to describe common biofoulers found in
their test site are invited to submit information for inclusion in
this guide. Please email us at info@poseidonsciences.com with
your digital photo and a general description of the organism. A. Biofoulers in Tuticorin Bay, Southeastern India B. Biofoulers in Link Port, Fort Pierce, Florida,
USA A.
TUTICORIN, INDIA Biofoulers in Tuticorin Bay, Southeastern India
Barnacle General
Information The barnacle (Balanus amphitrite)
is the most serious fouler faced by pearl oyster farmers in
India. This barnacle settles and grows on the shells of the pearl
oysters, while boring organisms riddle through the shells, rendering
them weak and fragile. Following the barnacle in terms of fouling are the mollusks, Avicula vexillum and Crassostrea sp. The tubiculous polychaetes (Hydroides sp.) have not been found to be significant, and they appeared in pearl oyster farms only in January. |
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B.neritina is considered a potential fouling organism. The colonies are erect and brush-like. Each colony is composed of a set of polymorphic individuals. Only these morphs are capable of feeding, and produce gametes. Embryonic development occurs withn a complex brood chambers and larvae are released at the conclusion of the embryonic period in response to an increase in light intensity. B. neritina larvae are released from brood sacks with a visible light shock and concentrated by the attraction to a fiber optic light source. The larvae are non-feeding and free-swimming only a few hours before settlement and metamorphosis. The major organs sensory units are the corona, pyriform groove, internal sac and the apical sense organ. The larva of B. neritina is avoid, about 350 μm high and 250 μm in diameter. Hydroids The worm is about 3 inches in length. The crown of the branchiae is long and slender, radiating from the united base. It builds calcareous tube often in coiled masses. The projecting heads have two fan shaped series of branchiae with plume like pinnae fifteen to eighteen in number with a color pattern variegated with pink. A dorsal filament on each fan has been modified into an operculum, one of which is fully developed, the other rudimentary. It is seen to be a double, handsomely patterned structure composed of two super imposed star like discs, the lower being the larger and made up of twenty five or more pieces like a vase or flower cup surmounting a stem. The body of this species is of a reddish orange colour. Hydroides elegans is a tough and cosmopolitan serpulid fouler. Sea Anemone
Very common on calcareous structures (shell,coral, calcerous algae, barnacles). Excurrent and incurrent papillaeproject out of substratum in living condition, but are highly contractile and only pores on substratum visible out of water. Pores are 0.5-2.0 mm. in diameter but subject to considerable variation. Larger pores accommodate excurrent and smaller, incurrent papillae. Papillae are green, golden yellow or red when live. Chambers found inside substratum are small, 2 to 5 mm. in diameter, but subject to considerable variation. All members, at least in early life, bore into calcareous matter and thus, are a menace to commercially important mollusks and coral reefs. There are 32 species belonging to this family in the Indian seas (Thomas 1979). They cause considerable damage to the pearl, chalk, and oyster beds of the Gulf of Mannar and Palk Bay in India. The sponge is massive, globular or irregular in the initial state, turning to a flat-topped structure in advanced stages of development. This particular sponge usually grows upright on the hard objects found at the sea bottom. The rough surface of the sponge also attracts foulants and bacteria alike. Hence, to protect them from fishes and foulants, they have to produce icthyotoxic and antifouling compounds. Extensive cavities found in this sponge are utilized by other animals such as amphipods, isopods, and stomatopods as shelter. Bivalve mollusk (Vulsella vulsella Lin) is seen buried into the body of the sponge. Why these animals are unaffected by chemicals produced by this sponge is unknown. B.
FORT
PIERCE, FLORIDA, USA Biofoulers in Link Port, Fort Pierce, Florida, USA
Algae
Bryozoans Bugula neritina (see under Biofoulers in Tuticorin Bay)
Hydroids
Molluscs Large intertidal and subtidal oyster commonly reaching up to 4 inches (10 cm) in length. It first appears as tan round plate conforming to the shape of the substrate to which it is attached. Crassostrea becomes elongated with growth; the new growth arching upward or away from the substrate and becoming wider than the older portion that initially attached to the substrate. This results in a deeply convex lower (relative to the substrate) shell and flatter upper shell, which assumes the appearance of a lid. The adductor muscle develops inside the narrow, older portion of the shell near the hinge of the bivalve. At the opposite end, spiny protrusions frequently form on the terminal ridges of the shell giving older oysters the overall appearance of the head of a fanged baleen whale. The tan shell color fades in time to an ashen white.
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Polychaetes Sabellid and serpulid polycheates are families of feather duster, or fan worms. Sabellids build membranous or sand-grain tubes. Serpulids secrete calcareous tubes that are attached to rocks, shells, or algae, enabling these worms to live on an otherwise inhospitable hard substratum. The most dorsal radiole on one or both sides of the serpullids is modified into a long stalked knob called an operculum, which acts as a protective plug at the end of the tube when the crown is withdrawn. Sabellids
The Serpulid
polychaete encases itself in a hard calcium carbonate tube. It
is easy to spot because of the shell-like color of the tube.
Tunicates Typical members of this genus have the body somewhat elongate, oval, laterally flattened, and attached by the posterior part of much of the left side. The apertures are on siphons, the branchial about eight-lobed and terminal, the atrial six-lobed and toward the dorsal side, and the test fairly tough but somewhat translucent, even semi-transparent.
The
colony in this species consists of a dense group or cluster of
elongate, club-shaped zooids, each with its own separate covering of
test. The
tests are connected by their tapering bases with a network of
stolons that adheres to the surface on which it grows.
The colony may entirely surround the object to which it is
attached. Zooids
are generally about 20mm long.
They are oblong, truncate at the anterior end where the two
apertures are situated, and abruptly tapered at the other end to a
narrow pedicel containing the vessel that connects each individual
to the colony. The tests are transparent and colorless, thicker on the ends
of the body. Mantle and
internal organs are also transparent, but shades into yellow,
orange, or pinkish orange on the anterior part of the body, the
color being largely due to pigment in cells in the branching vessels
in the mantle. The
intestinal loop is yellow or orange. Rarely, some colonies are entirely bright orange. Apertures on short tubes or slight elevations which do not project beyond the surface of the thick layer of test covering this end of the body. The branchial aperture is larger than the atrial. Both apertures are usually directed straight forward.
Perophora viridis (no photo available)
The branchial
orifice is terminal, or nearly so, the atrial a little way back on
the dorsal side; both usually surrounded by four rounded prominences
corresponding to the four sides of the square aperture, which lies
in the depression between them.
In small individuals these prominences are enormous.
In many individuals there is a conspicuous curvature of the
long axis of the body by which the apertures are brought towards
each other, and the ventral side of the body becomes more convex. The more conspicuous external characters of the species are furnished by the test and body surface. The lobes surrounding the apertures are marked with radiating purple brown lines. The surface is usually clean although ascidians, bryozoans, and other organisms sometimes grow upon it. In some individuals the surface is merely irregularly furrowed, or there are a few conspicuous, widely spaced, longitudinal furrows which are separated by broad, rounded ridges running toward the apertures and ending in the prominences described above. In many individuals the ridges are broken, especially on the anterior part of the body, into low but large, dome-shaped elevations, giving the body surface or parts of it, an appearance suggesting a coarse, unevenly laid cobblestone pavement. Large specimens may reach 7 cm in length. |
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Enteromorpha
lingulata
Bugula
stolonifera. Colonies
grayish tan, erect and branching, forming a fan or funnel (young
colonies) or a dense tuft (older colonies).
