Macoma tenta

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Macoma tenta
FMIB 52926 Macoma tenta.jpeg
Macoma tenta shell
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Subclass: Heterodonta
Order: Cardiida
Family: Tellinidae
Genus: Macoma
Species:
M. tenta
Binomial name
Macoma tenta
(Say, 1834)

Macoma tenta, the narrowed macoma clam or elongate macoma is a species of clam, a marine bivalve mollusk (bivalvia) in the family Tellinidae and genus Macoma. [1] Macoma tenta are one of two species of macoma clams that can be found in the Chesapeake Bay on the eastern shore of the United States in Maryland and Virginia. [2] The macoma tenta like their cousin in the Chesapeake, the Macoma balthica or Baltic macoma clam, are small marine bivalves with thin, chalky white shells. [2] They tend to live buried in the sandy or muddy areas of shallow water in the middle and lower Chesapeake Bay. [2] [3] Macoma clams are among the most abundant clams in the Chesapeake Bay. [2] [4] Macomas first appeared about 750,000 years ago. [5]

Contents

Appearance

Chesapeake Bay Macoma clams (both balthica and tenta) have thin and fragile shells. [2] [3] [6] The elongate macoma (Macoma tenta) get their name from their elongated shell with a shell proportion (width/length) that is greater than 1.5. [7] The narrowed macoma clam’s shells tend to be more elongated than the Baltic macoma’s shells and have a smoother, pearly sheen that is slightly iridescent. [2] [3] [6] [8] The smooth shell may have several fine concentric growth lines which indicate yearly growth. [6] [8] Their color is white to yellowish compared to the pinkish tint of the Baltic macoma clam. [2] [3] They have a narrowed posterior end that is slightly twisted or curved to the left and the anterior end is long and rounded. [3] [6] [8] These clams have one foot which helps to hold them in place and two siphons, tube-like structures in which water flows. [6] Their long, thin, flexible siphons are of unequal length and fully retractable. [4] The narrowed macoma clam only grows to a length of approximately three-quarters of an inch. [2] [3] [6]

Habitat and distribution

The macoma tenta clams tend to burrow under the sand, sandy mud, and mud along the shoreline and in shallow, subtidal waters of the middle and lower Chesapeake Bay. [2] [3] While populous in the Chesapeake Bay, the macoma tenta can also be found in other waters of North America and the Western North Atlantic Ocean including the Guld of Mexico and the Caribbean Sea. [1] [9] They can lie either vertically or horizontally in their sandy and muddy habitat and are able to shift positions frequently in search of food. [2] They will also quickly move or burrow down deeper when disturbed. [2] [6]

Prey and predators

The clam’s two siphons stick up above the surface when the clams are buried in the sand or mud. [2] [6] The longer of the two siphons sucks in tiny bits of food lying on the Bay’s bottom by brushing across the sediment; they also consume microplankton filtered through the siphoned sea water. [2] [4] Waste and unused water are then expelled through the second siphon. [2] [6] Macoma tenta clams’ long siphons resemble worms crawling along the bottom and thus attract many predators such as American eels. [2] Cownose rays also eat macoma clams by flapping their fins against the sand to reveal the buried clams. [10]

Reproduction

Male macoma clams release sperm into the water column and female macoma clams release eggs. Upon fertilization, eggs develop into clam larvae with two small transparent shells and a small foot. [2] The larvae float in the bay currents for a few weeks before settling to the bottom of the bay, anchoring themselves to sand grains. [2]

Ecology

Development along shorelines may have negative impacts on the habitats of these marsh-dwelling bivalves. Researchers have seen higher density and more diversity of some benthic bivalve species in natural marsh areas compared to those that have been impacted by residential, commercial or industrial development. [11] Deposit-feeding species are particularly vulnerable to depletion of their food source along the shoreline. [11]

Related Research Articles

Bivalvia Class of molluscs

Bivalvia, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. Bivalves as a group have no head and they lack some usual molluscan organs like the radula and the odontophore. They include the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. The shipworms bore into wood, clay, or stone and live inside these substances.

Cownose ray Species of cartilaginous fish

The cownose ray is a species of eagle ray found throughout a large part of the western Atlantic and Caribbean, from New England, United States to southern Brazil. Male rays often reach about 2 and 1/2 feet in width. Females typically reach about 3 feet in width. However, there have been reports of rays up to 7 feet in width. Sizes change depending on the geographical range. Females will usually grow larger than males, allowing for larger offspring. These rays also belong to the order Myliobatiformes, a group that is shared by bat rays, manta rays, and eagle rays.

Siphon (mollusc) Anatomical structure which is part of the body of some aquatic molluscs

A siphon is an anatomical structure which is part of the body of aquatic molluscs in three classes: Gastropoda, Bivalvia and Cephalopoda.

Pacific razor clam Species of bivalve

The Pacific razor clam, Siliqua patula, is a species of large marine bivalve mollusc in the family Pharidae.

Soft-shell clam Species of mollusc

Soft-shell clams or sand gaper, scientific name Mya arenaria, popularly called "steamers", "softshells", "piss clams", "Ipswich clams", or "Essex clams" are a species of edible saltwater clam, a marine bivalve mollusk in the family Myidae.

<i>Limecola balthica</i> Species of bivalve

Limecola balthica, commonly called the Baltic macoma, Baltic clam or Baltic tellin, is a small saltwater clam, a marine bivalve mollusk in the family Tellinidae.

Razor shell Species of bivalve

The razor shell, Ensis magnus, also called razor clam, razor fish or spoot (colloquially), is a bivalve of the family Pharidae. It is found on sandy beaches in northern Europe.

<i>Macoma nasuta</i> Species of bivalve

Macoma nasuta, commonly known as the bent-nosed clam, is a species of bivalve found along the Pacific Ocean coast of North America. It is about 6 cm (2.4 in) long. It is often found buried in sands of 10–20 cm (3.9–7.9 in) in depth. This rounded clam has no radial ribs. Archaeological data supports the use of this species by Native Americans such as the Chumash peoples of central California.

<i>Venerupis philippinarum</i> Species of bivalve

Venerupis philippinarum is an edible species of saltwater clam in the family Veneridae, the Venus clams.

<i>Panopea zelandica</i> Species of bivalve

Panopea zelandica, commonly known as the deepwater clam or New Zealand geoduck, is a large species of marine bivalve mollusc in the Panopea (geoduck) genus of the family Hiatellidae. It is also sometimes called a king clam, or a gaper – in reference to the shell not being closed at either end.

<i>Mya truncata</i> Species of bivalve

Mya truncata, common name the blunt gaper or truncate softshell, is a species of edible saltwater clam, a marine bivalve mollusk in the family Myidae.

<i>Ensis ensis</i> Species of bivalve

Ensis ensis, or the sword razor, is a razor clam, a marine bivalve mollusc in the family Pharidae. It lives buried in the sand and is found off the coasts of northwest Europe.

Abarenicola pacifica or the Pacific lugworm is a large species of polychaete worm found on the west coast of North America and also in Japan. The worms live out of sight in burrows under the sand and produce casts which are visible on the surface.

Phaxas pellucidus, the transparent razor shell, is a species of marine bivalve mollusc in the family Pharidae. It is found buried in the seabed in coastal waters of northwest Europe, often in great numbers.

<i>Cyrtopleura costata</i> Species of bivalve

Cyrtopleura costata, or the angel wing clam, is a bivalve mollusc in the family Pholadidae. It is found in shallow parts of the northwest Atlantic and also in the North Sea of Scotland coastline and west coast of the Adriatic Sea by a remote area in the Marche region in central Italy, living in the seabed, where it digs its burrows on a very slow revolving movement for years through soft sand and mud always to a max depth of 8ft but always below 3 feet (0.91 m) at the lowest tide.

<i>Mulinia lateralis</i> Species of bivalve

Mulinia lateralis, the dwarf surf clam or coot clam, is a species of small saltwater clam, a bivalve mollusc in the family Mactridae. It occurs in the western Atlantic Ocean and the Caribbean Sea.

Laternula elliptica is a species of saltwater clam, a marine bivalve mollusc in the family Laternulidae, the lantern shells. It is the largest bivalve found under the surface of the seabed in the Southern Ocean.

<i>Tresus nuttallii</i> Species of bivalve

Tresus nuttallii, common name the Pacific gaper, is a species of saltwater clam, a marine bivalve mollusk in the family Mactridae. It also shares the common name horse clam with Tresus capax, a species which is similar in morphology and lifestyle. Both species are somewhat similar to the Geoduck, though smaller, with shells up to eight inches long (20 cm), weight to 3–4 lb (1.4–1.8 kg).

<i>Venerupis corrugata</i> Species of bivalve

Venerupis corrugata, the pullet carpet shell, is a species of bivalve mollusc in the family Veneridae. It is found buried in the sediment on the sea bed in shallow parts of the eastern Atlantic Ocean. It is harvested for human consumption in Spain and other parts of Western Europe.

<i>Solecurtus strigilatus</i> Species of bivalve

Solecurtus strigilatus, also known as the rosy razor clam, is a species of saltwater clam, a marine bivalve mollusc in the family Solecurtidae. This mollusc is a suspension feeder and can burrow with great rapidity to escape predators. It is an unusual bivalve in that its shell valves are too small to contain all the soft tissue, and the animal is unable to retreat into its shell.

References

  1. 1 2 "Interagency Taxonomic Information System". Interagency Taxonomic Information System. Retrieved April 19, 2017.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 "Field Guide". Chesapeake Bay Program. Annapolis, MD: Chesapeake Bay Program.
  3. 1 2 3 4 5 6 7 Lippson, Alice; Lippson, Robert (1997). Life in the Chesapeake Bay (2nd ed.). Baltimore, MD: The Johns Hopkins University Press. p. 42. ISBN   080185475X.
  4. 1 2 3 Lippson, Alice; Lippson, Robert (1997). Life in the Chesapeake Bay (2nd ed.). Baltimore, MD: Johns Hopkins University Press. p. 83. ISBN   080185475X.
  5. ↑ "Encyclopedia of Life". Encyclopedia of Life. Retrieved April 19, 2017.
  6. 1 2 3 4 5 6 7 8 9 "Maryland Manual Online: Maryland at a Glance, Molluscs". Maryland Manual On-Line. Annapolis, MD: Maryland State Archives. Retrieved April 19, 2017.
  7. ↑ Polluck, Leland (1998). A Practical Guide to the Marine Animals of Northeastern North America. New Brunswick, NJ: Rutgers University Press. p. 164. ISBN   0813523990.
  8. 1 2 3 Bowling, Brenda. "Elongate macoma". Texas Parks and Wildlife Department. Retrieved April 19, 2017.
  9. ↑ "MolluscaBase - Macoploma tenta (Say, 1838)". www.molluscabase.org. Retrieved 2017-04-19.
  10. ↑ "Chesapeake Bay Program, Cownose Ray". Chesapeake Bay Program. Retrieved April 19, 2017.
  11. 1 2 Seitz, R. D.; Lipcius, R. N.; Olmstead, N. H.; Seebo, M. S.; Lambert, D. M. (2006-11-17). "Influence of shallow-water habitats and shoreline development on abundance, biomass, and diversity of benthic prey and predators in Chesapeake Bay". Marine Ecology Progress Series. 326: 11–27. doi: 10.3354/meps326011 .
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