BIOS
Marine Invertebrates of Bermuda

Leafy Jewelbox (Chama macerophylla)

By Sarah Bennett
and
James B. Wood (Ed)


Abstract Taxonomy  Habitat  Ecology  Recent Research  Commercial Importance  Bermuda Laws  Personal Interest  References  Links 


Chama macerophylla, Leafy Jewelbox

Abstract

Chama macerophylla, also know generally as the Leafy Jewelbox or the Bermuda Rock Cockle, is a common Bermudian mollusk that is found in coastal waters ranging from the mean low tide to a depth of 20 meters. It is a bivalve with heavy, unequal valves that lives attached by its left shell to hard substrata including rocks, coral, and manmade objects. The species, approximately ten centimeters in diameter is brightly colored, ranging from yellow, to orange, or purple. The shape of this mollusk is variable, as the left valve attached to a substrate often takes on the substrate’s shape, while the top valve often becomes damaged and loses its color and structure. Shells of the Leafy Jewelbox are covered with ribbed, leafy projections arranged in irregularly radiating rows, giving this bivalve its leafy look and name.

This species is a sessile part of the benthos and gains its sustenance by filter feeding particles from the water column. Members of this species are gonochoric, and fertilization occurs externally. The resulting larva is called a trochophore, and when it develops it becomes a veliger larvae. Both larval stages are planktonic and free-swimming and settle to hard substrata to become sessile adults. Although the Leafy Jewelbox has no commercial value in the seafood industry, it costs fishermen and corporations a great deal of money each year to prevent and remove this species from ships hulls and docks because of its characteristic fouling nature. Researchers have recently studied C. macerophylla to investigate the effects of dumping oil and gas wastewater into the ocean.


Taxonomy

Phylum: Mollusca
  Class: Bivalvia
    Order: Veneroida
      Family: Chamidae


Habitat

The native range for Chama macerophylla is the Atlantic Ocean from around northern North Carolina to just off the coast of Rio de Janeiro, Brazil, including the waters surrounding the offshore island of Bermuda (Pastorino 1991). This species is also present in Pearl Harbor, Oahu, but was unintentionally introduced as epifauna attached to the bottom of boats bound from the Caribbean to Hawaii (Coles et al. 1999).

The Leafy Jewelbox lives in inshore waters ranging from the mean low tide to a depth of 20 meters (Sterrer 1986). In this zone they live permanently attached to hard substrata, such as rocks and coral, but also on manmade surfaces such as concrete docks, buoys, and boats. These bivalves attach themselves so strongly to substrata with one shell, in particular their larger left-handed shell, that a chisel and hammer is needed to remove them (Coles et al. 1999).


Ecology

Chama macerophylla is a bivalve that lives its adult life as a sessile organism attached to hard substrata in shallow regions where there is great amount of particulate material in the water (Grizzle et al. 2006). This species is classified as a filter feeder, and filters bacteria and phytoplankton from the water column for sustenance. Because it is sessile as an adult, the Leafy Jewelbox must actively pump water across its body in great volumes every day to filter enough food to survive (Grizzle et al. 2006). The bivalve filters the water that is pumped through its body using cilia located on ctenidia, or gill filaments (Beninger et al. 1991). Lateral cilia beat in wave like motions to push water over the gills, while other cilia located along the gill’s surface trap particles with mucous netting. These particles are brought down toward to the mouth of the bivalve and digested (Beninger et al. 1991). Particle filtering by filter feeding organisms, especially bivalves, has been of interest to scientists looking at water quality and clarity (Grizzle et al. 2006).

The Leafy Jewelbox is a gonochoric species, meaning it has separate male and female sexes (Dame 1996). It also has two very distinct lifecycle stages: a planktonic, pre-settlement stage and a post settlement adult stage. Gametes from both male and female individual bivalves are shed into the water by the same pumping action that clears the filtered water after the bivalve feeds. Fertilization of egg and sperm is external in this species, and once joined, develop into free-swimming trochophore larvae. This larva develops further and is called a veliger larva, but both types of larvae are a part of the plankton. Once the veliger larva is ready, it settles out of the plankton to reside as a sessile organism on a hard substrate for the remainder of its life (Dame 1996). Research involving Chama macerophylla has been done to examine the morphology and function of gamete binding, which takes place during the fertilization process (Hylander and Summers 1977). This binding has been closely monitored in an attempt to dispel conflict surrounding fertilization in general and develop a consistent model for all of mollusks (Hylander and Summers 1977).

Members of the Genus Chama are often involved in mutualistic interactions with plants and small marine invertebrates which grow as epibionts on their valves (Vance 1978). These organisms make their habitat attached to the various leafy projections atop the shells of Chama spp. These epibionts grow densely on the valve and actually camouflage the bivalve beneath them, lowering the threat of predation from top-level predators of the bivalve. Since Chama spp. individuals tend to live in areas not highly predated by grazers, the epibionts in return are protected by the Chama spp. (Vance 1978). This symbiosis is most common in the Genus Chama, more so than bivalves with smooth shells, indicating an evolutionary relationship between members of the Genus Chama and small invertebrates and plants that grow on them (Kennedy et al. 1970).


Recent Research

Recently, researchers have been investigating the effects of the production of offshore gas and oil by looking at concentrations of heavy metals such as cadmium, iron, lead, zinc, copper, manganese, and cobalt (Turkmen et al. 2005). Water from the areas where offshore gas and oil are derived is called produced water. This water is piped to the surface where the oil or gas is separated out, and the resulting water, often full of dissolved metals, is either released into the adjacent waters, or piped back down to the bottom. Researchers analyzing the concentrations of metals and their effects have investigated benthic organisms including clams from the Genus Chama (Turkmen et al. 2005). One particular study of bioaccumulation in the Gulf of Mexico used members of the species Chama macerophylla in order to assess the consequences of this practice (Trefry et al. 1995). Concentrations of seven different metals were discovered in C. macerophylla in the Gulf of Mexico, but no statistically significant differences were seen between sites near produced water zones and sites far from produced water zones (Trefry et al. 1995).


Commercial Importance

Although many organisms within the Class Bivalvia are highly valued in the seafood industry, the Leafy Jewelbox is not considered to be a tasty species, though it does affect fisherman throughout the Atlantic (Coles et al. 1999). Chama macerophylla is often a tenacious fouling species that settles on the hulls of ships, buoys and docks and creates problems for both individuals and commercial enterprises. A great deal of money is spent each year around the Atlantic on anti-fouling efforts to both prevent and remove organisms including this species from docks and the hulls of ships to prevent paint erosion and water drag (Coles et al. 1999).


Bermuda Laws

There are no specific laws governing the protection of Chama macerophylla in Bermuda. Beginning in 1986, however, 29 marine-protected areas were established in the waters off the coast of Bermuda in an effort to protect the natural wildlife present there (de Putron 2007). These areas range in size between 100 and 1000m in radius, and any species that fall within them are protected from removal or damage by law. All populations of the Leafy Jewelbox that fall within these MPAs are protected by these laws that are enforced by the Fisheries Patrol in an attempt to protect the integrity of these areas from damage by boats, over-fishing, and tourism (de Putron 2007).


Personal Interest

I became interested in marine invertebrates upon taking an Organismal Diversity survey class offered by my university. Inspired to more intensely study these organisms, I enrolled in B-2-B program offered at the Bermuda Institute for Ocean Sciences and came to Bermuda ready to experience invertebrates in a hands on learning environment. It was during one of the labs of my Marine Invertebrate Zoology class that I first came into contact with the Leafy Jewelbox. We were asked to collect a rock from the mud flats of Ferry Reach in order to do a mini-rock diversity survey. The rock that I picked up was covered in many organisms such as polychaetes that I was able to identify, however there were two bright yellow organisms attached very strongly to the rock that I was unable to recognize. With the help of my TA, my professor, and a guide to marine fauna and flora of Bermuda, we were able to identify the unknown organisms as the species Chama macerophylla. I was fascinated with the Leafy Jewelbox morphology and its role in the ecosystem of the shallow flats of Ferry Reach. Upon researching this organism, I found out much more about its interesting lifestyle and am glad that it was my first test of classification in Bermuda.


References

Beninger, P. G., M. Le Pennec, and A. Donval. 1991. Mode of particle ingestion in five species of suspension-feeding bivalve mollusks. Marine Biology. 108: 255-261.

Cereme-Vivas, M. J. and I. E. Gray. 1966. The distributional pattern of benthic organisms of the continental shelf off North Carolina. Ecology. 47: 260-270.

Coles, S. L., R. C. DeFelice, L. G. Eldredge and J. T. Carlton. 1999. Historical and recent introductions of nonindigenous marine species into Pearl Harbor, Oahu, Hawaiian Islands. Marine Biology. 135: 147-158.

Dame, Richard F. 1996. Ecology of Marine Bivalves: An Ecosystem Approach. New York: CRC Press, Inc.

De Putron, S. “Climate change and natural resource management.” Bermuda Institute of Ocean Sciences. St. Georges, Bermuda. 1 March 2007.

Grizzle, R. E., J. K. Greene, M. W. Luckenbach, and L. D. Coen. 2006. A new in situ method for measuring seston uptake by suspension-feeding bivalve mollusks. Journal of Shellfish Research. 25: 643-649.

Hylander, B. L. and R. G. Summers. 1977. An ultrastructure analysis of the gametes and early fertilization in two bivalve mollusks, Chama macerophylla and Spisula solidissima with special reference to gamete binding. Cell Tissue Res. 182: 469-489.

Kennedy, W. J., N. J. Moris and J. D. Taylor. 1970. The shell structure, mineralogy and relationships of the Chamacea (Bivalvia). Palacontology. 13: 379-413.

Pastorino, G. 1991. The Genus Chama Linné (Bivalvia) in the marine quaternary of Northern Patagonia, Argentina. Journal of Paleontology. 65:756-760.

Sterrer, W., Ed. 1986. Marine Fauna and Flora of Bermuda: A Systematic Guide to the Identification of Marine Organisms. New York: John Wiley & Sons.

Tefry, J. H., L. Naito, R. P. Trocine, and S. Metz. 1995. Distribution and bioacclimation of heavy metals from produced water discharges to the Gulf of Mexico. Wat. Sci. Tech. 32: 31-36.

Turkmen, A., M. Turkmen, and Y. Tepe. 2005. Biomonitering of heacy metals from Iskenderun Bay using two species Chama pacifica Broerip, 1834 and Ostera stentina Payraudeau, 1826. Turkish Journal of Fisheries and Aquatic Sciences. 5: 107-111.

Vance, R. R. 1978. A mutualistic interaction between a sessile marine clam and it epibionts. Ecology. 59: 679-685.


Links

Introduced Marine Species of Hawaii

United States Geological Survey—Map of Leafy Jewel Box range

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