The cross-barred venus, Chione cancellata , is a small clam
belonging to family Veneridae. The cloudy white to yellow-white shells are
highly distinctive, with raised, bladelike concentric ridges superimposed
on strong radial ribs and giving the shells their characteristic cancellate
(crisscrossed) appearance. Zigzag purplish brown patterns are often
present and the interior of the shell usually has some purple (Rothchild
2004, Abbot and Morris 1995).
Stanley (1981) notes that experiments have demonstrated that the raised
ridges of C. cancellata shells hinder burrowing, but reduce scour
of sand from around the shells of partly exposed animals.
Some authorities recognize two distinct subspecies, Chione cancellata
cancellata and Chione cancellata mazycki. Additionally,
Roopnarine and Vermeij (2000) suggest specimens occurring along the
eastern United States and Central America south to Belize are a
separate species, Chione elevata, based on morphometric
Potentially Misidentified Species
Although many of the approximately 23 recognized species in the genus
Chione occur in Florida, the distinctive raised cross-bar pattern
and the other features noted above should allow a degree of certainty in
HABITAT AND DISTRIBUTION
This subtropical species from North Carolina to Florida, Texas, and the West Indies (Abbot 1974, Abbot and Morris 1995).
Chione cancellata occurs throughout the IRL.
LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan
Chione cancellata is a small bivalve, attaining a maximum shell length of a little over 3 cm (Abbot and Morris 1995).
Orth et al. (1984) report Chione cancellata abundance of just over
10 individuals per square meter within North Carolina Halodule
beaudettei (= wrightii) seagrass beds. The species was
sufficiently abundant to prompt Hoese (1960) to describe a specific Texas
estuary faunal assemblage as the "Mercenaria campechiensis-Chione
Cross-barred venus clams reproduce sexually. Sexes are separate and
fertilization is external via broadcast spawning of gametes. Individuals
reach maturity at around 15 mm shell length, at which time they become
reproductive males or females at a ratio of approximately 1:1 (Rothchild
Laboratory-based rearing studies reveal embryonic development from
fertilization to straight-hinge D-stage veliger larvae occurs in just 24
hours at 25°C. At this time the larvae possess a calcified shell,
a poorly developed digestive tract, an apical sense organ, a single mantle
fold, and a functional velum equipped with four ciliary bands (Moueza and
A study by LaBarbera and Chanley (1970) revealed lab-reared C.
cancellata larvae settled out of the water column when individuals
reached a size of 170-196 µm. D'Asaro (1967) reports larval duration as
typically being around 11 days from hatching to settlement.
The distribution of this species is limited to warm-temperate and
subtropical/tropical locations, likely due to intolerance to colder
Chione cancellata is a moderately euryhaline bivalve. Rothchild
(2004) reports can tolerate salinities as low as 18 ppt. LaBarbera and
Chanley (1970) collected animals from oceanic salinities.
Chione cancellata is a suspension feeder on water column phytoplankton.
Whelks (e.g., Busycon spp., Busycotupus spp.), horse conchs
(Pleuroploca gigantea), tulips (Fasciolaria spp.), murex
(Murex spp.), and moon snails (Polinices spp.) are among
the major gastropod predators of Chione cancellata (Paine
1963). Haefner (1990) indicates C. cancellata are also a prey
resource for the portunid crab Callinectes ornatus in Bermuda.
Cate and Evans (1994) notes that black drum (Pogonias cromis) in
lower Corpus Christy Bay, TX, consume cross-barred venus as well. The
shallow burrowing habits of the species leave it fairly vulnerable to
such predators (Rothchild 2004). Peterson (1982) notes that C.
cancellata is more susceptible to predation than the hard clam,
The shallow burrowing tendencies of Chione cancellata often leave
the shell posterior exposed at the sediment surface, offering a
colonization site for epibiotic macroalgae and polydorid polychaetes
Chione cancellata is a shallow-water species that occupies shallow
soft sediments to a typical sediment depth of 15 cm or less. It can be
found in both vegetated and unvegetated areas, but is usually more abundant
within vegetation (Abbot and Morris 1995, Rothchild 2004). Orth et al.
(1984) found a greater than 25-fold increase in seagrass-associated versus
bare substratum-associated C. cancellata in North Carolina. The
seagrass root and rhizome systems offer a partial predation refuge for the
Chione cancellata is edible, but its small size has prohibited
widespread commercial harvest of the species in North America. In xxx,
C. cancellata is referred to as "chaubette" and is harvested for
local consumption (Guelorget et al. 1990).
Abbot RT. 1974. American Seashells, The Marine Mollisca of the Atlantic and
Pacific Coasts of North America. Second Edition. Van Nostrand Reinhold
Company, New York. 663 p.
Abbot RT and PA Morris. 1995. Shells of the Atlantic and Gulf Coasts and
the West Indies. Peterson Field Guides. Houghton Mifflin Company, NY. 350
Cate AS and I Evans. 1994. Taphonomic significance of the biomechanical
fragmentation of live molluscan shell material by a bottom-feeding fish
(Pogonias cromis) in Texas coastal bays. Palaios 9:254-274.
D'Asaro CN 1967. The morphology of larval and postlarval Chione
cancellata Linne (Eulamellibranchia: Veneridae) reared in the
laboratory. Bull. Mar. Sc. 17: 949-972.
Guelorget O., Gaujous D., Louis M, and J-P Perthuisot. 1990.
Macrobenthofauna of lagoons in Guadeloupean mangroves (Lesser Antilles):
Role and expressions of the confinement. Journal of Coastal Research
Hoese HD. 1960. Biotic changes in a bay associated with the end of a
drought. Limnology and Oceanography 5:326-336.
LaBarbera M and P Chanley. 1970. Larval development of Chione
cancellata Linne (Veneridae, Bivalvia). Chesapeake Science, Vol.
11, No. 1 (Mar., 1970), pp. 42-49.
Mouza M, Gros O , and L Frenkiel. 2006. Embryonic development and shell
differentiation in Chione cancellata (Bivalvia, Veneridae):
An ultrastructural analysis. Invertebrate Biology 125:21-33.
Orth RJ, Heck KL, Jr, and J van Montfrans. 1984. Faunal communities in
seagrass beds: A review of the influence of plant structure and prey
characteristics on predator:prey relationships. Estuaries 7:339-350.
Paine RT. 1963. Trophic relationships of 8 sympatric predatory gastropods.
Peterson CH. 1982. Clam predation by whelks (Busycon spp.):
Experimental tests of the importance of prey size, prey density, and
seagrass cover. Marine Biology 66:159-170.
Roopnarine PD and GJ Vermeij. 2000. One species becomes two: The case of
Chiome cancellata, the resurrected C. elevata, and a phylogenetic
analysis of Chione. Journal of Molluscan Studies 66:517-534.
Rothschild SB. 2004. Beachcomber's Guide to Gulf Coast Marine Life: Texas,
Louisiana, Mississippi, Alabama, and Florida. Taylor Trade Publications,
MD. 200 p.
Stanley SM. 1981. Infaunal survival: Alternative functions of shell
ornamentation in the Bivalvia (Mollusca). Paleobiology 7, No. 3:384-393.