||Citharichthys spilopterus Günther, 1862
Lenguado Pardo (Spanish)
The bay whiff, Citharichthys spilopterus,
is a relatively small flatfish of the family Bothidae. Members
of this group are known as "lefteye flounders" because
both eyes and pigmentation are on the left side of the body.
Bothids are also characterized by separate dorsal and anal fins
and large eyes. As with other species of Citharichthys,
the lateral line of C. spilopterus is nearly straight
and the mouth is moderate in size (Robins & Ray 1986). The
body is mostly brown, often with small, obscure spots. Unlike
some other closely-related species, the opercle or gill cover
on the blind side has no cirri. Pelvic fins are asymmetrical,
with those of the eyed side located on the midline of the belly.
Average fin ray and other meristic counts documented for some
collected specimens are as follows: dorsal fin rays = 77-78;
anal fin rays = 56-59; pectoral fin rays = 9-10; lateral line
scales = 45; vertebrae = 33 (Castillo-Rivera & Kobelkowsky
1992, Ruiz-Carus & Rider 1998). Some species of flatfishes
often exhibit reversal of the external and/or internal organs,
with bothids appearing as dextral or righteye flounders. Such
a process is rare for C. spilopterus, but a few isolated
cases of reversal in eye symmetry, pigmentation, the olfactory
system, liver and intestines have been reported in Mexico, Florida
and North Carolina (Castillo-Rivera & Kobelkowsky 1992,
Ruiz-Carus & Rider 1998, Wilkins & Lewis 1971).
Potentially Misidentified Species
The bay whiff overlaps with the ranges
of several flatfishes. Of these, three similarly-sized species
of Citharichthys have been found in the Indian River
Lagoon: the Gulf Stream flounder, C. arctifrons; the
sand whiff, C. arenaceus; and the spotted whiff, C.
macrops. Although specimens have been located in the IRL,
the usual depth range for C. arctifrons is 46-365 m
(Robins & Ray 1986). This species also exhibits no obvious
color pattern, has a more elongated body than the bay whiff,
and hornlike projections originating from the snout. The sand
whiff is brown with dark flecks, and the dorsal and anal fins
are spotted or barred. Its range overlaps with C. spilopterus
from southeastern Florida to Brazil (Robins & Ray 1986).
The spotted whiff is pale yellowish to brown with multiple dark
spots on the body and fins. Unlike the bay whiff, the opercle
on the blind side has cirri. This species also prefers sandier
substrata than C. spilopterus.
HABITAT AND DISTRIBUTION
The range of C. spilopterus extends
from New Jersey to the Gulf of Mexico and from the Antilles
to Brazil (Robins & Ray 1986). Populations can be found
in a variety of shallow coastal habitats to a depth of 75 m.
Because of its wide environmental tolerances, the bay whiff
thrives at multiple latitudes and habitat types. Large numbers
have been found in several temperate to tropical locations,
including: Newport River and Back Sound estuaries, North Carolina
(Walsh et al. 1999); Barataria Bay, Louisiana (Allen
& Baltz 1997; Toepfer & Fleeger 1995a, 1995b); Tampamachoco
Lagoon, Mexico (Castillo-Rivera & Kobelkowsky 1992, Castillo-Rivera
et al. 2000); Mamananguá Inlet and Sepetiba
Bay, Rio de Janeiro, Brazil (Dias et al. 2005, Guedes
& Araújo 2008).
The bay whiff is found throughout
the IRL on muddy substrata in and around seagrass beds, mangroves
and salt marshes, including mosquito impoundments.
LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan
The maximum age and lifespan for C.
spilopterus is unknown. The maximum reported size for the
bay whiff is 20 cm (Robins & Ray 1986), but most specimens
collected in the field are between 1 and 10 cm (Allen &
Baltz 1997). Dias et al. (2005) found that the majority
of individuals larger than 17 cm were females, and males predominated
in size classes less than 13 cm. Because C. spilopterus
is a gonochorist, maintaining the same sex throughout its life,
the discrepancy in size is likely due to varying growth rates
between the sexes.
Broad surveys on the abundance of C.
spilopterus throughout its range are lacking. However,
it is reported to be the most common flatfish in several estuaries
along the Gulf of Mexico (eg. Castillo-Rivera et
al. 2000). It is the second most abundant flatfish in Barataria
Bay, Louisiana, with a total catch of 2,531 individuals over
a two-year period (Allen & Baltz 1997). Although common,
the bay whiff is often solitary and densities of individuals
can be quite low. Surveys in North Carolina found between 0.01
and 0.37 fish m-2.
Spawning seasons for C. spilopterus
vary with location, and is most likely a factor of water temperature
(Joyex et al. 1995). Populations in Brazil spawn from
March to May and November, the North Carolina season is restricted
to February and March, and Puerto Rico fishes spawn from November
to May (Joyex et al. 1995), and peak spawning occurs
in both winter and spring in Louisiana (Allen & Baltz 1997).
In Florida, the large presence of juveniles in May suggests
a spring spawning season. Dias et al. (2005) found
that C. spilopterus females in Brazil prefer to migrate
to deeper waters to spawn, returning to shallow areas at the
end of the season.
The reproductive behavior and embryology
of the bay whiff is poorly reported. However, Joyeux et
al. (1995) studied the growth rates of the species in Puerto
Rico and North Carolina. After spawning, larvae of C. spilopterus
usually metamorphose and settle in coastal habitats after approximately
40-50 days. Depending on water temperature and other factors,
growth in post-settlement juveniles can range from 0.44 to 0.69
mm per day.
The bay whiff is most abundant in tropical
and subtropical waters, but can be found in mild temperate climates
as well. In addition, the estuarine nature of the species often
subjects it to large variations in water temperature. Field
temperatures during specimen collections in Louisiana, North
Carolina, Florida, Mexico and Brazil ranged from 7 to 32°C
(Joyeux et al. 1995; Toepfer & Fleeger 1995a, 1995b).
Spawning times and seasonal migrations are likely tied to water
temperature fluctuations as well. Winter offshore movement of
the flatfish in Texas and Louisiana has been attributed to cooling
water temperatures (Gunter 1938, 1945), with documented inshore
return of populations along the Texas coast during the summer
months (Miller 1965).
As a euryhaline species, the bay whiff
has a wide salinity tolerance. Individuals have been found near
freshwater areas as low as 0.9 psu to coastal waters exceeding
35 psu (Allen & Baltz 1997, Dias et al. 2005).
Like many benthic and demersal organisms,
flatfishes are ambush predators. Juveniles and adults camouflage
themselves on or just below the sediment surface. When prey
swims overhead, the fish elevates itself with the benthic pectoral
fin to observe the organism before swiftly attacking and returning
to the benthos (Stickney et al. 1973). Ontogenetic
shifts in dietary preferences have been documented for the bay
whiff, with prey items varying with age or size of individuals.
Juvenile fishes prefer a wider range of foods, including: the
calanoid copepod, Acartia tonsa; amphipods; mysid shrimps;
and detritus. As the bay whiff grows, it begins to consume mostly
other fishes and larger crustaceans (Castillo-Rivera et
al. 2000, Guedes & Araújo 2008, Toepfer &
Fleeger 1995a). Changes in feeding habits with growth usually
occur in order to utilize available food resources, avoid competition,
and catch the largest and most nutritious prey for the least
energetic cost (Beyst et al. 1999, Amara et al.
2001, Amezcua et al. 2003), a behavior often known
as "minimum capture effort" (eg. Castillo-Rivera
et al. 2000).
Little information exists concerning the
predators of C. spilopterus. However, it is likely
that larvae are consumed by a variety of planktonic and filter-feeding
organisms. Cannibalism has even been reported among smaller
juveniles (Castillo-Rivera et al. 2000). Once settled,
the ability of the bay whiff to camouflage itself on the benthos
likely reduces predation risk. Still, this species is a relatively
small flatfish, and could be preyed upon by larger fishes and
As inhabitants of a variety of coastal
ecosystems, bay whiffs are associated with several organisms
common to mangroves, seagrass beds and sand flats. For extensive
lists of organisms found throughout the ecosystems in which
C. spilopterus occurs, please refer to the Habitats
of the IRL link at the left of this page.
No information is available at this time
Allen, RL & DM Baltz. 1997. Distribution and microhabitat
use by flatfishes in a Louisiana estuary. Env. Biol. Fish.
Amara, R, Laffargue, P, Dewarumez, JM,
Maryniak, C, Lagardère, F & C Luczac. 2001. Feeding
ecology and growth of 0-group flatfish (sole, dab and plaice)
on a nursery ground (Southern Bight of the North Sea). J.
Fish Biol. 58: 788-803.
Amezcua, F, Nash, RDM & L Veale. 2003.
Feeding habits of the Order Pleuronectiformes and its relation
to the sediment type in the north Irish Sea. J. Mar. Biol.
Assoc. UK. 83: 593-601.
Beyst, B, Cattrusse, A & J Mees. 1999.
Feeding ecology of juvenile flatfishes of the surf zone of a
sandy beach. J. Fish Biol. 55: 1171-1186.
Castillo-Rivera, M & A Kobelkowsky.
1992. First record of reversal in the flounder Citharichthys
spilopterus (Bothidae). Copeia. 1992: 1094-1095.
Castillo-Rivera, M, Kobelkowsky, A &
AM Chávez. 2000. Feeding biology of the flatfish Citharichthys
spilopterus (Bothidae) in a tropical estuary of Mexico.
J. Appl. Ichthyol. 16: 73-78.
Dias, JF, Fiadi, CB, Silbiger, HLN &
LSH Soares. 2005. Reproductive and population dynamics of the
bay whiff Citharichthys spilopterus Günther, 1962
(Pleuronectiformes: Paralichthyidae) in the Mamanguá
Inlet, Rio de Janeiro, Brazil. Neotrop. Ichthyology.
Guedes, APP & FG Araújo. 2008.
Trophic resource partitioning among five flatfish species (Actinoptergii,
Pleuronectiformes) in a tropical bay in south-eastern Brazil.
J. Fish Biol. 72: 1035-1054.
Gunter, G. 1938. Seasonal variations in
abundance of certain estuarine and marine fishes in Louisiana
with particular reference to life histories. Ecol. Monogr.
Gunter, G. 1945. Studies on marine fishes
of Texas. Publ. Inst. Mar. Sci. Univ. Texas. 1: 1-190.
Joyeux, J, Miller, JM, Aliaume, C &
A Zerbi. 1995. Growth of sand whiff Citharichthys arenaceus
and bay whiff Citharichthys spilopterus (Pleuronectiformes:
Bothidae) in Puerto Rico (Greater Antilles) and North Carolina
(USA), with comments on growth rate comparisons. Netherlands
J. Sea Res. 34: 211-220.
Miller, JM. 1965. A trawl survey of the
shallow Gulf fishes near Port Aransas, Texas. Publ. Inst.
Mar. Sci. Univ. Texas. 10: 10-107.
Robins, CR & GC Ray. 1986. A field
guide to Atlantic coast fishes of North America. Houghton
Mifflin Co. New York. USA. 354 pp.
Ruiz-Carus, R & SJ Rider. 1998. First
record of reversed symmetry in Etropus cyclosquamus
and second record in Citharichthys spilopterus (Bothidae,
Pisces) in the Gulf of Mexico, with a plausible genetic explanation
for reversal. Gulf Mexico Sci. 16: 8-14.
Stickney, RR, DB White & D Miller.
1973. Observations of fin use in relation to feeding and resting
behavior in flatfishes (Pleuronectiformes). Copeia.
Toepfer, CS & JW Fleeger. 1995a. Diet
of juvenile fishes Citharichthys spilopterus, Symphurus
plagiusa, and Gobionellus boleosoma. Bull.
Mar. Sci. 56: 238-249.
Toepfer, CS & JW Fleeger. 1995b. Effects
of marsh-edge habitat variables on feeding success by juvenile
bay whiff, Citharichthys spilopterus (Teleostei: Bothidae).
Southwest. Naturalist. 40: 297-300.
Tucker, Jr., JW. 1978. Larval development
of four species of bothid flatfish in the Citharichthys-Etropus
Complex: C. cornutus, C. gymnorhinus, C.
spilopterus, and E. crossotus. Master's Thesis.
North Carolina State Univ. Raleigh, NC. USA. 213 pp.
Walsh, HJ, Peters, DS & DP Cyrus.
1999. Habitat utilization by small flatfishes in a North Carolina
estuary. Estuaries. 22: 803-813.
Wilkins, EPH & RM Lewis. 1971. Occurrence
of reversal and staining in North Carolina flounders. Chesapeake
Sci. 12: 115-116.
Report by: LH Sweat, Smithsonian Marine Station
at Fort Pierce
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Page last updated: 24 July 2009