||Chasmodes saburrae Jordan & Gilbert, 1882
The Florida blenny, Chasmodes saburrae,
is a small fish displaying a brown mottled or spotted pattern
(Robins & Ray 1986). Like many other blenniids, C. saburrae
has a continuous dorsal fin with no separation between the spinous
and soft fin rays, which average 6 and 19, respectively. Other fin ray
counts are as follows: pectoral, 11-13; caudal, 10-13; and anal,
18-19 (Williams 1983). The mouth is large with prominent lip
flaps, and contains 10-14 large and 1-10 small upper pharyngeal
teeth, along with 5-6 small lower pharyngeal teeth immediately
in front of 6 larger canines. The number of mandibular teeth
increases with body size. The head slopes steeply toward the
mouth, bears at least six mandibular pores and no cirri. The
Florida blenny exhibits sexual dimorphism, and descriptive characters
of both sexes are detailed below.
Potentially Misidentified Species
The genus Chasmodes contains three
species: C. saburrae; the striped blenny, C. bosquianus;
and the stretchjaw blenny, C. longimaxilla. While all
three species are present in the southeast United States, their
ranges rarely overlap. Most of Florida is dominated by C.
saburrae, coinciding with C. bosquianus in the
northeastern region of the state and both C. bosquianus
and C. longimaxilla in northwestern Florida (Robins
& Ray 1986, Williams 1983). All species are very similar
in appearance, with subtle distinguishing characteristics evident
upon close inspection or through dissection. The striped blenny
has only four mandibular pores, four canines, a more gradual
slope to the head, and more prominent lip flaps than those of
C. saburrae (Robins & Ray 1986, Williams 1983).
In addition, the two species differ in the number of gill rakers
present, averaging 9-13 and 12-14 for C. saburrae and
C. bosquianus, respectively (Williams 1983). The remaining
species, C. longimaxilla, typically exhibits fewer
teeth and a longer maxillary, or upper jaw, than either the
Florida or striped blenny (Williams 1983).
HABITAT AND DISTRIBUTION
Regional Occurrence & Habitat Preference
The range of C. saburrae encompasses
most of the eastern coast of Florida, around the tip of the
state, and westward to the Chandeleur Islands, Louisiana (Williams
1983). Individuals can be found in a variety of estuarine habitats,
including: rocks and jetties (Peters 1981); around mangrove
roots; in seagrass beds; among reefs of the eastern oyster,
(Peters 1981); and inside empty valves of the stiff penshell,
Atrina rigida (Kuhlmann 1994, 1997). Where its range
overlaps with that of C. longimaxilla, C. saburrae
appears to prefer seagrass beds, restricting the former species
to oyster reefs (Williams 1983).
The Florida blenny is found throughout
the IRL in all of the habitats described above. However, most
specimens are located in seagrass beds and among oyster reefs.
LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan
The maximum age and lifespan for C.
saburrae is unknown. However, Peters (1981) documented
a developmental period of approximately three weeks from hatched
egg to juvenile during laboratory studies. Growth and mortality
rates vary with food availability, environmental conditions
and other factors. The maximum reported size for the Florida
blenny is 10 cm (Robins & Ray 1986), but most specimens
collected are between 2 and 6 cm (Carr & Adams 1973).
Though common, the Florida blenny is mostly
solitary. Therefore, large populations are rarely seen. No abundance
data have been published for C. saburrae in the IRL,
but populations living among oyster reefs in southwest Florida
average 1 to 3 individuals per square meter (Tolley et al.
The Florida blenny is sexually dimorphic,
and sex is determined primarily upon examination of the anal
spine (Smith-Vaniz 1980). In females, the first spine is greatly
reduced; whereas, males in courtship display enlarged spines
with associated fleshy structures and longitudinal folds of
skin. Coloration, body length and jaw length are secondary sexual
characteristics of C. saburrae (Williams 1983). Females
and immature or non-territorial males are variously mottled.
Territorial males often display a series of light longitudinal
lines over a darker olive or mottled background, an iridescent
blue spot on the membrane between the first and second dorsal
spines, with an orange streak running from the spot to the tenth
dorsal spine. In addition, these males have orange membranes
on the chest and gills, can grow at least twice as long as females,
and exhibit a longer jaw. Reproductive individuals have been
reported to spawn throughout the day, with one male fertilizing
the eggs of several females. After fertilization occurs, all
the females of a single male mate deposit eggs on one of several
surfaces, such as: empty shells of C. virginica or
A. rigida, holes in rocks, sponges, or inside discarded
cans (Peters 1981). The parental male then guards the clutches
for about three weeks until hatching. Presence of nests in the
field has indicated that spawning begins in early March and
lasts through October (Peters 1981). The spawning process is
continuous, and females lay eggs every one to two weeks throughout
the season, spawning at least 2,600 eggs over a lifetime (Peters
Embryology / Larval Development
Clutch size is determined by the number
of contributing females, the guarding ability of the male, and
the surface chosen. Peters (1981) found that oyster shells held
an average of 1,000 to 2,000 eggs, whereas a single can housed
about 11,000. Eggs range from 0.7 to 0.9 mm in diameter, are
bright yellow at deposition, and turn orange and then pale yellow
with age. At 27°C, eggs hatch in six days, releasing larvae
about 3.7 mm in length. Some newly-hatched individuals carry
a yolk sac, which is quickly absorbed. Larvae then feed on zooplankton
until settling to the benthos after about 21 days. Newly-settled
juveniles are approximately 6 mm long, and have developed fins
The Florida blenny is found in warm coastal
waters, and though isolated individuals have been reported as
far north as South Carolina, most thriving populations are restricted
to more subtropical locations (Williams 1983). Surface water
temperatures in shallow coastal areas can vary widely between
seasons, and specimens have been collected from waters ranging
between 14 and 33°C (Carr & Adams 1973, Kuhlmann 1994).
Larvae of C. saburrae have been successfully cultured
at temperatures of 21.4-27.7°C (Peters 1981).
As a primarily estuarine species, C.
saburrae has been reported in a wide range of salinities.
Populations in the Everglades National Park experience salinities
as low as 5.5 psu (Williams 1983), while those in east central
areas of Florida Bay have been found in waters up to 44 psu
(Sogard et al. 1987). Larvae of the Florida blenny
have been cultured successfully at both 26 and 35 psu, depending
on the salinity of the egg collection site (Peters 1981).
The Florida blenny is omnivorous, but its
specific dietary preferences appear to vary with age (Carr &
Adams 1973). Amphipods are a common prey item, and are consumed
by all size classes (Carr & Adams 1973, Reid 1954). However,
feeding behaviors change with growth and alter other food choices
of the blenny. Smaller fish are more carnivorous and consume
prey from the water column, including copepods and pelagic amphipods.
As the blennies grow, they begin to feed on or near the benthos,
adding detritus and plant material to their diets (Carr &
Adams 1973). Other less abundant prey items determined from
gut content analyses include: shrimps, tanaid crustaceans, polychaetes
worms, pelecypod mollusks, xanthid crabs, fish embryos and isopods
(Carr & Adams 1973, Reid 1954).
Little information exists concerning predators
of C. saburrae. However, it is likely that the hiding
behavior of adults and juveniles among bivalve shells reduces
predation risk. Still, blennies may be consumed by larger fishes
and invertebrates, and pelagic larvae are possible prey for
a host of organisms. Although the male parent guards each clutch,
predatory snails, small crabs and other fishes could prey on
fertilized eggs before hatching occurs.
As inhabitants of a variety of coastal
ecosystems, Florida blennies are associated with several organisms
common to mangroves, seagrass beds, oyster reefs and rocky intertidal
zones. As mentioned above, C. saburrae is closely associated
with the eastern oyster, C. virginica and the stiff
penshell, A. rigida, through its reproductive processes
(Kuhlmann 1994, 1997; Peters 1981). For lists of other organisms
found throughout the ecosystems in which C. saburrae
occurs, please refer to the Habitats of the IRL link at the
left of this page.
No information is available at this time
Carr, WES & CA Adams. 1973. Food habits
of juvenile marine fishes occupying seagrass beds in the estuarine
zone near Crystal River, Florida. Trans. Amer. Fish. Soc.
Kuhlmann, ML. 1994. Indirect effects of
a predatory gastropod in a seagrass community. J. Exp. Mar.
Biol. Ecol. 183: 163-178.
Kuhlmann, ML. 1997. Regulation of fish
reproduction by a predatory gastropod: an experimental investigation
of indirect effects in a seagrass community. J. Exp. Mar.
Biol. Ecol. 218: 199-214.
Peters, KM. 1981. Reproductive biology
and developmental osteology of the Florida blenny, Chasmodes
saburrae (Perciformes: Blenniidae). Northeast Gulf
Sci. 4: 79-98.
Reid, GK. 1954. An ecological study of
the Gulf of Mexico fishes in the vicinity of Cedar Key, Florida.
Bull Mar. Sci. 4: 1-94.
Robins, CR & GC Ray. 1986. A field
guide to Atlantic coast fishes of North America. Houghton
Mifflin Co. New York. USA. 354 pp.
Sogard, SM, Powell, GVN & JG Holmquist.
1987. Epibenthic fish communities on Florida Bay banks: relations
with physical parameters and seagrass cover. Mar. Ecol.
Prog. Ser. 40: 25-39.
Smith-Vaniz, WF. 1976. The saber-toothed
blennies, tribe Nemophini (Pisces: Blenniidae). Acad. Nat.
Sci. Philadelphia. Monog. 19: vii + 196 pp.
Tolley, SG, Volety, AK, Savarese, M, Walls,
LD, Linardich, C & EM Everham III. 2006. Impacts of salinity
and freshwater inflow on oyster-reef communities in Southwest
Florida. Aquat. Living Resour. 19: 371-387.
Williams, JT. 1983. Taxonomy and ecology
of the genus Chasmodes (Pisces: Blenniidae) with a
discussion of its zoogeography. Bull. Florida State Mus.
Biol. Sci. 29: 65-100.
Report by: LH Sweat, Smithsonian Marine Station at Fort Pierce
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Page last updated: 23 July 2009