(DRAFT) - Taxonomy
Species mullet, white
Species Id M010009
Date 26 AUG 96
TAXONOMY
NAME - mullet, white
OTHER COMMON NAMES - silver mullet and white mullet
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - Chordata,
CLASS AND SUBCLASS - Osteichthyes,
ORDER AND SUBORDER - Perciformes,
FAMILY AND SUBFAMILY - Mugilidae,
GENUS AND SUBGENUS - Mugil,
SPECIES AND SSP - curema,
SCIENTIFIC NAME - Mugil curema
AUTHORITY - Valenciennes, 1836
TAXONOMY REFERENCES - 48
COMMENTS ON TAXONOMY -
Other common name is Silver mullet.
Taxonomy - 1 (DRAFT) - Status
Species mullet, white
Species Id M010009
Date 26 AUG 96
STATUS
Coded Status
Unclassified
Commercial/bait
See Comments
REFERENCES FOR STATUS - 48
COMMENTS ON STATUS -
Because white mullet feed primarily on living and dead vegetable matter,
they are ecologically important as primary consumers in the food chains of
coastal and estuarine waters.*48*
Status - 1 (DRAFT) - Distribution
Species mullet, white
Species Id M010009
Date 26 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Estuarine
Palustrine
REFERENCES FOR NWI - 48
Habitat Associations - 1 (DRAFT) - Food Habits
Species mullet, white
Species Id M010009
Date 26 AUG 96
FOOD HABITS
TROPHIC LEVEL -
HERBIVORE
REFERENCES FOR TROPHIC LEVEL - 48
LIFESTAGE FOOD FOOD PART
Larva Microorganisms Not Applicable
Larva See Comments; Food
Juvenile Protozoans Not Applicable
Juvenile Cyanophyta Not Applicable
Juvenile See Comments; Food Not Applicable
Adult Cyanophyta Not Applicable
Adult See Comments; Food Not Applicable
Adult Detritus Not Applicable
REFERENCES FOR GENERAL FOOD - 48
REFERENCES FOR ADULT FOOD - 48
REFERENCES FOR JUVENILE FOOD - 48
REFERENCES FOR LARVAE FOOD - 48
COMMENTS ON FOOD -
Data on the food and feeding habits of white mullet are scarce. White and
striped mullet often feed on the same food at the same times and places.
Larval white and striped mullet feed and thrive on microcrustaceans. As
larvae grow, their ingestion of bottom sediments, detritus, and algae
increases. Juveniles do not usually feed on microcrustaceans, but juveniles
of both species may feed on dinoflagellates such as Kryptoperidinium; like
adults, they rely on trituration in their gizzard-like, pyloric stomachs to
break down food particles. The stomach contents of both juvenile and adult
white and striped mullet in Texas were very similar, both in the items
present (sediment particles, detritus, diatoms, green algae, and blue-green
algae) and in the proportions of each item.*48*
COMMENTS ON ADULT FOOD -
-see C. Food
COMMENTS ON JUVENILE FOOD -
Juveniles do not usually feed on microcrustaceans, but juveniles of
both species may feed on dinoflagellates such as Kryptoperidinium; like
adults, they rely on trituration in their gizzard-like, pyloric stomachs to
break down food particles. The stomach contents of both juvenile and adult
white and striped mullet in Texas were very similar, both in the items
present (sediment particles, detritus, diatoms, green algae, and blue-green
algae) and in the proportions of each item.*48*
COMMENTS ON LARVAE FOOD -
Larval white and striped mullet feed and thrive on microcrustaceans. As
Food Habits - 1 (DRAFT) - Food Habits
Species mullet, white
Species Id M010009
Date 26 AUG 96
larvae grow, their ingestion of bottom sediments, detritus, and algae
increases.*48*
Food Habits - 2 (DRAFT) - Environment Associations
Species mullet, white
Species Id M010009
Date 26 AUG 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Water Temperature: Specified in Comments
J
A
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 48
REFERENCES FOR FEEDING ADULT ENVIRONMENTAL ASSOC_ - 48
REFERENCES FOR FEEDING JUVENILE ENVIRONMENTAL ASSOC_ - 48
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
While mullet have been collected at water temperatures of 19 to 36 degrees
C in Texas, 20.1 to 31.5 degrees C in Virginia, and 19.5 to 35.4 degrees C
in Florida. The species is tropically adapted, and experimental evidence
suggests a high (28 degrees C or somewhat greater) optimum temperature for
white mullet. The decreasing water temperatures in late fall may induce
juveniles to emigrate from estuaries north of Florida, but changes in
photoperiod have not been ruled out as important stimuli.*48*
On the penisular gulf coast of Florida, juvenile white mullet were caught
in salinities ranging from 4 to 25 ppt. In a study in Texas, white mullet
adults were abundant only in salinities of 25 to 36 ppt. Few enter
brackish waters in the northern Gulf of Mexico. However, adult white
mullet have been collected from freshwater in Crystal River, Florida.
Relevant data on the effects of dissolved oxygen, substrate, depth,
currents, diseases and parasites on white mullet are sorely lacking.*48*
COMMENTS ON FEEDING ADULT ENVIRONTAL ASSOC_ -
-see C.Environ
COMMENTS ON FEEDING JUVENILE ENVIRONMENTAL ASSOC_ -
The decreasing water temperatures in late fall may induce juveniles
to emigrate from estuaries north of Florida, but changes in photoperiod
have not been ruled out as important stimuli.*48*
On the penisular gulf coast of Florida, juvenile white mullet were caught
in salinities ranging from 4 to 25 ppt.*48*
Environment Associations - 1 (DRAFT) - Life History
Species mullet, white
Species Id M010009
Date 26 AUG 96
LIFE HISTORY
Morphology and Identification Aids:
Dorsal fin IV + I spines, 8 rays; anal fin III spines, 9 rays (II, 10 in
juveniles). Lateral line scale count 33-39 (usually 38-39). Anal and second
dorsal fins scaled; origin of first dorsal fin midway between middle of
caudal base and tip of snout; caudal fin often has dark posterior border;
sides of body silvery without conspicuous stripes; back blue or olive;
gold spot on opercle usually apparent; adipose eyelid present.
The white mullet and striped mullet are easily separated taxonomically. The
white mullet has 9 anal rays and the pectoral fin lengths are 77%-84% of the
head lengths; the striped mullet has 8 anal rays and the pectoral fins are
66%-74% of the head length.*48*
Spawning:
In 1954, a school of thousands of spawning white mullet was observed at
night on the surface in about 60 m of water off south Florida. Eggs and
early larvae were collected near the surface from that depth out to the axis
of the Gulf Stream and northward to North Carolina. Eggs have been
collected in Biscayne Bay. On the basis of the distribution of larvae, it
was concluded that white mullet in Florida spawn primarily from April
through June (extremes March through September). In the Gulf of Mexico off
Texas, White mullet with gonads were collected in post-spawning condition in late spring and early
fall, but not in the summer, and the possibility of interrupted spawning
season or two populations that spawn at different times was suggested. Two
spawning seasons, summer and winter, were reported for Cuban waters.
Unfertilized white mullet eggs average 0.82 mm in diameter. The shell has a finely etched or
finely etched or scratched appearance, the yolk is an opaque mass with
little or no perivitelline space, and there is a pale yellow oil globule
averaging 0.03 mm in diameter atop the yolk mass. Soon after fertilizaion
the egg increases to an average diameter of 0.90mm. Dimensions of the egg
and oil globule are relatively constant until the egg hatches 40-42 hours
after fertilization. The following fecundity equation for Cuban white
mullet was presented, where F = number of eggs and W = weight in grams: F =
959.54439W-102947.552.*48*
Larvae and Juveniles:
Newly hatched larvae lack a mouth, fins, and eye pigment. About 32 hours
after hatching, when the larvae are about 2.6 mm long (all lengths are total
lengths (TL) unless otherwise indicated), the pectoral fin buds begin to
appear and the mouth forms. Full complements of fin rays in anal and both
dorsal fins characterize larvae 5.3 mm long, and the two spines and ten rays
are discernible in the anal fin of larvae about 14.5 mm long. Larvae retain
the "II, 10" anal fin until about 30-40mm long, when they may be considered
juveniles; the "III,9" anal fin is thereafter retained through
maturity. Laboratory-reared fish were 36 mm long 36 days after hatching.
Larvae begin appearing inshore along beaches and in estuaries when about 25
mm long and 28 days old. By the end of their first year, juveniles probably
reach a length of 200 mm standard length (SL), and become sexually mature.
Young white mullet carried north by the Gulf Stream have been reported as
far north as Canada.
Juveniles enter the estuaries and live in the inner marshes for the summer
Life History - 1 (DRAFT) - Life History
Species mullet, white
Species Id M010009
Date 26 AUG 96
of their first year; they emigrate seaward to Florida or further in the fall
Juveniles become scarce along the coast of Texas after October and along
Georgia's coast after mid-December. Immigrants from Georgia probably migrate
to inshore waters of Florida, and the Texas mullet probably migrate to
Mexican waters, where they reside until the following spring.*48*
Adults:
After their first year, white mullet are rarely collected north of Florida.
Males taken from a school of spawning fish off the south Florida coast
averaged 189 mm SL; females averaged 209 mm SL. The average length of white
mullet caught by commercial fishermen in Florida was about 250 mmSL, and the
maximum was about 350mm SL. Males in Cuban waters greatly outnumber females
at lengths shorter then 31 cm FL. There were no sexual differences in the
length-weight relationship. In Florida, a sex ratio of about 1:1 was
reported.*48*
Growth Characteristics:
A growth rate of 17 mm per month over 1 year appears to correspond well to
the size at that age, but it is also possible for a higher summer growth
rate and a much slower winter growth rate to result in the same size at 1
year.
Predation and Competition:
Information on predation and competition that specifically concerns white
mullet is scarce, but in one instance juveniles were collected with injuries
probably sustained during attacks by predators such as weakfish (Cynoscion
regalis), bluefish (Pomatomus saltatrix), and red drum (Sciaenops ocellata).
In Florida, major predators of adults are piscivorous fish and birds. No
evidence for interspecific competition exists.*48*
REFERENCES FOR LIFE HISTORY- 48
Life History - 2 (DRAFT) - Management Practices
Species mullet, white
Species Id M010009
Date 26 AUG 96
MANAGEMENT PRACTICES
COMMENTS ON MANAGEMENT PRACTICES -
The gears used most often to catch white mullet are trammel nets, gill nets,
and seines. There are no regulations or closed seasons on white mullet.*48*
Management Practices - 1 (DRAFT) - References
Species mullet, white
Species Id M010009
Date 26 AUG 96
References
48* Collins, M. 1985. Species Profiles: Life Histories and
Environmental Requirements of Coastal Fishes and Invertebrates
(South Florida)--White Mullet. U.S. Fish and Wildlife Service
Biol. Rep. 82(11.39) pp 7.
References - 1