(DRAFT) - Taxonomy
Species crab, blue
Species Id M070002
Date 26 AUG 96

TAXONOMY

NAME - crab, blue

OTHER COMMON NAMES - jimmies, sally crabs, jooks, she crabs, sponge crabs, soft shells, common edible crabs, edible blue crabs, sooks, sallies, spongers and hard crabs

ELEMENT CODE -

CATEGORY - Aquatic Crustaceans

PHYLUM AND SUBPHYLUM - Arthropoda, Crustacea

CLASS AND SUBCLASS - Malacostraca, Eumalacostraca

ORDER AND SUBORDER - Decapoda, Dendrobranchiata

FAMILY AND SUBFAMILY - Portunidae,

GENUS AND SUBGENUS - Callinectes,

SPECIES AND SSP - sapidus,

SCIENTIFIC NAME - Callinectes sapidus

AUTHORITY - Rathbun, 1896

TAXONOMY REFERENCES - 197, 174 and 254

COMMENTS ON TAXONOMY -
common edible crab,edible blue crab (02) young females called sally crabs
adult = jooks, jimmies, jimmy-dicks, or channelers (Van Engel 1958).

Taxonomy - 1 (DRAFT) - Status
Species crab, blue
Species Id M070002
Date 26 AUG 96

STATUS

Coded Status
Game (Consumptive Recreational)
Commercial/consumption
Commercial

REFERENCES FOR STATUS - 194

Status - 1 (DRAFT) - Distribution
Species crab, blue
Species Id M070002
Date 26 AUG 96

DISTRIBUTION

Distribution - 1 HABITAT ASSOCIATIONS

HABITAT - AQUATIC

REFERENCES FOR HABITAT - 194

NATIONAL WETLAND INVENTORY CODES

NWI NWICLS NWIMOD NWISPEC

Marine AB.
Estuarine AB.
Estuarine, subtidal AB.
Estuarine, intertidal AB.
Estuarine UB3
Estuarine, subtidal UB3
Estuarine, intertidal UB3

Habitat Associations - 1 (DRAFT) - Food Habits
Species crab, blue
Species Id M070002
Date 26 AUG 96

FOOD HABITS

TROPHIC LEVEL -
OMNIVORE

REFERENCES FOR TROPHIC LEVEL - 194 and 136

LIFESTAGE FOOD FOOD PART
General Zosteraceae Roots
General Zosteraceae Buds
General Zosteraceae Leaves/Needles
General Poaceae Roots
General Poaceae Buds
General Poaceae Leaves/Needles
General Other Plant Species Not Specified
General Detritus Not Specified
General Detritus - Organic Not Specified
General Molluscs Not Specified
General Bivalve Molluscs Not Specified
General Snails Not Specified
General Crustaceans Not Specified
General Osteichthyes Not Specified
Larva Pyrrophyta Not Specified
Larva Molluscs Not Specified
Larva Crustaceans Larva stage
Larva Copepods Larva stage
Larva Osteichthyes Larva stage
Juvenile Zosteraceae Roots
Juvenile Zosteraceae Buds
Juvenile Zosteraceae Leaves/Needles
Juvenile Poaceae Not Specified
Juvenile Other Plant Species Not Specified
Juvenile Detritus - Organic Not Specified
Juvenile Molluscs Not Specified
Juvenile Bivalve Molluscs Not Specified
Juvenile Snails Not Specified
Juvenile Crustaceans Not Specified
Juvenile Osteichthyes Not Specified
Adult Zosteraceae Roots
Adult Zosteraceae Buds
Adult Zosteraceae Leaves/Needles
Adult Poaceae Roots
Adult Poaceae Buds
Adult Poaceae Leaves/Needles
Adult Other Plant Species Not Specified
Adult Detritus - Organic Not Specified
Adult Molluscs Not Specified
Adult Chitons Not Specified
Adult Bivalve Molluscs Not Specified
Adult Snails Not Specified
Adult Crustaceans Not Specified
Adult Chamaeriformes Not Specified
Larva Zooplankton Not Specified
Food Habits - 1 (DRAFT) - Food Habits
Species crab, blue
Species Id M070002
Date 26 AUG 96

LIFESTAGE FOOD FOOD PART
Larva Osteichthyes See Comments
Larva Aquatic plants Not Specified
Larva Molluscs Not Specified
Adult Invertebrate Cordates Not Specified
Juvenile Invertebrate Cordates Not Specified
Adult Osteichthyes Not Specified
Juvenile Osteichthyes Not Specified
Adult Aquatic plants Not Specified
Juvenile Aquatic plants Not Specified
Adult Detritus Not Specified
Juvenile Detritus Not Specified
Adult Bivalve Molluscs Not Specified
Juvenile Bivalve Molluscs Not Specified
Adult Molluscs Not Specified
Juvenile Molluscs Not Specified

REFERENCES FOR GENERAL FOOD - 194 and 254

REFERENCES FOR ADULT FOOD - 194 and 136

REFERENCES FOR JUVENILE FOOD - 194 and 136

REFERENCES FOR LARVAE FOOD - 194 and 136

COMMENTS ON FOOD -
At various stages in the life cycle, blue crabs serve as both prey and as
consumers of plankton, small invertebrates, fish and other crabs. They are
important detritivores and scavengers throughout their range.*194*
In general, blue crabs are opportunistic omnivores and scavengers, feeding
on a variety of plants and animals including other blue crabs. Food is
located by a combination of chemoreception and taction.*254*

Blue crabs are generally considered omnivorous. Blue crab may be a major
factor in the control of benthic populations *136*.

COMMENTS ON ADULT FOOD -
Some common food items are dead and live fish, crabs, organic debris, shrimp
molluscs, and aquatic plants. Roots, shoots, and leaves of eelgrass, ditch
grass, sea lettuce, and salt marsh grass were commonly eaten by crabs in
salt marshes, tidal creeks, and other shallow estuarine areas.*194*

Adult blue crabs are also omnivorous, feeding on benthic macroinvertebrates,
small fish, aquatic vegetation and associated fauna, and dead organisms.
The blue crab is known to prey on young quahogs and seed oysters under
experimental conditions. It will also prey on oyster spat, newly set
oysters and clams, or young oysters if other food is unavailable *136*.

COMMENTS ON JUVENILE FOOD -
Post-larval crabs are considered general scavengers, bottom carnivores,
detritivores, and omnivores.*194* Megalope are more omnivorous than zoeae
preying unton fish larvae, small shellfish, and aquatic plants. Juvenile
Food Habits - 2 (DRAFT) - Food Habits
Species crab, blue
Species Id M070002
Date 26 AUG 96

blue crabs feed mostly on molluscs, crustaceans, and fish.*254*

Juvenile blue crabas are also omnivorous, feeding on benthic
macroinvertebrates, small fish, aquatic vegetation and associated fauna, and
dead organisms *136*.

COMMENTS ON LARVAE FOOD -
Zoeae are phytoplanktivorous and readily consume dinoflagellates and
copepod nauplii. The omnivorous megalopa eats fish larvae, small shellfish,
and aquatic plants. *194* Larval blue crab are believed to feed on
phytoplankton and zooplankton.*254*

The zoeae and megalopae prey primarily upon zooplankton. The megalopae
will also feed upon pieces of fish or shellfish and aquatic plants *136*.

Food Habits - 3 (DRAFT) - Environment Associations
Species crab, blue
Species Id M070002
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
G Dissolved Oxygen: Specified in Comments
G Dissolved Oxygen: Unknown
LIM Water Temperature: Greater than 27 degrees C
LIM Water Temperature: Below 15 degrees C
LIM Water Temperature: Specified in Comments
LIM Dissolved Oxygen: Specified in Comments
LIM Dissolved Oxygen: Unknown
LIM Water pH: Specified in Comments
L Water Temperature: Specified in Comments
J Water Temperature: Specified in Comments
A Water Temperature: Specified in Comments
LIM Water pH: Between 5.0-6.5
A Water pH: Between 5.0-6.5
G
G
G
G
G
G Air Temperature: Specified in Comments
BA
G Water Temperature: Specified in Comments
G Water Temperature: Between 21-27 degrees C
G Water Temperature: Between 15-21 degrees C

REFERENCES FOR ENVIRONMENTAL ASSOC_ - 194 and 136

REFERENCES FOR BREEDING ADULT ENVIRONMENTAL ASSOC_ - 136

REFERENCES FOR RESTING LARVAE ENVIRONMENTAL ASSOC_ - 194

COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
No optimal parameters are reported, instead optimum conditions are a result
of synergism. That is optimal temperature depends on salinity and other
parameters such as pollutants, predation, disease, food availability

00020S: Water temperature requirements vary, and are considered important
but no optimal range is reported. Growth occurs above 15 deg C
00030S: DO is important, but no optimal range established
Environment Associations - 1 (DRAFT) - Environment Associations
Species crab, blue
Species Id M070002
Date 26 AUG 96

00220S: Salinity is important, but requirements vary by lifestage
Generally optimum is 3 - 15ppt
00030S: DO Limits unknown but crabs are known to die due to anoxia
Very susceptible to chemical pollution. Best example is impact of
chlorinated Hydrocarbon, Kepone (Mirex) in James River. Toxic as contact
or stomach poison 00220S: Tolerance range reported as 2-21 ppt
00020S: Temp above 33 deg C. lethal
00040S: Tolerance range is pH 6-8. pH less than 6 is lethal
Other stresses include pesticides, herbicides, domestic and industrial
wastes.*194,174*

Blue crabs are found from the mouth of the Bay to tidal fresh areas. There
are distinct differences in the ranges of males and females. During the
summer month, males are found from freshwater to the polyhaline zone,
although they occur in the greatest numbers in salinities of 3-15 ppt.
Maximum numbers of females occur down Bay at salinities of 10 ppt to ocean
salinities. When air temperatures drop below 10 oC, adult crabs leave
shallow, inshore waters and seek deeper areas where they bury themselves and
remain in a state of torpor throughout the winter *136*.

Blue crab growth is regulated by water temperature. Growth occurs from late
April to mid-October when temperatures are above 15 oC *136*.

COMMENTS ON RESTING ADULT ENVIRONMENTAL ASSOC_ -
00020S: Susceptible to sudden drops in temperature 1.0 ppmDDT and 10.0
ppm Toxaphene were each 100% lethal to adults within 72 hrs *08* 1.3 - 1.9
of Methoxychlor is lethal.*194,174*

COMMENTS ON FEEDING ADULT ENVIRONTAL ASSOC_ -
Same as RA

COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ -
Mating usually takes place in low salinities of the tidal fresh to upper
region of the mixing zone. After mating, females move to the seawater
zone, while males often remain in the upper reaches of the estuary. The
females brood the eggs (sponge females), and larvae are released in higher
salinities. Development through the late zoeal stages occurs
offshore.*254*

After mating, females migrate south in the Bay toward higher salinity
waters. Blue crab spawning appears to be concentrated at the mouth of
Chesapeake Bay in the channel region between Cape Henry and Cape Charles
where salinities are near oceanic *136*.

COMMENTS ON RESTING JUVENILE ENVIRONMENTAL ASSOC_ -
002205: Salinities less than 2 ppt or greater than 11 ppt
reduce survival and growth. Inverse relation between salinity and
abundance
00020S: Susceptible to sudden temperature drops

COMMENTS ON LARVAE ENVIRONMENTAL ASSOC_ -
Females brood the eggs (sponge females), and larvae are released in higher
salinities. Development through the late zoeal stages occurs offshore.
Environment Associations - 2 (DRAFT) - Environment Associations
Species crab, blue
Species Id M070002
Date 26 AUG 96

Megalope are recruited back into the estuary and disperse throughout the
salinity zones. As they approach maturity, blue crabs seek lower
salinities. There appears to be a primary spawning ground located in the
apalchicola Bay region that serves as a source area for the entire Florida
peninsular Gulf coast blue crab fishery. A hypthesis for redistribution of
larvae to southwestern Florida includes transport through circulation
patterns associated with the Loop current and the Apalachicola River.*254*

COMMENTS ON RESTING LARVAE ENVIRONMENTAL ASSOC_ -
00020S:Zoeae (early larvae) do not develop at temperatures less than
21 degrees centigrade or greater than 30 deg C. Megalopae mortality is
greater than 50% at temperature below 15 deg C. (upper limit is not
specified)*194*
Megalopae survival and growth drops at 5ppt or less salinity not
critical to post larvae. When salinity is very low (unspecified
level) eggs hatch prematurely and larvae die in pre-zoeal stage

COMMENTS ON FEEDING LARVAE ENVIRONMENTAL ASSOC_ -
Same as for Resting larvae

COMMENTS ON EGG ENVIRONMENTAL ASSOC_ -
00220S: Hatching drops off at salinities less than 22ppt or more than 28ppt
*194,174*

The timing of egg hatching is seasonally dependent *136*.

Environment Associations - 3 (DRAFT) - Life History
Species crab, blue
Species Id M070002
Date 26 AUG 96

LIFE HISTORY

Physical Description: Grayish or bluish or brownish green, with red on
carapace spines. Males have blue pincers on chelipeds, females have red
pincers. Underparts are off white with yellow or pink tints. Young are often
brown with white markings. Male pincers are tipped in red. The carapace with
spines is 2.5 times as wide as long, moderately convex and nearly smooth.
The anterior and lateral margin of the carapace are serrated, with 4 in the
median and 8 in each lateral region. The abdomen of the male is shaped like
an inverted "T". The immature female has a triangular abdomen. The mature
female has a roughly semi-circular abdomen. Reproduction: In the
Chesapeake Bay, mating occurs from May to October in areas of relatively low
salinity (upper estuaries and lower reaches of rivers). Mating and spawning
are not synchronous. Males may mate during 3 - 4 intermediate phases
after maturing. Females mate only once, but store sperm in seminal
receptacles. The sperm is used as often as spawns (usually two or more times
in 1 or 2 years). Males carry females after spawning until females shell
hardens. In the Chesapeake Bay, females spawn in the spring following
mating. Fertilized eggs are extruded and attached to setae on the
pleopods as an egg mass. Eggs remain there until hatching. Females spawn in
high salinity waters. Sexual maturity is reached after 18 - 20 post larval
months at 1 to 1.5 years. After mating, females move to deeper, more
saline water for rest of life.

Mating and Spawning in the Gulf of Mexico:
Spawning occurs in waters less than 20 m deep in bays and estuaries,
and in the Gulf of Mexico where it is limited to the shallow inshore areas
in bay water masses. The females are extremely vulnerable to cannibalism
and predation during these molts. As a result, the recognition of amorous
males is fairly important. Females approaching their pubertal or terminal
molts initiate mating behavior upon recognition of a mature male via
olfactory and visual stimuli. Males recognize the females via a pheromone
that triggers male mating behavior. Copulation occurs while the female
molts. During the female's molt, the male protects her by grasping her with
his first pair of walking legs and "cradle-carries" her in an upright
position underneath him. Males transmit their spermatophores by tube-like
pleopods into the female's seminal receptacle. The sperm are stored in the
seminal recepticle until fertilization; inseminated females can retain
viable sperm for at least one year. Fertilization is accomplished by
passing the eggs from the ovaries to the seminal receptacles before being
extruded onto the females' pleopods. Egg extrusion onto the pleopods may be
completed within 2 h. Spawning typically occurs within two months after
spring and summer matings, but may be postponed until the following spring
after fall matings.

Behaviour: Growth and development consists of series of larval,
juvenile and adult stages. Growth follows molt (shedding rigids
exoskeleton). Zoeae bear little resemblance to adults, live in high
salinity surface waters, as filter feeding zooplankton forms this stage may
last 49 days. Megalopa are in a free swimming stage lasting up to 20
days, they live in nearshore lower estuarine high salinity waters near the
bottom Juveniles gradually migrate into shallower less saline
water in upper estuaries and rivers. Males tend to migrate further upstream
Life History - 1 (DRAFT) - Life History
Species crab, blue
Species Id M070002
Date 26 AUG 96

than females. Molting and growth cease during winter. Adult
males tend to remain in lower salinity waters, while mature females prefer
higher salinity of lower estuary and adjacent marine waters. Migration
is related to life cycle, season, environmental conditions and sex.

Species Origin Within State: This native species is found in the Chesapeke
bay, estuaries, and tributaries of the bay, from polyhaline salinities to
freshwater. Principal tributaries include the James, York, Rappahanock, and
Potomac Rivers.

Limiting Factors: Critical lifestages are during the larval stage, and
during the pre and post molt periods (non susceptible to predation during
molts). Variations in salinity, temperature, pollutants,
predation, disease, habitat loss, and food availability affect
survival. Temperature, salinity and substrate are primary
factors affecting growth, survival, and distribution in the Chesapeake
Bay. Sudden drops in temperature and red tides have been
responsible for larvae mortalities. Premolt and postmolt periods are
phases of high metabolic activity, therefore this crab is more susceptible
to environmental stresses. Nursery area conditions are a major limiting
factor in determining success of a year class.

Population Attributes:
Maximum observed age is 4 years. In the Chesapeake Bay, maximum age is 3
years and very few live longer than 2 years. Density dependent and
density indepedent variables influence larval and juvenile population.
On the average, 1 out of every million eggs (approx. 1 egg mass survives to
become a mature adult). Population fluctuations may be caused by cold
weather, low salinities, heavy rains, predation, parasitism and predation.

Species Interaction: The blue crab is preyed on by many species
including man. Eggs are eaten by many fish. Larvae are eaten by fish,
shellfish, jellyfish. Juveniles and adults are important foods of
spotted seatrout red drum, croaker, gars, sheepshead, and fresh and salt
water catfish. Birds (such as Herons and diving ducks) and mammals
(like Raccoons and otters) feed on this crab.

SPAWNING AND RANGE: After mating, females migrate south in the Bay toward
higher salinity waters. The timing of egg hatching is seasonally dependent.
If mating occurs during spring, then the first egg mass, or sponge, may
hatch in July. Most females mate during the late summer season in July,
August, or September, with hatching delayed until the following summer. A
female may also produce two or more egg sponges later in the summer. Blue
crab spawning appears to be concentrated at the mouth of Chesapeake Bay in
Life History - 2 (DRAFT) - Life History
Species crab, blue
Species Id M070002
Date 26 AUG 96

the channel region between Cape Henry and Cape Charles where salinities are
near oceanic. A study examined seasonal, horizontal and vertical
distribution of blue crab larvae in the mouth of the Chesapeake Bay and
nearshore waters. Only early stage zoeae (mainly Stages I-III) and megalopae
were found present in abundance offshore. It concluded that larval
development occurs in the rich coastal waters and recruitment back to the
estuary occurs in the post-larval or juvenile stages. Juvenile crab
migration up the Chesapeake Bay and its tributaries begins in August. Male
and female juvenile crabs apparently have differnt migratory patterns.
Juvenile crabs, predominantly males, move into the Chesapeake and Delaware
Canal area in late spring. This distribution of sexes is quite unlike the
sex distribution of juvenile crabs in the lower Bay, around Tangier Sound,
suggesting there is a separation of the sexes at an early stage which is
probably due to differences in migratory behavior *136*.

GROWTH: Blue crab growth is regulated by water temperature. Growth occurs
from late April to mid-October when temperatures are above 15 oC. They grow
by shedding their hard shells (molting). Molting is a major physiological
event of crustacean life history. Blue crabs molt frequently during the
early juvenile stages (7-10 days). The periodicity decreases with age and
size. The premolt and postmolt phases are periods of high metabolic
activity; therefore, the animal may be more susceptible to environmental
stress during these periods. The crabs reach adult size (130 mm or larger)
while on the "nursery grounds," brackish water habitats in the tributaries
and mainstem of the Bay *136*.

LIFE HISTORY CODES -

Stocked

Breeding/Spawning Season: July
Breeding/Spawning Season: August
Breeding/Spawning Season: September
Number of Broods/Litters (Reproductive Efforts) Per Ye
Number of Broods/Litters (Reproductive Efforts) Per Ye
Number of Broods/Litters (Reproductive Efforts) Per Ye

COMMENTS ON LIFE HISTORY -
Critical life stage includes the pre-molt and post-molt period.*136*

REFERENCES FOR LIFE HISTORY- 194, 174, 254 and 136

Life History - 3 (DRAFT) - Management Practices
Species crab, blue
Species Id M070002
Date 26 AUG 96

MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE

Adverse Applying insecticides
Adverse Applying pesticides
Adverse Clearing/snagging
Beneficial Developing/maintaining brackish marsh
Beneficial Regulating harvest - setting bag/creel limits
Beneficial Regulating harvest - setting seasons
Beneficial Regulating harvest - setting size limits

REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 92 and 194

REFERENCES FOR ADVERSE MANAGEMENT PRACTICES - 92 and 194

COMMENTS ON MANAGEMENT PRACTICES -
All south Atlantic States have a 127mm minimum size (carapace width) for
hard crabs and some have a 76 mm for soft or peeler crabs.

Management Practices - 1 (DRAFT) - References
Species crab, blue
Species Id M070002
Date 26 AUG 96

References

136 * Chesapeake Bay Program. 1988. Habitat Requirements for
Chesapeake Bay Living Resources. Chesapeake Executive
Council pp 86.

194 * Hill, Jennifer, Dean Fowler, Michael van Den Avyle. 1989.
Species Profiles: Life Histories and Environmental Requirements
of Coastal Fishes and Invertebrates (Mid-Atlantic)--Blue Crab.
82(11.1) (ed.). U.S. Fish and Wildlife Service Washington,
DC:18.

174 * Prager, Michael H. 1989. Fecundity of Blue Crab, Callinectes
sapidus, In Chesapeake Bay; Biological, Statistical, and
Management Considerations. Bulletin of Marine Science:29.

92* Perry, H. M. (ed.). 1984. A Profile of the Blue Crab Fishery of
the Gulf of Mexico. 9. Gulf States Marine Fisheries Commission
Ocean Springs, MS pp 80.

138 * Gusey, W.F. 1976. The fish and wildlife resources of the
middle Atlantic bight. (ed.). Shell Oil Company Houston, TX:546.

176* Huner, J.V. (ed.). 1985. Crustacean and Mollusk Aquaculture in
the United States. AVI Westport, Connecticut:476.

References - 1