(DRAFT) - Taxonomy
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

TAXONOMY

NAME - croaker, Atlantic

OTHER COMMON NAMES - Croaker and Golden croaker

ELEMENT CODE -

CATEGORY - Fish

PHYLUM AND SUBPHYLUM - ,

CLASS AND SUBCLASS - Pisces,

ORDER AND SUBORDER - Perciformes,

FAMILY AND SUBFAMILY - Scianenidae,

GENUS AND SUBGENUS - Micropogon,

SPECIES AND SSP - undulatus,

SCIENTIFIC NAME - Micropogon undulatus

AUTHORITY - Linnaeus

TAXONOMY REFERENCES - 265

COMMENTS ON TAXONOMY -
South of the U.S. the taxonomy of the croakers becomes confused, as this
species or a very similar one may occur as far south as Argentina. M.
furnieri (Desmarest), which occurs on the Mexican coast, may venture
sometimes into our area, however, records of that species often show it to
be confused with M. undulatus. It differs from M. undulatus because of its
larger scales (seven between the dorsal origin and the lateral line vs. nine
in M. undulatus) and because of its spots on the scales above the lateral
line form more continuous vertical lines *265*.

A few croakers survive that second year and go on to attain a size
of from 4 to 5 pounds on the Texas coast. They are known as golden croakers
*265*.

Taxonomy - 1 (DRAFT) - Status
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

STATUS

Coded Status
Sport Fish
Migrant
See Comments

REFERENCES FOR STATUS - 265

COMMENTS ON STATUS -
Croaker are probably the most common sport fish in the Cedar Lakes area
*265*.

The mean number of Atlantic croaker per trawl during the study was: upper
bay -- 219.2, middle bay -- 111.5, and lower bay -- 125.5 *265*.

"Runs" of large croaker from Bay to Gulf in fall cause some sportsmen to
fish the passes. One major area is Rollover Pass. Atlantic croaker have
comparatively little value due to small size obtained. Combined commercial
landing for 1973-74 were 294,521 lbs, $20,194. Catch is negatively
correlated with salinity and conductivity and positively correlated with
turbidity, nitrate-N, and total phosphate-P *265*.

The fact that few fish over 2 years old and 290 mm long survive is the chief
reason why croakers decline in numbers in fall and winter and also the
reason why they are not produced commercially on a large scale in Texas
waters. According to federal fishrey statistics, Texas produced annually an
average of 42,300 pounds from 1936 to 1940. They variation in the yearly
catch was from 10,200 to 82,600 pounds *265*.

An estimated 101,966 anglers in Galveston Bay caught 662,280 fish from June
1964 to June 1965. In Galveston Bay, San Antonio Bay, Aransas Bay and upper
Laguna Madre, croaker make up 10 % of fish harvest from June 1974 to
November 1974. Best months for fishing are July to November. Shrimp is the
preferred bait *265*.

Status - 1 (DRAFT) - Distribution
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

DISTRIBUTION

Distribution - 1 HABITAT ASSOCIATIONS

HABITAT - MARINE
AQUATIC

REFERENCES FOR HABITAT - 265

LAND USE -
Water
Bays and Estuaries
Beaches

REFERENCES FOR LAND USE - 265

NATIONAL WETLAND INVENTORY CODES

NWI NWICLS NWIMOD NWISPEC

Estuarine
Marine

REFERENCES FOR NWI - 265

COMMENTS ON HABITAT ASSOCIATIONS -
Atlantic croaker frequents bays and Gulf Beaches *265*.

Atlantic croaker is perhaps the commonest bottom-dwelling estuarine species,
with the young occuring in the deeper parts of the bays in the summer but
departing in the fall *265*.

Postlarval croakers seem to be largely bottom forms. Large numbers of
croaker apparently enter the bays on some flood tides *265*.

Atlantic croaker are found in euryhaline habitats. Fish tend to stay in
fresher water and are known to enter freshwater. They can tolerate
hypersalinity to 70 ppt *265*.

Large numbers of young croakers remain in the Gulf, although most are in
shallow water. At the approach of their second winter, they go to deeper
waters of the bays and Gulf. In winter they move offshore from estuaries
*265*.

Atlantic croaker are considered a summer resident in the surf *265*.

ANIMAL/PLANT SPECIES ASSOCIATIONS -
Red drum
Nematode

REFERENCES FOR SPECIES ASSOCIATIONS - 265

Habitat Associations - 1 (DRAFT) - Food Habits
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

FOOD HABITS

TROPHIC LEVEL -
CARNIVORE

REFERENCES FOR TROPHIC LEVEL - 265

LIFESTAGE FOOD FOOD PART
General Molluscs Not Specified
General Crustaceans Not Specified
General Malacostraca Not Specified
General Bivalve Molluscs Not Specified
General Clupeiformes Not Specified
General Annelids Not Specified
General Plants Not Specified
General Detritus Not Specified
General Osteichthyes Not Specified
General Zooplankton Not Specified
General Benthos Not Specified
General Animals See Comments
General Copepods Not Specified
General Malacostraca Not Specified
General Ostracods Not Specified
General Snails Not Specified
General Protozoans Not Specified
Adult Crustaceans Not Specified
Adult Malacostraca Not Specified
Adult Annelids Not Specified
Adult Bivalve Molluscs Not Specified
Adult Osteichthyes Not Specified
General Polychaetes Not Specified
General Insects Not Specified
General Arachnids Not Specified
General Cirripeds Not Specified
General Sponges Not Specified
General Algae Not Specified
General Plants Not Specified
Juvenile Zooplankton Not Specified
Juvenile Crustaceans Not Specified
Juvenile Copepods Not Specified
General See Comments; Food See Comments
Adult See Comments; Food See Comments
Juvenile See Comments; Food See Comments

REFERENCES FOR GENERAL FOOD - 265

REFERENCES FOR ADULT FOOD - 265

REFERENCES FOR JUVENILE FOOD - 265

COMMENTS ON FOOD -
Comparison of the present diet data with those of 1954, prior to the
Food Habits - 1 (DRAFT) - Food Habits
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

introduction of Gulf water into the bay, revealed an increase in the
frequency of occurrence of mollusks from 44.7% during the earlier study to
97.5% during 1955. Conversely, shrimps occurred in 12.8% of the stomachs
examined in 1954, as compared to 6.8% in 1955. Although it might not be
specious to reason that the decrease in shrimp catch was due entirely to
increased salinity in the bay, the increased frequency of occurrence of
mollusks might well be correlated with decreased availability of shrimps to
feeding croaker *265*.

In a study, the pelecypod, Macoma mitchelli, occurred in 76.7% of the
stomachs. Fish remains were found in 8.2% of the stomachs, the only
identifiable form being a species of anchovy, probably Anchoa mitchilli
diaphana which was abundant in the bay. Shrimps were eaten by 6.8%, and
crabs by 6.8% of the croakers. Annelids occurred in 4.1% of the stomachs,
Plant debris and unrecognizable organic detritus were found in 13.7% of the
fish. In view of the frequency and amount of debris present in the
stomachs, it is suggested that the material may serve as an energy source
*265*.

In another study, 55% had eaten shrimps; 13%, annelids; 12%, fishes; 5%,
crabs; and 5% had ingested mollusks. Smaller fish, 14 to 20 cm in length,
had eaten mainly annelids *265*.

Four food stages are recognized: zooplankton; micro-bottom animals;
detritus; and larger animals *265*.

Atlantic croaker have been found to eat fish, mud shrimp Calianassa,
mollusks, shrimp and crabs. They also eat calanoid copepods and schizopods.
Fish 25-50 mm ate copepods, amphipods, isopods, ostracods, snails and
foraminiferans; 50-200 mm ate detritus and organic material; over 200 mm ate
larger animals, annelids, crabs, clams, and small fishes. They also feed on
polychaetes and crustaceans *265*.

Food items of Atlantic croaker from Lake Pontchartrain, Lousisiana and Clear
Lake, Texas include: bryozoa, branchiopoda, ostracoda, copepoda, mysid
shrimp, palaemonid shrimp, penaeid shrimp, shrimp, crabs, isopoda,
amphipoda, cirripedia, stomatopoda, insecta, arachnida, annelida, mollusca,
sponges, foraminifera, vertebrata (fish), algae, vascular plants, detritus,
mud and sand *265*.

COMMENTS ON JUVENILE FOOD -
Smaller fish, 14 to 20 cm in length, were found to eat mainly annelids
*265*.

Food Habits - 2 (DRAFT) - Environment Associations
Species croaker, Atlantic
Species Id TSNL0010
Date 27 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 Coastal Wetlands: Sounds and bays
G Coastal Wetlands: Specified in Comments
G Estuarine habitat zone: bay
G Estuarine habitat zone: specified in comments
G Coastal Features: Specified in Comments
G Water Depth Preference: 25-50 ft.
G Water Depth Preference: 10-25 ft.
G Water Depth Preference: 50-100 ft.
G Water Depth Preference: Specified in Comments
G Water Temperature: Greater than 27 degrees C
G Water Temperature: Between 21-27 degrees C
G Water Temperature: Between 15-21 degrees C
G Water Temperature: Below 15 degrees C
G Water Temperature: Specified in Comments
G Water Depth Preference: Specified in Comments
G Air Temperature: Specified in Comments
BA Water Depth Preference: Specified in Comments
G Dissolved Oxygen: Specified in Comments
J Water Depth Preference: Specified in Comments
J Coastal Wetlands: Sounds and bays
J Coastal Wetlands: Specified in Comments
J Estuarine habitat zone: bay
J Estuarine habitat zone: specified in comments
G
G
A Water Depth Preference: 100-200 ft.
A Water Depth Preference: Specified in Comments
L Water Depth Preference: Specified in Comments
BA Water Temperature: Specified in Comments
FJ Water Depth Preference: Specified in Comments
FA Water Depth Preference: Specified in Comments
G Water Depth Preference: 200-500 ft.
A
A
A
J
J
J
A
A
Environment Associations - 1 (DRAFT) - Environment Associations
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
A
A
G
G
G
G
G
G
G Aquatic Vegetation [specified type]: Specified in comments
G Specific Conductances [uMhos]: Specified in comments
G Turbidity: Specified in Comments
G Currents: specified in comments
G Water Depth Preference: 500-1000 ft.
L Coastal Wetlands: Sounds and bays
L Coastal Wetlands: Specified in Comments
J Coastal Wetlands: Sounds and bays
J Coastal Wetlands: Specified in Comments
L Water Depth Preference: Specified in Comments
J Water Depth Preference: Specified in Comments
G Turbidity: Murky water [High turbidity]
G Turbidity: Specified in Comments
G Water Velocity [Instream Flow Group Increments]: Specified in Comments
G Bottom Type [Aquatic]: Sand
G Bottom Type [Aquatic]: Gravel
G Bottom Type [Aquatic]: Specified in Comments

REFERENCES FOR ENVIRONMENTAL ASSOC_ - 265

REFERENCES FOR ADULT ENVIRONMENTAL ASSOC_ - 265

REFERENCES FOR FEEDING ADULT ENVIRONMENTAL ASSOC_ - 265

REFERENCES FOR BREEDING ADULT ENVIRONMENTAL ASSOC_ - 265

REFERENCES FOR JUVENILE ENVIRONMENTAL ASSOC_ - 265

REFERENCES FOR FEEDING JUVENILE ENVIRONMENTAL ASSOC_ - 265

REFERENCES FOR LARVAE ENVIRONMENTAL ASSOC_ - 265

COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
Atlantic croaker frequents bays and Gulf Beaches *265*.

In a 1955 study, the salinity ranged between 25.0 and 30.5 ppt during June.
The temperature of the water during the day ranged from 27.2 to 31.6 oC.
During a similar period in 1954, the salinity varied from 25.0 to 32.3 ppt,
and the surface temperature ranged near 30 oC *265*.

Large numbers of croaker apparently enter the bays on some flood tides
*265*.

Environment Associations - 2 (DRAFT) - Environment Associations
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

Atlantic croaker have been found in Galveston Bay from 0.4 to 35.5 oC
*265*.

The temperature range where fish were caught was from 9.1 to 32.0 oC. The
lowest salinity at which the croaker was caught was 2.0 ppt and the highest
was 36.7. The fish were taken in greatest numbers below salinities of 15.0
ppt. The Atlantic croaker tend to stay in fresher water.
They are known to enter fresh water. Catch was found to negatively
correlate with salinity and conductivity. They tolerate hypersalinity to
70 ppt *265*.

Five hydrologic parameters were found to correlate significantly with the
catch of Atlantic croakers. Negative relationships were found with
salinity and conductivity. Positive correlations with catch included
turbidity, nitrate-nitrogen and total phosphate-phosphorus *265*.

Atlantic croaker are considered a summer resident of the surf *265*.

Atlantic croaker is a bottom dweller and is found at depths of over 100
fathoms *265*.

Micropogon undulatus were found in areas where the water was murky, the
current was slow, and the river bottom was sand and some gravel *265*.

Seasonal abundance of Atlantic croaker in Thalassia beds was roughly
concurrent with seasonal temperature changes. Golden croaker larger than
100 mm were most abundant in the deepest Thalassia bed and least abundant
in the shallowest Thalassia bed. Micropogon undulatus followed a pattern
of seasonal and day to night occurrence in Thalassia *265*.

Micropogon undulatus are taken in large numbers at all salinities. They
can be taken below a salinity of 5.0 ppt *265*.

COMMENTS ON ADULT ENVIRONMENTAL ASSOC_ -
Adult Atlantic croaker have been found in salinities from 0.2-70 ppt with
the peak from 6-20 ppt *265*.

Adults reside at sea and spawn during the winter and early spring in close
access to their estuarine nursery grounds *265*.

COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ -
Spawning takes place close to shore *265*.

In the Gulf, spawning takes place near the mouths of passes leading to bays
*265*.

Micropogon undulatus breed at the time of falling or low temperatures
*265*.

COMMENTS ON JUVENILE ENVIRONMENTAL ASSOC_ -
The young occur in the deeper parts of the bays in the summer but depart in
the fall *265*.

Environment Associations - 3 (DRAFT) - Environment Associations
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

Juvenile Atlantic croaker have been found in salinities from 0.1-21.2 ppt
with peak from 3-9 ppt *265*.

Young-of-the-year enter nursery areas of the bays about November. Large
numbers fill the passes on each incoming tide *265*.

The young move directly into the bays and lagoons, using these shallow,
nutrient-rich waters during postlarval and juvenile development and return
to the Gulf during late summer or fall *265*.

COMMENTS ON LARVAE ENVIRONMENTAL ASSOC_ -
Postlarval croakers seem to be largely bottom forms, which come to the
surface during slack water and especially during flood tide *265*.

Environment Associations - 4 (DRAFT) - Life History
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

LIFE HISTORY

South of the U.S. the taxonomy of the croakers becomes confused, as this
species or a very similar one may occur as far south as Argentina. M.
furnieri (Desmarest), which occurs on the Mexican coast, may venture
sometimes into our area, however, records of that species often show it to
be confused with M. undulatus. It differs from M. undulatus because of its
larger scales (seven between the dorsal origin and the lateral line vs. nine
in M. undulatus) and because of its spots on the scales above the lateral
line form more continuous vertical lines *265*.

Three year classes entered esturaries in winter and spring. Most fish
apparently left the estuary in fall. Croakers used nursery areas 7 or 8
months, then began Gulfward emigration at sizes of 45-80 mm *265*.

Spawning takes place close to shore. It has been assumed that croaker spawn
at the mouths of passes, but larval croakers were found at all alongshore
stations. Also ripe males were taken as far offshore as 18 fathoms. If
spawning were localized at the inlet mouth, it would seem that the chances
of larvae being swept away by alongshore currents would be large. However,
spawning over a wide area might insure at least some reaching the bays 265*.

Postlarval croakers seem to be largely bottom forms, which come to the
surface during slack water and especially during flood tide, at least some
times. Large numbers of croaker apparently enter the bays on some flood
tides. At other times there was no apparent influx of croakers into the
bays *265*.

Several studies have suggested an extended spawning season sometime between
October and March. Ripe or ripening croakers have been found in October,
November and December *265*.

One year old fish were found to have 40,000 eggs. A 390 mm female contained
180,000 eggs. The eggs averaged 0.34 mm in diameter. Atlantic croaker are
oviparous *265*.

Half the males reach maturity in their second year. The smallest mature
male found was 240 mm in length *265*.

Atlantic croaker spawn in the fall continuing at least through the winter,
as early as August and ends as late as April. At most, it is a 9 month
duration. They spawn near the mouths of passes leading to bays in the Gulf
*265*.

A minimum size for mature females was 410 mm. Some say sexual maturity is
possible in one year, but in New Jersey it may take 3-4 years. A study
found that the croaker spawn in the late fall in the open Gulf near the
passes. It stated that a noticeable migration of ripe adults from the bays
to the Gulf took place in September and October. One fish, 24.2 cm long,
was found with mature milt in the Aransas Bay. Females, 21.5-30.5 cm, with
yellow roe were taken in Aransas Bay. One had cream colored roe. Males,
23.5-27.0 cm, had ripening milt. In November and December, 1941 one male
25.0 cm long and 2 females 24.0 and 30.5 cm with ripe gonads were caught on
Life History - 1 (DRAFT) - Life History
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

the Gulf beach. Three spent fish from 29.5 to 37.0 cm long were taken at
the same time *265*.

Atlantic croaker probably does not spawn in upper Laguna Madre *265*.

Young-of-the-year, which are mobile, enter nursery areas of the bays about
November. Large numbers fill the passes on each incoming tide *265*.

Post-larval, which are mobile, leave the estuary in fall. They use nursery
areas 7 or 8 months and begin Gulfward emigration at sizes of 45-80 mm
*265*.

Growth rate averages: 12.1 mm/mo for the first year resulting in a croaker
length of 145.6 mm; 5.3 mm/mo for the second resulting in 208.8 mm; and 3.6
mm/mo for the third year resulting in 251.4 mm. Only a few large fish live
past their first year. The average weight of fish in sport catches is less
than 1 lb to larger fish up to 3 lbs. The record is 5 lb. 2 oz in Galveston
Bay *265*.

In October, December, January and March, a study took hundreds of small
croakers from 3 to 70 mm long in the passes or scattered out over the bays.
The fish entered the passes with incoming tides and were distributed over
intercoastal waters. No fish less than 53 mm long was taken during May and
afterwards. Fish which were from 53 to 83 mm in length in March appear to
have attained a length of from 103 to 173 mm in length in October when they
were approaching an age of one year. There was some overlapping of sizes of
small croakers noted in January, February, March and April. This was no
more than would be explained, whoever, by a long breeding season and a
better fortuitous catch in some months than in others or possible two
spawning peaks in a season. In August two groups ranged from 83 to 173 and
from 213 and 283 mm long respectively. These fish belong to year classes 0
and 1. Two fish in class 3 were 353 to 368 mm long. No indications were
found of four year old fish. The data corroborates with the theory that most
croakers disappear following spawning at about the age of 2 years. If the
croaker attains a length of 380 mm in the fourth year of life, then the
growth rate must be far slower than that of the closely related flat
croaker. A few croakers survive that second year and go on to attain a size
of from 4 to 5 pounds on the Texas coast. They are known as golden croakers
*265*.

Adults reside at sea and spawn during the winter and early spring in close
access to their estuarine nursery grounds. The young move directly into
the bays and lagoons, using these shallow, nutrient-rich waters during
postlarval and juvenile development and return to the Gulf during late
summer or fall *265*.

Juveniles are rare and are only found during February *265*.

Life History - 2 (DRAFT) - Management Practices
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

MANAGEMENT PRACTICES

Management Practices - 1 (DRAFT) - References
Species croaker, Atlantic
Species Id TSNL0010
Date 27 AUG 96

References

265 * Texas System of Natural Laboratories. 1982. Texas System
of Natural Laboratories Ecological Atlas of Texas, Fishes of
Texas Waters Matrix Manuscript. A species profile: Micropogon
undulatus, Atlantic croaker. Texas System of Natural
Laboratories Ecological Atlas of Texas (ed.). TSNL Austin, TX. Additional
references available at the Austin Office.

References - 1