(DRAFT) - Taxonomy
Species rockfish, black
Species Id M010171
Date 26 AUG 96
TAXONOMY
NAME - rockfish, black
OTHER COMMON NAMES - black rockfish
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - Chordata,
CLASS AND SUBCLASS - Osteichthyes,
ORDER AND SUBORDER - Scorpaeniformes,
FAMILY AND SUBFAMILY - Scorpaenidae,
GENUS AND SUBGENUS - Sebastes,
SPECIES AND SSP - melanops,
SCIENTIFIC NAME - Sebastes melanops
AUTHORITY - Girard
TAXONOMY REFERENCES - 208
Taxonomy - 1 (DRAFT) - Status
Species rockfish, black
Species Id M010171
Date 26 AUG 96
STATUS
Coded Status
Sport Fish
Commercial
See Comments
REFERENCES FOR STATUS - 208
COMMENTS ON STATUS -
The black rockfish is significant in the California ocean sport fishery and
is also taken in the commercial fishery *208*.
Status - 1 (DRAFT) - Distribution
Species rockfish, black
Species Id M010171
Date 26 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
REFERENCES FOR HABITAT - 208
LAND USE -
Water
Bays and Estuaries
REFERENCES FOR LAND USE - 208
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Estuarine
Marine OW0
Marine OW0
REFERENCES FOR NWI - 208
COMMENTS ON HABITAT ASSOCIATIONS -
Larvae off Oregon are captured in the water column from April to June.
They are pelagic at lengths less than 40-50 mm and benthic at larger sizes.
In the kelp beds of Monterey Bay, California, juveniles live both in the
canopy and on the bottom. They are recruited to the bottom primarily in
June. The June transition from pelagic to benthic habitat is marked by a
distinct inshore movement to estuaries, tidepools, and nearshore depths of
less than 20 m. Small juveniles thus occur in three habitats: pelagic
individuals offshore at <60 mm SL in summer; nearshore on bottom at 40-70
mm SL in June; and in estuaries at 35-92 mm SL from April to October,
often in eelgrass. Off Oregon, the larger fish tend to be in the deeper
(20-50 m) water. Abundance in shallow water declines in winter and
increases in summer *208*.
Black rockfish are primarily in midwater, usually in kelp or around cover
such as pilings and piers, although they are occasionally offshore in open
waters. A significant proportion of (usually smaller) black rockfish are
benthic on rocky bottom *208*.
ANIMAL/PLANT SPECIES ASSOCIATIONS -
PARASITES
leeches
a myxosporidean in the heart
5 copepods
6 diageneans
2 hirudinoids
2 monogeaneans
1 protozoan
REFERENCES FOR SPECIES ASSOCIATIONS - 208
COMMENTS ON SPECIES ASSOCIATIONS -
PARASITES
Parasites include leeches on fins and body in Oregon, and a myxosporidean in
the heart in central California. In all, 5 copepods, 6 diageneans, 2
hirudinoids, 2 monogeaneans, and 1 protozoan have been reported *208*.
Black rockfish are known to be eaten by lingcod and yelloweye rockfish
*208*.
Habitat Associations - 1 (DRAFT) - Food Habits
Species rockfish, black
Species Id M010171
Date 26 AUG 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
REFERENCES FOR TROPHIC LEVEL - 208
LIFESTAGE FOOD FOOD PART
General Nekton Not Specified
General Crustaceans Larva stage
General Crustaceans Not Specified
General Zooplankton Not Specified
General Clupeiformes Not Specified
General Salmoniformes Not Specified
Juvenile Crustaceans Larva stage
Juvenile Copepods Not Specified
Adult Crustaceans Not Specified
REFERENCES FOR GENERAL FOOD - 208
REFERENCES FOR ADULT FOOD - 208
REFERENCES FOR JUVENILE FOOD - 208
COMMENTS ON FOOD -
Food off Oregon is primarily pelagic nekton (smelt, anchovies) and
zooplankton such as salps, mysids, and crab megalops. Black rockfish also
eat kelp clingfish, Rimicola muscarum. Off Oregon in the spring, crab
megalops make up 25% of the diet by weight *208*.
Most feeding is probably during the day and at twilight. The rate of
gastric evacuation of ingested squid and fish (dry weight) is about 6% per
hour and about 76 hours are required for stomach clearance *208*.
COMMENTS ON ADULT FOOD -
Adult prey off central California have been found to eat juvenile rockfish,
euphausiids, and amphipods during upwelling periods, but at other times
primarily invertebrates. The percent of empty stomachs during non-upwelling
periods was found to be nearly double that during upwelling. Food overlap
with co-occcurring congeners decreased during non-upwelling periods,
suggesting that food may then be a limiting factor for rockfish occurring in
kelp forests *208*.
COMMENTS ON JUVENILE FOOD -
Off central California, juveniles ate copepods and zoea *208*.
Food Habits - 1 (DRAFT) - Environment Associations
Species rockfish, black
Species Id M010171
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 Bottom Type [Aquatic]: Specified in Comments
J Water Temperature: Between 15-21 degrees C
J Water Temperature: Below 15 degrees C
J Water Temperature: Specified in Comments
J Aquatic Vegetation [specified type]: Specified in comments
J Water Depth Preference: Specified in Comments
A Currents: upwelling
A Currents: specified in comments
A Water Depth Preference: Specified in Comments
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 208
REFERENCES FOR RESTING ADULT ENVIRONMENTAL ASSOC_ - 208
REFERENCES FOR RESTING JUVENILE ENVIRONMENTAL ASSOC_ - 208
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
Small black rockfish tend to be epibenthic, and the larger ones occur well
up in the water column, usually near or in such shelter as kelp or pilings,
though they may live in deeper waters in winter. Black rockfish off Oregon
and off California were relatively much more abundant on shallow reefs than
on deeper ones *208*.
Black rockfish are primarily in midwater, usually in kelp or around cover
such as pilings and piers, although they are occasionally offshore in open
waters. A significant proportion of (usually smaller) black rockfish are
benthic on rocky bottom *208*.
COMMENTS ON RESTING ADULT ENVIRONMENTAL ASSOC_ -
Adults occur from the surface to at least 366 m, but are most abundant in
water less than 54 m deep. In Carmel Bay, California, fish usually live at
depths of12 m or less, but may be abundant as deep as 17 m during
upwelling. The fish tend to be close to the bottom during non-upwelling
periods. Off Oregon, the larger fish tend to be in the deeper (20-50 m)
water. Abundance in shallow water declines in winter and increases in
summer *208*.
Black rockfish are more closely associated with the bottom during
non-upwelling seasons suggesting that the warmer surface waters may not
then be suitable for adults; however, this behavior could also be a result
of decreased food in the water column *208*.
Environment Associations - 1 (DRAFT) - Environment Associations
Species rockfish, black
Species Id M010171
Date 26 AUG 96
Small black rockfish tend to be epibenthic, and the larger ones occur well
up in the water column, usually near or in such shelter as kelp or pilings,
though they may live in deeper waters in winter. Black rockfish off Oregon
and off California were relatively much more abundant on shallow reefs than
on deeper ones *208*.
COMMENTS ON RESTING JUVENILE ENVIRONMENTAL ASSOC_ -
Juveniles occur at water temperatures of 8 to 18 degrees C. The June
transition from pelagic to benthic habitat is marked by a distinct inshore
movement to estuaries, tidepools, and nearshore depths of less than 20 m.
Small juveniles thus occur in three habitats: pelagic individuals offshore
at ,60 mm SL in summer; nearshore on bottom at 40-70 mm SL in June; and
in estuaries at 35-92 mm SL from April to October, often in eelgrass *208*.
Small black rockfish tend to be epibenthic, and the larger ones occur well
up in the water column, usually near or in such shelter as kelp or pilings,
though they may live in deeper waters in winter. Black rockfish off Oregon
and off California were relatively much more abundant on shallow reefs than
on deeper ones *208*.
Environment Associations - 2 (DRAFT) - Life History
Species rockfish, black
Species Id M010171
Date 26 AUG 96
LIFE HISTORY
MORPHOLOGY/IDENTIFICATION
Rockfishes off California are difficult to identify because about 60 similar
species occur there. The characters given here should be used with caution.
Many, if not all species of Sebastes are venomous. Poison glands are
associated with some or all of the spines of the first dorsal, anal, and
pelvic fins *208*.
The black rockfish is distinguished by its body color of black or blue-black
mottled with gray. First dorsal fin with black spots. Occasionally has a
"dirty white" stripe along the lateral line. The upper jaw extends to or
behind the eye. Dorsal fin XIII, 13-16; anal fin III, 7-9; pectoral fin
18-20; gill raker teeth on first arch 33-39; lateral line pores 46-53 *208*.
SPAWNING
Larger females produce more offspring. All rockfishes have internal
fertilization and bear live young. The young receive substantial nourishment
from the mother, probably by the consumption and assimilation of ovarian
fluid. Spawning probably occurs once a year. Eggs developing in August
have been reported. Parturition occurs from February to April off British
Columbia and probably occurs in January off Oregon. Although there are no
reports from California, parturition probably occurs in January or somewhat
earlier. Spawning areas are unknown. It has been suggested that spawning
may occur in offshore waters *208*.
LARVAL STAGE
Larvae and small juveniles are pelagic for periods of several months to a
year. Off California they are abundant and widely distributed in the
California Current. Black rockfish larvae and their development off Oregon
are well known. At birth, the larvae are about 5.5 mm long. The occurrence
of larvae is highly seasonal; they are captured in the water column from
April to June. They are pelagic at lengths less than 40-50 mm and benthic
at larger sizes *208*.
JUVENILES
In the kelp beds of Monterey Bay, California, juveniles live both in the
canopy and on bottom often associated with kelp holdfasts and sporophylls.
They are recruited to the bottom primarily in June. Different color forms
reflect habitat--orange when associated with kelp, darker when in the water
column. Off Oregon, age 0 juveniles occur seasonally from June to October.
The June transition from pelagic to benthic habitat is marked by a distinct
inshore movement to estuaries, tidepolls, and nearshore depths of less than
20m. Small juveniles thus occur in three habitats: pelagic individuals
offshore at <60 mm SL in summer; nearshore on bottom at 40-70 mm SL in
June; and in estuaries at 35-92 mm SL from April to October, often in
eelgrass. Larger juveniles up to 15 cm long (ages I or II) may live in
rocky holes, but use of these is directly reduced by competition with
obligate benthic species *208*.
ADULTS
Adults occur from the surface to at least 366 m, but are most abundant in
water less than 54m deep. Black rockfish tend to form shcools of mixed sex
in midwater, especially in shallow water. The fish tend to be closer to the
Life History - 1 (DRAFT) - Life History
Species rockfish, black
Species Id M010171
Date 26 AUG 96
bottom during non-upwelling periods. In kelp beds, larger adults seemingly
migrate outside the kelp diurnally, returning before dusk; juveniles and
small adults remain in the kelp and also tend to be closer to bottom at
night. Adults usually remain in one area, but may travel more than 600 km.
Off Oregon, the larger fish tend to be in the deeper water (20-50m).
Abundance in shallow water declines in winter and increases in summer *208*.
MATURITY AND LIFE SPAN
Off central California, fish reach at least 21 years of age. Males may be
sexually mature at 3 years of age (250 mm); all are mature by 10 years (430
mm). Females may mature at 5 years (300 mm); all are mature by 11 years
(480 mm). Off Oregon, sexual maturity occurs at 5 years in males and 6
years in females. The Oregon Department of Fish and Wildlife considers 50%
of fish 400 MM fork length (FL) to be sexually mature *208*.
GROWTH CHARACTERISTICS
Maximum length is 60 cm. Growth rates are directly related to temperature,
if food is abundant. Juveniles may select higher temperatures, which
maximizes growth. Winter-caught fish have been reported to be distinctly
smaller than those captured in summer and fall *208*.
PREDATION AND COMPETITION
Black rockfish are known to be eaten by lingcod and yelloweye rockfish
Sebastes ruberrimus *208*.
Competitive relations are poorly known. Benthic black rockfish compete with
other species for hiding places; the abundance of juvenile black rockfish
on small reefs decreases as that of several other species increases *208*.
PARASITES
Parasites include leeches on fins and body in Oregon, and a myxosporidean in
the heart in central California. In all, 5 copepods, 6 diageneans, 2
hirudinoids, 2 monogeaneans, and 1 protozoan have been reported *208*.
LIFE HISTORY CODES -
Foraging Sites: Standing water: Profundal zone
Breeding/Spawning Season: January
Breeding/Spawning Season: February
Breeding/Spawning Season: March
Breeding Spawning Season: April
Number of Broods/Litters (Reproductive Efforts) Per Ye
Dispersion: Clumped
Periodicity: Other (specify in comments)
REFERENCES FOR LIFE HISTORY- 208
Life History - 2 (DRAFT) - Management Practices
Species rockfish, black
Species Id M010171
Date 26 AUG 96
MANAGEMENT PRACTICES
COMMENTS ON MANAGEMENT PRACTICES -
Rockfish are caught commercially with trawls, gill nets and with
hook-and-line *208*.
Management Practices - 1 (DRAFT) - References
Species rockfish, black
Species Id M010171
Date 26 AUG 96
References
208 * Stein, David, Thomas Hassler. 1989. Species Profiles: Life
Histories and Environmental Requirements of Coastal Fishes and
Invertebrates (Pacific Southwest)--Brown Rockfish, Copper
Rockfish, and Black Rockfish. Fish and Wildlife Service Species
Profiles 82(11.113) (ed.):15.
References - 1