(DRAFT) - Taxonomy
Species halibut, California
Species Id M010014
Date 27 AUG 96
TAXONOMY
NAME - halibut, California
OTHER COMMON NAMES - California halibut
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - Chordata,
CLASS AND SUBCLASS - Osteichthyes,
ORDER AND SUBORDER - Pleuronectiformes,
FAMILY AND SUBFAMILY - Bothidae,
GENUS AND SUBGENUS - Paralichthys,
SPECIES AND SSP - californicus,
SCIENTIFIC NAME - Paralichthys californicus
AUTHORITY - Ayres
TAXONOMY REFERENCES - 68
Taxonomy - 1 (DRAFT) - Status
Species halibut, California
Species Id M010014
Date 27 AUG 96
STATUS
Coded Status
Sport Fish
Depleted
Commercial
See Comments
REFERENCES FOR STATUS - 68
COMMENTS ON STATUS -
The California halibut supports a small but valuable sport and commercial
fishery in California *68*.
Status - 1 (DRAFT) - Distribution
Species halibut, California
Species Id M010014
Date 27 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
REFERENCES FOR HABITAT - 68
LAND USE -
Water
Bays and Estuaries
REFERENCES FOR LAND USE - 68
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Estuarine
Estuarine
Marine OW0
Marine FL2
REFERENCES FOR NWI - 68
COMMENTS ON HABITAT ASSOCIATIONS -
The eggs are demersal. The larval and postlarval stages of the California
halibut are pelagic for several months before the postlarvae settle to the
bottom. In southern California, the planktonic larval stages, about 10 mm
standard length (SL), are pelagic and live in water 12 to 45 m deep and 1.9
to 5.4 km out from shore. Larger and older larvae live closer to shore, and
most are suspected to live in embayments *68*.
Juveniles begin to settle and assume bottom dwelling habits in June *68*.
Adults occur over sandy bottoms from the surf zone to 100 m *68*.
Habitat Associations - 1 (DRAFT) - Food Habits
Species halibut, California
Species Id M010014
Date 27 AUG 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
REFERENCES FOR TROPHIC LEVEL - 68
LIFESTAGE FOOD FOOD PART
General Molluscs Not Specified
General Crustaceans Not Specified
General Fish Not Specified
General Osteichthyes Not Specified
General Clupeiformes Not Specified
General See Comments; Food Not Applicable
Adult Crustaceans Not Specified
Adult Fish Not Specified
Adult Osteichthyes Not Specified
Adult See Comments; Food Not Applicable
Juvenile Plankton Not Specified
Juvenile Crustaceans Not Specified
Juvenile Copepods Not Specified
Juvenile See Comments; Food Not Applicable
Larva Plankton Not Specified
Larva See Comments; Food Not Specified
REFERENCES FOR GENERAL FOOD - 68
REFERENCES FOR ADULT FOOD - 68
REFERENCES FOR JUVENILE FOOD - 68
REFERENCES FOR LARVAE FOOD - 68
COMMENTS ON FOOD -
Halibut 230 mm TL long or longer feed heavily on fish, and to a lesser
extent, on shrimp *68*.
Juvenile and adult California halibut are especially adapted for catching
and digesting fish because they are equipped with long heavily toothed gill
rakers that aid in holding and swallowing, an intestine with a simple loop,
and a brain with large optic lobes. This raptorial predator has sharp
canine-like teeth and a large mouth *68*.
In one study the stomachs of halibut 12 to 510 mm long contained 65% fish,
34% crustaceans, and 1% mollusks, though the diet of these fish changed as
the fish grew. For example, halibut less than 55 mm long ate mostly small
fish (gobies) and small crustaceans such as amphipods, copepods and mysids.
Fish from 55 to 230 m ate larger prey. The northern anchovy, Engraulis
mordax, is probably the most important prey of the California halibut *68*.
COMMENTS ON ADULT FOOD -
As California halibut grow to adulthood they become piscivorous *68*.
Halibut 230 mm TL long or longer feed heavily on fish, and to a lesser
extent, on shrimp *68*.
Food Habits - 1 (DRAFT) - Food Habits
Species halibut, California
Species Id M010014
Date 27 AUG 96
COMMENTS ON JUVENILE FOOD -
Young juveniles are planktivorous. In one study, fish less than 55 mm long
ate mostly small fish (gobies) and small crustaceans such as amphipods,
copepods and mysids. Fish 55 to 230 m ate larger crustaceans and fishes
*68*.
COMMENTS ON LARVAE FOOD -
The larvae and young juveniles of the California halibut are planktivorous
*68*.
Food Habits - 2 (DRAFT) - Environment Associations
Species halibut, California
Species Id M010014
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 Aquatic Habitat Zonation: Open water [pelagic zone]
G Aquatic Habitat Zonation: Specified in Comments
G Water Depth Preference: Specified in Comments
A Water Temperature: Between 21-27 degrees C
A Water Temperature: Between 15-21 degrees C
A Water Temperature: Specified in Comments
A Substrate: Sand
A Substrate: Specified in Comments
A Bottom Type [Aquatic]: Sand
A Bottom Type [Aquatic]: Specified in Comments
A Water Depth Preference: 100-200 ft.
A Water Depth Preference: 200-500 ft.
A Water Depth Preference: Specified in Comments
BA Water Depth Preference: 10-25 ft.
BA Water Depth Preference: 25-50 ft.
BA Water Depth Preference: 50-100 ft.
BA Water Depth Preference: Specified in Comments
J Water Temperature: Specified in Comments
J Water Depth Preference: Specified in Comments
L Water Temperature: Specified in Comments
L Water Depth Preference: 25-50 ft.
L Water Depth Preference: 50-100 ft.
L Water Depth Preference: 100-200 ft.
L Water Depth Preference: Specified in Comments
L Estuarine habitat zone: bay
L Estuarine habitat zone: specified in comments
LIM Estuarine habitat zone: bay
LIM Estuarine habitat zone: specified in comments
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 68
REFERENCES FOR LIMITING ENVIRONMENTAL ASSOC_ - 68
REFERENCES FOR ADULT ENVIRONMENTAL ASSOC_ - 68
REFERENCES FOR BREEDING ADULT ENVIRONMENTAL ASSOC_ - 68
REFERENCES FOR JUVENILE ENVIRONMENTAL ASSOC_ - 68
Environment Associations - 1 (DRAFT) - Environment Associations
Species halibut, California
Species Id M010014
Date 27 AUG 96
REFERENCES FOR LARVAE ENVIRONMENTAL ASSOC_ - 68
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
In spring, halibut emigrate from relatively deep offshore waters to shallow
coastal waters to spawn at depths of 5 to 18 m. California halibut spawn
from February through July, peaking in May. The eggs are demersal. After
spawning the adults return to water about 40 to 100 m deep *68*.
The planktonic larval stages are pelagic and live in water 12 to 45 m deep
and 1.9 to 5.4 km out from shore. Larger and older larvae live close to
shore, and most are suspected to live in embayments *68*.
Juveniles remain in shallow water, then begin to emigrate to deeper water
when they are about 200 mm total length (TL) *68*.
COMMENTS ON LIMITING ENVIRONMENTAL ASSOC_ -
Shallow bays and estuaries may be critical habitat for the survival and
growth of larvae and young juveniles, and the shallow waters of the open
coast almost surely serve as nursery grounds for California halibut.
Consequently, major alterations of bays and estuaries along the coast of
California could be harmful to halibut habitat and reduce the abundance of
halibut *68*.
COMMENTS ON ADULT ENVIRONMENTAL ASSOC_ -
After spawning the adults return to water about 40 to 100 m deep *68*.
Laboratory behavioral studies have indicated that California halibut in age
group II and older tend to be stenothermal.
Adults prefer deeper water. The California halibut inhabits offshore
waters as deep as 100 m, but most are caught commercially on the bottom at
water depths of 6 to 40 m *68*.
Adult California halibut occur over sandy bottoms from the surf zone to 100
m *68*.
COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ -
In spring, halibut emigrate from relatively deep offshore waters to shallow
coastal waters to spawn at depths of 5 to 18 m.
COMMENTS ON JUVENILE ENVIRONMENTAL ASSOC_ -
Laboratory behavioral studies have indicated that California halibut in age
groups 0 and I are eurythermal *68*.
Those in age group II and older tend to be stenothermal *68*.
Age I+ fish and II+ and older fish segregate by depth, with older juveniles
and young adults occurring deeper than younger juveniles *68*.
Young juveniles remain in shallow water and do not move extensively.
Juvenile halibut begin to emigrate to deeper water when they are about 200
mm total length (TL) *68*.
COMMENTS ON LARVAE ENVIRONMENTAL ASSOC_ -
Laboratory behavioral studies have indicated that California halibut in age
groups 0 and I are eurythermal *68*.
The larval and postlarval stages are pelagic for several months before the
postlarvae settle to the bottom. In southern California, the planktonic
larval stages are pelagic and live in water 12 to 45 m deep and 1.9 to 5.4
km out from shore. Larger and older larvae live closer to shore, and most
are suspected to live in embayments *68*.
Environment Associations - 2 (DRAFT) - Life History
Species halibut, California
Species Id M010014
Date 27 AUG 96
LIFE HISTORY
MORPHOLOGY/IDENTIFICATION AIDS
Fin rays - dorsal 66-76, anal 49-59, pectoral 10-13; lateral line scales
about 100; gill rakers 7-11 + 18-23; vertebrae 34-36; eyes sinistral or
dextral. Body elliptical, slender; head small; mouth large, maxillary
extending to or beyond rear edge of lower eye; teeth strong and sharp on
both sides of head; eyes small; interorbital space wide, flat; lateral
line with high arch over pectoral fin; scales small, smooth; caudal fin
indented *68*.
Color in life: eyed side grayish or greenish-brown, sometimes mottled with
lighter and darker shades; small white spots; and blind side white to
cream. Young fish with bluish-white to cream. Young fish with
bluish-white spots; partial pigmentation has been reported on the eyed side
*68*.
SPAWNING
The major spawning areas for the California halibut are unknown. In spring,
halibut emigrate from relatively deep offshore waters to shallow coastal
waters to spawn at depths of 5 to 18 m. California halibut spawn from
February through July, peaking in May. The eggs are demersal. After
spawning the adults return to water about 40 to 100 m deep *68*.
LARVAL STAGE
The larval and postlarval stages of the California halibut are pelagic for
several months before the postlarvae settle to the bottom. In southern
California, the planktonic larval stages, about 10 mm standard length (SL),
are pelagic and live in water 12 to 45 m deep and 1.9 to 5.4 km out from
shore. Larger and older larvae live closer to shore, and most are suspected
to live in embayments *68*.
JUVENILES
Juveniles begin to settle and assume bottom dwelling habits in June. They
remain in shallow water and do not move extensively. Juvenile halibut begin
to emigrate to deeper water when they are about 200 mm total length TL)
*68*.
MATURITY AND LIFE SPAN
Most halibut females are sexually mature at 430 mm TL or at the end of their
third year of life. Most males mature when about 230 mm TL long or at the
end of their second year of life *68*.
Halibut are generally long-lived. Both males and females may live as long
as 30 years, though generally the males do not grow as large or live as long
as the females. Halibut are about 1,080 mm TL long when they are 12 years
old *68*.
FEEDING HABITS
The larvae and young juveniles of the California halibut are planktivorous,
but as they grow to adulthood they become piscivorous *68*.
Halibut 230 mm TL long or longer feed heavily on fish (primarily during
daylight) and, to a lesser extent, on shrimp *68*.
Juvenile and adult California halibut are especially adapted for catching
and digesting fish because they are equipped with long heavily toothed gill
Life History - 1 (DRAFT) - Life History
Species halibut, California
Species Id M010014
Date 27 AUG 96
rakers that aid in holding and swallowing, an intestine with a simple loop,
and a brain with large optic lobes. This raptorial predator has sharp
canine-like teeth and a large mouth *68*.
LIFE HISTORY CODES -
Breeding/Spawning Season: February
Breeding/Spawning Season: March
Breeding Spawning Season: April
Breeding/Spawning Season: May
Breeding/Spawning Season: June
Breeding/Spawning Season: July
Periodicity: Active in day
REFERENCES FOR LIFE HISTORY- 68
Life History - 2 (DRAFT) - Management Practices
Species halibut, California
Species Id M010014
Date 27 AUG 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial
Beneficial Other management practices [specified in comments]
Adverse Shoreline modification/development
Adverse Other management practices [specified in comments]
REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 68
REFERENCES FOR ADVERSE MANAGEMENT PRACTICES - 68
COMMENTS ON MANAGEMENT PRACTICES -
The California halibut supports a small but valuable sport and commercial
fishery. A sharp reduction in California halibut landings from California
in the late 1920's and declinging landings in recent years have prompted
scientists to determine the cause. To date little is known about its
biology and life history *68*.
Shallow bays and estuaries may be critical habitat for the survival and
growth of larvae and young juveniles, and the shallow waters of the open
coast almost surely serve as nursery grounds for California halibut.
Consequently, major alterations of bays and estuaries along the coast of
California could be harmful to halibut habitat and reduce the abundance of
halibut *68*.
Management Practices - 1 (DRAFT) - References
Species halibut, California
Species Id M010014
Date 27 AUG 96
References
68 * Kucas, S.T., T.J. Hassler. 1986. Species Profiles: Life
Histories and Environmental Requirements of Coastal Fishes and
Invertebrates (Pacific Southwest) -- California Halibut. U.S.
Fish and Wildlife Service Biol. Rep. 82(11.44) pp 8.
References - 1