(DRAFT) - Taxonomy
Species bloodworm
Species Id M090001
Date 26 AUG 96
TAXONOMY
NAME - bloodworm
OTHER COMMON NAMES - beak thrower
ELEMENT CODE -
CATEGORY - Other Aquatic Invertebrate Taxa
PHYLUM AND SUBPHYLUM - Annelida,
CLASS AND SUBCLASS - Polychaeta,
ORDER AND SUBORDER - ,
FAMILY AND SUBFAMILY - Glyceridae,
GENUS AND SUBGENUS - Glycera,
SPECIES AND SSP - dibranchiata,
SCIENTIFIC NAME - Glycera dibranchiata
AUTHORITY -
TAXONOMY REFERENCES - 168
COMMENTS ON TAXONOMY -
Large bulbous proboscis, armed at the end with 4 small black fangs,
can be completely withdrawn and as quickly extended, providing an alternate
name, Beak Thrower.*177*
Taxonomy - 1 (DRAFT) - Status
Species bloodworm
Species Id M090001
Date 26 AUG 96
STATUS
Coded Status
Commercial
Commercial/bait
REFERENCES FOR STATUS - 168
COMMENTS ON STATUS -
Harvesting may have a significant effect on the abundance of worms.
However, no data are available on fishing mortality of bloodworms.
Shippers, diggers, and sportfishermen have noted a decline in the size and
abundance of worms in recent years. Many worms that are missed in the
process of digging may be damaged or left exposed to temperature extremes
and predation. Other factors that may potentially reduce worm abundance are
shoreline construction, dredging, toxic discharges or spills. Information
on the effects of these factors is lacking.*168*
Status - 1 (DRAFT) - Distribution
Species bloodworm
Species Id M090001
Date 26 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Marine, subtidal UB3
Habitat Associations - 1 (DRAFT) - Food Habits
Species bloodworm
Species Id M090001
Date 26 AUG 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
REFERENCES FOR TROPHIC LEVEL - 177
LIFESTAGE FOOD FOOD PART
Adult Detritus
Adult Polychaetes
Adult Crustaceans
REFERENCES FOR ADULT FOOD - 168
COMMENTS ON ADULT FOOD -
Adult bloodworms feed primarily on detritus and are especially abundant in
areas rich in detritus. Other food items include polychaetes (including
other bloodworms) and small crustaceans.
Food Habits - 1 (DRAFT) - Environment Associations
Species bloodworm
Species Id M090001
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
L
L Water Temperature: Between 15-21 degrees C
G
G Dissolved Oxygen: Specified in Comments
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 177 and 5
REFERENCES FOR FEEDING LARVAE ENVIRONMENTAL ASSOC_ - 168
REFERENCES FOR RESTING LARVAE ENVIRONMENTAL ASSOC_ - 5
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
The bloodwork can tolerate low-oxygen conditions and minimum salinity of 5
ppt or less.*177*
COMMENTS ON RESTING LARVAE ENVIRONMENTAL ASSOC_ -
Larvae are known to require temperatures under 20 degrees C for extended
periods immediately after fertilization, and optimal salinity for the
larvae was found to be 22 to 26 ppt.
Sediment type and/or detritus content may also have some effect on the
population of bloodworms. Evidence of sediment or detrital requirements is
incomplete.*168*
Environment Associations - 1 (DRAFT) - Life History
Species bloodworm
Species Id M090001
Date 26 AUG 96
LIFE HISTORY
The bloodwornm is a polychaete that burrows in unconsolidated sediments
largely in the intertidal zone. From within the burrow the worm feeds on
detritus and small invertebrates. It generally migrates only locally within
the substrate but at certain times of the year bloodworms have been found in
the water column. This polychaete may reach a length of 16 inches (400 mm)
and have up to 300 segments. The bloodworm is one of the two species that
form the basis of the commercial marine bait worm industry centered in
coastal Maine.
Reproduction:
Like most polychaetes, this species has two sexes. Sexual maturity is
reached probably in the 3rd year, and the rate of maturation appears to be
dependent upon both temperature and the physiological condition of the
organism.
The bloodworm spawns primarily in June in Maine; however, rare occurrences
of winter spawning have also been observed. The formation of eggs and sperm
begins in the fall and by March the females are swollen with eggs. The
number of eggs per individual varies from about 3 million to almost 10
million depending on the size of the individual. The species undergoes
limited epitoky prior to spawning, a phenomenon typical of certain
polychaetes, in which the worm's body becomes structurally modified. The
body wall becomes thin and fragile and the skin changes pigmentation. Males
and females may be distinguished just prior to spawning by color
differences. Males are light cream in color and females are brown.
Spawning bloodworms leave their burrows and swim to the surface in swarms to
release their gametes. What controls the timing of swarming is not known,
though temperature at the place of spawning, tidal amplitude, and hormonal
factors may affect it. A minimum temperature of 13 degrees C for spawning
in Maine was reported. It is not known if the presence of both
sexes is required for the release of gametes during swarming. Gametes
are emitted as a result of the muscular contraction in swimming. After
gametes have been shed the adult is spent, and its body collapses and sinks
to the bottom. Although it was concluded that all bloodworms die
after spawning, it is believed that some spawners may survive.
The fertilized eggs apparently settle to the bottom, develop to the larval
stage, and become pelagic for a short time. It was found that
during intense periods of spawning activity numerous bloodworm larvae were
present in the plankton. These and later larval stages were observed in the
plankton for only a short period after spawning. The apparent disappearance
of larvae from the plankton is unexplained, but they may leave the water
column and live on the surface of the bottom. No information is available
about the length of the larval stage.*168*
REFERENCES FOR LIFE HISTORY- 168
Life History - 1 (DRAFT) - Management Practices
Species bloodworm
Species Id M090001
Date 26 AUG 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Existing Regulating harvest of species being described
Beneficial Restricting/regulating human use of habitats
REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 168
REFERENCES FOR EXISTING MANAGEMENT PRACTICES - 168
COMMENTS ON MANAGEMENT PRACTICES -
A license is required for taking more than 125 worms/day. The method of
harvest is limited to hand-powered devices, and recently a ban has been
placed on digging on Sunday.
No management plan has been adopted for these marine resources, although the
industry has taken exceptional initiative in supporting research and
exploration of managment alternatives. Aquaculture was attempted in the
early 1970s with little success.*168*
Management Practices - 1 (DRAFT) - References
Species bloodworm
Species Id M090001
Date 26 AUG 96
References
*168* Fefer, Stewart, Patricia Schettig. 1980. An Ecological
Characterization of Coastal Maine. 1-3. Department of the
Interior.
*5* Wilson, H., Ruff, E. 1988. Species Profiles: Life Histories and
Environmental Requirments of Coastal Fishes and Invertebrates
(North Atlantic) - Sandworm and Bloodworm. U.S. Fish and
Wildlife Service Biol. Rep. 82(11.80) pp 23.
*177* Gosner, K.L. 1978. A Field Guide to the Atlantic Seashore:
Invertebrates and Seaweeds of the Atlantic Coast from the Bay of
Fundy to Cape Hatteras. The Peterson Field Guide Series.
Houghton Mifflin Company Boston, MA:329.
References - 1