BIOTIC

BIOTIC Species Information for Macoma balthica

Researched by

Lizzie Tyler

Data supplied by

University of Sheffield

Refereed by

This information is not refereed.

Taxonomy

Scientific name

Macoma balthica

Common name

Baltic tellin

MCS Code

W2029

Recent Synonyms

None

Phylum

Mollusca

Subphylum

Superclass

Class

Pelecypoda

Subclass

Order

Veneroida

Suborder

Family

Tellinidae

Genus

Macoma

Species

balthica

Subspecies

Additional Information

Taxonomy References

Hayward et al., 1996, Hayward & Ryland, 1995b, Fish & Fish, 1996,

General Biology

Growth form

Bivalved

Feeding method

Passive suspension feeder
Active suspension feeder
Surface deposit feeder
Sub-surface deposit feeder

Mobility/Movement

Crawler
Burrower

Environmental position

Infaunal

Typical food types

Diatoms, deposited plankton, suspended phytoplankton & detritus.

Habit

Burrow dwelling

Bioturbator

Flexibility

None (< 10 degrees)

Fragility

Intermediate

Size

Small(1-2cm)

Height

Insufficient information

Growth Rate

3 mm/year

Adult dispersal potential

100-1000m

Dependency

Independent

Sociability

Solitary

Toxic/Poisonous?

General Biology Additional Information

Abundance
Stephen (1929) reported typical abundances of Macoma balthica from the Firth of Forth to be 0-89/m² and maximum abundance to be 288/m². Ratcliffe et al. (1981) reported adult densities in the Humber Estuary, UK, between 5,000/m² and 40,000/m² depending on time since a successful spatfall. Bonsdorff et al. (1995) reported juvenile density in the Baltic Sea following settlement to be 300,000/m² decreasing to a stable adult density of 1,000/m².
Size at maturity
Caddy (1967) reported Macoma balthica from the River Thames reaching maturity in their 2nd year at a size of 5-6mm, whereas in the Netherlands, first year animals larger than 4mm had developed gonads during the spawning season (Lammens, 1967). Lavoie (1970) (cited in Gilbert, 1978) reported that a population of Macoma balthica from a French estuary did not achieve sexual maturity until their second year at a mean length of 3.57mm. Given that the growth rate varies significantly between populations, Gilbert (1978) suggested that Macoma balthica may mature in its 2nd year of life regardless of size or during its first year if a certain size is achieved. Harvey & Vincent (1989), however, consider that sexual maturity is a function of size rather than age in Macoma balthica, maturation occurring when the shell reaches 6mm with corresponding ages of individuals from the same population varying between 10 and 22 months.
Growth rate
Gilbert (1973) reported mean annual growth rate of Macoma balthica to be 3.3mm/yr with an average length of 18-20mm for fully grown individuals. However, other studies show considerable variations in growth patterns in relation to habitat and depth. McLusky & Allan (1976) reported the maximum growth rate of Macoma balthica in the laboratory to be 1mm over an 8 month period for 5-7mm long animals maintained at 15°C and 25psu.
Toxicity
Macoma balthica is not normally considered to be toxic but may transfer toxicants through the food chain to predators. Macoma balthica was implicated in the Mersey bird kill in the late 1970's, owing to bioconcentration of alklyC-lead residues (Bull et al., 1983).

Biology References

Fish & Fish, 1996, Bonsdorff, 1984, Harvey & Vincent, 1989, McLusky & Allan, 1976, Brafield & Newell, 1961, Clay, 1967(b), Stephen, 1929, Gilbert, 1973, Gilbert, 1978, Caddy, 1967, Lammens, 1967, Ratcliffe et al., 1981, Bonsdorff et al., 1995, Tebble, 1976, Bull et al., 1983, Hayward & Ryland, 1990, Julie Bremner, unpub data,

Distribution and Habitat

Distribution in Britain & Ireland

Common in estuarine environments around the British Isles, with the exception of the south coast.

Global distribution

Macoma balthica has an extensive geographic range that reaches from temperate to arctic coastal waters in both the North Atlantic and North Pacific oceans.

Biogeographic range

Not researched

Depth range

Migratory

Non-migratory / Resident

Distribution Additional Information

Studies have indicated that eastern and western North Atlantic populations of Macoma balthica are morphologically and genetically different from one another, and that they may have diverged as sibling species (Meehan & Carlton, 1988).
Depth preferences
Macoma balthica occurs in a wide depth range between the mid shore and 190m but is most abundant at moderate depths on muddy and sandy bottoms (Olafsson, 1986). However, in British waters Macoma balthica is mainly an intertidal species.
Local distribution
Macoma balthica is a resident species but because of near-surface habitat preference, populations may be subject to tidal re-location and scouring. Also observations of propulsion stimulus to scallops may assist in local relocation (Langston, W.J., pers. comm.)

Substratum preferences

Mud
Muddy sand
Sandy mud

Physiographic preferences

Ria / Voe
Estuary
Enclosed coast / Embayment

Biological zone

Upper Eulittoral
Mid Eulittoral
Lower Eulittoral

Wave exposure

Sheltered
Very Sheltered
Extremely Sheltered

Tidal stream strength/Water flow

Moderately Strong (1-3 kn)
Weak (<1 kn)

Salinity

Variable (18-40 psu)
Reduced (18-30 psu)
Low (<18 psu)

Habitat Preferences Additional Information

Distribution References

Hayward et al., 1996, Hayward & Ryland, 1995b, Fish & Fish, 1996, Clay, 1967(b), Meehan & Carlton, 1988, Olafsson, 1986, Ratcliffe et al., 1981, Bonsdorff et al., 1995, Tebble, 1976, Picton & Costello, 1998, JNCC, 1999, Bruce et al., 1963, Hayward & Ryland, 1990, Julie Bremner, unpub data,

Reproduction/Life History

Reproductive type

Gonochoristic

Developmental mechanism

Planktotrophic

Reproductive Season

Spring and autumn

Reproductive Location

Insufficient information

Reproductive frequency

Annual episodic

Regeneration potential

Life span

6-10 years

Age at reproductive maturity

Generation time

1-2 years

Fecundity

30000

Egg/propagule size

Fertilization type

Insufficient information

Larvae/Juveniles
Larval/Juvenile dispersal potential	>10km	Larval settlement period	Insufficient information
Duration of larval stage	1-6 months

Reproduction Preferences Additional Information

Life span
Gilbert (1973) reviewed longevity records of Macoma balthica. Life span is typically 5-10 years but may be as long as 30 years in populations from deep, cold water. The data presented suggest that maximum size and growth rate decrease and longevity increases with increasing latitude and associated cooler temperatures.
Age at maturity
Caddy (1967) reported Macoma balthica from the River Thames reaching maturity in their 2nd year at a size of 5-6mm, whereas in the Netherlands, first year animals larger than 4mm had developed gonads during the spawning season (Lammens, 1967). Lavoie (1970) (cited in Gilbert, 1978) reported that a population of Macoma balthica from a French estuary did not achieve sexual maturity until their second year at a mean length of 3.57mm. Given that the growth rate varies significantly between populations, Gilbert (1978) suggested that Macoma balthica may mature in its 2nd year of life regardless of size or during its first year if a certain size is achieved. Harvey & Vincent (1989), however, consider that sexual maturity is a function of size rather than age in Macoma balthica, maturation occurring when the shell reaches 6mm with corresponding ages of individuals from the same population varying between 10 and 22 months.
Gametogenesis and spawning
Caddy (1967) studied gametogenesis and spawning in a population of Macoma balthica from the Thames Estuary, UK. The primary gonad passed through a male phase, maturation being achieved in the 2nd year of life. Gametogenesis was associated with a system of follicle cells which broke down as the gametes approached maturity. The arrangement of the follicle cells was characteristic of the sex. In the female, gametocytes were peripheral to the follicle cells, while in the male they were interstitial. Spermatogenesis proceeded most rapidly in the centre of the follicle, resulting in a gradient of spermatogenic stages of increasing maturity from the periphery to the centre.
Spawning occurred principally in the spring and to a lesser extent in the autumn. Several spawnings were identified within a season, but repeated cycles of gametogenesis were absent. Ejection of eggs occurred from the exhalant siphon and continued for 40 minutes with brief spawning bursts at 3 minute intervals. Eggs were expelled at considerable speed to a height in the water column of approximately 8cm and settled out of suspension slowly. Females of approximately 17mm shell length were estimated to have expelled between 10,000 and 50,000 eggs.

Reproduction References

Fish & Fish, 1996, Harvey & Vincent, 1989, Gilbert, 1973, Gilbert, 1978, Caddy, 1967, Lammens, 1967, Ratcliffe et al., 1981, Bonsdorff et al., 1995, Eckert, 2003, Julie Bremner, unpub data,