BIOTIC

BIOTIC Species Information for Thyasira gouldi
All Taxonomy Biology Distribution Reproduction

Researched by	Angus Jackson	Data supplied by	MarLIN
Refereed by	This information is not refereed.
General Biology
Growth form	Bivalved	Feeding method	Symbiont contribution Active suspension feeder
Mobility/Movement	Burrower	Environmental position	Infaunal
Typical food types	Suspended organic matter and digestion of mutualistic bacteria.	Habit	Burrow dwelling
Bioturbator		Flexibility	None (< 10 degrees)
Fragility	Intermediate	Size	Very small(<1cm)
Height	Insufficient information	Growth Rate	1 mm/year
Adult dispersal potential	Not researched	Dependency	Mutualist with/on/in
Sociability	Solitary
Toxic/Poisonous?	No
General Biology Additional Information	Thyasira gouldi has been found up to 1,500 individuals per square metre but typically below 500. Such abundances may no longer exist in Scottish waters. It is difficult to define an adult size range as there appears no specific point where juveniles become adult. Values provided are roughly maximum size where size refers to shell length. Large numbers of a mutualistic bacterium live sub-cuticularly in the gills of Thyasira gouldi (and several other thyasirids). The bacteria are chemoautotrophic and oxidise sulphur in order to assimilate carbon dioxide. Carbon isotope ratios indicate that digestion of these bacteria contributes considerably to the nutrition of this species. Although the bacteria utilise sulphur the bivalves inhabit sediment with very little free sulphide. The relationship is not thought to be obligate but the presence of the bacterium is very beneficial to the brachiopod. Eleven percent of a population of Thyasira gouldi in Loch Etive was infected with the parasitic copepod Axinophylus thyasirae Blacknell & Ansell, 1975). This parasite inhabits the mantle cavity and causes lower body weights and indirect castration. The female parasites reach sizes of 4.5 mm and there can be up to five parasites per host causing massive restriction of the cavity and interfering with feeding currents.
Biology References	Blacknell & Ansell, 1975, Southward, 1986, Blacknell & Ansell, 1974, Southward & Southward, 1991, Dando & Southward, 1986, Anonymous, 1999(g),