SPLASH page for Atrina fragilis

General Biology

Adult Atrina fragilis embedded in sea bed.
Image: Sue Scott

	Click here for distribution maps
	Click here for more images

Typical Abundance	Very low density
Male size range	Insufficient information	Male size at maturity	Insufficient information
Female size range	Insufficient information	Female size at maturity	Insufficient information
Growth Form	Bivalved	Growth rate	c. 3-4 cm/year
Body Flexibility	None (less than 10 degree)	Mobility	Burrower Temporary attachment
Characteristic feeding method	Active suspension feeder	Typically feeds on	No text entered
Sociability	Gregarious Solitary	Environmental position	Infaunal

Supports	Host for Commensal Pinnotheres pinnotheres (Pea Crab) and Capulus ungaricus (Hungarian hat shell).
Is the species toxic?	No
Additional information
Anon (1999c) suggested that growth is relatively slow (c. 3 -4 cm/year), based on annular growth rings in specimens from Valentia Bay, Ireland. Bulter et al. (1993) note that the growth of Pinna bicolor is indeterminate, rapid when small and slow after 2 years of age. Shell margin is easily damaged to produce sharp edges. These edges may cut the feet of bathers (Anon 1999c). Fan mussels rapidly repair the shell (Yonge, 1953). Fan mussel communities have been poorly studied in the UK and information is only available from the Mediterranean, South Australia and the USA. Pseudofaeces results in biodeposits that reduce the variability of nematode meiofauna in Atrina zealandica beds (Warwick et al. 1997). Pinna bicolor hosts a species rich epifauna (Kay & Keough, 1981; Ward & Young 1984). In St Joseph Bay, Florida shells of dead Atrina rigida, predated by the horse conch, provide shelter for crabs, fish and octopus and were used as 'nests' by blennies, clingfish and toadfish (Kuhmann 1997)