*Images in development
Key to Nuculidae species
Growth stages clear, widely spaced, found to edge of shelf (to 200m)
Nucula nucleus
Posterior and anterior margins almost straight, sculpture of raised granules, depths from 500 to 2000m
Ennucula granulosa
Posterior and anterior margins rounded, no granulations on surface
Posterior and anterior margins broadly rounded, radial riblets and commarginal lines, crenulate inner margin, 500-4000m,
Nucula atacellana
Anterior broadly rounded, posterior convex lunule margin, postrior tip acutely rounded, commarginal sculpture, 200-4000m
Ennucula corbuloides
Commarginal sculpture only
Radial lines or riblets, giving decussate appearance in older shells
A northern species - Norwegian shelf (200-500m), commarginal sculpture, elongate trigonal outline - anterior margin very long, very tumid shell, swollen umbos
Ennucula corticata
Not restricted to the north, British shelf or abyssal slope (to 4000m), umbos not swollen but can be prominent
Umbos prominent, point up, found to 4000m, pale, straw coloured periostracum, angular posterior margin
Ennucula corbuloides
Umbos can be eroded, point towards posterior, found to 200m, oliver green to brown periostracum, rounded posterior margin
Ennucula tenuis
Periostracum appears matt. Posterior margin curved, lunule protrudes
Periostracum appears glossy, even when dry. Glossy greenish, lunule barely noticeable in profile, flattened.
Nucula nitidosa
Ignoring the lunule, the posterior margin is concave, curving in slightly. Corrugations on lunule, often coated in black manganese deposit
Nucula sulcata
Ignoring lunule postreior margin is straight. No corrugations on lunule, often coated in manganese,
Moderately tumid, matt periostracum, grey green to olive, often coated in Manganese deposit, commarginal bands are common, rarely with rays
Nucula nucleus
Shell compressed, not tumid, smooth silky to matt periostracum, grey green to olive, frequently with orange or reddish rays and sometimes commarginal bands
Nucula hanleyi