Hydrobia ulvae. Shell height 5mm. Female; no penis behind tentacles. 3 ribs of grey ctenidium just visible over top edge of body at rear (magnify image to see). From large muddy salting pool on upper Dee Estuary, Flintshire, salinity 29 p.p.t. (variable).
Hydrobia ulvae. Shell height 5mm. Female; no penis behind tentacles. 3 ribs of grey ctenidium just visible over top edge of body at rear (magnify image to see). From large muddy salting pool on upper Dee Estuary, Flintshire, salinity 29 p.p.t. (variable).
Hydrobia ulvae. Shell height 5mm. Female; no penis behind tentacles. 3 ribs of grey ctenidium just visible over top edge of body at rear (magnify image to see). From large muddy salting pool on upper Dee Estuary, Flintshire, salinity 29 p.p.t. (variable).
