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01 Littorina saxatilis [R] (Olivi, 1792) sensu stricto, nigrolineate form. Ribadeo, Galicia, N.W. Spain. May 2014. Leg. & © Dr Alexandra Richter.
Because of the dark spiral grooves this form of L. saxatilis s.s. is sometimes mistaken in Iberia, where it is frequent, for L. compressa (e.g. www.asturnatura.com/especie/littorina-compress…
02 Littorina saxatilis s.s. A12. Shell height 11.5 mm. Mature female. N. Yorkshire, September 2014.
1, 2 & 5 seen through translucent mantle.
1: large brood pouch containing brown shelled-embryos.
2: ctenidium (partly covered by brood pouch).
3: mantle edge.
4: head.
5: red-brown edged osphradium, tests quality of water approaching ctenidium (gill).
Specimen A.
No full account yet of this sp…
03 Littorina saxatilis s.s. B90. Shell height 6 mm. Mature male removed from shell. Inland Sea, Anglesey. March 2014.
1: pink prostate and ciliated field visible through translucent mantle.
2: mantle edge.
3: head.
4: filament of penis.
5: mamilliform glands of penis.
6: base of penis.
7: mucronate tip on broad rounded distal end of penis.
Characteristic typical penis of L. saxatilis, diagnostic when present…
04 Littorina saxatilis sensu stricto. Sheltered/brackish ecotype. Height 6 mm. Mature male. Inland Sea, Anglesey. March 2014.
Thin shell with tall spire. On this one the spire eroded, and thin outer calcite layer lost from penultimate whorl exposing black-brown aragonite layer. Rounded unconstricted aperture. No sculpture apart from fine growth lines. Colour of this ecotype is most often uniform-brown, or pale-brown with d…