Stranded ram's horn shell covered in small goose barnacles. Found on the beach in Port Alfred (Eastern Cape, South Africa), 2024. Shell cylindrical, forming a loose, flat spire, and made up of a series of chambers.Rarely seen, the animal is squid-like, with eight short arms and two long tentacles. About 25 mm. The live animal… Continue reading Ram’s horn shell (Spirula spirula)
Tag: mollusc
Spotted sea hare (Aplysia oculifera)
Spotted sea hare oozing purplish chemical deterrent ink in a rock pool. Eastern Cape, South Africa (2021). A typical smooth-skinned sea hare with prominent tentacles and ear-like rhinophores. Green-brown, speckled with small, white-centred black spots. Up to 150 mm in length. Common in shallow bays and estuaries. Hides by day and emerges at night to… Continue reading Spotted sea hare (Aplysia oculifera)
Southern periwinkle (Afrolittorina knysnaensis)
Gang of Southern periwinkles hiding in a rock crack. Port Alfred, Eastern Cape (2024) - iNaturalist Aperture rounded and closed by a transparent, horny operculum. Shell smooth, with a short conical spire. Colour from flecked brown with a dark ring around each coil to almost pure black. Usually under 10 mm. Congregates in crevices, or… Continue reading Southern periwinkle (Afrolittorina knysnaensis)
Common dogwhelk (Nucella dubia)
Details of the yellow speckled foot of the common dogwhelk. Doringbaai, Western Cape (2020). Extraordinarily variable (hence, dubia). Aperture usually large. Body whorl weakly ridged. Colour variable, from grey with black flames, to red-brown with dotted bands, plain grey or brown. Aperture usually dark, often purple. About 20 mm. Extends almost to the high-tide mark… Continue reading Common dogwhelk (Nucella dubia)
Striped bubble shell (Hydatina physis)
Details of the two eye-spots visible in the gap of the headshield. Port Alfred, Eastern Cape (2024) - iNaturalist Also called the striped paper bubble, green-lined paper bubble, brown-lined paper bubble, and rose petal bubble shell. Shell external, delicate and oval, bearing numerous spiral brown lines. Foot large and pink with thin wavy margin edged… Continue reading Striped bubble shell (Hydatina physis)
Sun oyster (Saccostrea cuccullata)
Sun oyster bed on a Natal rocky shore. Port St Johns, Wild Coast, Eastern Cape (2021) - iNaturalist Previously known as Crassostrea cuccullata. Also referred to as the Natal rock oyster. Lower valve deeply hollowed below the hinge and cemented to the rock. Upper valve relatively flat. Margins of both valves form a series of neatly… Continue reading Sun oyster (Saccostrea cuccullata)
Brown mussel (Perna perna)
Eroded and less eroded brown mussels in a bed. Old Woman's River, Eastern Cape (2018). Shell smooth and yellow-brown, sometimes tinged with green or with a chevron pattern. Specimens from crowded intertidal beds often very elongated and almost rectangular in cross-section. Submerged, fast-growing specimens are taller and narrower. Up to 125 mm. The dominant mussel… Continue reading Brown mussel (Perna perna)
Mediterranean mussel (Mytilus galloprovincialis)
Mediterranean mussel bed surrounded by algae of all sorts. Yzerfontein, Western Cape (2020). Shell smooth, typically black or blue, shading to brown on the lower surface, but rarely light brown. Broad in cross-section and usually widest at base. Distinguished from Choromytilus meridionalis by pits in the resilial ridge. Up to 140 mm. Thought to be… Continue reading Mediterranean mussel (Mytilus galloprovincialis)
Ribbed mussel (Aulacomya atra)
Lone eroded mussel in a rock crevice. Hondeklipbaai, Northern Cape (2020) - iNaturalist Easily recognised by the strong wavy ridges running the length of the shell. Shell brown in juvenile, but becomes blue-black in larger individuals. Eroded areas are white. Up to 90 mm. Forms extensive beds low in the intertidal and on rocky reefs… Continue reading Ribbed mussel (Aulacomya atra)
