Bivalves · Marine Life · South Africa

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)

Marine Life · Sea Slugs

Lemon pleurobranch (Berthellina granulata)

Details of the tubes housing the rhinophores. Port Alfred, Eastern Cape (2023) - iNaturalist Also called lemon gumdrop. Body smooth, yellow to orange, often with white spots. Shell fragile and internal. Single gill under the mantle edge on the right side. About 30 mm in length. Commonly found in pairs under boulders intertidally and on… Continue reading Lemon pleurobranch (Berthellina granulata)

Chitons · Marine Life

Tulip chiton (Rhyssoplax polita)

Close-up of a tulip chiton on a bed of coralline algae. Port Alfred, Eastern Cape (2023) - iNaturalist Previously Chiton tulipa. An attractive chiton with smooth pink valves streaked and flecked with a wide range of brown patches and zigzags. Girdle striped, covered with large, smooth overlapping scales. Typically 30 - 40 mm. A well-known… Continue reading Tulip chiton (Rhyssoplax polita)

Anemones · Cnidarians · Marine Life

Striped anemone (Anthothoe stimpsonii)

Two striped anemones partially open in the crack of a rock pool. Port Alfred, Eastern Cape (2024) - iNaturalist Also called humbug anemone. Live anemones exist in many different colours, ranging from green to orange. Column light green, brown, orange, yellow, white, transparent, grey or flesh. Column and tentacles without bright spots. Column smooth, not… Continue reading Striped anemone (Anthothoe stimpsonii)

Crabs & Others · Hermit Crabs · Marine Life

Common sand hermit crab (Diogenes brevirostris)

Adult hermit crab walking around. Cape Agulhas, Western Cape (2020) - iNaturalist Body dirty-white with darker speckles and spines. Brown stripes on last segments of walking legs. Left nipper thorny and much larger than the right. About 30 mm. Endemic to South Africa. Extremely common on sheltered sandbanks and in sandy pools. Buries in sand… Continue reading Common sand hermit crab (Diogenes brevirostris)

Chitons · Marine Life

Giant chiton (Dinoplax gigas)

Adult chiton, with badly eroded valves, found in a rock crevice. Port Alfred, Eastern Cape (2021) - iNaturalist Also called 'armadillo'. Shell large with steeply arched grey or brown valves, usually badly eroded. Girdle brown and dotted with distinct tufts of small brown hairs. 70 to 100 mm in length. Usually found partially or totally… Continue reading Giant chiton (Dinoplax gigas)

Flatworms · Marine Life

Tentacled flatworm (Planocera gilchristi)

Two tentacled flatworms on the underside of a rock. Old Woman's River, Eastern Cape (2021) - iNaturalist Also referred to as Gilchrist's flatworm or the spotted flatworm. Body broadly oval, both ends being similarly rounded. Margin of the body 'frilly' (strongly folded) but dorsal surface smooth. Fairly firm consistency and very little transparent. Mottled brown… Continue reading Tentacled flatworm (Planocera gilchristi)

Barnacles · Marine Life

Eight-shell barnacle (Octomeris angulosa)

Old barnacle at the edge of a mussel bed (blue mussel, Mytilus galloprovincialis), with the circle of apertures forming at its base. Yzerfontein, Western Cape (2020). Moderately large with eight shell plates extremely rugged, irregular, massive, generally much corroded, steeply conical or even sub-cylindrical. Colour dirty-white, often slightly tinted yellow from the investing membrane, and… Continue reading Eight-shell barnacle (Octomeris angulosa)

Echinoderms · Marine Life · South Africa · Starfish

Dwarf cushion star (Parvulastra exigua)

Yellow starfish wrapped around algae. Doringbaai, Northern Cape (2020). Previously known as Patiriella exigua and Asterina exigua. Tiny, flattened, pentagonal starfish, with poorly developed arms. Dorsal surface made up of tile-like plates, each with a cluster of tiny knob-like spines. Gonophores on lower (oral) surface.Uniformly khaki-green of the West Coast, but variegated patterns of orange,… Continue reading Dwarf cushion star (Parvulastra exigua)