Anne Frijsinger & Mat Vestjens, Holland
Info
Sertularella polyzonias (Deshayes & Milne Edwards, 1836)
Sertularella polyzonias is a fairly widespread hydrozoan that lives independently of light, therefore does not require zooxanthellae and can therefore also colonize shady areas.
Description: The main stems and lateral branches are thin, wavy and bright yellow in color. The main stem branches irregularly.
The lateral branches bear alternate hydrothecae, one on each internode. The hydrothecae are bulbous at the base and taper towards the margin. The margin has four tubercles and an operculum consisting of four triangular lobes.
The gonothecae are generally ovoid and rough in texture. A raised tubular structure with four vertically projecting denticles surrounds the opening. Although the male and female are similar in shape, the male is much smaller and white, while the female is yellow in color. The colonies are typically 40-50 mm in size.
Habitat: This hydrozoan often grows attached to mussels or algae, usually when there is considerable water movement.
Distribution: This species is widespread throughout the British Isles.
Similar species: Several species of Sertularella could be confused with this species.
Important identification features:
Hydrothecae borne alternately on main and lateral branches.
Rather loose and irregular branching.
Synonyms:
Sertularella falsa Millard, 1957
Sertularia polyzonias Linnaeus, 1758
Synonymised names
Sertularella polyzonias var. ellisi · unaccepted (is distinct, full species)
Sertularia ellisii Deshayes & Milne-Edwards, 1836 · unaccepted (basionym)
Sertularella polyzonias is a fairly widespread hydrozoan that lives independently of light, therefore does not require zooxanthellae and can therefore also colonize shady areas.
Description: The main stems and lateral branches are thin, wavy and bright yellow in color. The main stem branches irregularly.
The lateral branches bear alternate hydrothecae, one on each internode. The hydrothecae are bulbous at the base and taper towards the margin. The margin has four tubercles and an operculum consisting of four triangular lobes.
The gonothecae are generally ovoid and rough in texture. A raised tubular structure with four vertically projecting denticles surrounds the opening. Although the male and female are similar in shape, the male is much smaller and white, while the female is yellow in color. The colonies are typically 40-50 mm in size.
Habitat: This hydrozoan often grows attached to mussels or algae, usually when there is considerable water movement.
Distribution: This species is widespread throughout the British Isles.
Similar species: Several species of Sertularella could be confused with this species.
Important identification features:
Hydrothecae borne alternately on main and lateral branches.
Rather loose and irregular branching.
Synonyms:
Sertularella falsa Millard, 1957
Sertularia polyzonias Linnaeus, 1758
Synonymised names
Sertularella polyzonias var. ellisi · unaccepted (is distinct, full species)
Sertularia ellisii Deshayes & Milne-Edwards, 1836 · unaccepted (basionym)
