Platynereis B sp. nov. Kara, Macdonald and Simon, 2019

Status
Common, Indigenous

Description
Body colour variable: medium – light brown to dark brown red/brown matter colour. White luminescent pigmentation between four pairs of dark brown eye spots on prostomium. Lateral sides of anterior segments dark green with colour more prominent at segment boundaries. Dull yellow dorsal midline in anterior chaetigers and from 16th chaetiger to posterior colour luminescent cream/white in a characteristic chain-like pattern, common for Platynereis. Body swollen anteriorly and tapering posteriorly. Pair of frontal antenna. Pair of palps with swollen base and rounded distal ends. Four pairs of tentacular cirri. Pharynx armed with a pair of black/brown jaws with 6 teeth. Paragnaths on pharynx in distinct areas and consist of rods in tight lines or rows: Area I & II: 0, III: 3 discontinuous rows, IV: 5 rows, V: 0, VI: 2-3 rows, arc shape, VII-VIII: 2-3 rows in 5-6 groups. Dorsal and ventral cirri present. Chaetae consist of thick heterogomph falcigers with terminal tendons, homogomph spinigers, heterogomph spinigers and heterogomph falcigers.

Ecology/habitat
Very common in the lower intertidal zone under Ulva sp. Laurencia flexuosa and Jania verrucosa beds. Found in soft flexible tubes made out of mucous secretions, sand and detritus.

Distribution
Lamberts Bay in the Western Cape to Kidds Beach in the Eastern Cape of South Africa. More abundant along the cooler West coast. Species also recorded from Namibia and Angola by Day (1967).

Notes
Previously mistaken as the Mediterranean species Platynereis dumerilii. Found to be part of a true cryptic species complex with another indigenous South African species, Platynereis massiliensis s.l. and that of the Platynereis species complex in the Mediterranean.

List of relevant papers
Kara J (2019). Taxonomic and molecular assessment of the apparently alien and cosmopolitan Nereididae Blainville, 1818 polychaetes from South Africa. PhD Thesis. Stellenbosch University, South Africa.
Wäge J, Valvassori G, Hardege JD, Schulze A, Gambi MC (2017) The sibling polychaetes Platynereis dumerilii and Platynereis massiliensis in the Mediterranean Sea: are phylogeographic patterns related to exposure to ocean acidification? Marine Biology 164:199.
Day, J. H. (1967). A Monograph on the Polychaeta of Southern Africa. The British Museum of Natural History: London.

Cite as: Kara J (2019). Taxonomic and molecular assessment of the apparently alien and cosmopolitan Nereididae Blainville, 1818 polychaetes from South Africa. PhD Thesis. Stellenbosch University, South Africa.