Chrysochromulina acantha, C. hirta, C. pachycylindra, and C. cf.polylepis(Haptophyceae = Prymnesiophyceae) are new records, based on transmission electron microscopy, for New Zealand coastal waters. The morphology and growth characteristics ofC. acanthaandC. hirta, and of C.simplexandC. ericina(also New Zealand isolates), are described.C. ericinaof the present study has a shorter haptonema (12–24 urn; non‐coiling), larger plate and spine scales, and fewer spine scales (with broader bases), than northern hemisphere isolates. Scales ofC. simplexfit the emended type description, whereas the large spine scales ofC. hirtaare shorter (≤ 11 μm) than the type description (20–30 μm).C. ericinaandC. hirtafall into a temperate (15–20°C), andC. acanthaandC. simplexinto a sub‐tropical (20–25°C), temperature group. All species tested grew well in brackish salinities (c. 23 through to 36);C. hirtagrew optimally at a salinity of 23. All tolerated 25–150 umol m−2s−1photon flux and pH of 7.5 to c. 8.4.C. acanthahad significantly faster growth rates (doublings d−1) with nitrate than with urea or ammonium chloride as nitrogen source, andC. hirtawith urea and ammonium chloride rather than with nitrate; none required selenium. None of the species tested was toxic toArtemia salina. C. ericinaandC.acanthawere phagotrophic. Calcofluor assisted in the identification ofC. quadrikontafrom other spine‐bearing species and FITC‐conjugated wheat germ lectin aided differentiation of theChrysochromulinaspecies fromPrymnesium parvumandP. patelliferum.