New Zealand Coelenterates Ctenophores from Cook Strait
Discussion
Discussion
Cestum is predominantly a warm water ctenophore, (Mayer, 1912) although it has been recorded from the White Sea (Wagner, 1885). Mayer and Mortensen (1912) consider that the specimens described by Wagner were swept northward along the Norwegian coast by the Gulf Stream Drift. The South Equatorial current may have been responsible for the presence of C. veneris in New Zealand waters, but it has no reputation like the Gulf Stream in this respect. Moreover in latitude 41° S., a water temperature of 12.25°C. does not indicate a warm current. We suggest that they have not been reported from the temperate regions for two reasons, viz: the necessary calm periods with brilliant sunshine for collection are not of sufficient duration; and secondly, that C. veneris is not readily netted but must be sighted and then collected by a method of dipping.