Tintinnida from coastal waters of the S.W.-Netherlands I. The genus Tintinnopsis stein

Summary

The species of the Tintinnid genus Tintinnopsis Stein, occurring in the coastal waters of the SW.-Netherlands, are figured and described. We demonstrated a large variability of several species in relation to the shape of the lorica. Nearly all lorica characters appeared to vary considerably, particularly the shape of the aboral portion of some species (T. beroidea Stein). The oral diameter of the lorica, on the other hand, varied much less. The many forms were classified into 7 species only: T. baltica Brandt, T. beroidea Stein, T. campanula (Ehrbg) Daday, T. cylindrica Daday, T. fimbriata Meunier, T. lobiancoi Daday, T. turbo Meunier. Loricae of some species demonstrated extreme variability, notably those of T. beroidea. Others on the contrary, appeared rather constant: T. cylindrica, T. fimbriata. Very strong individual variation was demonstrated in local populations (fig. 2 and 3). Therefore it is not justified to describe new species from sparse material. For descriptive work, especially on neritic Tintinnids, investigations of a great number of specimens is advocated.