Cuvierina tsudai, Burridge, Alice K., Janssen, Arie W. & Peijnenburg, Katja T. C. A., 2016

Burridge, Alice K., Janssen, Arie W. & Peijnenburg, Katja T. C. A., 2016, Revision of the genus Cuvierina Boas, 1886 based on integrative taxonomic data, including the description of a new species from the Pacific Ocean (Gastropoda, Thecosomata), ZooKeys 619, pp. 1-12 : 4-5

Taxon classification Animalia Thecosomata Cuvierinidae

Cuvierina tsudai sp. n.

Cuvieria columnella Rang, 1827: 323 (partim).

Cuvierina columnella : Boas 1886: 132, 217, pl. 6 fig. 95g (partim, non Rang); Rampal 2002: 214 (partim, non Rang).

Cuvierina columnella (Rang, 1827) forma columnella (Rang, 1827) - Van der Spoel 1967: 79 (partim, non Rang); Van der Spoel 1970: 120, fig. 19 (partim, non Rang).

Cuvierina (Cuvierina) pacifica Janssen, 2005: 46 figs. 18-20 (partim, northern Pacific specimens only, non figs. 14-17 = Cuvierina pacifica ).

Cuvierina pacifica N (Janssen, 2005): Burridge et al. 2015: 5, fig. 2.

Holotype.

RMNH.5004167, also see Fig. 1A and Table 1.

Type locality.

8°47'N, 158°49'W.

Paratypes.

See Fig. 1 B–I and Table 1 for all specimen information. Three specimens from the type locality (RMNH.5004168); three specimens from the Zoological Museum of the University of Copenhagen, Denmark (ZMUC, not registered) illustrated by Janssen (2005, figs. 18-20); five specimens from four locations (RMNH.5004169-72) studied by Burridge et al. (2015, referred to as Cuvierina pacifica N therein). The latter five specimens have COI mtDNA and 28S rDNA sequences available at GenBank (see Table 1).

Additional material examined.

Specimens recorded as Cuvierina pacifica from the North Pacific Ocean in Janssen (2005: 49, 71), housed in the Muséum National d’Histoire Naturelle (MNHN, Paris, France) and ZMUC (Copenhagen, Denmark). Specimens from Burridge et al. (2015), referred to as Cuvierina pacifica N in Table S1 therein, with photographs deposited at the Dryad repository (http://dx.doi.org/10.5061/dryad.7n1q4) and COI mtDNA (KP292730-72) and 28S rDNA sequences (KP292636-42) deposited at GenBank. These specimens are housed in Naturalis Biodiversity Center (Leiden, The Netherlands) and ZMUC (Copenhagen, Denmark). Registration numbers, if available, from Janssen (2005).

Diagnosis.

Shell moderately small, adult specimens 7.2-8.8 mm high, height/width-ratio 2.77-3.46 (mean 3.14), position of maximum shell width 33-42% (mean 37%) of shell height from septum upwards. Aperture triangular. No longitudinal micro-ornamentation.

Description.

The shell shape of Cuvierina tsudai differs from other Cuvierina species. Its shell height is smaller than in Cuvierina columnella , Cuvierina cancapae , and Cuvierina atlantica , but larger than in Cuvieria urceolaris , and of similar size compared to Cuvierina pacifica . The position of maximum shell width is distinctly higher than for Cuvierina columnella and Cuvierina atlantica and lower than for Cuvierina pacifica . It is more cylindrical in shape than the inflated (bottle-shaped) Cuvieria urceolaris but less cylindrical than Cuvierina atlantica and Cuvierina pacifica . It differs from Cuvieria urceolaris and Cuvierina cancapae by the absence of micro-ornamentation. It has a more triangular and wider aperture than Cuvieria urceolaris and Cuvierina pacifica (Fig. 3, Janssen 2005, Burridge et al. 2015).

Distribution.

Cuvierina tsudai has a wide, exclusively Pacific distribution between 36°N and 39°S, in which it co-exists with Cuvierina columnella , Cuvieria urceolaris , and Cuvierina pacifica . It has been found most often in the North Pacific, but also occurs in the South Pacific. It has not been found thus far in the central, oligotrophic parts of the South Pacific subtropical gyre, the southeast Pacific, the coral triangle west of the Philippines or southwest of Papua New Guinea.

Etymology.

Named after Atsushi Tsuda, professor in biological oceanography at the University of Tokyo, Japan, for sending us pteropod samples from the Pacific Ocean and in recognition of his services to the zooplankton research community.