Zonosagitta pulchra (Doncaster, 1902)

Choo, Seohwi, Jeong, Man-Ki & Soh, Ho Young, 2022, Taxonomic reassessment of chaetognaths (Chaetognatha, Sagittoidea, Aphragmophora) from Korean waters, ZooKeys 1106, pp. 165-211 : 165

Zonosagitta pulchra (Doncaster, 1902)

Sagitta pulchra : Doncaster, 1902: 213 p.; Fowler 1906: 72 p.; Michael 1919: 251-253 p., tables 7, 8; Burfield and Harvey 1926: 100 p., fig. 30; Thomson 1947: 19-20 p.; Kitou 1966: 239 p., table 1; Alvariño 1967: 34-35 p., figs 20-21; Francisco 1977: 231-233 p.; Srinivasan 1979: 29-30 p., fig. 16.

Material examined.

Korea Strait (34°17.868'N, 128°15.854'E), 0-60 m depth, oblique towing with MOCNESS, Feb 2020 (one specimen) .

Description.

Rigid and transparent body. Collarette present. Intestinal diverticula absent. Grasping spine gently curved. Two rows of stout teeth arranged in comb shape. Two pairs of lateral fins partially rayed, anterior fins begin at the end of ventral ganglion. Seminal vesicles elongated with an anterior protruding part usually roughly round and touching both lateral fins and caudal fin.

Distribution.

The species is found in the epipelagic zone (0-200 m depth) of the Pacific and Indian Oceans ( Pierrot-Bults and Nair 1991) and off the coast of Philippines ( Noblezada and Campos 2008). In this study, it was found in the epipelagic zone (0-120 m depth) of the northern East China Sea, the Korea Strait and the Yellow Sea (Fig. 1 : station KS02).

Ecology.

Z. pulchra is considered to be a neritic species ( Bieri 1959; Pierrot-Bults and van der Spoel 2003). The temperature range in the sampling stations of this study was 11.95-14.79 °C and the salinity range was 33.59-34.00 psu.

Remarks.

Only one immature individual was collected in this study. The examined Korean specimen belongs to the genus Zonosagitta by the absence of intestinal diverticular and the presence of rayless zone in the anterior part of anterior fins. This Korean specimen was identified as Z. pulchra because its anterior fins were more angled than those of Z. bedoti or Z. nagae . The seminal vesicles of Korean specimen were not sufficiently mature compared to description of Alvariño (1967).

Figures

Figure 1. Sampling stations in Korean waters. Empty circles, sampling stations; filled circles, the stations where the chaetognaths were secured.