Pterosagitta draco (Krohn, 1853)

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

publication ID	https://dx.doi.org/10.3897/zookeys.1106.80184
publication LSID	lsid:zoobank.org:pub:EFA7EF37-2B83-458D-931D-9A53DB311472
persistent identifier	https://treatment.plazi.org/id/8AD65EE5-7DA2-5B6B-B749-64AABD5A4383
treatment provided by	ZooKeys by Pensoft
scientific name	Pterosagitta draco (Krohn, 1853)
status

Treatment

Figs 3B View Figure 3 , 4B View Figure 4 , 10B View Figure 10 and 12A-D View Figure 12

Spadella draco : Grassi, 1883: 15 p.; Beraneck 1895: 154 p.; Aida 1897: 20 p., fig. 12; Doncaster 1902: 214-215 p.

Pterosagitta draco : Michael, 1919: 264-265 p., table 18; Thomson 1947: 22-23 p.; Tokioka 1965: 351-352 p.; Alvariño 1967: 21-22 p., fig. 11A-D; Srinivasan 1979: 34-35 p., fig. 19A-E; Michel 1984: 29 p., fig. 5; Kim 1987: 33-34 p., plate 12; Park et al. 1990: 71-73 p., fig. 50.

Material examined.

Northern East China Sea (32°30.000'N, 127°5.100'E), 0-120 m depth, oblique towing with conical net, Feb 2020, NIBRIV0000895299 (one specimen) GoogleMaps .

Description.

Total body length ranged between 6.5 and 9.1 mm and tail 38.4-40.1% of body length. Hooks 8. Anterior teeth 10 and posterior teeth 12. Rigid and translucent body (Fig. 12 View Figure 12 ). Wide and angular head (Fig. 12 View Figure 12 ). Wide collarette extending over entire body and reaching anterior of seminal vesicles (Fig. 12A View Figure 12 . C). Rectangular eyes with “T” shaped eye pigments (Fig. 12B View Figure 12 ). Intestinal diverticula absent (Fig. 3B View Figure 3 ). Lateral fins 20.7% of body length. Starting point of lateral fins 65.2% and ending points of lateral fins 86.3% of body length, respectively. One pair of lateral fins triangular-shaped and completely rayed, with forward ends at level of caudal septum (Fig. 12A, D View Figure 12 ). Seminal vesicles posteriorly elongated with anterior knob touching lateral fins (Fig. 12C-D View Figure 12 ). Eggs reaching middle of body. Corona ciliata anteriorly opened with horseshoe shape beginning in neck region and ending just behind eyes (Figs 10B View Figure 10 , 12A View Figure 12 ).

Distribution.

This species is located in the epipelagic (0-200 m depth) and mesopelagic zones (200-500 m depth) of the Pacific, Indian and Atlantic Oceans ( Pierrot-Bults and Nair 1991), the epipelagic zone (0-200 m depth) of the Caribbean Sea (Michel,1984), the coastal waters surrounding India ( George 1952) and the Tosa Bay in Japan ( Ohnishi et al. 2014). In this study, it was found in the epipelagic zone (0-120 m depth) of the northern East China Sea (Fig. 1 View Figure 1 : station nECS02).

Ecology.

This species is widely distributed in warm water masses and appears all year round in Korean waters, except in the Yellow Sea ( Kim 1987). The temperature range of the Caribbean Sea was reported as 22-29 °C, and salinity range was 33-38 psu ( Michel 1984). At the sampling stations of this study, the temperature ranged between 15.83-28.80 °C and salinity ranged between 31.38-34.60 psu.

Remarks.

The largest specimen collected in this study was 9.1 mm in length, which was at stage 4 maturity. It was smaller than the specimen from New Zealand (16 mm) reported by Lutschinger (1993). It had characteristics consistent with the Pterosagitta draco reported from the Pacific ( Alvariño 1967; Michel 1984), such as the presence of two rows of teeth, one pair of lateral fins, a corona ciliata located between the back of the eye and the neck and a broad collarette extending from the head to seminal vesicles. We observed one specimen for CBE staining pattern: dorsomedian line, 8 dots; dorsolateral line, 25 dots; lateral line, 10 dots; receptors on the lateral fin, 2 dots; anterolateral receptors on the caudal fin, 3 dots; posterior receptors on the caudal fin, 6 dots.