Iiella elegans ( Tattersall, 1960 )

Fukuoka, Kouki, 2011, A new species of the genus Iiella Băcescu, 1968 (Crustacea: Mysida: Mysidae) from Malaysia, with notes on I. elegans (Tattersall, 1960), Zootaxa 3091, pp. 60-68 : 66

Iiella elegans ( Tattersall, 1960)

( Fig. 4 )

Gastrosaccus elegans Tattersall, 1960: 173 –175, fig. 3. — Ii 1964: 581–582 (only remarks). Iiella elegans .— Jo & Murano 1992: 185.

Material examined. Holotype: adult female (8.0 mm), BM(NH) 1960.3.28. Paratypes: 1 adult male (6.8 mm), 1 immature male (4.0 mm) and 5 adult females (5.7–8.1 mm), BM(NH) 1960.3.28.

Supplemental description. Third pleopod of male ( Fig. 4 A) biramous; endopod extending slightly beyond distal margin of first segment of exopod; exopod 4-segmented; first segment divided into 4 subsegments, 3 short basal subsegments occupy proximal 0.33 of first segment; second segment longest, 1.17 times as long as first segment; third segment 0.8 of second segment in length; fourth segment 1.1 times longer than third segment.

Lateral margin of telson ( Fig. 4 C, D) armed with one spiniform seta near base, followed by unarmed space to proximal 0.25–0.27, then with 12–18 subequally sized spiniform setae.

Remarks. Iiella elegans was originally described on the basis of the male and female specimens collected from Singaporean waters ( Tattersall, 1960), and it has not been recorded since. As for the third male pleopod, Tattersall (1960) provided a brief description, but no illustrations. The present reexamination of type specimens clarified that the first segment of the exopod is divided into four subsegments composed of one long and three short subsegments.

On the telson, Tattersall (1960) illustrated the most proximal lateral spiniform seta of the distal series as located at the proximal 0.3 to 0.33 of the lateral margin. However, in the present reexamination, the most proximal lateral seta was found to be located at the 0.25 to 0.27 proximal end of the telson ( Fig. 4 C, D).

Figures

FIGURE 4. Iiella elegans (Tattersall, 1960) A, D, paratype (male, 6.8 mm), BM (NH) 1960.3.28; B, C, holotype (female, 8.0 mm), BM (NH) 1960.3. 28. A, right third pleopod (lateral view); B, uropodal endopod (ventral view); C, uropods and telson (dorsal view); D, uropodal endopod and telson (dorsal view).