Hansenocaris aquila Olesen & Grygier, 2022

Figs 2, 9D–E

Hansenocaris aquila Grygier &Olesen, 2022: 307, fig. 6.

Hansenocaris aquila – Olesen et al. 2024: fig. 2.

Material examined

JAPAN – Okinawa, Sesoko I., laboratory pier, 26°38ʹ09.4ʺ N, 127°51ʹ55.2ʺ E • 2 LSN; 1991–2005 (Tables 1 and S1).

Description

LAST-STAGE NAUPLIUS (LSN). Lecithotrophic. Body spoon-shaped in dorso-ventral view; about twice as long as wide; cephalic shield broadly rounded, with sharp discontinuity in body outline leading into trunk. In lateral view, trunk axis bent downwards ca 40° with respect to cephalic axis. Length 400 µm (ventral view of mounted exuvia, without dorso-caudal spine), greatest width ca 210 µm, dorso-ventral thickness ca 120 µm. Labrum with goblet-shaped outline in ventral view, its free posterior margin extending into large medial spine (‘stem’ of ‘goblet’), preceded by four small spines on labral midline; labral surface divided into facets by cuticular ridges. Trunk dorsum with four longitudinal rows of spines. Caudal end attenuate, terminating in 100 µm long, robust dorso-caudal spine armed with many smaller spines and accompanied ventrally at base by pair of small, ca 5 µm long furcal spines; long axis of dorso-caudal spine upturned 15° with respect to trunk axis.

CYPRID VIEWED THROUGH CUTICLE OF LSN. No live specimens examined.

Identification and variation

Easily recognizable by its labrum with the posterior margin extended into a large, eagle-beak-like median spine preceded by ca four small spines on the midline; also distinguished by the four dorsal rows of longitudinal spines on the trunk and the very long, robust and distinctly spinose dorso-caudal spine.

Distribution

Japan (Sesoko Island, Okinawa).