Catriona lucerna Korshunova, Martynov, Lundin & Malmberg, 2022

Location: Gorilla Chop, Okinawa Island (Motobu and Northern area), Okinawa, Japan
Date: 2020/12/29
Length: 14mm
Depth: 10.0m
Water temperature: 23.0℃

Description

Up to 14 mm in total length. The body is moderately narrow. Rhinophores are similar in size to the oral tentacles and smooth. Cerata are relatively long and elongated, ranging from fusiform to lamp-shaped. The ground colour is translucent whitish. The basal half of the rhinophores is covered with orange pigment, whereas the oral tentacles lack orange pigment. Both the rhinophores and oral tentacles bear opaque white pigment towards their tips. The digestive branches inside the cerata are creamy to pale brownish with a faint pink hue. Near the tip of each ceras there is a broader opaque whitish band and, below it, a narrower yellowish-to-orange band. The ceratal tips are translucent with opaque white pigment. Some dorsal areas also bear white pigment, but distinct white lines along the length of the cerata are absent.

Distribution

Type locality: Nha Trang region, Vietnam. Recorded only from Vietnam at the time of original description, but a broader distribution across the Indo-West Pacific has been suggested.

Etymology

The specific epithet lucerna is Latin for "candle" or "lamp", referring to the lamp-like shape of the cerata.

Remarks

Found in shallow areas at 1-3 m depth in hydroid-rich fouling communities. Distinguished from the phylogenetically related Catriona maua (Marcus & Marcus, 1960), which lacks distinct coloured bands near the tips of the cerata, by its conspicuous orange rings. Differs from the closely related Catriona osezakiensis in the colour of these rings: this species shows orange-dominant rings, whereas C. osezakiensis shows yellow-dominant rings.