Jorunna hervei Innabi, Stout & Á. Valdés, 2023

Location: Kutama, Amakusa, Kumamoto, Japan
Date: 2026/05/17
Length: ??mm
Depth: ??m
Water temperature: ??℃

Description

A small discodorid (11–25 mm) with an oval, flattened body entirely covered with caryophyllidia, giving a velvety texture. The background colour varies from pale brown to grey, with numerous irregular dark patches, in some animals surrounded by white pigment. The gill has nine short, tripinnate leaves and the rhinophores bear seven or eight lamellae; both are the same colour as the dorsum. Living animals are highly cryptic on the sponge on which they occur.

Distribution

Type locality: Koumac, New Caledonia, on sponges at 3–8 m depth. Although the original description suggested it might be endemic to New Caledonia, specimens from Japan have since been confirmed as this species by DNA analysis, indicating a wider western Pacific range.

Etymology

The specific epithet hervei honours Jean-François Hervé, a pioneer in the study of New Caledonian sea slugs and an accomplished collector, who took part in the Koumac expeditions during which the type material was collected.

Remarks

One of seven externally similar ("cryptic") Discodorididae described from New Caledonia in 2023. The pale brown egg mass is a tightly coiled ribbon of about seven whorls with small eggs (~105 µm). In Japanese waters this species and the externally near-identical Jorunna sp. 7 occur together but use different host sponges and have differently shaped egg masses, which separate them reliably. It is sister to Jorunna daoulasi, differing externally in lacking a network of white pigment (present in J. daoulasi), and is also similar to Jorunna liviae from Mozambique.