Scyllaea pelagica Linnaeus, 1758

Location: Manazuru, Kanagawa, Japan
Date: 2019/02/28
Length: 30mm
Depth: 0.3m
Water temperature: 13.0℃

Description

A pelagic dendronotid with a laterally compressed body and a longitudinally grooved dorsum that is used to clamp onto floating algae. Two pairs of large palmate ceratal lobes project upright along the back, each fringed with white claw-like papillae at the apex. The tail is leaf-like, and the dorsal midline carries 4–6 conspicuous bright violet-blue spots. Easily confused with Notobryon wardi.

Distribution

Cosmopolitan in tropical and warm-temperate seas, drifting with floating Sargassum and other macroalgae across the Atlantic, Mediterranean, Indian and Pacific Oceans. The type locality is "Pelagi Fuco natante" — open-sea floating seaweed.

Etymology

The genus Scyllaea alludes to Scylla, the sea monster of Greek mythology. The specific epithet pelagica is the Latin feminine of pelagicus, "of the open sea", in reference to the species' pelagic, Sargassum-rafting habit.

Remarks

Originally described in Systema Naturae, 10th edition (Holmiae, 1758) and reprised in the 12th edition (1767: 1094 §294 sp.1). Linnaeus had earlier figured the same animal as "Lepus pelagicus" in his Museum Adolphi Friderici (1754: 55). The genus Scyllaea was erected by Linnaeus in 1758 with this species as type. Feeds on hydroids growing on floating algae.