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Analogium spec. nov. 1
(fig. 3a-c, pl. 2 fig. 6, pl. 3 fig. 1)
Gymnodoris sp. 14 Debelius & Kuiter, 2007: 88 (Indonesia).
Gymnodoris sp. 21 Gosliner et al., 2008: 154 (Indonesia).
Analogium sp. Hervé, 2010: 169 (New Caledonia).
Non-Indonesian material.— RMNH.MOL.131667, Sangat Island, N of Busango Island, Philippines, < 5 meters depth, v.2009, one specimen 30 mm (26 × 18 mm pres. well relaxed), leg. J. Hinterkircher.
Description.— This new species of Analogium is distinctive: this specimen was orange in life, with the dark gut showing through in the centre of the animal (pl. 3 fig. 1). Colour appears to vary with flash: the close-up photographs are more yellow (pl. 2 fig. 6), and the colour of individuals in the synonymy and on NudiPixel are also variable. The body is shaped like those of A. striatum and A. amakusanum, broad anteriorly and tapering from the level of the gills to the tail. The fourteen gills are present as an nearly straight band across the dorsum, located in the posterior half of the animal beyond the midline. They are simply pinnate branches which arch posteriorly; the gonopore is closer to the rhinophores than the gills. The broadly pointed tail appears keeled, but this may be due to the wrinkles on the mantle which extend to the tip. Between the rhinophores and the gills the (seven) wrinkles are symmetrical and almost parallel. The thick coloured mantle edge extends from in front of the rhinophores to the tail. The bulbous rhinophores were orange with 9-10 lamellae which were darker at the edges. The gills were white with only the main axes pigmented orange. The foot was very broad, extending far beyond the mantle edge in all directions, with a wide band of pigment along its edge. It was elliptical in shape, and slightly broader anteriorly than posteriorly.
The preserved specimen is cream in colour, with the seven dorsal wrinkles opaque cream. The anterior portion of the animal and the fourteen gill leaflets are extended (fig. 3a), but the posterior portion of the body is contracted. The foot and the mantle are squared anteriorly; the wide foot margin is contracted to a thick rope. There was a small white parasitic copepod egg case on the gills, but it fell off before it could be photographed. The tiny radula has a formula of 11-12 × 21.1.0.1.21. The teeth are typical of the genus Analogium in having short bases with very long hooks; the small first lateral has a relatively large base with a hooked cusp (fig. 3b, c).
Remarks.— The photographs in the books listed in the synonymy and on NudiPixel clearly depict this species, ranging in colour from greenish yellow through brownish yellow to orange, all with yellow wrinkles. Eight of these are recorded from Indonesia, five from the Philippines, two from Thailand, and one from New Caledonia; the species appears to have a distribution limited to the western Pacific and eastern Indian oceans. At present only two species of Analogium are formally named and described, both with orange or yellow ridges. A fourth species is described below and differs in that it is covered in pustules, not ridges. However, the radulae of these four species of Analogium are virtually identical. Of the two named species of Analogium, A. striatum is recorded from the Indo-West Pacific (Jensen, 1998; Marshall & Willan, 1999, and P. Bidgrain, pers. comm.,) but more commonly from the Red Sea (Yonow, 1990, 2008) whereas A. amakusanum Baba, 1996, appears to be limited to the western Pacific Ocean (Rudman & Darvell, 1990; Baba, 1996; Cobb & Willan, 2006).