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Family Gymnodorididae
Analogium spec. nov. 1
next section(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).
Analogium spec. nov. 2
(fig. 4a-c, pl. 3 fig. 2)
? Gymnodoris sp. Wells & Bryce, 1993: 89, sp. no. 102.
? Gymnodoris sp. 1 Debelius & Kuiter, 2007: 83 (Bali).
Material.— RMNH.MOL.131666, RBE Stn 30, Suli, Ambon, 5-7 m depth, 29.xi.1990, leg. A. Fortuin, “small orange active nudibranch in sand,” 5 × 2 mm pres., photos M. Lavaleye 35-3/4.
Description.— The body was white with large slightly raised yellow-orange pustules and a continuous single row of elongated pustules along the pallial line, head, and top of the tail; an additional row of pustules was present along both sides. Sixteen pustules on the dorsum were loosely arranged in longitudinal series in front of the gills but in no definite pattern beyond the gills (pl. 3 fig. 2). No pustules or colour marked the margins of the foot. The genital aperture was located on the right side close to the rhinophore, approximately one-third of the distance between the rhinophores and the gills. The rhinophores were retracted in the photographs, but appear to have been white without orange tips. Thirteen gills are arranged in a transverse row, touched with yellow-orange on their frontal surfaces.
The preserved specimen is minute and appears to have partially dried out at some point. The buccal bulb projects out of the mouth (also visible in pl. 3 fig. 2), and the conical genital papilla is located below and behind the right rhinophore. The elongated rhinophores have six overlapping diagonal lamellae and a round terminal knob (fig. 4a). The gills are all united basally and each branch is simply pinnate (fig. 4b). The radula is missing but some pieces and a few teeth were obtained from the storage vial, appearing form a complete half row of 8-9 teeth (fig. 4c). The first lateral differs from the remainder, small with three spikes on the end; the larger second tooth is bent in the middle, nearly 90o; the remaining teeth straighten along the row and have a small square base with a long cusp. The second and remaining laterals have a small peg at the base where the cusp meets the base; this becomes smaller near the end of the row.
Remarks.— Despite the lack of recent literature on the genera Gymnodoris and Analogium and the very small size of this specimen, this species is distinct from the named species of Analogium as well as from the new species described above. The genus was first introduced by Risbec (1928) and resurrected by Hamatani (1995) to distinguish those gymnodorids with a transverse band of plate-like gills, but this is not accepted by some authors (Rudman & Darvell, 1990; Gosliner et al., 2008). There are several illustrations of spotted species of Analogium from the western Pacific (e.g. Wells & Bryce, 1993; Gosliner et al., 2008; all as Gymnodoris) so it is more prudent to await more material. Externally, Analogium spec. nov. 2 differs from known species in having raised pustules instead of ridges although consideration must be given to its small size: the 22— 24 mm specimens of A. striatum illustrated by Hamatani (1995) show the dorsal ridges broken up into pustules, although the pallial margin is a continuous ridge. The radulae of all four species are extremely similar, as illustrated by Vayssière (1912), Baba (1937, 1996), Hamatani (1995), and in this work. It is probable that the rows available for this specimen are complete half rows; in comparison, there were 6-18 teeth in the rows of the radula of a 25 mm specimen of A. striatum (Hamatani, 1995).
Gymnodoris aurita (Gould, 1852)
(fig. 5, pl. 3 fig. 3)
Doris aurita Gould, 1852: 299, pl. 23, figs 394.
Gymnodoris aurita Gosliner & Behrens, 1997: 287, figs 1A, 2A-D, 3A-D; Gosliner et al., 2008: 146.
Material.— Bali, Indonesia, photos of one individual, 26.xi.2005, E. Kodiat.
Non-Indonesian material.— RMNH.MOL.131664, Anilao, Batangas, Philippines, night dive 8 m depth, v.1996, two specimens 25 mm and 35 mm long both pres. (totally flat), leg. and photos H. Debelius.
Description.— Both specimens were bright orange with scattered raised yellow pustules and a large open circlet of red and yellow gills, spreading beyond the width of the animal (pl. 3 fig. 3). The foot and unusual tubular oral tentacles were bordered by yellow, and the small rhinophores were also yellow. The radula of the 35 mm specimen is incomplete, but it has at least 14 rows with a maximum of 33 teeth per half row. The first lateral is small in comparison to the remainder, approximately 1/3 the size (fig. 5). It has a broad base with a large flattened cusp. The remainder have a thin and elongated cusp, and the last three teeth in each row have reduced bases.
Remarks.— The photographs of external morphology and the radula of the specimens described here compare favourably with those given by Gosliner & Behrens (1997). Originally described from Fiji and more recently from the Philippines, the species has been reliably photographed from Indonesia (Tonozuka, 2003; E. Kodiat, pers. comm.; numerous photographs on NudiPixel). Gymnodoris aurita is limited to the central and western Pacific where it grows to 100 mm.
Gymnodoris impudica (Rüppell & Leuckart, 1828)
(fig. 6a, b, pl. 3 fig. 4)
Doris impudica Rüppell & Leuckart, 1828: 33, pl. 10 figs a-c.
Trevelyana rubropapulosa Bergh, 1905: 191, pl. 4 fig.15, pl. 17 figs 27-31, pl. 18 figs 1-3 (Selayer, Indonesia).
Gymnodoris impudica White, 1951: 242; Yonow, 2008: 135.
Gymnodoris ceylonica Baba, 1989: 192— 194, fig. 1 [non G. ceylonica (Kelaart, 1858)].
Gymnodoris rubropapulosa Rudman & Darvell, 1990: 50.
Non-Indonesian material.— RMNH.MOL.131663, Ningaloo Reef, West Australia Bay, NW Australia, 2 m depth, xi.1989, leg. H. Debelius, two specimens 24 × 15 mm and 25 × 15 mm pres.; N of Busango, Philippines, v.2009, photos of one individual 32 mm, J. Hinterkircher.
Description.— Gymnodoris impudica is easily recognized by its large white body covered in large and small soft orange pustules: these are slightly raised and often darker around their edges. The gills and rhinophores are also orange (pl. 3 fig. 4). The 9-11 gills are arranged in a circle around the anal papillae. No colour or raised spots remain on the preserved specimens. The radular formula is 25 × 45-55.0.55-45: the innermost lateral has a duck-bill-shaped base and a short straight cusp with a swollen tip (fig. 6a). The subsequent laterals have smaller bases and longer thinner cusps. The tip is slightly bent on the last few teeth (fig. 6b).
Remarks.— Bergh (1905) described a specimen (65 mm) from Indonesia with 11 gills arranged around the anal papilla, and a radular formula of 40 × 33.0.33. White’s (1951) 45 mm preserved specimen from the Red Sea had a radular formula of 28 × 41.0.41.
This large species is widely distributed from the Red Sea through the Indian Ocean as far south as South Africa, across to Indonesia and the Philippines to Japan. Gymnodoris impudica was only recently identified with its older name in a work investigating the Red Sea fauna (Yonow, 2008): Bergh described and illustrated Trevelyana rubropapulosa from Selayer in 1905 but Rüppell & Leuckart had already described and illustrated Doris impudica from the Red Sea in 1828. This name is chosen in accordance with Article 24.2.2 (ICZN, 1999) for First Reviser, chosen because Rüppell & Leuckart’s endeavours were clear and unambiguous, and most of their species are recognisable today.
Gymnodoris subflava Baba, 1949
(fig. 7a, b, pl. 3 fig. 5)
Gymnodoris subflava Baba, 1949: 135, pl. 12 fig. 44, text fig. 38; Rudman & Darvell, 1990: 50.
Trevelyana ? Bergh, 1905: pl. 5 fig. 15 (no accompanying text) syn. nov.
Material.— RMNH.MOL.131662, RBE Stn 34, Ruhmatiga, Hitu, 3 m depth, 3.xii.1990, leg. K. van Egmond, two very contracted specimens 6 mm and 7 mm and two more extended specimens 10 × 6 mm and 10 × 5 mm, photos M. Lavaleye 39-20/24.
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Fig. 7. Gymnodoris subflava. a, Left rhinophore of 10 mm specimen; b, radular teeth near old end, left half of radula, showing one rotated 1st lateral (left of photo), 7 mm specimen; scale bar 50 µm. |
Description.— When alive, the body colour was uniformly deep yellow with small slightly darker yellow pustules (pl. 3 fig. 5). The >20 gills are located in the last third of the dorsum and are the same colour as the body. They are arranged in a horseshoe-shape in both the preserved specimens and the photographs, as simple upstanding lamellae. The rhinophores were a darker yellow-orange, and the genital papilla is located just behind and below the right rhinophore. The rhinophores are very bulbous in the preserved material, with eight thick diagonal widely-spaced lamellae and a rounded terminal knob (fig. 7a). The foot appears to have a darker yellow-orange margin in the photographs.
The larger specimen was dissected to extract the radula; the visceral casement is black. The radula is small and compact with the formula 14 (+2-3) × 11.1.0.1.12, and the teeth are minute in comparison to those of G. aurita and G. impudica. The first lateral is not so different from the marginals, with a weaker base and shorter cusp; however, in all rows on both sides, the base of the first tooth is rotated 180o from the outside to the centre of the radula. The cusp still points anteriorly, but is connected to the base along the central line of the radula. The remaining teeth have a strong oval to angular base with a long curved cusp set at almost right angles (fig. 7b).
Remarks.— The gymnodorids are notoriously difficult to identify, and there is no recent taxonomic work reviewing this group. Gymnodoris subflava was described from Japan, and recorded from Hong Kong; this appears to be the second record since the original description, apart from few photographs posted on various internet sites. The black visceral casement, visible through the skin in the living specimens, is diagnostic, as is the open horse-shoe shape of the gill insertions. Bergh’s illustration (1905, pl. 5, fig. 15) of “Trevelyana?” is probably this species, and shows the black visceral casement clearly; the gills in the tiny painting are arranged in an elongated oval. Baba’s (1940) original description is not very detailed, and the radula is different in both formula (27 × 13-16.1.0.1.13-16) and in the shape of the first lateral, which he states is much larger and has a short acutely pointed cusp. His illustration of the rhinophores is like those of this specimen, but that of the gills is not. These specimens are best placed in G. subflava despite radular differences, until further collections with radular diagnoses from other localities provide more information. Currently G. subflava is recorded from Japan, Hong Kong, and now Indonesia.