Goniobranchus verrieri (Crosse, 1875)

Soong, Giun Yee, Bonomo, Lynn J., Reimer, James D. & Gosliner, Terrence M., 2022, Battle of the bands: systematics and phylogeny of the white Goniobranchus nudibranchs with marginal bands (Nudibranchia, Chromodorididae), ZooKeys 1083, pp. 169-210 : 169

Goniobranchus verrieri (Crosse, 1875)

Figures 3e, f , 6c, d , 11a-f

Doris marginata Pease, 1860: 30 (junior homonym of both Doris marginata Montagu, 1804: 79 and Doris marginata Quoy & Gaimard, 1832: 255-256).

Goniodoris verrieri Crosse, 1875: 313, 314, pl. 12, fig. 5.

Chromodoris marginata : Bergh, 1880: 27, pl. 13, figs 22, 23; Risbec 1928: 133-136, fig. 33, pl. 6, fig. 4; Risbec 1953: 63-66, fig. 26; Kay 1979: 467, 468, fig. 150D.

Glossodoris verrieri : Pruvot-Fol 1951: 155.

Chromodoris verrieri : Risbec 1953: 80; Rudman 1985: 262-267, figs 12A, 13A, 14, 15A; Gosliner et al. 2008: 221, top photograph.

Chromodoris trimarginata (Winckworth, 1946): Kay and Young 1969: 205, 206, figs 45, 55 (misidentification).

Goniobranchus verrieri : Gosliner et al. 2015: 223, top right photograph; Gosliner et al. 2018: 153, top right photograph.

Chromodoris sinensis Rudman, 1985: 263, fig. 12C; Yonow 2001: 26, pl 3, fig. 6 (misidentifications).

Type locality.

Noumea, New Caledonia.

Type material.

Most likely lost to science. Crosse’s types are deposited in the Muséum national d’Histoire naturelle (Paris), but the list of types by Valdés and Heros (1998) of Recent and fossil opisthobranchs does not mention any material of Goniodoris verrieri Crosse, 1875. We base our identification from Crosse’s illustration (1875: pl. 12, fig. 5), which agrees with the morphological study of Rudman (1985).

Geographical distribution.

Widely distributed around the tropical and subtropical Indo-Pacific oceans ( Rudman 1985; Debelius 1996; Debelius and Kuiter 2007; Coleman 2008; Gosliner et al. 2008, 2015, 2018) with reports from across South Africa, Madagascar, Indonesia, Papua New Guinea, Philippines, Midway Atoll, Hawaiian Islands ( Gosliner et al. 2018), Australia ( Slack-Smith and Bryce 2004; Nimbs and Smith 2016), Tanzania ( Rudman 1985), Thailand ( Mehrotra et al. 2021), Mozambique ( Strömvoll and Jones 2019), Japan ( Nakano 2018; Ono and Katou 2020), Taiwan ( Jie et al. 2009), New Caledonia ( Hervé 2010), Marshall Islands ( Rudman 1985), and Mariana Islands ( Carlson and Hoff 2003).

Material examined.

CASIZ 203059 (morphotype A), one specimen (3 mm preserved), subsampled for molecular data and dissected, Balibago dive site, 13.932°N, 120.611°E., Verde Island Passage Coast, Calatagan , Batangas Province , Luzon Island , Philippines, 12 m depth, 17 May 2014, S. Matsuda, 2014 Verde Island Passage Expedition. CASIZ 208442 (morphotype B), one specimen (5 mm preserved), subsampled for molecular data and dissected. Culebra (Bonito) Island, 13.617°N, 120.933°E, Maricaban Island , Tingloy, Batangas Province, Luzon, Philippines, 3-30 m depth, 18 April 2015, G. Paulay, 2015 Verde Island Passage Expedition .

Description.

External morphology. Living animals approximately 11-17 mm in length. Body oval, with two marginal bands of similar widths on the mantle edge. Gill and rhinophores are translucent red with a mix of red and white edges. Four to eight unipinnate gill branches. Ten or eleven lamellae on rhinophores. The color patterns of this species can be divided into two distinct morphotypes. Morphotype A (Fig. 3e ) has an opaque white body. The outermost portion of the mantle edge is surrounded by a red margin and a yellow submarginal band with both bands of similar widths. Morphotype B (Fig. 3f ) has a translucent creamy white body with small orange spots on the notum. The outermost portion of the mantle edge is surrounded by a very thin opaque white band, followed by a red and a yellow submarginal band.

Buccal mass and radula (morphotype A). The muscular portion of the buccal mass is approximately the same size as the oral tube length (Fig. 6c ). The chitinous labial cuticle found at the anterior end of the muscular portion of the buccal mass bearing bifurcated and short jaw rodlets (Fig. 11a, b ). The radular formula of CASIZ 203059 is 37 × 28.1.28 (Fig. 11c ). The rachidian tooth is flame-like in shape and short. The inner and outer surfaces of the inner lateral teeth have three denticles on each side (Fig. 11d ). The central cusp on the inner lateral tooth is ~ 2 × the length of the adjacent denticles. The middle lateral teeth have a short central cusp with approximately four or five denticles (Fig. 11e ). The outer lateral teeth have a rounded tooth shaped with ~ 2-4 denticles (Fig. 11f ).

Reproductive system (Fig. 6d ). The thick, tubular ampulla narrows into a diverging short oviduct and long vas deferens. The proximal prostatic portion of the vas deferens is wide and convoluted and transitions into the muscular ejaculatory portion. The long, narrow, convoluted ejaculatory portion transitions into a wider, long penial bulb, which joins with the distal end of the vagina. The thick muscular vagina is elongated and transitions into a larger, spherical bursa copulatrix. At this junction of the vagina and bursa copulatrix, the smaller pyriform receptaculum seminis also connects. The moderately long uterine duct that emerges from the junction of the vagina, bursa copulatrix, and receptaculum seminis enters into the female gland mass. This uterine duct junction also extends proximally on one side and includes a larger portion of the vagina. The female gland mass has small albumen and membrane glands and a large mucous gland.

Remarks.

Goniobranchus verrieri was originally described by Crosse (1875) from New Caledonia. The species had been previously described by Pease (1860) as Doris marginata from Hawaiʻi. However, the name Doris marginata was pre-occupied: several different species had been given the same name and Goniobranchus verrieri is the next available name for this species. Crosse described the animal as having a white body and the mantle edged in a light red margin and a yellow tinged submarginal band. This description matches the external morphology of the G. verrieri morphotype A in this study and specimens studied by Rudman (1985).

Goniobranchus verrieri morphotype B has a creamy translucent body with small orange spots on the notum and three marginal bands on mantle edge. Although this pattern did not match with the original description of G. verrieri , the phylogenetic and species delimitation analyses in this study showed that G. verrieri morphotype B is clustered with morphotype A. Based on this result, we consider morphotype B a color variation of G. verrieri . Both morphotypes also showed little genetic differences (intraspecific p -COI distance within G. verrieri = 1.3-3.7%), also suggesting that G. verrieri has morphological variation, similarly observed in some other white Goniobranchus species with marginal bands in this study. The vast majority of specimens of G. verrieri closely resemble morphotype A and there has been relatively little confusion of this species with others that have a white body and marginal bands. Spotted specimens of G. verrieri could be confused with G. preciosus , but have a more spreading gill plume whereas G. preciosus always have an erect gill plume.

Figures

Figure 3. a-d Goniobranchus sinensis a CASIZ 176759, morphotype A, Peninsular Malaysia b MISE- 018 - 19, morphotype B, Okinawa, Japan c MISE- 55 - 19, morphotype B, Okinawa, Japan d MISE- 039 - 19, morphotype C, Kagoshima, Japan e, f Goniobranchus verrieri e CASIZ 203059, morphotype A, Philippines f CASIZ 208442, morphotype B, Philippines. Photographs a, e, f TMG; b-d GYS. Scale bars: 1 cm.

Figure 6. a buccal mass of Goniobranchus sinensis, MISE- 047 - 19 b reproductive system of Goniobranchus sinensis, MISE- 047 - 19 c buccal mass of Goniobranchus verrieri, CASIZ 203059 d reproductive system of Goniobranchus verrieri, CASIZ 203059 e bBuccal mass of Goniobranchus fabulus sp. nov., CASIZ 191271 f reproductive system of Goniobranchus fabulus sp. nov., CASIZ 191271. Abbreviations: am, ampulla; bb, buccal bulb; bc, bursa copulatrix; ej, ejaculatory duct; es, esophagus; fgm, female gland mass; ot, oral tube; p, penis; pr, prostate; ra, radular sac; rs, receptaculum seminis; va, vagina. Scale bars: 0.1 mm (c, d, e, f); 1 mm (a, b).

Figure 11. Scanning electron micrographs. Goniobranchus verrieri, CASIZ 203059, Philippines. a jaw b jaw rodlets c radula d central teeth e mid-lateral teeth f outer lateral teeth.