Actinopyga varians ( Selenka, 1867 )

Netchy, Kristin, Samyn, Yves & Paulay, Gustav, 2025, Dividing the monopoly: the most broadly distributed Actinopyga is two species (Holothuroidea: Holothuriidae), Zootaxa 5673 (1), pp. 27-44 : 32-39

Actinopyga varians ( Selenka, 1867)

( Figs 2A–C, 3A–D, 4A, 5A, 6, 7)

Holothuria (Psolus) monacaria Lesson, 1830: 225 , pl. 78.

Holothuria guamensis Quoy & Gaimard, 1834: 137 , no figure; original artwork subsequently published in Cherbonnier 1952: pl. II, Fig. 1.

Holothuria (Psolus) monacaria — Selenka 1867: 331.— Cherbonnier 1951a: 295–298.— Clark & Rowe 1967: 126–128.— ICZN 1970: 31–32 (name suppressed, ICZN Opinion 914), not Holothuria monacaria of authors. lsid:zoobank.org:act: E7E66233- 0BDA-400A-AE59-80FB89869154.

Mülleria mauritiana (non Quoy & Gaimard, 1834)— Semper 1868: 276.— Ludwig 1882: 134.— Théel 1886: 201.— Ludwig 1888: 812.— Mitsukuri 1912: 53, text fig. 11, pl. 3, figs 25–27.

Holothuria guamensis — Clark 1963: 383; ICZN 1966: 15 (name suppressed, ICZN Opinion 762). urn:lsid:zoobank.org:act:AA8E84AB-2375-4E67-8387-794FE7BFF575 .

Mulleria guamensis — Brandt 1835: 74.— Théel 1886: 202.

Mülleria varians Selenka, 1867: 310 , pl. 17, figs 4–9.— Selenka 1868: 116. urn:lsid:zoobank.org:act:6149D99C-81CE-47C2-AFE9-87E27BC76333 .

Actinopyga mauritiana (non Quoy & Gaimard, 1834)— Fisher 1907: 648, pl. 67, fig 1a–d.— Panning 1944: 54–55, figs 23, 24 a–z.— Clark 1946: 440.—Cherbonnier 1951: 11.— Domantay 1954: 349.— Rowe & Doty 1977: 228, fig. 2f, pl. 6d (colour picture).— Féral & Cherbonnier 1986: 72 (colour picture).— Paulay 1989: 27.— Rowe & Gates 1995: 287.— Massin 1996: 11, fig. 5 A–B.— Paulay 2003: 577.

Actinopyga varians ( Selenka, 1867) — Michonneau et al. 2013: 534–535.

Material examined:

Lectotype (here designated)

ZMH E.2497 (formerly MG.1165 ex Museum Godeffroy, Hamburg) Fidji.

Paralectotypes

Society Islands, Hawaii • MCZ: IZ: HOL-827 (4 specimens) • MCZ: IZ: HOL-828 (18 specimens) • Hawaii, MCZ: IZ: HOL-829 (12 specimens, not examined) .

Indonesia: RMNH 5399: Indonesia (only photo of specimen seen); USNM E 24620: Borneo, Sangihe Islands, 1–18 m; USNM E 24613: Sulawesi.

Philippines: USNM E 16674: Luzon Island, Camarines Sur, Nato, anchorage; USNM E 45682 : Negros Oriental, Apo Island, NW side; USNM E 27338: Zamboanga del Norte, Mindanao Island, SW side Silino Island; USNM E 2487: Luzon Island, near Mariveles; UF 4577: Batan.

Taiwan: USNM E 9152: Taiwan.

Japan: UF 10390 : Ryukyu Islands, Okinawa Island, Okinawa, Cape Maeda ; RUMF _ZE-00210*: Okinawa .

Papua New Guinea: RMNH 5405 : Papua New Guinea (only photo of specimen seen) ; RBINS I.G. 26373/ HOL.1539: Papua New Guinea; UF 14483 : Madang Province, Sair Island ; UF 14546 *: Madang Province, Kranket Island, Cape Jantzen , 13 m.

Mariana Islands: RBINS I.G.31558/ HOL.1666: USA, Guam, Tanguisson; UF 4578, 4582, 4583*, 4584: Guam, Hagatna Bay, Oca Point, fore reef, 3–6 m; UF 4765: Guam, Gun Beach, north side of cable track, outer reef slope, 2–4 m; UF 1695: Guam, North Pago Bay, reef flat, 0–1 m; UF 6307: Guam, Cocos Island, ocean side, intertidal, 0–1 m; UF 6724: Guam, Hagatna, south of Adelup Island, fore reef, 0–1 m; UF 12215: Guam, Piti Bay, inner reef margin; UF 1222: Guam, Pago Bay, near marine lab, 50m from shore; UF 12222: Guam, Pago Bay, inner reef flat, in Sargassum ; UF 12223: Guam, NCS Beach, outer reef flat, on wave washed rocks; UF 12224: Guam, Adelup Point, outer reef flat, rock. UF 12568: Agrihan Island, south tip of island, 12–13 m; UF 5009: Alamagan Island, surgy, exposed coast, 6 m; UF 3228: Saipan Island; UF 3119: Saipan Island, just North of Banzai; UF 4413: Saipan Island, Garapan, patch reef in just south of Lighthouse Channel. 5–8 m; UF 4533, 4534, 4998: Saipan Island, Garapan Lagoon, in front of Dai Ichi Hotel, 2–3 m; USNM E 16720: Guam, Apra Harbor, outside breakwater; USNM E 16722: Guam, Oca Point; USNM E 22704 : Guam, Oca Point; USNM E 31672: Guam; USNM E 51760 : Guam, Tumon, Reef Flat at Tumon.

Federated Stated of Micronesia (FSM): UF 6953 : Kosrae Island ; UF 3194 , 3299 , 3300 , 3302 : Pohnpei Island ; UF 13336 : Pohnpei Island, around Temwen Island , reef flat ; UF 11392 : Yap Island, Colonia Channel, seagrass, sandflat, wreck, 0–3 m ; UF 5881 *: Yap Island, Colonia, S side of Woneeday Channel, outer reef flat, near reef crest, 0–6 m ; USNM E 22723 : Kapingamarangi Atoll, Touhou .

Marshall Islands: UF 6760*: Majuro Atoll, Eneko, channel (West side of the island), intertidal rocks and pools, 0 m; UF 6762: Majuro Atoll, Rita, channel (North end of main island) intertidal rocks and seagrass, 0 m; UF 7032: Majuro Atoll, Arrak, lagoon side, reef slope, relatively high coral cover, some sand, 2–4 m; USNM E 21369 : Bikini Atoll, Enyu Island, lagoon side, tide pools; USNM E 21368 : Marshall Islands: Bikini Atoll, Enyu Island, SE corner of, outer reef; USNM E 22681 : Bikini Atoll , south end; USNM E 22701 : Enewetak Atoll, Arambiru Island, ocean reef; USNM E 29495: Bikini Atoll, Bikini Island; USNM E 35418 : Enewetak Atoll, Parry and Igurin Island; USNM E 35331: Enewetak Atoll, Parry Island, Elmer Reef.

Wake Island: UF 4490, 4491: forereef; UF 11516, 11524: ocean side of atoll.

Kiribati: Tungaru /Gilbert Islands: USNM E 16872 : Onotoa Atoll USNM E 16807 : Onotoa Atoll, About 7100 Ft S 50 Degrees West from Tekawa Church at Seaward Edge of Aon Te Baba Reef .

Line Islands: UF 5935*: Kingman Reef, NE/E of Atoll; UF 5759: Kiritimati Atoll, west side of atoll, N of passage; UF 5808*: Palmyra Atoll, South Atoll barrier reef rim seaward of sand islet.

Hawaiian Islands : UF 6156*: French Frigate Shoals; UF 1275: Maui Island, Hekili Point; UF 18329*: Oahu Island, Kaneohe Bay, Coconut Island, mammal pens; UF 18375*: Oahu Island, Kaneohe Bay, inshore ( SW) of Kapapa Island; UF 1765: Oahu Island, Ala Moana Beach, Magic Island; UF 4592*: Oahu Island, Ko Olina, West of Harbor Channel; UF 4593: Oahu Island, Ko Olina, West of Harbor Channel; USNM 30366 Hawaii Island, Kealakekua Bay, Palemano Point; USNM 30451: Niihau Island, Kamalina Bay; USNM 30453: Hawaii Island, Puako Bay; USNM 30450: Hawaii Island, Puako Bay; USNM 30448: Molokai Island, Laau Point, South of; USNM 30452: Oahu Island, Waialua; USNM 30449: Niihau Island, Kamalina Bay; USNM E 16783, Oahu Island, Waimea; USNM E 17049: Hawaii Island, Hilo Bay; USNM E 21295 : Oahu Island, Kahuku, Pupukea Beach Park; USNM E 22630 : Oahu Island, Near Waimea Bay; USNM E 22444 : Oahu Island, Near Waimea Bay; USNM E 22449 : Oahu Island, Near Waimea Bay; USNM E 25731: Oahu Island, Makapuu; USNM E 2691: Kailua; USNM E 45689 : United States, Hawaii. USNM E 16733: United States, Hawaii; USNM 30479: United States Hawaii.

Australia: UF 10211 *: Queensland, Heron Island ; UF 13373 : Australia, Queensland, Heron Island .

New Caledonia: UF 15777, 15746: Cook Reef; UF 15752: Huon Atoll, North tip; UF 15740: Portail Atoll.

Vanuatu: UF 4315 : Sanma Province, Tutuba Island , south shore near “crossroads” dive site .

Niue Island: UF 1494: Avaiki at Tuapa; UF 1953: reef flat at Tuapa, near shore in pools; UF 1958: reef flat at Tuapa, near shore in pools.

Fiji: UF 1581: Lau Islands, Matuku Island.

Tonga: UF 3147 : Tongatapu Island, Atata Island ; USNM E 21301 , 21396 , 22688 , 27488 : Vava’u Group, Niuafo’ou Island .

Cook Islands: USNM E 35714: Rarotonga Island, just west of Ava Avaroa; UF 1330: Cook Islands, Mauke Island, west side, on reef; UF 1975: Cook Islands, Mauke Island, west side, on reef; UF 931: Cook Islands, Rarotonga Island, Arorangi, fringing reef.

French Polynesia: UF 13223: Gambier Islands, NE of Aukena Island; UF 13951: Marquesas Islands; UF 14026: Marquesas Islands, Nuku Hiva, Baie des Contrôleurs; UF 14055: Marquesas Islands, Haut fond Est de Motane—Point 18; UF 14071: Marquesas Islands, UaPou-Hakaheteau; UF 14080: Marquesas Islands, Hatu Iti; UF 14081: Marquesas Islands, Hatu Iti; UF 15739: Marquesas Islands, Nuku Hiva, Les 4 grottes; UF 11213: Marquesas Islands Eiao Island, Charner Bay, E side of bay, North side of island; UF 11296: Marquesas Islands, Fatu Hiva Island, Mahitoa Point, SW side of island; UF 11176: Marquesas Islands Nuku Hiva Island, Haahopu Bay, in front of the wharf, West side of island; UF 11220: Marquesas Islands Nuku Hiva Island, Baie du Contrôleur, East side of bay near exit; UF 11298: Marquesas Islands, Nuku, Hiva Island Haahopu Bay, in front of the wharf, West side of island; UF 13658: Marquesas Islands, Nuku Hiva Island, Haahopu Bay, in front of the wharf, West side of island; UF 11268: Marquesas Islands, Tahuata Island Namahana Point, exit of Anaete Bay, west side of island; UF 11231*: Marquesas Islands Ua Huka Island, south of Teaeopiki Point, between Motukeokoo and Hemeni islets, east coast of island; UF 9109: Society Islands, Moorea Island, reef front and very narrow reef flat off north end of airfield; UF 614: Tuamotu Islands, Tikehau Atoll, hoa at east end of Tuaherahera Motu and adjacent outer reef flat SE of hoa, just off Ohotu Motu; USNM E 22660 : Tuamotu Archipelago, Mataiva Atoll, outer fringing reef north of main pass; USNM E 24489 : Tuamotu Archipelago, Raroia Atoll; USNM E 8255: Tuamotu Archipelago, Tikahau Atoll, causeway south of Matiti Island; USNM E 9938: Society Islands, Tahiti, Papeete, reef; USNM E 9922: Gambier Islands, Mangareva Island; USNM E 9933: Society Islands, Tahiti, Papeete, reef; USNM E 9941: Tuamotu Archipelago, Rangiroa Atoll, Mohegan Reef; USNM E: 9939, Tuamotu Archipelago, Makatea Island; USNM E 21388 : Society Islands, Bora Bora, Motu Tapin, west of outer leeward reef; USNM E 17091: Tuamotu Archipelago, Makemo Island.

Pitcairn Islands: USNM E: 37097, Pitcairn Islands (-24.37, -128.32).

Panama: USNM E 22543 , 22637 : Panama, Perlas Archipelago .

Description of ZMH.E.2497, lectotype from Fidji 5. Specimen well-relaxed, fixed and preserved, with a ventral longitudinal dissection, not eviscerated. Body dorsally rounded and ventrally flattened, with rounded anterior and posterior extremities. Length 70 mm; width 30 mm. Mouth ventral. Anus terminal. Color of dorsal body wall beige, with distinct whitish circles surrounding the dark podia. Color of ventral body wall slightly lighter, podia beige, not circled by white rings. Bivium clearly separated from trivium. Tentacles beige. Anal teeth white. Body wall smooth to the touch, 2–3 mm thick. Tube feet of trivium predominantly in ambulacral areas, but with considerable spreading into the interambulacrae. Dorsal podia less numerous than ventral ones, dispersed regularly. The number of tentacles could not be determined without further dissection, 11 were observed 6. Collar of papillae around the mouth missing. Anus surrounded by five anal teeth. 3 Polian vesicles (2 small, 2 mm long; 1 large, 10 mm long). About 10 stone canals. Cloaca 15 mm long. No Cuvierian tubules observed.

5 Féral & Cherbonnier (1986) provided an accurate description of a freshly collected specimen of this species (identified as

A. mauritiana by them), and they noted that the ventral mouth is surrounded by a circle of papillae and 25 large, brown tentacles. Cherbonnier & Féral (1986) did not report Cuvierian tubules. Two specimens of A. varians , recently (2010)

collected in Guam as present in the RBINS collection (I.G. 31558/ HOL.1666) also have a collar of papillae and 25 large brown tentacles. No Cuvierian tubules were observed in the latter two specimens. These observations complement the description of A. varians as here provided through the description of the lectotype .

6 24–26 (rarely a few fewer) tentacles were counted in live and preserved non-type specimens (KN, pers. obs.).

Ossicles. Tentacles with straight to slightly curved rods, not bifurcating, rugose-spiny at ends, 100–190 μm long ( Fig. 3A). Dorsal body wall with rosettes, 20–45 μm long, and spiny, sometimes bifurcating rods, 55–100 μm long (fig. 3B). Ventral body wall with grains, 7.5–20 μm long, and straight to slightly curved smooth rods with ends somewhat ragged, 50–65 μm long ( Fig. 3C & C’). Dorsal papillae with simple rosettes, 20–35 μm long, and unbranched, straight rods with spiny ends, 75–100 μm long ( Fig. 3D). Cloacal retractor muscles with straight, smooth, 30–50 μm long, spiny unbranched and branched rods, 30–80 μm long ( Fig. 3E), but the branched spiky rods might be a contamination from the cloacal wall. Longitudinal muscles with smooth, straight rods, 30–55 μm long ( Fig. 3F).

Live coloration

The bivium of Actinopyga varians is relatively smooth, “glossy”, with some lumpiness, but lacks the pronounced fine creasing seen in A. mauritiana . It is a mixture of vivid, slightly reddish brown intermixed with creamy white, giving a mottled appearance, with some irregular banding. In some individuals, brown, in others cream base color (e.g., type illustration of A. guamensis ) predominates. Papillae are brown and tend to be surrounded by a whitish ring often even in the brown patches. The trivium is white-grey to pale reddish-brown covered with numerous, densely-packed, pale-brown tube feet.

Distribution

Indonesia to Hawaii and Pitcairn Islands, and Panama. Panama records are based on two specimens ( USNM E22543 & E22637 ) from the Perlas Islands , so identified originally by Deichmann and reported on by Alvarado et al. (2010). These are two small specimens that fit the species, although they have not been sequenced. We are not aware of any other records and none have appeared in iNaturalist to date (18 Sept. 2024) that are attributable to Actinopyga .

Remarks

Muelleria varians is the first available name for the Pacific form in the Actinopyga mauritiana complex. This species was however first described as Holothuria (Psolus) monacaria by Lesson (1830) from Tahiti and Bora Bora in the Society Islands. Cherbonnier (1951a), in his review of Lesson’s species, recognized that the excellent original figure and description in Lesson fits well with A. mauritiana . He noted that while the “ holotype ” from Tahiti is lost, several of Lesson’s specimens from Bora Bora survived at the NMNH. As Lesson did not designate a holotype, all his specimens should be viewed as syntypes. No other species in the Society Islands can be confused with A. varians .

Holothuria monacaria Lesson, 1830 was however misinterpreted by most authors, beginning with Semper (1868) who put H. gyrifer Selenka, 1867 in its synonymy, thus effectively equating the concept of H. monacaria with the sea cucumber currently known as Holothuria hilla Lesson, 1830 . This misinterpretation was consolidated by Théel (1886) and followed by most holothurian workers in the ensuing 50 years. Deichmann (1938) was the first to point out that H. monacaria did not fit the current concept of H. hilla and began using H. gyrifer for the latter. Cherbonnier (1951b) then showed that another of Lesson’s species, H. hilla , is the oldest available name for H. monacaria aucttorum, and the senior synonym of H. gyrifer . Clark & Rowe (1967) petitioned the ICZN to suppress H. monacaria to preserve the well-known A. mauritiana , and this was granted by ICZN (1970) opinion 914.

Holothuria guamensis Quoy & Gaimard, 1834 , the next available name for Actinopyga varians , was also suppressed because of perceived confusion about its identity ( Clark 1963) by ICZN (1966) Opinion 762. Paulay (2003) discussed the history of this species that has been interpreted as either H. nobilis ( Cherbonnier 1952) or A. mauritiana ( Rowe & Doty 1977) . Quoy & Gaimard’s (1834) figure, together with their description that describes 26 tentacles clearly match A. varians .

The next and only other available name for this species is Muelleria varians Selenka, 1867 , name and identification that here we formally recognize.