Paleanotus inornatus, Watson, Charlotte, 2015

Watson, Charlotte, 2015, Seven new species of Paleanotus (Annelida: Chrysopetalidae) described from Lizard Island, Great Barrier Reef, and coral reefs of northern Australia and the Indo-Pacific: two cryptic species pairs revealed between western Pacific Ocean and the eastern Indian Ocean, Zootaxa 4019 (1), pp. 707-732 : 711-714

publication ID	https://doi.org/ 10.11646/zootaxa.4019.1.24
publication LSID	lsid:zoobank.org:pub:DCC47F0B-859E-475A-A7AB-493434F24DF8
DOI	https://doi.org/10.5281/zenodo.6121348
persistent identifier	https://treatment.plazi.org/id/903F87E0-A873-FFA7-FF56-FAC9FBF4FC75
treatment provided by	Plazi
scientific name	Paleanotus inornatus
status	sp. nov.

Treatment

Paleanotus inornatus View in CoL n. sp.

( Figs 1 View FIGURE 1. A C; 2A −I)

Type material. Holotype: NTM W.25390, Western Pacific Ocean, Australia, Queensland, GBR, Day Reef, 14º28.33’S, 145º31.41’E, CReefs, LI-10-074, clean coralline rubble, 5−10 m, coll. C. Buxton, Sep 2010, (26E, L: 2.2 mm, W: 0.5 mm). Paratypes: NTM W.25391, same locality as holotype (4 NE).

Other material examined. NTM W.23679, Day Reef, 14º26.87’S, 145º29.95’E, Stn. LI-09-048, rubble, 30 m, coll. CReefs, Feb 2009, (4: 30E, L: 2.2mm, W: 0.55 mm; 33E, L: 3.4 mm, W: 0.65 mm; 2NE); NTM W.23692, Yonge Reef, 14º34.38’S, 145º31.13’E, CReefs, LI-10-126, rubble, coll. C. Buxton, Sep 2010, (1, 31E, L: 2.2 mm, W: 0.65 mm); NTM W.23684, MacGillivray Reef, 14º38.87’S, 145º29.19’E, CReefs, LI-10-041, coral rubble, 14– 20 m, Aug 2010, (3NE); NTM W.25631, CReefs, LI-10-034, rubble, 14–20 m, Aug 2010, (1E); NTM W.23203, North Direction Island, 14º44.62’S, 145º30.72’E, CReefs, LI-08-19, rubble, 2 m, coll. C. Glasby, Apr 2008, (7:1, 23 E, L: 3 mm, W: 0.5 mm); NTM W.25632, High Rock, 14º34.38’S, 145º31.13’E, CReefs, LI-10-135, clean coralline rubble, 30 m, coll. C. Buxton, Sep 2010, (4: 1,23E, L: 2.3 mm, W: 0.45 mm); NTM W.23661, Snake Pit, 14º40.20’S, 145º34.04’E, CReefs, LI-10-054, Halimeda beds, 30 m, coll. CReefs, Feb 2010, (1 male, 25NE); AM W.23344, Outer Barrier, Cooks Passage, Cod Hole, coral rubble, 10 m, coll. A. Murray, Sep 1995, (1, 31E, W: 0.76 mm, female); NTM W.23712, Coral Sea, Flora Reef, 16º45’S, 147º43.7’E, fine rubble, 42 m, coll. C. Buxton, Oct 2010, (1, 17 NE, W: 0.47 mm); NTM W.23194, Heron Island, CReefs, HI-09-001, North Wistari Reef, 23º 27.11S, 151º 52.02 E, Nov 2009, (1NE); NTM W.23192, CReefs, HI-09-045, Harry’s Canyons, 15 m, rubble, Nov 2009, (1, 26E); NTM W. 23659, CReefs, HI-10-040, 12 m, rubble under overhang, coll. M. Capa, Nov 2010, (1); NTM W.3021, Arafura Sea, NT, Channel Island, Darwin, washings Halimeda , 0.1 m, coll. C. Watson, Oct 1985, (1, 22NE, L: 3.4 mm, W: 0.66 mm); NTM W.25787, Indian Ocean, WA, Kimberleys, Stn. 127-146 K13, 14 m, coll. L. Avery, Sep 2013, (1, 36E); NTM W.23187, Ningaloo Reef, off northern passage near Tantabiddi, 21º51.15’S, 113º2.04’E, CReefs, NR-08-3B, coll. N. Bruce, June 2008, (fragment); NTM W.23453, CReefs, NR-10-021, coral blocks, 30 m, coll. Merrick, May 2010, (1NE); NTM W.23654, Outer Ningaloo Reef, 22º39.33’S, 113º37.00’E, CReefs, NR-09-004, May 2009, (1NE); NTM W.23726, Norwegian Channel, Stn. CReefs, NR-10-021, coral blocks, 30 m, coll. Merrick, May 2010, (1NE); AM W.33493, North end of Long Island, Stn.WA 522, 28º27.9’S, 113º46.3’E, dead coral substrate covered in coralline & brown algae, 5−6 m, coll. C. Bryce, May 1994, (1); AM W.33491, Goss Passage, 28º25.5’S, 113º47’E, Stn. 526, dead coral substrate embedded in fine sediment at base of reef slope, 33 m, coll. P. Hutchings, May 1994, (3: 1, 39E); AM W.36171, Dampier Archipelago, Legendre Island, Stn. WA 645, 14 m, Aug 2000, coll. P. Hutchings & L. Avery, (1NE); AM W. 36168, Angel Island, Stn. WA 642, dead coral, 14 m, Aug 2000, coll. P. Hutchings & L. Avery, (1NE); NTM W.7573, New Guinea, Madang, Sandy Bay behind Wongat Island, 5º10’S, 145º50’E, Stn. 99, coral rubble in sand, 3–6 m, coll. J.R. Hanley, 19 Oct 1991, (1, 45E, male, L: 6 mm, W: 0.7 mm); NTM W.25261, Indonesia, Flores, Maumere, 8º35’S, 112º13’E, Halimeda and rubble, 3–6 m, coll. B. Russell, Nov 1991, (fragments); NTM W.25620, Philippines, Luzon, Batangas province, Batangas Bay, Sombrero Island, 13º41.91’N, 120º49.37’E, coral blocks, 20 m, coll. G. San Martin, 9 Dec 2010, (1, 19 E, L: 2.2 mm, W: 0.7 mm, plus fragments); CAS 185685, Bonito Island, 13º63’N, 120º95’E, coral rubble, 1−15 m, coll. C. Piotrowski, 16 May 2011, (1E, ovigerous female).

Paleanotus inornatus species complex

AM W.23352, Tasman Sea, NSW, Middleton Reef, Stn. 8, 15 m, coll. P. Hutchings, Dec 1987, (2 NE); AM W.23354, Elizabeth Reef, Stn. 43, reef flat, Dec 1987, coll. P. Hutchings, (2E); AM W.38737, southern NSW, Tathra, Little Kianinny Gutter, Stn. NSW 2397, in algae Delicea pulchra, Mar 2004 , coll. AM team, (1, 19E, L: 1.5 mm, W: 0.49 mm); AM W.38736, Stn. NSW 2388, Guerilla Bay, in algae Dilophus intermedius, Mar 2004 , (5); NTM W.23464, Eastern Pacific Ocean, French Polynesia, Moorea, Stn. 487, outer reef between Opunohu Bay & Motus Islands, 15−18 m, coll. J. Moore, Oct 2010, (1NE, ovigerous female).

Description. (based on holotype and other material where noted). Slender, pale to white bodied with dark gut (gut often red when alive, blackish/green when preserved). Flat dorsum with paleael notochaetae silvery sometimes with pale golden shine; neuropodia tucked under notopodia. Live eye colour bright red. Notopodia of chaetiger 1 with 2–4 short paleae with broad tips; same shape as lateral paleae down body.

Notochaetae of mid-body notopodium composed of 2 lateral paleae either both with broad symmetrical tips or superior one slightly pointed; posterior one always broad-tipped with 5–7(8) ribs. Subunit 1 paleae number 1–2; slender, short, pointed distally, with 5–6 ribs ( Fig. 2 View FIGURE 2 A, H, I). Main paleae rounded distally with very fine serration on brow leading to small apical space and apice. Ribs number 11–13, 14 (15) including about 5 fine, b.l. ribs, most visible basally; very finely spaced horizontal straie. Dorsal cirri, slender, subulate ( Figs 1 View FIGURE 1. A C, 2A, I). Broad median paleae (particularly distally), number 3, with 10–12 ribs; very finely raised 4–7 b.l. ribs present, central raised rib absent ( Fig. 2 View FIGURE 2 B, H).

Neurochaetae of mid-body neuropodium composed of 2 long, slender superior falcigers, 2–3 shorter long falcigers ( Fig. 2 View FIGURE 2 D); 10 mid- superior, medium length falcigers with longer basal serration; 10 shorter falcigers midinferior position; 10 inferior shortest falcigers; total number about 35. Ventral cirri subulate ( Fig. 2 View FIGURE 2 A, C–G).

Remarks. Paleanotus inornatus n. sp. is a small species characterized by broad, distally rounded main paleae and distinctive, broad median paleae that lack distinct raised ribs. These features are present in all northern Australian reefal material: GBR, QLD; Darwin, NT; Kimberley and Ningaloo Reef, WA. Majority of mature specimens attain a length to 4 mm, width to 0.6 mm and to 36 segments entire. One New Guinea male specimen was larger at 45 segments (length 6 mm, width 0.7 mm).

Material from N and NW Australia possess slightly different shaped median paleae group in comparison to that from NE Australia. The tallest median palea is more slender and the shortest is broader compared to the median paleae group of GBR specimens (cf Fig. 2 View FIGURE 2 B & 2H); there is also displayed a more obvious ‘broken line’ pattern. The rib numbers of the median and all paleae groups are in the same range between specimens from western and eastern Australian coasts. It is possible West Australian coast P. inornatus n. sp. material is a different species, but until comparative DNA work is undertaken there is only one species identified.

Examined material of P. inornatus n. sp. from the Western Pacific (New Guinea, Indonesia and Philippines) and Eastern Pacific (Moorea) exhibit main and median paleae shape and paleal rib numbers similar to those of the GBR. Females possessing typical ‘flower’ glands, large eggs and oil globules are observed in GBR, Philippine and Moorea specimens ( Fig. 2 View FIGURE 2 I).

In comparison to other Paleanotus species described in this paper P. inornatus n. sp. forms the most widespread Indo-Pacific cryptic complex. Individuals examined from the Red Sea and Eastern Mediterranean reefs are being described as a new species (Watson & Chatzigeogiou, submitted) and it has been recorded from Moorea in the eastern Pacific. Paleanotus inornatus species complex is found from eastern Australian localities at Middleton and Elizabeth Reefs, Tasman Sea and southern NSW. Tropical chrysopetalid fauna may be recorded in these latter areas (e.g., Treptopale homalos from Middleton Reef by Watson 2010).

Paleanotus inornatus n. sp. is commonly found sympatrically with, and has some morphological similarity to, P. adornatus n. sp. Both possess similar sized small bodies and number of segments, translucent to silvery/pale golden coloured paleae with a dark gut often showing through and a flat dorsum with neuropodia tucked under notopodia. Observation of chaetal differences between the two species reveal Paleanotus inornatus n. sp. possess lateral paleae with broader tips; broader, rounded main paleae with slightly higher rib number (11–14 (15)) vs 11– 13 (14)); finer horizontal striae, and very ‘clean, smooth‘ paleael surface with little ornamentation. Paleanotus inornatus n. sp. also possesses much broader median paleae with multiple broken line ribs compared with the pointed apices and single, overt raised rib in P. adornatus median paleae (cf Figs 2 View FIGURE 2 B & 3C).

Etymology. The specific name, inornatus , comes from the Latin and refers to the ‘unadorned’ median paleae group possessing only a faint ‘broken line’ type of sculpture, lacking raised and ornamented ribs.

Habitat / Distribution. Paleanotus inornatus n. sp. is found primarily from a rubble habitat in coral reefs of the northern and southern GBR, northern Australia, NW Australia and New Guinea, Indonesia and the Philippines; intertidal to 42 m. Paleanotus inornatus species complex includes material examined from Moorea, eastern Pacific; reefs of the Tasman Sea and temperate, mainland rocky coasts of NSW.