Paleanotus aquifolia, 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 : 717-718

Paleanotus aquifolia n. sp.

( Figs 1 E; 4A −I)

Type material. Holotype: NTM W.25615, Western Pacific Ocean, Australia, QLD, GBR, MacGillivray Reef, 14º39.41’S, 145º29.68’E, CReefs, LI-09-034, coral rubble, 2−12 m, coll. C. Watson, Feb 2009, (29E, L: 3.0 mm, W: 0.7 mm). Paratypes: NTM W.125710, same locality as holotype, (3: 1, 39E, L: 5.2 mm, W: 0.7 mm).

Other material examined. NTM W.23451, MacGillivray Reef, 14º39.41’S, 145º29.68’E, CReefs, LI-10-028, coral rubble, 24 m, coll. M. Capa, Aug 2010, (2); NTM W.23440, Martin Reef, 14º38.73’S, 145º27.2’E, CReefs, LI-10-140, rubble & sediment, 18 m, coll. L. Avery, Aug 2010, (1, 44NE, W: 1.1 mm, ovigerous female); NTM W.23686, Martin Reef, CReefs, LI-10-035, silty sand & rubble, 5 m, coll. C. Watson, Sep 2010, (1, 33NE); NTM W.23204, Lizard Island, North Point, 14º38.73’S, 145º27.2’E, CReefs, LI-08-20, rubble, 2 m, coll. C. Watson & N. Bruce, Apr 2008, (1, 32NE, L: 4 mm, W: 0.8 mm); NTM W. 23449, North Direction Island, CReefs, LI-10-009, sand & rubble, 7–8 m, coll. M. Capa, Aug 2010, (1, 21NE, male, W: 0.9 mm); NTM W.23675, High Rock, 14º34.38’S, 145º31.13’E, CReefs, LI-10-135, clean coralline rubble, 30 m, coll. C. Buxton, Sep 2010, (1, 26E, L: 2.5 mm, W: 0.7 mm); NMV F.214514, Coral Sea, wreck of HMS Pandora , 11°21.25’S, 143°59.17’E, Stn. NQ 18, 1982, coll. G. Poore & H. Lew Ton, (1, 28NE, L: 5 mm); MV F.125884, Fantome Island, 18º40’S, 146º31’E, Stn NQ14, coral rubble, 9 m, coll. G. Poore & H. Lew Ton, Dec 1982, (1, 26NE); NTM W.25616, Heron Island, CReefs, HI-10-020A, sand & rubble, 12–16 m, coll. C. Buxton, Nov 2010, (1NE); NTM W.23462, CReefs, HI-10- 0 51, sand & rubble, 12–16 m, coll. C. Buxton, Nov 2010, (3:1, 17E, L: 1.00 mm, W: 0.5 mm; 2 NE); NTM W.23655, Harry’s Bommie, CReefs, HI-10-002, dead coral, 10 m, Nov 2010, (1E, W: 0.5 mm); NTM W.25617, Philippines, Luzon, Balayan Bay, Batangas, Sombrero Island, coral blocks, 17 m, coll. G. San Martin et al., Dec 2010, (1, ovigerous female); NTM W.25843, same locality, coral & sponges, 1−2 m, coll. C. Watson, Dec 2010, (1, 35E, ovigerous female).

Description. (based on holotype and other material where noted). Live colour yellow body, prostomium with two pairs of dark maroon eyes. Paleal fans appear less flattened; with distinct golden shine. Neurochaetae extend out a little from paleal fans. Notochaetae of mid-body notopodium composed of 2 (3) slender, pointed laterals with 4-6 ribs; 1 small pointed, su1 palea often present with 4–5 ribs ( Fig. 4 A, C, I). Main paleae number to 10, with 9, 10–12 ribs with up to 9 b.l. ribs, 2 often full length. Long, narrow- shaped main paleae possess pointy apices with small hoods; sloping brow with distinct finely raised margin serration ( Figs 1 E; 4B, C, I). Median paleae number 3 with 7–9 (10) ribs and central raised rib; pointed distal tips ( Fig. 4 A, B); dorsal cirri 2/3 length of main.

Neurochaetae of mid-body neuropodium composed of 2 superior very long falcigers with fine serration; 2 midsuperior long falcigers (not much shorter than superior) with long serrations especially basally; about 6–8 midgroup falcigers with basal serrations; 4–6 inferior-group falcigers with long, slender blades; ventral cirri subulate ( Fig. 4 C, D, H, I).

Remarks. Paleanotus aquifolia n. sp. is characterized by long, narrow main paleae with a distinct sloping brow; comparatively narrower lateral and sub-unit 1 paleae and robust neurochaetal types. Chaetal morphology and body measurements are similar between Lizard Island localities, reefs off Townsville and Heron Island, GBR. Paleanotus aquifolia n. sp. is found only along the NE Australian coast and the Philippines.

The Philippine female has large eggs in clusters stuck interamally and on the dorsal main paleae (220 µm diameter). Four eggs take up most of the body cavity and have similar measurements to that of the Lizard Island ovigerous specimen. Numbers and shapes of paleae types and rib numbers are also exactly the same as those found in GBR material. A Lizard Island male individual was observed to have sperm in lumps attached to the ventrum plus copious oil globules. As observed in other Paleanotus species the inter-ramal cilia appear particularly long in mature individuals and inter-ramal glands are enlarged ( Fig. 4 A, C, I).

On the NE Australian coast P. aquifolia n. sp. can be confused with P. adornatus n. sp. as the numbers of ribs of laterals, main and median overlap. The narrow, pointed shape of the main and median paleae and longer, slender articles of the neurochaetal falcigers distinguish P. aquifolia n. sp. from P. adornatus n. sp. (full comparison under P. adornatus n. sp. Remarks).

Paleanotus aquifolia n. sp. from GBR appears most similar to Paleanotus latifolia n. sp. from NW Australian coast (Darwin to Ningaloo Reef). Both species possess a similar body and eye colouration and are found in coral rubble with a predominantly silty sand component. Morphological similarities shared between east and west coast species include possession of comparatively narrower lateral paleae and robust apices forming a peak in main and median paleae. In both species the neurochaetae include robust, mid-superior falcigerous blades almost the same length as those of superior falcigers (cf Figs 4 D, E & 5D, E).

Paleanotus aquifolia n. sp. appears to be a slightly larger species (largest 44 E, length 5.6 mm, width to 1.1 mm) compared to Paleanotus latifolia n. sp, (largest 28E, length 4.4 mm, width to 0.7 mm). The main paleae shape is different in each species. Main paleae brow of Paleanotus aquifolia n. sp. is narrow and sloping compared to the brow of P. latifolia n. sp. which is rounded to sloping with distinctive close-set brow serration and apices slightly more centred ( Fig.1 E cf 1F). There are also differences in numbers of paleae types and ribs. Lateral paleae number is less in P.aquifolia n. sp. compared to latifolia (2 vs 2–3); main paleae rib numbers less (11–13 vs 12–14); 1 very small sub unit1 palea (1–2 ribs) vs often 2 broad sub unit 1 paleae with up to 7 ribs (cf Figs 4 I & 5A).

Paleanotus aquifolia n. sp. occurs in more sandy micro-habitats in clear water coral reefs of the NE coast and P. latifolia n. sp. in muddier coral reef areas in sediment laden waters of the N and NW Australian coasts.

Etymology. Species name P. aquifolia n. sp. is from a Latin compound noun, meaning ‘pointed leaf’. It refers particularly to the shape of the pointed apices of main and median paleae.

Habitat / Distribution. Paleanotus aquifolia n. sp. is recorded from the Western Pacific Ocean: NE Australia, Great Barrier Reef (north and south), and the Philippines, South-east Asia. Habitat is predominantly coral rubble and sediment; depth 2– 30 m.

Figures

FIGURE 4. Paleanotus aquifolia n. sp. A – B: NTM W. 23449: North Direction Island, GBR. A. Notopodium and neuropodium (neurochaetae omitted); B. Median and main paleae detail; C. Ovigerous female, notopodium, NTM W. 23440: Martin Reef, GBR. D – H: Neurochaetal types. D. Superior; E. Mid-superior; F – G. Mid-group; H. Inferior group; I. Micropic, notopodium in part & neuropodium; NTM W. 25843: Philippines. Abbreviations: c = cilia, e = egg, la = lateral paleae, me = median paleae, mm = medial main paleae, o. g = oil globules, sp = sperm, su 1 = sub-unit 1 palea. Scale bars: A = 200 µm, B = 30 µm, C = 100 µm, D – H = 30 µm.

FIGURE 1. A. Paleanotus generalized notochaetal fan; B. Main paleae sculptural detail. C – I: Comparative micropics of main palea in Paleanotus new species. C. Paleanotus inornatus n. sp., NTM W. 23684; D. P. adornatus n. sp., NTM. W. 23660; E. P. acquifolia n. sp., NTM W. 23440; F. P. latifolia n. sp., NTM. W. 23710; G. P. silus n. sp., NTM. W. 23731; H. P. silopsis n. sp., NTM W. 23186; I. P. chrysos n. sp., NTM. W. 25641. Abbreviations: b. l = ‘ broken line’sculpture, c = cilia, gl = gland, h. s = horizontal striae, la = lateral paleae, ma = main paleae, me = median paleae, r. r = raised rib, su 1 = sub-unit 1 palea.