Paleanotus silopsis, 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 : 724-726

Paleanotus silopsis n. sp.

( Figs 1 H; 7A −D)

Type material. Holotype: NTM W.24186, Western Pacific Ocean, Australia, QLD, GBR, Lizard Island, Mermaid Cove, 14º38.76’S, 145º27.216’E, CReefs, LI-10-19, coral rubble, 2 m, coll. C. Watson, Sep 2010, (1, 100NE, L: 11 mm, W: 0.64 mm). Paratype: NTM W.22923, same details as holotype, (1, 30 E, L: 3.2 mm, W: 0.8 mm).

Other material examined. NTM W.24186, High Rock, CReefs, LI-10-134C, 6 m, coral rubble, coll. C. Buxton, Sep 2010, (1 fragment, male); NTM W.23203, Day Reef, CReefs, LI-09-019, coral rubble, 10 m, coll. M. Blazewicz-Paszokowycz, Feb 2009, (1NE); AM W.46151, Lizard Island, MI QLD 2359, (1); SIO A3633, Indonesia, West Papua, Raja Ampat, Moiskon Island, coll. G. Rouse, 2012, (2: 1, male, 36E, L: 4.6 mm; W: 0.5 mm; 1, 23NE, anterior end, L: 1.5 mm; W: 0. 35 mm);

NTM W.25639, Philippines, Luzon Island, Batangas Bay, Koala Point, 13º44.3’N, 120º53.4’E, rubble & yellow sponge, 10−16 m, coll. San Martin et al., Dec 2010, (1, 64 NE, W: 0.45 mm); NTM W.24188, Palawan Island, El Nido, 11º41’N, 119º25’E, coral rubble with Lithothamnion , small red coralline algae, 3−12 m, Dec 2010, coll. C. Watson et al., (1, 70 NE, ovigerous female, L: 6.5 mm, W: 0.51 mm).

P. silopsis species complex

NTM W.25637, Eastern Pacific, Moorea, Outer reef between Opunuhu Bay & Motus Islands, Stn. 487, 15– 18m, coll. J. Moore, Oct 2010, (1, 92E; 1NE, mid-body fragment, male with sperm, W: 0.37 mm).

Description. (based on holotype and other material where noted). Long, slender body with small parapodia, short, notochaetal paleal fans transparent to pale golden colour. Live Philippine specimen with pale body, bright, lightgold paleae. Holotype 100 segments not entire, length 11 mm, width 0.64 mm. Anterior end same as that described for P.s i l u s n. sp. with two pairs of maroon-red eyes dominating prostomium; median antenna comparatively more subulate, not with swollen tip ( Fig. 7 A).

Notochaetae of mid-body notopodium composed of 2–4 pointed lateral paleae with slender, fine serrate margins, 4–6 ribs; single sub-unit 1 palea with 7–9 ribs; short spine may be present ( Fig. 7 C). Main paleae number up to 10 with shallow apices, serrate convex margin to apex (tiny hoods may be present); 14–17 ribs, nearly all with full length b.l. pattern. Median paleae number 3–5 with (13), 14–17 ribs, including 3−4 noticeable raised ribs and up to 14 b.l. ribs; median broad, leaf-shaped with pointed tips ( Fig. 7 B, D).

Neurochaetae of mid-body neuropodium composed of 2 superior long falcigers; 1 slightly shorter midsuperior; 15 mid-group falciger; about 5 inferior shortest falcigers. Total number approximately 25 with all compound articles slender; ventral cirrus subulate ( Fig. 7 C).

Remarks. Paleanotus silopsis n. sp. is represented by two entire specimens from Thailand and Indonesia; other specimens are broken with no anterior or posterior ends present. One GBR individual of 100 segments, not entire, has a length of 11 mm. Diagnostic characters of Paleanotus silopsis n. sp. include broad, leaf shaped and pointed median paleae; broad main paleae rounded distally with a slightly more distinct apex; greater degree of serrated paleae margins and b.l. projection and ventral cirri basally more broad ( Figs 1 H; 7B, D).

Paleanotus silopsis n. sp. (western Pacific Ocean) is very similar to P. silus n. sp. (eastern Indian Ocean) but possesses median paleae of a different shape with a greater number of ribs and main paleae with a slightly greater number of ribs (detailed comparison in P. s i l u s n. sp. see Remarks).

One male from Raja Ampat had sperm visible in segments 6 to 36 of an entire specimen. A Philippine ovigerous female had large eggs, similar in size to those observed in P. silus n. sp. Segments full of gametes may appear bead-like. A live male from Moorea had a clear body with yellow oil globules inside and white pigment on each segment, indicative of white granules; a condition seen in mature Treptopale species ( Watson 2010).

Eastern Pacific, Moorea specimen ( P. silopsis species complex) exhibits characters similar to the western Pacific P. s i l o ps i s n. sp., but agrees more with Caribbean Sea material collected by the author. These constitute a new species which will be described as part of a genetic study of the ‘ silus / silopsis ’complex (Watson in prep.).

Etymology. The species name silopsis refers to this species being very similar in appearance to silus . Silus refers to the pug-nosed shape of the main paleae and the Latin suffix ‘ opsis ’ refers to a likeness.

Habitat / Distribution. Paleanotus silopsis n. sp. is present along the western Pacific Ocean rim at Lizard Island, GBR, Indonesia and the Philippines. Found amongst coral rubble from 1− 16 m.

Figures

FIGURE 7. Paleanotus silopsis n. sp. A. Micropic of anterior and mid-body section, dorsal view, SIO A 3633: Indonesia, West Papua, Raja Ampat; B. Micropic of median paleae and medial main palea, NTM W. 24186: High Rock, GBR; C. Lateral paleae group and neuropodium, SIO A 3633: Indonesia, West Papua, Raja Ampat; D. Detail of median paleae group and medial main paleae, NTM W. 24188: Philippines. Abbreviations: la = lateral paleae, me = median paleae, mm = medial main paleae. Scale bars: D = 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.