Hyalopale angeliensis, Watson & Tilic & Rouse, 2019

Watson, Charlotte, Tilic, Ekin & Rouse, Greg W., 2019, Revision of Hyalopale (Chrysopetalidae; Phyllodocida; Annelida): an amphi-Atlantic Hyalopale bispinosa species complex and five new species from reefs of the Caribbean Sea and Indo-Pacific Oceans, Zootaxa 4671 (3), pp. 339-368 : 355-356

publication ID	https://doi.org/ 10.11646/zootaxa.4671.3.2
publication LSID	lsid:zoobank.org:pub:99459D5F-3C35-4F7D-9768-D70616676851
persistent identifier	https://treatment.plazi.org/id/9106A06A-97A8-4D5D-A208-0F9C91152008
taxon LSID	lsid:zoobank.org:act:9106A06A-97A8-4D5D-A208-0F9C91152008
treatment provided by	Plazi
scientific name	Hyalopale angeliensis
status	sp. nov.

Treatment

Hyalopale angeliensis View in CoL sp. nov.

urn:lsid:zoobank.org:act:9106A06A-97A8-4D5D-A208-0F9C91152008

Figs 1E View FIGURE 1 ; 9 View FIGURE 9 A–D

Material examined. Holotype. AM W.3166, Eastern Indian Ocean, Western Australia, Dampier, Angel Island , Stn. WA639, 20° 48’ S, 116° 81’ E, 1 Aug 2000, coll. P. A. Hutchings, L. Avery, 13E, L: 0.92mm, W: 0.4mm.

Additional material. USNM 1076948 View Materials , Western Indian Ocean , Seychelles, Round Island, 19° 45’ S, 57° 50’E, Sta. 14, intertidal from sponge, coll. K. Buchanan, Dec 1975, 1, 13E, L: 1.1mm, W: 0.55mm GoogleMaps .

Diagnosis. Mid-body main paleae narrow with well-defined apices, (16)18–22 ribs, 4–6 shallow raised ribs.

Description (based on holotype except where noted).

Slightly wasted entire individual; body pale yellow, three pairs of melded dark red eyes; cirri intact, some neurochaetal types loosening in posterior body. Segment II with 4 short, curved notochaetal spines; segment III with lateral spine, 8 main paleae. Mid-body notochaetal fan with single lateral spine, 10 main paleae with 18–22 internal ribs, 4–6 patchy shallow raised ribs; midline spines absent. Main paleae slender with sloping brow, small blunt apices, inner margin may be slightly folded with minute serrations, convex margin with widely spaced serrations mid-way, becoming finer on brow leading to apex ( Fig. 9A View FIGURE 9 , Western Australia; Fig. 9B View FIGURE 9 , Seychelles). Narrower, lateral-most main with 16–17 ribs and 2–3 smaller, more symmetrical-shaped, midline-most main with lower number of ribs ( Fig. 9C View FIGURE 9 , see 16–11 ribs). Neurochaetae mid-body comprise: four superior group very long-bladed; three mid superior group long-bladed; 8 mid-group with slightly shorter-blades, basal serration; 4–5 inferior group slightly shorter bladed. Mid-body neuropodia with broader mid-group falcigers ( Fig. 9D View FIGURE 9 , Seychelles).

Remarks. The two specimens of Hyalopale angeliensis sp. nov. are found at localities occurring on a similar parallel at ~ 20° S in the Eastern and mid-Indian Ocean. Hyalopale angeliensis sp. nov. is a small species, pos- sessing a relatively low number of paleal ribs; material examined from north-western Western Australia and the Seychelles Islands exhibit very similar, relatively narrow main paleae shape (respectively Fig. 9A,B View FIGURE 9 ) with slightly upswept apices, 18–22 ribs and 4–6 shallow raised ribs. Both individuals also consistently possess 2–3 smaller, midline-most main paleae ( Fig. 9C View FIGURE 9 ); other Hyalopale species may only have 1–2 (rarely 3) smaller, midline-most main paleae. Hyalopale angeliensis sp. nov., and H. sapphiriglancyorum sp. nov. have a general similarity in the narrow- shaped main paleae (cf Fig. 1 E, G View FIGURE 1 ), but the former has more distinct ‘upswept’ apices, a slightly higher range of rib numbers and absence of midline spines, compared to the latter. The absence of midline spines seen in Hyalopale angeliensis sp. nov. (Eastern Indian Ocean) is also observed in H. furfuricula sp. nov. (Western Indian Ocean) but both species possess very different main paleae shape and raised rib patterns (cf Fig. 1 E, D View FIGURE 1 ). Unfortunately, no DNA sequences could be acquired for this new species.