Hyalopale cf. bispinosa, 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 : 344-347

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/771987EF-7766-3A34-2AFE-C360FACBDA90
treatment provided by	Plazi
scientific name	Hyalopale cf. bispinosa
status

Treatment

Hyalopale cf. bispinosa View in CoL

Fig. 1B View FIGURE 1

Material examined. Mediterranean Sea, USNM 1076945 About USNM , North Africa, Tunisia, Stn. 202B, coll. M.L. Jones, August 1973, 1, 10NE, L: 0.8mm, W: 0.6mm ; NTM W.25601, Spain, coll. Rafael Sarda, 2: 1, 10E, L: 1.14mm, W: 0.72mm ; 1, 14NE (gametes). NTM W.25602, Eastern Mediterranean , Greece, Crete, Elounda, 15m, coll. Chatzigeogiou et al, 2007, 1, 12E, L: 0.6mm, W: 0.35mm ; NTM W.25603, Elounda , 15m, coll. Chatzigeogiou et al, 2007, 2: 1, 9E, 1, 16E ; NTM W.25600, Elounda , 20m, coll. Chatzigeogiou et al, 2008, 1 anterior end

Diagnosis. Hyalopale with mid-body main paleae with sloping convex margin, 23/24 (26) ribs, 3–4 shallow raised ribs.

Description. Older Mediterranean museum material collected from Spain light brown colour; more recent fresh collections from Crete comprise individuals coloured a dark red-brown. Notopodium of segment II with four simple spines. Mid-body notochaetal fan with single lateral spine, 6–8 (9) main paleae, 1–2 short, curved midline spines. Main paleae with 23–24 (26) ribs with ~ 3–4 very shallow raised ribs ( Fig. 1B View FIGURE 1 ), lateral and midline-most main paleae with 19 ribs. Tunisian specimen poorly preserved. Main paleae shape similar to other Mediterranean material and possesses up to 22 ribs and four shallow raised ribs.

Remarks. In the absence of additional material from the locality the Tunisian specimen is provisionally included within Hyalopale bispinosa species complex. Mediterranean individuals of Hyalopale cf. bispinosa exhibit a similar shaped notochaetal fan and shape of main paleae when compared with that of H. bispinosa s.s., Western Atlantic, but the main paleae of the former possess a slightly lower range of rib numbers and includes shallow raised ribs; both share similar shaped apices but the brow is a little more rounded in the Mediterranean form (cf. Fig. 1A, B View FIGURE 1 ; Key). Mature specimens examined in this present study from the western and eastern Mediterranean did not exceed 16 segments with a length of 1.1mm; this is in comparison with Western Atlantic material of H. bispinosa s.s., e.g. Florida, 20E, L: 2.8mm and Bahamas, 17NE, L: 2.75mm. However, the number of ribs of the main paleae in the Mediterranean specimens (up to maximum 26), is similar between H. bispinosa material from the Eastern and Western Atlantic Oceans. In this paper, Mediterranean material of H. cf. bispinosa is represented by a DNA sequence from the island of Crete but cannot be confirmed as H. bispinosa s.s. until sequences are available for comparison from the type locality in the western Atlantic.

About twelve specimens, including mature individuals, were collected from Elounda and Alykes sites in Crete, predominantly from algae on rocky substrates at 15– 20m.

The Mediterranean Hyalopale cf. bispinosa , provides the only example to date of a Hyalopale species dwelling in deeper water. Specimens are also much darker coloured, which may indicate a degree of camouflage within a dark algal habitat. In comparison, all other Hyalopale species are found in shallow waters (0–2m) associated with lighter green algae and possess pale and patchy green coloured bodies. The Hyalopale feeding mode is hypothesized as predatory on algal-living invertebrates and is based on the buccal structure: a pair of small, pointed stylet jaws with an inner longitudinal groove and a muscular, barrel-like pharynx which includes calcified pharyngeal muscle; imaged through micro-CT for H. cf. bispinosa (as H. bispinosa ) from Crete ( Watson & Faulwetter 2017).