Loandalia gladstonensis, Marks, Shona & Hocknull, Scott, 2006

Marks, Shona & Hocknull, Scott, 2006, New species of Loandalia (Polychaeta: Pilargidae) from Queensland, Australia, Zootaxa 1119, pp. 59-68 : 65-66

Loandalia gladstonensis sp. nov.

Fig 3 , a–d.

Etymology:

Gladstone Harbour, type locality.

Type Material:

Holotype. QMC G222948, Loandalia gladstonensis sp. nov. [Gladstone Harbour; station GH144, S23°57’ 976”, E151°20’ 908”; depth 0–5m]. Paratypes. QMC G222949, [Gladstone Harbour; station GH148, S23°50’ 894”, E151°13’ 811”; intertidal]. QMC G222950, [Gladstone Harbour; station GH038, S23°47’ 162”, E151°13’ 276”; intertidal]. QMC G222951, [Gladstone Harbour; station GH140, S23°51’ 170”, E151°18’ 892”; depth 0–5m]. QMC G222952, [Gladstone Harbour; station GH016, S23°44’ 431”, E151°08’ 132”; intertidal]. QMC G222953, [Gladstone Harbour, station GH014; S23°43’ 562”, E151°13’ 276”; depth 0–5m]. Habitat is intertidal or at depths of 0–5m, usually with sand or muddy substrates.

Diagnosis:

Bifid palpostyles; chaetigers 1–5 inflated; pharynx with distal ring of papillae (2 groups of 5); chaetiger 1 uniramous with remaining chaetigers biramous; single notochaeta present; straight emergent spine from chaetiger 7–8; ventral cirri present from chaetiger 5; 5–6 neurochaetae; posterior most segment possesses emergent notopodial spines and neuroacicula, with reduced parapodial lobes.

Description:

Pilargids of small size, length 30–62mm, with 79–114 chaetigers. Body of preserved individuals creamy/white to reddish/brown. Body slender with chaetiger 1–5 inflated; segmentation inconspicuous. Posterior segments slightly dorso­ventrally flattened. Prostomium discrete; palpophores divided; palpostyles papilla­like and bifid. Pharynx eversible with distal ring of 10 papillae, 5 dorsal and 5 ventral to pharyngeal slit; papillose band on pharynx, proximal to prostomium; pharyngeal slit vertical. Eye spots present, subdermal at chaetiger 1 ( Fig 3 , a). First parapodium uniramous with remaining chaetigers biramous; first neuropodia positioned dorsally compared to remaining chaetigers. Notopodial lobes fully developed by chaetiger 4; a single notochaetae present from chaetiger 2; notopodial spines emerging at chaetiger 7–8, increasing in length in posterior most 10 segments. Neuropodial lobe larger than notopodia, reduced in chaetiger 1–2; neurochaetae capillaries with numerous whorled teeth; 5–6 neurochaetae present per parapodia; emergent acicular from chaetiger 2. Ventral cirri from chaetiger 5( Fig 3 , b). Posterior most segment possesses emergent notopodial spines and neuroacicula, with considerably reduced parapodial lobes. Pygidium as an anal plate, dorsally concave with dorsal terminating anus, positioned at base of concave plate; 3 anal cirri present, papillaelike, 2 laterally and 1 mid ventrally positioned ( Fig 3 , c&d).

Remarks:

Loandalia gladstonensis differs from all species of Loandalia (except L. bennei , L.

evelinae and L. riojai ) by possessing bifid palpostyles. L. bennei , L. evelinae and L. riojai possess bifid palpostyles. L. gladstonensis further differs from L. gracilis and L. indica by possessing uniramous parapodia. L. gladstonensis differs from L. riojai , L. indica , L. ocularis , L. fauveli and L. americana by possessing a higher number of pharyngeal papillae (10). L. gladstonensis differs from L. evelinae , L. bennei and L. riojai by possessing a large rounded plate as the pygidium with papillae­like anal cirri. L. gladstonensis differs from L. evelinae , L. ocularis and L. vivianneae by the presence of emergent spines and neuroacicula on the last segment. L. gladstonensis differs from L. aberrans by lacking dorsal cirri. L. salazarvallejoi and L. fredrayorum differ from L. gladstonensis by possessing emergent notopodial spines starting at chaetiger 9 and 10 respectively; higher neurochaetae counts, 10–12 and 20–24 respectively. L. gladstonensis differs from L. maculata and L. tricuspis by possessing ventral cirri starting at chaetiger 5, versus chaetiger 4 in L. tricuspis and chaetiger 6 in L. maculata . Distinguishing features summarised in table 1.

Figures

FIGURE 3. Loandalia gladstonensis sp. nov. Holotype QMC G 222948 a) Anterior region, dorsal view. Scale = 0.5 mm. b) Parapodia of chaetiger 25, anterior view, left side. Not to scale. c) Posterior region, dorsal view. Scale = 0.2 mm. d) Posterior region, ventral view. Scale = 0.2 mm.