Phylo fimbriata (Moore, 1903)

Sun, Yue, Yu, Lei & Li, Xinzheng, 2021, A new species and a new species record of Orbiniidae Hartman, 1942 (Annelida, Polychaeta) from China, ZooKeys 1068, pp. 1-11 : 1

publication ID	https://dx.doi.org/10.3897/zookeys.1068.71925
persistent identifier	https://treatment.plazi.org/id/6CE87C04-0F9A-5BEE-A185-8F6652DE9309
treatment provided by	ZooKeys by Pensoft
scientific name	Phylo fimbriata (Moore, 1903)
status

Treatment

Figures 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6

Aricia fimbriata Moore, 1903: 464-467, pl. XXIV, figs 33-35; Okuda 1937: 99-101, figs 1, 2.

Phylo fimbriata : Hartman 1957: 267.

Material examined.

YCTU000006: ECS, Sta. 3100-8, 31°00'N, 126°00'E, 51 m, soft mud substrate, Jun. 2014. YCTU000007: ECS, Sta. I3, 33°00'N, 123°00'E, 34 m, soft mud substrate, 20 Sep. 2015. MBM009966: ECS, Sta. 4134, 29°30'N, 123°00'E, 50 m, soft mud substrate, 20 Jan. 1959. MBM 023276: ECS, Sta. 4007, 33°30'N, 122°30'E, 37 m, soft mud substrate, 13 Apr. 1959.

Description.

All specimens incomplete, posterior end missing. Body elongate, about same width throughout; thorax depressed, abdominal chaetigers cylindrical.

Prostomium short, conical, tapering to rounded tip; eyepots absent; nuchal organs narrow groove at junction with peristomium. Peristomium an asetigerous segment, distinctly separated from prostomium and chaetiger 1; mouth with anterior oral lip arising from posterior margin of peristomium, posterior oral lip from anterior margin of chaetiger 2. Proboscis everted, consisting of 2 large, inflated lobes.

Thorax with 16 chaetigers, divided into anterior and posterior sections: anterior thorax with 12 chaetigers, posterior thorax with modified spines from chaetiger 13 continuing over 4 chaetigers. Intersegmental annulations first present from chaetiger 1, well developed (Fig. 4A View Figure 4 ).

Both thoracic notopodia and neuropodia with fringed postchaetal lobes; notopodium half as broad as the neuropodium, broadly palmate (Figs 4A View Figure 4 , 5A View Figure 5 ). Notopodia with single conical postchaetal lobe from chaetiger 1, increasing gradually to about 6 lobes on posterior thoracic chaetigers; postchaetal lobes equivalent in size and shape on anterior chaetigers, with inner lobe separate and becoming longer than the outer ones on the posterior chaetigers (Fig. 4A, C View Figure 4 ). Abdominal notopodial postchaetal lobe arising from narrow base, broadly triangular (Fig. 4B View Figure 4 ).

Thoracic neuropodia thick, elongate, strictly lateral, bearing numerous subuluncini and capillaries (Fig. 4A, C View Figure 4 ). Neuropodium with 1-3 conical postchaetal lobes from chaetiger 1, increasing gradually to about 15 lobes on chaetigers 9 (Figs 4A, C View Figure 4 , 6A View Figure 6 ). Subpodial lobes or stomach papillae present on chaetiger 17-19, numbering 2 or 3. Abdominal neuropodia bilobed, with inner lobe blunted, outer lobe cirriform (Fig. 4B View Figure 4 ). First abdominal chaetiger with 3-6 extra lobes or ventral cirri ventral to neuropodium, then reduced to a single cirrus on subsequent chaetigers (Fig. 4B View Figure 4 ). Interramal cirrus absent.

Branchiae from chaetiger 5, each anterior branchia broad, tapering to narrow rounded tip (Fig. 4C View Figure 4 ), subsequent branchiae narrower and longer, leaflike and ciliated (Fig. 4B View Figure 4 ).

Thoracic notopodia with fascicles of crenulated capillaries (Figs 5A View Figure 5 , 6A, B View Figure 6 ). Abdominal notopodia with fewer long, thin capillaries, 3 or 4 furcate chaetae and 4-8 imbedded aciculae (Fig. 4B View Figure 4 ). Anterior thoracic neuropodia with numerous yellow subuluncini and crenulated capillaries (Figs 5B View Figure 5 , 6A View Figure 6 ). Subuluncini arranged in dense phalanx, with anterior ranks strongly curved, much shorter than posterior ranks (Fig. 5A, B View Figure 5 ). Subuluncini tapering to narrow pointed tip, covered with sheath, shaft with transverse rows of minute ribs or barbs (Fig. 5C View Figure 5 ). Posterior thoracic neuropodia with 4 or 5 modified spines, several subuluncini and crenulated capillaries ventral to the modified spines (Fig. 6B View Figure 6 ). Modified spines large, superior one projecting from neuropodium, with glandular pouch (Figs 4D View Figure 4 , 5D View Figure 5 , 6B, C View Figure 6 ). Abdominal neurochaetae including thin capillaries and 1-3 aciculae (Fig. 5B View Figure 5 ).

Pygidium not observed.

Distribution.

East China Sea (China); Suruga Bay, Miyagi Prefecture (Japan).

Remarks.

Phylo fimbriata (Moore, 1903), which was first reported by Moore (1903) from Suruga Bay and North Japan, has fringed postchaetal lobes on the thoracic notopodia unlike most species of Phylo . Okuda (1937) redescribed this species based on specimens from Miyagi Prefecture. The morphology of present specimens agrees well with the original description of specimens from Japan.