Research Article |
Corresponding author: Xinzheng Li ( lixzh@qdio.ac.cn ) Academic editor: Christopher Glasby
© 2021 Yue Sun, Lei Yu, Xinzheng Li.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Sun Y, Yu L, Li X (2021) A new species and a new species record of Orbiniidae Hartman, 1942 (Annelida, Polychaeta) from China. ZooKeys 1068: 1-11. https://doi.org/10.3897/zookeys.1068.71925
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A new species of the orbiniid genus Phylo Kinberg, 1866, P. heterochaetus sp. nov., is described based on material collected from the northern Yellow Sea, China. This is the thirteenth species in Phylo. The new species can be easily identified by the combination of the following characters: anterior thorax with 13 chaetigers, interramal cirri absent, anterior thoracic neuropodia with 4 or 5 rows of uncini, intermixed with a few subuluncini in the first 1 or 2 rows, and a ventral fringe of numerous stomach papillae present on chaetigers 12–24. Phylo fimbriata is recorded for the first time from China seas.
China Seas, new record, Phylo, taxonomy
Phylo Kinberg, 1866 belongs to Orbiniidae Hartman, 1942 and differs from the other genera of that family in having species with modified spines on posterior thoracic chaetigers. Although species of Phylo are closely related to Orbinia species based on molecular analyses (
The genus Phylo is characterized as follows: branchiae first present from chaetiger 5–7; thoracic neuropodia fringed, with several postchaetal lobes; posterior thorax and anterior abdominal chaetigers with subpodial lobes, usually forming a ventral fringe; thoracic neurochaetae including blunt uncini or subuluncini and crenulated capillaries; posterior thoracic chaetigers with modified spines.
According to Liu (2008), four species have been documented from Chinese waters: Phylo felix, Phylo ornatus (Verrill, 1873), Phylo kupfferi (Ehlers, 1874), and Phylo nudus (Moore, 1911). We checked specimens previously identified as P. felix deposited in the Marine Biological Museum of the Chinese Academy of Science and found the report of the species from Chinese waters to be a misidentification. These specimens were identified as a new species, which is described and illustrated in this study. Additionally, we describe and illustrate Phylo fimbriata based on specimens collected from the East China Sea. This is the first record of P. fimbriata from Chinese waters.
Material checked in this study was collected from the northern Yellow Sea and East China Sea and deposited in the Marine Biological Museum of Chinese Academy of Science, with a few specimens retained by the present college of the first author (Yancheng Teachers University, YCTU). All the specimens were preserved in 75% ethanol solution. Detailed morphological structures were examined under a Zeiss Stemi 2000-C stereomicroscope. Photography and line drawings were made using an AxioCam MRc 5 digital camera attached to a stereomicroscope and a compound microscope. Specimens were stained with rose bengal to observe details of parapodial lobes and subpodial lobes. For SEM observations, selected parapodia were detached from the specimens, rinsed in absolute ethanol, dehydrated, coated in gold, observed, and photographed using a scanning electron microscope.
The following abbreviations are used:
MBM Marine Biological Museum;
YCTU Yancheng Teachers University;
spec specimen;
Sta. station;
ECS East China Sea;
nYS Northern Yellow Sea;
SEM scanning electron microscope.
Subfamily Orbiniinae Hartman, 1942
Phylo felix Kinberg, 1866
Holotype : MBM286984: nYS, Sta. 3875–04, 38°45'N, 123°30'E, 64 m, 16 Dec. 2015. Paratype: MBM286985: nYS, Sta. 16, 39°07'N, 122°54'E, 31 m, 18 Dec. 2016. MBM286986: nYS, Sta. C3, 39°00'N, 122°55'E, 45 meters, 18 Dec. 2016. Sta. MBM286987: nYS, Sta. A1, 39°05'N, 122°35'E, 36 m, 18 Dec. 2016. MBM023255: nYS, Sta. 2049, 122°45'N, 38°09'E, 51 m, coll. Mu Chen. 11 Jul. 1959.
All specimens incomplete, posterior end missing, holotype with 60 chaetigers, 34 mm long and 5 mm wide. Body elongate, about same width throughout; thorax depressed, abdomen cylindrical.
Prostomium short, conical, tapering to rounded tip; eyepots absent, nuchal organs narrow groove at junction with peristomium (Fig.
Holotype with 21 thoracic chaetigers, divided into anterior and posterior sections: anterior thorax with 13 chaetigers (Figs
Branchiae from chaetiger 5, on anterior chaetigers short, triangular, tapering to narrow papillate rounded apex (Fig.
Thoracic notopodia with fascicles of crenulated capillaries. Abdominal notopodia with few long, thin capillaries, 2–4 furcate chaetae and 3–5 imbedded aciculae, furcate chaetae with unequal tynes, each tyne with fine needles directed medially, shaft with transverse rows of barbs (Fig.
Anterior thoracic neuropodia with 4 rows and 1 short posterior rows of yellow uncini, and posterior row of crenulate capillaries (Figs
Anterior thoracic neuropodia with 5 or 6 rows of yellow uncini and posterior row of crenulate capillaries (Figs
Pygidium not observed.
One paratype (MBM286986) with 13 and 14 anterior thoracic chaetigers on left and right side respectively, posterior thorax with 9 and 8 chaetigers, respectively. Holotype and other specimens with 13 anterior thoracic chaetigers, posterior thorax with 4–8.
The species is named for the thoracic neuropodia with two kinds of uncini.
Northern Yellow Sea, China.
This species is unusual in the genus in having anterior thoracic neuropodia with 5 or 6 rows of uncini intermixed with a few subuluncini in the first 1 or 2 rows. Phylo heterochaetus sp. nov. is similar with P. ornatus (Verrill, 1873) for: 1) anterior thoracic neuropodia with rows of uncini, 2) lacking interramal cirri, 3) anterior thorax with 13 or 14 chaetigers. They can be easily distinguished by 1) species of P. heterochaetus sp. nov. with 4–8 posterior thoracic chaetigers, while the latter species with 13 or more chaetigers; 2) species of P. heterochaetus sp. nov. with 10 or 11 subuluncini intermixed with first 2 rows uncini, while the latter species lacks subuluncini; 3) modified spines hastate in P. heterochaetus sp. nov. and acicular in P. ornatus.
Aricia fimbriata
Moore, 1903: 464–467, pl. XXIV, figs 33–35;
Phylo fimbriata:
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.
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.
Both thoracic notopodia and neuropodia with fringed postchaetal lobes; notopodium half as broad as the neuropodium, broadly palmate (Figs
Thoracic neuropodia thick, elongate, strictly lateral, bearing numerous subuluncini and capillaries (Fig.
Branchiae from chaetiger 5, each anterior branchia broad, tapering to narrow rounded tip (Fig.
Thoracic notopodia with fascicles of crenulated capillaries (Figs
Pygidium not observed.
East China Sea (China); Suruga Bay, Miyagi Prefecture (Japan).
Phylo fimbriata (Moore, 1903), which was first reported by
We thank the managers of the Marine Biological Museum of the Chinese Academy of Sciences for their help in sorting the studied material. This study was supported by the National Natural Science Foundation of China (no. 32000349), Jiangsu Provincial Key Laboratory for Bioresources of Saline Soils Open Foundation (no. JKLBS2019004).