INTRODUCTION

The genus Glycera Lamarck, 1818 is one of the largest groups in the glycerids and distributed worldwide from the intertidal to deep sea (Fauchald and Jumars 1979; Böggemann 2002, 2009; Rizzo et al. 2007). Recent increasing of our knowledge on the taxonomy of genus Glycera was accomplished by Böggemann (2002), who revised more than hundred species of worldwide Glycera including re-examination of the type materials of almost species available. He finally listed only 36 Glycera species as valid ones (Böggemann 2002). Thereafter, nine new species were added by several studies on the genus Glycera (Imajima 2003, 2009; Rizzo et al. 2007; Böggemann 2009; Böggemann et al. 2012; Magalhaes and Rizzo 2012).

In Korean waters, nine Glycera species, G. alba (Müller, 1776), G. capitata Örsted, 1843, G. chirori Izuka, 1912, G. convoluta Keferstein, 1862, G. decipiens Marenzeller, 1879, G. dentribranchia Lee, 1985, G. onomichiensis Izuka, 1912, G. rouxii Audouin and Milne Edwards, 1833, and G. subaenea Grube, 1878, have been recorded (Paik 1975, 1978, 1982, 1989; Rho and Song 1974, 1975; Lee 1984). However, the Korean fauna of Glycera is in need of a detailed revision including re-evaluation of several recorded species that have to be synonymized as follows: G. chirori was synonymized into G. nicobarica Grube, 1868; G. convoluta into G. tridactyla Schmarda, 1861; G. decipiens into G. nicobarica; G. rouxii into G. unicornis Lamarck, 1818; G. subaenea into G. macintoshi Grube, 1877 (Böggemann 2002; Imajima 2003).

During investigating on the glycerid polychaetes, the authors met with the materials of G. fallaxQuatrefages, 1850 new to Korean fauna. In this study, we describe this species with detailed description and illustration, and provide a key to Glycera species from Korean waters.

MATERIALS AND METHODS

Samples were collected from mud of the tidal flat in the southwestern coast of Korea. The specimens were sorted by using sieves with a pore size of 0.5 mm, fixed initially with 5% formaldehyde-seawater solution, and transferred to 85% ethyl alcohol after sorting in the laboratory. The characteristics of the whole body were observed and the appendages were dissected in a petri dish by using dissection forceps or surgical knives and needles under stereomicroscope (SMZ 1500; Olympus, Tokyo, Japan). Dissected specimens were mounted on temporary slides using glycerol or permanent slides using polyvinyl lactophenol solution. Drawings were made by the stereomicroscope and light microscope (LABOPHOT- 2; Nikon, Tokyo, Japan) with the aids of drawing tubes. The examined materials are deposited in Chosun University and the National Institute of Biological Resources (NIBR) in Korea.

RESULTS AND DISCUSSION

Class Polychaeta Grube, 1850 다모 강

Order Phyllodocida Örsted, 1843 부채발갯지렁이 목

Family Glyceridae Grube, 1850 미갑갯지렁이 과

Genus Glycera Savigny, 1818 참미갑갯지렁이 속

1Glycera fallaxQuatrefages, 1850 구슬아가미미갑갯지렁이 (신칭) (Fig. 1)

Synonyms: Glycera fallaxQuatrefages, 1850: 358; Böggemann, 2002: 59, Figs. 73-75.

Glycera giganteaFauvel, 1923: 387, Fig. 152d-k; Berkeley and Berkeley, 1941: 34; Hartman, 1950: 75; Imajima and Hartman, 1964: 162; Day, 1967: 362, Fig. 16.2l-n.

Material examined: Korea, 4 specimens, Jeollanam-do, Muan-gun, Hyeongyeong-myeon, Haeun-ri (126°25′40″E, 35°03′33″N) 19 Dec 2011, Choi HK.

Description: Body smooth, about 33.0 mm long with 95 segments and width 1.5 mm including parapodium at 20th setiger; life color red, whitish brown in alcohol. Body rings biannulated; anterior annulus with parapodia and dorsal cirri; posterior annulus slightly longer than anterior ones (Fig. 1A, B).

Prostomium large conical-shaped, consisted of 10 or 11 rings, and length slightly longer than basal width; 4 short antennae present on anterior end (Fig. 1A, B).

Proboscis bat-shaped, with 4 sickle-shaped jaws on anterior end and vertical white rows on mid-region (Fig. 1A, B), and closely covered with 2 kinds of soft papillae; most papillae long oval shaped and with 3 ridges (Fig. 1C), and remaining other papillae broadly subglobular form without ridges (Fig. 1D).

Ailerons (jaw support) with single prolongation and subtriangular base, without denticle (Fig. 1E).

Parapodia uniramous on first 2 setigers, and biramous on following setigers with 2 presetal and 2 postsetal lobes. Presetal lobes of parapodia digitiform, pointed distally, deeply divided, and much longer than postsetal lobes; notopodial lobes on anterior and mid-body regions as long as neuropodial lobes, and notopodial and neuropodial lobes on posterior region nearly equal in length. Postsetal lobes of parapodia short, blunt, slightly divided, and nearly equal in length; notopodial lobes bluntly triangular in shape on anterior regions, but bluntly rounded on mid-body and posterior region, and neuropodial lobes bluntly rounded (Fig. 1F-K).

Dorsal cirrus from 3rd parapodium, oval-shaped, attached above parapodial basis (Fig. 1F-K).

Ventral cirrus large, slender, triangular-shaped, and shorter than presetal lobes but longer than postsetal lobes (Fig. 1F-K).

Branchiae (Fig. 1H) single, blister-like in shape, attached on anterior surface of parapodia, present on 45-60 segment regions, and usually retractile state (Fig. 1F).

Remarks:Glycera fallax had long been ignored because of its poor original description (Quatrefages 1850). Instead of this species, G. gigantea Quatrefages, 1866 had long been widely known in the genus Glycera (Fauvel 1923; Berkeley and Berkeley 1941; Hartman 1950; Imajima and Hartman 1964; Day 1967). However, recent work revealed that G. fallax is a valid species and G. gigantea is a junior synonym of G. fallax based on the examination of their type materials (Böggemann 2002).

In this study, the authors examined the Glycera materials from Korean waters, and could find that those can be classified as G. fallax according to the following distinguishable characteristics: the proboscis has the conical papillae bearing three ridges and subglobular papillae; the ailerons have sub-triangular bases; the postsetal lobes on mid-body are blunt and more or less rounded, and the length of them are nearly similar; the branchiae are simply retractile and blister-like on the anterior surface of parapodia (Böggemann 2002). However, a minor difference is observed in Korean materials in the number of prostomial ring, 10 or 11 rings are in Korean materials while 14-17 rings are in the type materials of G. fallax (Böggemann 2002).

Among Glycera species known from Korean waters, G. unicornis, which was previously reported as G. rouxii, is appeared to be closely resembled with G. fallax in the following common diagnostic features: conical-shaped papillae with three ridges on the proboscis, two postsetal lobes of nearly equal length, and retractile branchiae (Lee 1984; Paik 1989; Böggemann 2002). However, these two species differ from each other in term of the postsetal lobes and branchiae: the postsetal lobes on mid-body of G. fallax are blunt and more or less rounded usually, while those of G. unicornis are slender and triangular-shaped; the parapodia on mid-body possess simply blister-like branchiae in G. fallax, but those in G. unicornis possess one or two digitiform ones (Böggemann 2002).

Habitat: This species was collected from mud of the tidal flat in the southwestern coast of Korea.

World distribution: North Atlantic, New Britain, Western and Southern Europe, Mediterranean, Laccadive Sea, Northeastern Australia, Northeastern Pacific Ocean, Southern California, Panama, Japan, Korea.

Deposition: NIBRIV0000307827.

Identifiers: Hyun Ki Choi, Seong Myeong Yoon.

Key to the species of genus Glycera from Korea