The pelagic polychaetes were found in the samples collected by the investigators of the First Chinese Antarctic and Southern Ocean Expedition, with plankton net in February and March of 1985 from the South Shetland Islands, the Biscoe Islands and their vicinities, between 61°15'20S-65°30'16S, (Fig. 1).

Eight species belonging to 5 genera in 4 families have been identified, of which 4 species are recorded for the first time from the South Shetland Islands and 2 species are endemic to Antarctic. It is sorry that the specimens collected during the expedition are insufficient. However, we believe that the numbers of species of pelagic polychaetes would increase largely with the future systematic expeditions. Here is a report based on the present data.

Phyllodocidae 1 Pelagobia longicirrata Greeff. 1879

Pelagobia longicirrata: Uschakov, 1957:268; Tebble, 1960:202; Hartman, 1964:64, pl. 19, figs. 5, 6; 1968:327, figs. 1-3; Day, 1967:163, fig. 5, 7 f-i; Dales and Peter, 1972:59; O'Sullivan, 1982:47, fig, 19; Wu Baoling and Meng Fan and Qian Peyian, 1986:148, fig. 1.

Collection: Stas. S10, S9, S3, S2, L1, L3, M4, M6, R1, R2, R4, J, S26, S25, S24, S23, S21, S20, S11.

Body 2-12 mm long with 10-15 setigers; a pair of small eyes present; second setiger without dorsal cirri. Parapodia uniramous with long acicular lobes; heterogomph spinigers with smooth shafts, blades serrated on one side. Middle parapodia often yellowish brown.

The is a species that has the most abundant numbers of individuals of pelagic polychaetes and is widely distributed in the South Ocean and Antarctic waters. Some juveniles with 10 setigers and many adults with ova are obtained in the samples of zooplankton nets.

According to Chen Mu and Wu Baoling (1983), the first two pairs of parapodia are without dorsal cirri, which may fall off.

Distribution: P. longicirrate have been found from Antarctic to Arctic waters throughout the world in a recorded depth range of, 0-3000 m.

2 Maupasia coeca Viguier, 1886, (Fig. 2)

Maupasia coeca: Dales, 1957b:662; Dales and Peter, 1972:61; Uschakov, 1957b:268, fig. 1; Tebble, 1958:66; 1960:204; 1962:421, figs, 23, 2; Hartman, 1964:63, pl. 19, figs. 3, 4; Day, ) 1967:164, fig. 5, 7 j-i; Wu Baoling and Sun Ruiping, 1978:216, fig. 2; O'Sullivan, 1982:49, fig, 20.

Collection: Sta. S26.

This species found singly. Body 4 mm long, short and broad, with 17 segments. Prostomium square without eyes; two pairs of antennae subequal to width of prostomium; proboscis without jaws: first segment bearing a pair of nuchal epaulette, and a few setea between dorsal and ventral cirri. Three pairs of tentacular cirri composed of ventral cirri of first setiger; and dorsal cirri of first and second setigers; second dorsal cirrus twice as long as first one; swollen, flask-shaped; Setigerous lobes conical (Fig. 2); setae compoud with smooth shafts and very long fine blades bearing faintly serrated edge on one side.

This species is recorded for the first time in the iSouth Shetland Islands, whose difference from the reported specimens from the Xisa Island of China is that the acicular of setigerous lobe do not extend out of body.

Distribution: M. coeca is known to be cosmopolHan in surface depths to 750 m.

Alciopidae 3 Rhynchonerella petersii (Langerhans, 1880) (Fig. 3a , b)

Callizona setosa: Wesenberg-Lund, 1939:43; Uschakov, 1957:281, fig. 6.

Rhychonerella petersii: Stop-Bowitz, 1948:34; Dales, 1957:133; 1963:502; Dales and Peter, 1972:70; Tebble, 1962:398, fig. 12a-c; 1963:33; Hartman, 1964:61, pl. 18, figs. 4, 5; Day, 1967:192, fig. 7, 4i-m; O'Sullivan，1982:15, fig. 5.

Collection: Stas. S3, R2.

Body 4 mm long, 2 mm wide for first 22 segments, with 5 antennae; black eyes directed obliquely forwards; proboscis short with 10 low marginal papillae; tentacular cirri arranged in 1+1/1+1/N. Parapodia all with one short cirriform appendage, one large cordate dorsal cirrus and one small ventral cirrus. Segmenglands do not appear until 14th parapodium. Setae include fine compoud spinigers and acicular setae which are composite until 8th parapodiam (Fig. 3a. b) and lessen gradually to single in posterior.

This species was once found in the East Antarctic waters by Eblers 1912, 1913; Monro, 1939. It is recorded for the first time in the South Shetland Islands.

This species have two differences from the reported specimens collected in the Xisa Islands of China, whose arrangement of tentacular cirri is 1+1/1+1/1 and whose acicular setae remain composite in middle parapodia.

Distribution: This Species is known to be cosmopalitan in the surface depths to 200 m.

4 Rhynchoneealla bongraini (Gravier, 1911) (Fig. 4a. b).

Callizona bongraini: Gravier, 1911:312; Benham, 1929:189, pl. 1, figs., 11, 12.

Callizonella bongraini: Monro, 1936:119; Fauvel, 1936a:18, 1936b: 119.

Kroknia bongraini: Stp-Bowitz, 1948:33; 1949:11, figs, 3, 4; 1951:8.

Rhychonerella bongraini: Tebble, 1960:191, fig. 12; Hartman, 1964:59, pl. 18, figs. 1-3; Dales and Peter, 1972:70; O'Sullivan, 1982:15, fig. 4.

Collection: Sta. R1.

The specimen found singly, 10 mm long, and 1 mm wide for the first 38 segments. Pros-tomium extends forwards beyond eyes; two pairs of antennae set close together at the frontal margin; a single median one in groove between the two eyes; five pairs of tentacular cirri arranged in 1+1/1+1/1. Proboscis everted, long with 12 blunt papillae at the frontal margin. Each parapodium has a large foliaceous dorsal cirrus and a small foliaceous ventral cirrus; a small cirriform appendage at the end of the acicular lobe (Fig. 4. a). First 8 segments with both staight and curved short compound setae; middle segments with stout acicular setae and long compound spinigers; posterior segments with a single acicular setae and simple spinigers. Segment glands absent.

The species is collected in the top 545 m of water and recorded for the first time in the South Shetland Islands.

Distribution: This species is known to be endemic to the Antarctic Ocean.

Tomopteridae 5 Tomopteris planktonis Apstein, 1900

Tomopteris planktonis: Fauvel, 1953:142, fig. 71. f; Stp-Bowitz, 1948:52, 1949:13; 1951:9; Dales, 1957:663; 1963:503; Dales and Peter, 1972:75; Tebble, 1958:166; 1960:171, figs. 6a-f; 1962:383; Rullier, 1965:873; Day, 1967:206, fig. 8, 2n-o; O'Sullivan, 1982:18, fig. 10.

Collection: Stas. S11, S9, S5.

Body 5 mm long, with 14 pairs of parapodia; tail absent. Prostomium not notched between antennae; a pair of eyes slightly prominent. Well-developed chromophil glands present from the 4th segmant onwards and located in the inferior half of the ventral pinnule where they cause an obvious swelling. Spur glands absent. Hyaline glands indistinct but present at the apices of the ventral pinnules from the first pair of parapodia onwards; gonads in the dorsal rami from the second or the third segment onwards.

This species is recorded for the first time in the South Shetland Islands.

Distribution: T. planktonis is cosmopolitan, recorded in the surface depths to 4190 m.

6 Tomopteris septentrionalis Steenstrup, 1847

Tomopteris septentrionalis: Dales, 1957a: 145, fig. 51f, 52g, 54; Tebble, 1960:176, fig. 8a, b; Imajima, 1961:9; 1962:382. fig. 5; Pettibone, 1963:97, fig. 25c; Day, 1967:205, fig. 8, 21 m; Hartman, 1968:355, figs. 1.2; O'Sullivan, 1982:28, fig. 11.

Collection: Stas. S20, S21, M4.

Body 12 mm long, with 23 pairs of parapodia; Tail absent. Prostomium notched between two antennae and bearing a pair of brown eyes; the second cirrus almost as long as the length of body. Pinnules oval; chromophil glands present from the 2nd 4th parapodia onwards at the apex of ventral pinnule and become well-developed in posterior. Hyaline glands small, distinct at above chromophil gland; gonads in dorsal rami from the second parapodia to 14th onwards.

It is found that the specimens collected from the South Ocean have a larger body and more segement number than those reported from the Xisa Islands of China.

Distribution: T. septentrionalis is known to be cosmopolitan in cold water masses in the surface depths to 4000 m.

7 Tomopteris carpenteri Quatrefages, 1865 (Fig. 5)

Tomopteris carpenteri: Quatrefages, 1865:227, pl. 20, figs. 1, 2; McIntosh, 1885:20; Augener, 1929: 304; Monro, 1930:84; 1936:126; Tebble, 1958:166; 1960:175; Hartman, 1964:67, pl. 21, fig. 1; Day, 1967: 204, fig. 8, le, f: Dales and Peter, 1972:73; O'Sullivan; 1982:21, fig. 7.

Collection: Stas. S5, S6, S9, S10, S19, S21.

Body large, 25-60 mm long, and 10-20 mm wide, with 26-36 Pairs of parapodia; tail absent. Prostomium not notched; neck short and broad (Fig. 5 a); a pair of small eyes black. First pair of cirri absent but the second almost reach back the 3/4 length of body. Pinnules oval, extend to distal ends of the parapodial trunks (Fig. 5 b). Hyaline glands distinctly red from 3rd parapodia onwards in superior half of ventral pinnules; chromoplil glands large, first appear from 6th parapodium in inferior half of ventral pinnules; gonads present in both dorsal and ventral rami from first parapodia onwards; spur glands absent.

The species described by Hartman (1964) and Day (1967) have chromopil gland first appearing from the 4th parapodia, which differ from the our specimens that have chromophil glands from the 6th parapodia onwards.

This species was collected with IKMT nets. The main differences from the above two species is that T. carpenteri have a larger body, numerous segements, well-developed chromopil glands and distinct hyaline glands.

Distribution: The species is known to be endemic to the Antarctic and Subantarctic zone in the top 2800 m depths of water.

Typhloscolecidae 8 Typhloscolex muelleri Busch, 1851

Typhloscolex muelleri: Dales, 1960:485; 1963:503; Dales and Peter, 1972:80; Tebble, 1960:145; 1962:407; Hartman, 1964:67, pi. 20, fig. 13; 1968:343, figs. 1-3; Day, 1967:208, fig. 9, Ia, b; O'Sullivan, 1982:33, fig. 12.

Collection: Stas. S2, S3, R1.

Body 3-5 mm long with 24 segments. Prostomium blund and bearing a palpode with a ventral swelling; dorsal cilliated lobe with a pair of small nuchal lappets on the sides. Head enfolded along sides by 3 pairs of flattened cirri. Dorsal and ventral cirri both cordate; a pair of anal cirri ovate.

Distribution: This species is known to be cosmopolitan in the top 3000 m depths of water.