Synelmis levinae, Salazar-Vallejo, 2003

Salazar-Vallejo, Sergio I., 2003, Revision of Synelmis Chamberlin, 1919 (Annelida, Polychaeta, Pilargidae), Zoosystema 25 (1), pp. 17-42 : 33-36

publication ID	https://doi.org/ 10.5281/zenodo.5392022
persistent identifier	https://treatment.plazi.org/id/1C7A6034-FF88-D036-5854-234548570237
treatment provided by	Marcus
scientific name	Synelmis levinae
status	sp. nov.

Treatment

Synelmis levinae View in CoL n. sp.

( Fig. 10 View FIG )

TYPE MATERIAL. — Syntypes: eastern Pacific Ocean, western Mexico, Hoke Seamount, 32°04.36’N, 126°55.57’W, coarse-grained cream-colored calcareous oozes, Atlantis with DSRV Alvin, cruise 112-13, stn AD 1466, 810 m, Box Core 2A, core fraction 0-2 cm, 18.X.1984, 2 syntypes ( LACM-AHF- 2098).

TYPE LOCALITY. — Hoke seamount (32°04.36’N, 126°55.57’W), western Mexico.

ETYMOLOGY. — This species is named for Dr Lisa A. Levin, for her many publications on ecology of polychaetes in general, and especially for her studies on seamounts which allowed her to collect this interesting material.

OTHER MATERIAL EXAMINED. — Eastern Pacific Ocean. Western Mexico, Hoke Seamount, 32°04.36’N, 126°55.57’W, coarse-grained creamcolored calcareous oozes, Atlantis with DSRV Alvin, cruise 112-13, stn AD 1466, 810 m, Box Core 2A, core fraction 2-10 cm, 18.X.1984, 1 specimen (slide in alcohol-glycerol, LACM-AHF).

DISTRIBUTION. — Apparently restricted to seamounts in western Mexico in 800 m depth.

DESCRIPTION

Body filiform, small, 6-7 mm long, 0.2-0.3 mm wide, 37-39 setigers plus one or two asetigers.

Body pale, translucent, anterior gut dark or black ( Fig. 10A View FIG ). Integument smooth except by palps which are slightly rugose. Ventral longitudinal furrow present.

Prostomium trapezoidal, with separate biarticulated palps, palpostyles massive knobs and long ventrolateral papillae present ( Fig. 10B View FIG ). Three similar cirriform antennae, laterals emerge from middle of prostomium and do not surpass the length of palps; median antenna slightly longer than laterals and placed at posterior prostomial margin. Eyes cannot be detected. Two pairs of long cirriform tentacular cirri, slightly longer than cirri of setiger 1.

Parapodia with cirriform cirri without basal expansions, setal lobe as long as two thirds the length of dorsal cirri. Notopodia reduced to dorsal cirrus; notospines from setiger 5, straight, become thicker and longer posteriorly, protrude slightly more on posterior setigers ( Fig. 10C View FIG ).

Notosetae restricted to notospines, smooth and slightly curved distally. Neurosetae of three kinds, limbate setae more common, become smaller ventrally, in addition one or two smooth straight capillaries and one or two asymmetrical furcate setae. Pre-pygidal region with one or two asetigerous segments, parapodial cirri short, cirriform; two anal cirri about as long as two previous segments ( Fig. 10D View FIG ). Non-everted pharynx about three setigers long, has pigment in transverse fine lines and darker muscular wall. Posterior gut less pigmented but muscle cells easily seen ( Fig. 10A View FIG ). Brain bilobed, about three setigers long.

REMARKS

Synelmis levinae n. sp. belongs to the group of species that have cirriform antennae and cirri, but is distinguished by its lateral antennae which arise from the middle of the prostomium and not from the base of the palps.

Synelmis rigida (Fauvel, 1919) n. comb. ( Figs 1G, H View FIG ; 11 View FIG A-F)

Ancistrosyllis rigida Fauvel, 1919a: 337-339 View in CoL , fig. 1a-e; 1919b: 373, fig. IV; 1920: 206, 210, 211; 1923: 16- 19, fig. 3a-e; 1953a: 110, 111, fig. 53. — Hartman 1954: 625 (only Lidilbut Island). — Reish 1968: 213 partim.

Synelmis simplex Chamberlin, 1919: 177-179 View in CoL , pl. 28, figs 1-5.

Kynephorus inermis Ehlers, 1920: 27-29 View in CoL , pl. 3, figs 1-9. Synelmis albini View in CoL – Pettibone 1966: 191-195, figs 19-21 (only fig. 20a, b, Saipan). — Gibbs 1971: 137 (both non Langerhans 1881, partim).

MATERIAL EXAMINED. — Indian Ocean. Mission Gravier, Récif Messageries, Djibouti, Red Sea, in corals, 3.I.1904, 1 posterior fragment ( MNHN A71); 2 slides of the same fragment in the Fauvel collection (IEA-D63 and D63’) (63 has three setigers with duplicate aciculae, cirriform cirri).

Western Pacific Ocean. Mohican Reef, Rangiroa Island , Paumotu (= Tuamotu ) Islands , French Polynesia, 23.IX.1899, 2 types of Synelmis simplex Chamberlin, 1919 (holotype USNM 19480 About USNM , paratype USNM 19481 About USNM ). — Mission Seurat , Takaerero Island (perhaps Takaroa), Tuamotu Archipelago, French Polynesia, on pearl oyster, 25 m, 25.V.1904, 2 syntypes of Ancistrosyllis rigida ( MNHN A71 About MNHN ) ; 1 slide in the Fauvel collection (IEA-C92’; it indicates Tokaerero b but it has another adhesive tag with San Thomé ) four parapodia but three are collapsed, one seems to be the one drawn for the description. — Moluccas Islands , Pulo Edam , Nordwatcher , Amboina , 3.41°S, 128.10°E, Indonesia, 2 syntypes of Kynephorus inermis ( ZMH-324 a). — Marshall Islands, Saipan , Geological Survey stn D-9 1949, P. E. Cloud coll. (id. O. Hartman as A. rigida ; id. M. Pettibone as S. albini ), 1 specimen ( USNM 26080 About USNM ). — Royal Society Expedition, Martin Island, 4.VIII.1965, P. E. Gibbs, 1 specimen ( BMNH 1970.309 ) GoogleMaps ; Mamara Pt , N Guadalcanal Island, Solomon Islands, 24.VIII.1965, 1 specimen ( BMNH 1970.310 ) ; Batuona Island , 3.IX.1965, 1 specimen ( BMNH 1970.311 ) ; Maramasite (=? Maramasike Passage), Maraita-Maramasike Islands, 26.XI.1965, 2 specimens ( BMNH 1970.313 ) ; Graham Point , SE Guadalcanal Island, Solomon Islands, 2 specimens ( BMNH 1970.312 ). — Marshall Islands, no further data, 1 complete specimen ( LACM-AHF 1504 ) .

DISTRIBUTION. — Tropical central and western Pacific Ocean, Mariana Islands, Solomon Islands, and Tuamotu Archipelagos. In mixed or coraline bottoms or in the sediments over pearl oysters, all in shallow water.

DESCRIPTION

Syntypes of Ancistrosyllis rigida with subcylindrical body, tapering towards both ends, dark colored in alcohol. Complete syntype 12 mm long, 0.8 mm wide, with 82 setigers and about four asetigers. Posteriorly incomplete syntype slightly distorted anteriorly, setigers 25-28 slightly swollen; 7 mm long, 0.8 mm wide, with 50 setigers.

Prostomium rectangular, wider than long, with palps biarticulated, palpostyles contracted making palps seem completely fused, but in ventral view a longitudinal furrow indicates fusion. Ventral papillae tiny, lateral to palpostyles. Three similar fusiform antennae, laterals emerge from two transverse depressions at middle of prostomium, do not reach the palps tip; median antenna on the posterior margin of prostomium, has a dark spot in its base. After over-night immersion in glycerin, two eyes can be seen, tiny and behind lateral antennae in complete syntype but incomplete syntype has two pairs of fused eyes.

Parapodia with subequal fusiform cirri; setal lobe can be as much as half the length of cirri. Notospines start in setiger 15 in complete syntype and in setiger 13 in anterior fragment. Prepygidial region with slimmer cirri; pygidium with dorsal anus and two anal cirri as long as the two previous segments.

Neurosetae of three kinds; spinulose capillaries which appear limbate most abundant, some straight smooth capillaries and one or two straight nearly symmetrical furcate setae per setal bundle ( Fig. 1G, H View FIG ). Posterior end contracted, segments well marked; one or two asetigerous segments and two ventrolateral anal cirri. Noneverted pharynx around 10 setigers long, followed by a convolute portion of 8-10 setigers long.

Holotype of Synelmis simplex (examined by H. K. Dean): body very dark, 43.8 mm long, 0.8 mm wide. Prostomium with tiny eyespots in a line. Pharynx difficult to see but it is about 10 setigers long. Emergent notospines in right setiger 23 and left setiger 19. Most setae broken.

Paratype of Synelmis simplex : mature specimen with body dark with a intersegmental dark band between setigers 4-5 and other smaller ones, less pigmented, over the next segments. Interparapodial glandular areas dark purple or black, wider towards the posterior end. Pigmentation less intense in anterior end, darker from setiger 20. Paratype 43 mm long, 1.1 mm wide, with more than 190 setigers.

Prostomium short, palps biarticulated, separate, palpostyles massive knobs with ventrolateral papilla ( Fig. 11A View FIG ). Three subequal antennae, laterals arise from base of palps, median one posteriorly placed. Four tiny eyespots on right side of the prostomium (see comments below).

Parapodia with subequal fusiform cirri, setal lobe in median setigers as long as half the length of dorsal cirri, posteriorly becomes slightly longer, towards the pygidium become smaller. Notospines start at setiger 21 (23 on the left side). Pygidium with terminal anus ( Fig. 11G View FIG ); two lateroventral anal cirri as long as the previous three segments. Neurosetae mainly limbate setae but most broken, furcate setae were not seen. Everted pharynx short, globose, smooth, it is two setigers long. Non-everted pharynx about 11 setigers long.

Larger syntype of Kynephorus inermis is 46 mm long, 1.0 mm wide, with 152 setigers (224 in the original description, see Ehlers 1920). Prostomium deeply contracted ventrally making difficult to detect the eyes; palps massive, biarticulated with tiny papillae. Antennae fusiform but its tips have been eroded, laterals placed about middle of prostomium and median posterior. Tentacular cirri cirriform and slightly eroded in the tips. First notospine appear in setiger 16. Pharynx reaches setiger 12. Pygidium regenerating, an asetiger and two lateral anal cirri bordering terminal anus. Smaller syntype of K. inermis is anterior end and a median fragment; first 10 mm long, 0.9 mm wide (pharynx 3 mm long), and second 21.5 mm long, 1.0 mm wide at about the middle, with 75 setigers.

Another specimen (USNM 26080) lacks posterior end and has some almost transverse cuts over its anterior end; it is 20 mm long, 1.0 mm wide, with 126 setigers. There are three eyes over the left and four eyes over the rigth sides of the prostomium. Notospines start from setiger 17 and its pharynx is nine setigers long. It has pigmented glands behind the parapodial lobes, they are small in the first 10 setigers and become bigger in posterior setigers. Its ventral furrow is deep and extends over the whole body.

Specimens from the Solomon Islands are 23- 62 mm long, 0.9-1.0 mm wide, with 131- 167 setigers. Body dark. Prostomium with two lateral almost symmetrical series of two to six eyes each; series had two eyes in one side in two specimens, three eyes in one side in six specimens, four eyes in one side in three specimens, and there were five or six eyes in one side in two specimens ( Fig. 11B View FIG ). Parapodia with cirriform cirri of about the same length, narrower than the setal lobe. Notospines start in setigers 16-21 (setiger 17 in five specimens), missing in anterior parapodia ( Fig. 11C View FIG ), become progressively longer and more emergent in more posterior setigers ( Fig. 11D, E View FIG ), become as long as the dorsal cirrus by setiger 100. Pharynx can be 11-14 setigers long.

REMARKS

The main differences between S. rigida n. comb. and other species in the genus can be noticed in the key; the most important are the development of the cirri, the start of the notospines and the eye development. It is closely related to S. sotoi n. sp. but they differ in that the dorsal cirrus is similar to the ventral one in S. rigida n. comb. while in S. sotoi n. sp., dorsal cirri is smaller than ventral one. On the other hand, the publication by Fauvel (1919a) has priority over the publication by Chamberlin (1919); the first one was deposited in the library of The Natural History Museum, London, on 26 June 1919 while the second one was printed in July 1919 (Muir 1997 pers. comm.). Pettibone (1966) illustrated a specimen from Saipan Island, Mariana Islands, with three or four eyes in a row on either side of the prostomium. This agrees with the description by Chamberlin (1919). The syntypes of A. rigida are smaller and heavily pigmented, which might explain the difference in the observed number of eyes between both descriptions.