Polynoid polychaetes associated with a whale skeleton in the bathyal Santa Catalina Basin

11 Pages·1993·5.3 MB·

by  M H Pettibone

PROC. BIOL. SOC. WASH.
106(4), 1993, pp. 678-688
POLYNOID POLYCHAETES ASSOCIATED WITH A
WHALE SKELETON IN THE BATHYAL
SANTA CATALINA BASIN
Marian H. Pettibone
—A
Abstract. whale-fall community dominated by microbial mats ofsulfur-
oxidizing bacteria in the Santa Catalina Basin is inhabited by species similar
to those associated with hydrothermal vents in the northeast Pacific. Polynoid
polychaetes associated with the skeleton include: Bathykurila guaymasensis
(Macellicephalinae); Peinaleopolynoe santacatalina, new species (Branchino-
togluminae, emended); and Harmothoe craigsmithi, new species, and Subadyte
mexicana (Harmothoinae). Both the holotype oiPeinaleopolynoe sillardi Des-
&
bruyeres Laubier and additional specimens ofSubadyte mexicana Fauchald,
were examined and descriptions supplemented.
Oceanographers aboard the deep sub- for identification by Dr. Craig R. Smith,
mergence research vessel (DSRV)Alvin dis- University ofHawaii, Manoa. Included are
m
covered an intact, 20 long skeleton of a four species in three subfamilies: Bathyku-
m
blue or fin whale at a depth of 1240 in rila guaymasensis Pettibone, 1989 (Macel-
the Santa Catalina Basin (33°14'N, licephalinae), originally described from the
118°30'W) during November, 1987. Sub- Guaymas Basin hydrothermal mounds;
sequent collections revealed a characteristic Peinaleopolynoe santacatalina, new species
"whale-fall" community associated with the (Branchinotogluminae Pettibone, 1985a,
skeleton (Smith et al. 1989, Allison et al. emended); Harmothoe craigsmithi, new
1991, Smith 1992). The skeleton was par- species, and Subadyte mexicana Fauchald,
tiallyburiedandthebonesurfaceswerecov- 1972 (Harmothoninae). The subfamily
ered by a white "furry" microbial mat con- Branchinotogluminae is emended to in-
sisting oflarge filamentous sulfur-oxidizing clude Peinaleopolynoe sillardi Desbruyeres
bacteria (Beggiatoa sp.). The site was a sul- & Laubier, 1988, obtained from artificially
fide rich, reducing habitat similar to those enriched substrates placed ata depth of4800
m
associated with hydrothermal vents. In ad- in the northeast Atlantic off' Spain. The
dition, numerous invertebrate species, in- original description ofP. sillardi is supple-
cluding large clams, mussels, limpets and mented, based on an examination of the
snails, were associated with the bones in holotype kindly sent on loan from the Mu-
ways that were similar to those of hydro- seum National d'Histoire Naturelle, Paris
thermal vent faunas ofthe Galapagos Rift, (MNHNP). Harmothoe craigsmithi is sim-
Guaymas Basin and Juan de Fuca Ridge. ilar to H. tenebricosa Moore, 1910, which
These species were unreported from the was described from southern California in
Santa Catalina Basin (Smith & Hamilton 914-1463 m. Subadyte mexicana was orig-
1983, Smith 1985, Kukert & Smith 1992). inally described from western Mexico in
AdditionalAlvin dives to the whale-fall site 567-844 m. Its description is also supple-
were made in February 1991. mented based on additional specimens from
Polynoid polychaetes collected on or the Santa Catalina Basin and Channel Is-
m
within 0.5 ofthe bones were sent to me lands.
VOLUME NUMBER
106, 4 679
The larger polynoids, collected by theAl- mens have small ventral papillae on seg-
vin, were part ofthe epifauna on the whale ments 10, 11, 12 (not reported previously).
bones and designated by Bone Implant Remarks.—The specimens have numer-
number (1 or 2) or Vertebra (V) number. ous filamentous sulfur-bacteria attached
The smaller polynoids, part ofthe infauna, {Beggiatoa sp.), characterized by their glid-
were collected by Ekman cores (E), and sep- ing motility and internal globular elemental
arated into subcores (A-D) and from 0-1, sulfur, described and figured by Nelson et
1-5, and 5-10 cm below the sediment sur- al. (1989).
face. In their report on the fauna ofthe Santa
Types and additional specimens are de- Catalina Basin, Smith & Hamihon (1983:
posited in the collections ofthe Department 916) stated: "an undescribed macellicepha-
ofInvertebrate Zoology, National Museum lin polychaete made frequent excursions
ofNatural History, Smithsonian Institution high above the sediment." The specimen,
(USNM), the Natural History Museum of collected by Dr. Kenneth L. Smith of the
Los Angeles County (AHF-LACM), and Scripps Institution of Oceanography, was
with the donor ofthe collection, Dr. Craig sent to me for identification and described
R. Smith (CRS), of the Department of as anewmacellicephalan species, Natopoly-
Oceanography, University of Hawaii at noe kensmithi Pettibone (1985b:747).
Manoa.
Subfamily Branchinotogluminae
Family Polynoidae
Pettibone, 1985a, emended
Subfamily Macellicephalinae
Hartmann-Schroder, 1971, The subfamily is emended to include
emended Pettibone, 1976 Peinaleopolynoe sillardi Desbruyeres &
Genus Bathykurila Pettibone, 1976 Laubier, 1988 and P. santacatalina, new
Bathykurila guaymasensis Pettibone, 1989 species. Instead of 10 pairs of elytra and
elytrophores on segments 2, 4, 5, 7, 9, 11,
Bathykurila guaymasensis Pettibone, 1989:
13, 15, 17, 19, and dorsal cirri on the non-
159, figs. 1, 2. elytrigerous segments, including segments
Material. —Santa Catalina Basin, Cali- 20 and 2 there may be 9 pairs of elytra,
1,
fornia, 33°12'N, 118°30'W, 1240 m, Alvin with the elytra and elytrophores lacking on
Dives in Whale-fall site, in Feb 1991, buck- segment 19, but also lacking dorsal cirri and
AD
et washes: 2332, 20 Feb, Implant 1, 1 thus not a typical cirrigerous segment, as in
(USNM
specimen 157592), Implant 2, 4 P. sillardi or 1 pairs ofelytra with the ely-
specimens (USNM 157593), 1 specimen trophores and elytra extra small on segment
AD
(CRS); 2334, 22 Feb, Bone V21, 1 spec- 19, as in P. santacatalina. Notopodial bracts
imen (USNM 157594); AD 2336, 24 Feb, are not present on some or all ofthe elytri-
Bone VI5, 5 specimens (USNM 157595). gerous segments, as in other members ofthe
Description. —The specimens agree with subfamily. Also the arborescent branchiae
those previously described from the vents may begin on segment 2 and not on segment
in the Guaymas Basin in 2004-2020 m. The 3, as indicated previously.
mm
largest specimen measures 10 long, 8
mm
wide, with setae, with 15 segments, and Genus Peinaleopolynoe
7 pairs ofmelmytrophores; smamllmer specimens Desbruyeres & Laubier, 1988, emended
are 1.5-4 long, 1.5-3 wide, with
10-13 segments. Long ventral papillae on Type species.—Peinaleopolynoe sillardi
segment 1 1 (Fig. IC, in Pettibone 1989) are Desbruyeres & Laubier, 1988, by mono-
present on 4 of the 12 specimens; 3 speci- typy. Gender feminine.
680 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
The genus includes the type species, P. Material —Northeast Atlantic Ocean,
sillardi, and a new species, P. santacatalina. 46°02'N, 16°40'W, 4800 m, from enriched
Diagnosis.—Body short, with 21 seg- module of colonization, 23 Jul 1985, ho-
(MNHNP
ments. Elytra and elytrophores numbering lotype UB631).
9 or 10 pairs, on segments 2, 4, 5, 7, 9, 11, Supplementary description. —The elytra
13, 15, 17, and 19 or lacking on 19. Elytra and elytrophores are lacking on segment 19,
large, subreniform, overlapping, covering thus there are 9 pairs ofelytra, as originally
dorsum, without tubercles or papillae. Dor- indicated. However, segment 19 also lacks
sal cirri with short cylindrical cirrophores dorsal cirri, thus suggesting that it has sec-
and long distal styles; dorsal tubercles, in ondarilylostthe characteristic structure. The
line with elytrophores, on non-elytrigerous large elytra are subreniform, thick, white,
segments. Arborescent branchiae attached opaque, without tubercles or papillae, ex-
on dorsal tubercles and bases ofnotopodia, cept for some small posterior extensions,
beginning on segment 2 and continuing to variable in size, shape, and number (Fig.
near end ofbody. Prostomium bilobed, with lA). The notopodia and neuropodia ofthe
triangular anterior lobes bearing minute biramous parapodia are subequal in size,
frontal filaments, with median antenna in both with projecting acicular processes; the
anteriornotchandpairedpalps; withoutlat- notosetae are short to longer, not as long as
eral antennae or eyes. First or tentacular the neurosetae (Fig. IC). The stout acicular
segment not visible dorsally; tentaculo- notosetae, without spines, taper to rounded
phores lateral to prostomium, each with tips (Fig. ID). The slender neurosetae have
small acicularlobe on inner side, dorsal and slightly hooked bare tips, with double rows
ventral tentacular cirri, without setae. Sec- of spines along one border; the upper neu-
ond orbuccal segmentwith firstpairofelyt- rosetae are more slender than the middle
rophores, biramous parapodia, and ventral ones (Fig, IE). Segmental ventral papillae
or buccal cirri attached to basal parts of are present on segments 12-15; they are
neuropodia, lateral to ventral mouth; styles short and curved laterally (Fig. IB).
longer than following ventral cirri. Para-
podia biramous, with notopodia almost as Peinaleopolynoe santacatalina,
long as neuropodia. Notopodia without no- new species
topodial bracts, bulbous basally, extending Fig. 2
distally into acicular processes; neuropodia
Material. —Ssintsi Catalina Basin, Cali-
with longer conical presetal lobes with acic-
fornia, 33°14'N, 118°30'W, 1240 m, Alvin
ularprocesses andshortertruncate postsetal
Dives in Whale-fall site, in Feb 1991, buck-
lobes. Notosetae stouter than neurosetae, AD
straight, acicular, smooth or with lateral et washes:(USNM2332, 20 Feb, Implant 1,
paratype 157588), Implant 2, 2
spines. Neurosetae long, slender, finely spi- (USNM
paratypes 157589); paratype (CRS);
nous,with sHghtlyhookedtips. Pharynxwith (AD 2334, 22 Feb, Bone V21, holotype
7 pairs ofborder papillae; jaws with lateral (USNM
157587).
teeth. Ventral segmental papillae on seg- Description. -Holotype (USNM 157587)
ments 12-15. Pygidium with pair of anal mm mm
22 long, 14 wide with setae, 21
cirri. (USNM mm
segments; paratype 157588) 20
mm
long, 13 wide, 21 segments; 3 smaller
Peinaleopolyn&oe sillardi paratypes (USNM 157589) 9-12 mm long,
Desbruyeres Laubier mm
7-10 wide, 21 segments, last 2 very
Fig. 1 small. Dorsum with ciliated transverse
&
Peinaleopolynoe sillardi Desbruyeres bands, 2 per segment, extending onto bases
Laubier, 1988:331, figs. 1, 2. of elytrophores and dorsal tubercles (Fig.
VOLUME NUMBER
106, 4 681
Fig. 1. Peinaleopolynoe sillardi, holotype (MNHNP UB631): A, Right 3rd elytron from segment 5, with
detail ofposterior extensions; B, Ventral view ofcentral part ofleft side ofsegments 12-15, showing ventral
segmental papillae; C, Right elytrigerous parapodium from segment 5, anterior view; D, Tips oflong and short
notosetae from same; E, Upper and middle neurosetae from same, with detail ofparts. Scales = 2.0 mm for A;
mm mm mm
2.0 for B; 1.0 for C; 0.1 for D, E.
2A, B). Elytrophoreslarge, bulbous, 10 pairs, lacking on segment 21; on elytrigerous seg-
on segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, ments, branchiae forming single large groups
smaller on segment 19 (Fig. 2A, B, F); elytra between elytrophores and bases of noto-
all missing, except for minute elytron on left podia; on cirrigerous segments, branchiae
19th elytrophore of one paratype. Dorsal in small groups attached to dorsal tubercles
tubercles and dorsal cirri on non-elytriger- and larger groups near bases of notopodia
ous segments; cirrophores rather long, cy- (Fig. 2A, B, F, G).
lindrical, on posterior sides of notopodia; Prostomium oval, deeply bilobed, form-
styles long, filiform, extending beyond se- ing triangular anterior lobes with delicate
tae, shorter on segment 21 (Fig. 2B, G). frontal filaments; median antenna with bul-
Branchiae compact, arborescent, with nu- bous ceratophore in anterior notch, style
merous short bulbous terminal filaments, short, only slightly surpassing prostomium;
beginning on segment 2 and continuing to without eyes; palps stout, tapering, about
near posterior end, small on segment 20, twice length of prostomium; tentaculo-
682 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
Fig. 2. Peinaleopolynoesantacatalina, A-C, F-I,holotype(USNM 157587);D,E,paratype(USNM 157589):
A, Dorsal view ofanterior end, left dorsal tentacular cirrus missing; B, Dorsal view ofposterior end, including
segments 17-21, stylesofdorsalcirriofsegment20andanalcirrimissing; C,Ventralviewofleftsideofsegments
12-15, showing ventral segmental papillae; D, Dorsal border papillae ofpharynx; E, Jaw; F, Right elytrigerous
parapodium from segment 9, anterior view, acicula dotted; G, Right cirrigerous parapodium from segment 10,
posterior view; H, Long notoseta from same; I, Supraacicular neuroseta from same, with detail of parts; J,
mm mm mm
Subacicular neuroseta from same, with detail ofparts. Scales =1.0 for A, B; 2.0 for C; 0.2 for
mm mm
D, E; 1.0 for F, G; 0.1 for H, L
VOLUME NUMBER
106, 4 683
phores of segment 1 lateral to prostomium making 10 pairs ofelytra, instead oflacking
and palps, achaetous, each with small acic- elytrophores, elytra and dorsal cirri, and 9
ular process on medial side, long dorsal ten- pairs ofelytra. The stout acicular notosetae
tacular cimis about as long as palp and have double rows of spines on one side in
slightly shorter ventral tentacular cirrus, and P. santacatalina and are smooth in P. sil-
forming anterior and lateral lips of ventral lardi.
mouth (Fig. 2A). Segment 2 or buccal seg-
ment with first pair of large elytrophores,
Subfamily Harmothoinae Willey, 902
branchiae, biramous parapodia, and ventral 1
Genus //<2rmo//zo^ Kinberg, 1856
buccal cirri inserted basally and extending
Harmothoe craigsmithi, new species
beyond tips of neuropodia, with contribu-
Fig. 3
tions to posterior lip ofventral mouth (Fig.
2A). Pharynx (dissected)with 7 pairs ofdor- Material. —Santa. Catalina Basin, Cali-
sal andventralborderpapillae; hookedjaws fornia, 33°12'N, 118°30'W, 1240 m, Alvin
with small and larger teeth on innerborders Dives in Whale-fall site, in Nov 1988: AD
(Fig. 2D, E). 2138, 1 1 Nov, E2 A 0-1, holotype (USNM
Notopodia of biramous parapodia bul- 157590), E6 B 0-10, paratype (CRS); AD
bous basally, extending into long acicular 2133, 6 Nov, WS-6, bone scrapings, para-
processes on lower sides; neuropodia with type (USNM 157591).
mm
subtriangular presetal lobes extending into Description. —HolotypQ 22 long, 8
mm
long acicular processes, postsetal lobes wide with setae, 37 segments. Com-
(USNM mm
shorter, truncate (Fig. 2F, G). Notosetae pleteparatype 157591) 24 long,
mm
forming radiating bundles, short to long, al- 8 wide, 37 segments. Dorsum darkly
most as long as neurosetae, stout, acicular, pigmented, with low ciliated transverse
tapering to blunt tips, with double alter- bands, 2 per segment, continuing on bases
nating rows of short spines on one side, 3- ofelytrophores and dorsal tubercles. Elytra
4 pairs on shorter notosetae and up to 11 15 pairs, on bulbous elytrophores, on seg-
pairs on longer ones (Fig. 2F-H). Neuro- ments 2, 4, 5, 7, alternate segments to 23,
setae forming fan-shaped bundles, very nu- 26, 29, 32. First elytra round, with long pa-
merous, slender, with slightly curved tips pillae on border and scattered on surface,
and double rows of spines; supraacicular with conical microtubercles throughout but
neurosetaewith more prominent spines than more concentrated near borders (Fig. 3B).
in subacicular neurosetae (Fig. 2F, G, I, J). Following elytra subreniform, with long pa-
Ventral cirri with small cirrophores on mid- pillae on lateral borders, surfaces with con-
dle ofneuropodia, styles short, tapering, of- ical microtubercles and long papillae, most-
ten curveddistallyonposteriorsides ofneu- ly confined to lateral halves; medial halves
ropodia (Fig. 2F, G). Ventral segmental bare or with scattered small microtubercles
papillae 4 pairs, on segments 12-15, rather (Fig. 3C). Prominent bulbous dorsal tuber-
long, curved laterally (Fig. 2C); ventral seg- cles and dorsal cirri on non-elytrigerous seg-
mental papillae small, rounded, on smaller ments; cirrophores short, bulbous, on pos-
paratype. Pygidium enclosed in parapodia teriorsides ofnotopodia; styles slender, long,
ofsegments 19-21, last 2 smaller, with pair extending far beyond setae, with long pa-
of anal cirri (sometimes missing. Fig. 2B). pillae (Fig. 3E).
Etymology.—The new species is named Prostomium oval, bilobed, wider than
for the collecting site, Santa Catalina Basin. long, with small anterior peaks; 2 pairs of
Remarks.—Peinaleopolynoe santacatali- rather large eyes, anterior pair anterior to
na differs from P. sillardi in having small widest part of prostomium, posterior pair
elytrophores and elytra on segment 19, near posterior border; median antenna with
684 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
Fig. 3. Harmothoe craigsmithi, holotype (USNM 157590): A, Dorsal view ofanteriorend, styles ofmedian
antenna and tentacularcirri missing; B, Right 1st elytron; C, Right middleelytron, with detail ofmicrotubercles
and papillae; D, Left elytrigerous parapodium, anterior view, acicula dotted; E, Left middle cirrigerous para-
podium, posterior view; F, Long and short notosetae from same; G, Upper, middle and lower neuroseta from
same, with detail ofparts. Scales = 0.1 mm for A; 0.5 mm for B, C; 0.5 mm for D, E; 0.1 mm for F, G.
bulbous ceratophore in anterior notch, style small acicularlobe and 3 notosetae on inner
missing; lateral antennae with ceratophores side and dorsal and ventral tentacular cirri
insertedventrally, styles short, subulate, pa- (missing) (Fig. 3A). Second segment with
pillate; palps stout, tapering about twice first pair of large elytrophores, biramous
length of prostomium; tentaculophores of parapodia and long ventral buccal cirri lat-
segment I lateral to prostomium, each with eral to ventral mouth (Fig. 3A).
VOLUME NUMBER
106, 4 685
Notopodium of biramous parapodium Subadyte sp. A. Jones & Thompson, 1987:
almost as long as neuropodium, rounded, 128, fig. 3a (list).
with long acicular process on lower side;
neuropodium with subconical presetal Material—^di]2i California, vicinity of
acicular lobe with digitiform supraacicular Cedros Island, 27°38'N, 1 15°16'W, 792-844
process, postsetal lobe shorter, rounded (Fig. m, mud and glauconitic sand, holotype
(LACM-AHF
3D, E). Notosetae numerous, forming ra- 1008).
diating bundle, stouter than neurosetae, Santa Catalina Basin, California, 33°12'N,
shorter, slightly curved to longer, nearly 1 18°30'W, 1240 m, Alvin Dives in Whale-
straight, with numerous spinous rows and bone habitat, Nov 1988: m distance from
AD A
short, bare tips; longer ones mostly faint whale bones: 2133, 6 Nov, E2 0-2,
(USNM AD
split tips (Fig. 3F). Neurosetae numerous, 1 specimen 157601); 2138, 11
forming fan-shaped bundle, with numerous Nov, E6 A 0-10, E6 C 0-10, E6 D 0-10; E7
spinous rows and bare, slightly hooked tips; D-0-5, 4 specimens (USNM 157602-5). 0.5
m AD
middle and upper ones with slender sec- distance from whale bones: 2133, 6
ondary tooth and more prominent spinous Nov, Ell B 0-1, 1 specimen (USNM
rows; lower ones with shorter spinous 157600); AD 2135, 8 Nov, ElO C 0-1, 1
(USNM AD
regions and entire tips (Fig. 3G). Ventral specimen 157596); 2137, 10
cirri with cirrophores on middle of neuro- Nov, E6 D 0-1, E9 B 5-10, E9 C 5-10, 3
(USNM AD
podia; styles short, tapered (Fig. 3D, E). specimens 157597-9); 2138,
Etymology.—The speciesis namedforDr. 11 Nov, El A 0-1, E2 C 0-1, 2 specimens
Craig R. Smith, the collector of the poly- (CES).
noids from the whale-fall site, sent foriden- Channel Islands, California, R/V Velero
AHF
tification. IV, (as Subadyte sp. A): 22970, Santa
Remarks.—Harmothoe craigsmithi is Rosa Island, 33°5rN, 120°08'W, 368 m, 1
AHF
close to H. tenebricosa Moore (1910:351- specimen (LACM): 23000, Santa Rosa
353), which was described from off Cali- Island, 33°48'N, 120°04'W, 127 m, 1 spec-
m AHF
fornia in 914-1463 (also see Pettibone imen (LACM); 23093, Santa Rosa Is-
1969b:31^2) andis widely distributedfrom land, 33°39'N, 119°58'W, 113 m, 1 speci-
Japan and the Bering Sea to Lower Califor- men (USNM 157610); AHF 23182, San
nia, in 203-1990 m. Harmothoe craigsmithi Miguel Island, 33°57'N, 120°22'W, 118 m,
differs from H. tenebricosa in the following: 2 specimens (USNM 15761 1); AHF 24241,
the elytra have marginal and surface papil- San Miguel Island, 33°57'N, 120°23'W, 139
lae and microtubercles, instead of lacking m, 2 specimens (LACM).
them; the eyes are rather large, instead of Southern California, R/V Thomas G.
small or absent; the notopodia are almost Thompson Cruise 113, 1977 (as Subadyte
AHF
as long as the neuropodia, instead ofshort- sp. A): 82801, offHuntington Beach,
er; the neuropodial presetal acicular lobe 33°23'N, 117°54'W, 536-543 m, 2 speci-
AHF
has a long digitiform supraacicular process, mens (LACM); 80201, offSanta Bar-
instead ofa small rounded process; the no- bara, 34°22'N, 119°57'W, 329-340 m, 1
AHF
tosetae have distinct spinous rows, instead specimen (LACM); 80546, San Mi-
ofnearly smooth or faint spinous rows. guel Island, 33°57'N, 120°26'W, 213-251
AHF
m, specimen (LACM); 81010, Santa
1
Cruz Island, 33°46'N, 119°49'W, 444-500
Genus Subadyte Pettibone, 1969a AHF
m, 3 specimens (LACM); 81735, Tan-
Subadyte mexicana Fauchald, 1972
ner Bank, 32°47'N, 119°15'W, 511-530 m,
Figs. 4, 5 specimen (LACM).
1
Subadyte mexicana Fauchald, 1972:27, pi. Type material. —The holotype consists of
mm mm
l:figs. a-e. an anterior fragment 4, 5 long, 2
686 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
D F
Fig. 4. Subadyte mexicana, A, B (USNM 157601), C (USNM 157603), D-F (USNM 157597): A, Dorsal
view ofanterior end, left tentacular cirri and left dorsal cirrus ofsegment II missing; B, Ventral view oflateral
antennae and facial tubercle (not to scale); C, Left 1st elytron from segment II; D, Right middle elytrigerous
parapodium, anterior view, acicula dotted; E, Short and longer notosetae, from same, with detail ofparts; F,
Neuroseta, from same, with detail ofparts. Scales = 0.2 mm for A, C; 0.1 mm for D-F.
wide without setae, and 12 segments. Most from Santa Catalina Basin, oval, with long
ofthe parapodia are broken off, with elytra papillae on surface (Fig. 4C), covered with
missing. foreign material, including filamentous bac-
Supplementarydescription. —All 12 spec- teria (Beggiatoa sp.). Elytra remaining on
imens from Whale-bone site incomplete, specimens from Channel Islands more nu-
some with developing posterior ends; fig- merous: large, delicate, oval, with papillae
mm
ured specimen (USNM 157601) 2.5 scattered on surfaces andnearborders, vari-
mm
long, 3 wide with setae, and 9 segments; able in size and shape, some short with cla-
largest specimen with 16 segments, plus vate tips and some longer, bulbous basally,
posterior end of 3 developing segments with clavate tips (Fig. 5A, B). Cirrigerous
(USNM mm mm
157597), 2.5 long, 2 wide segments with inconspicuous dorsal tuber-
with setae. Of 15 specimens from Channel cles; cirrophores ofdorsal cirri short, cylin-
Islands, largest specimen incomplete drical, on posterior sides ofnotopodia, with
(USNM 157610), 8.5 mm long, 4 mm wide styles long, extending beyond setae, papil-
with setae and 25 segments. late, with filamentous tips (Fig. 4A).
Body flattened, with long parapodia and Prostomium (Fig. 4A, B) oval, deeply bi-
setae, giving aspect ofpelagic form (Fig. 4A, lobed, wider than long, with small anterior
D). Elytrophores large, bulbous, on seg- peaks; 2 pairs ofsmall eyes on posteriorhalf
ments 2, 4, 5, 7, continuing on alternate of prostomium; median antenna with bul-
segments to 23, or more? Elytra mostly bous ceratophore in anterior notch of pro-
missing; remaining left elytron on specimen stomium, style long, papillate, with long fil-
VOLUME NUMBER
106, 4 687
Fig. 5. Subadyte mexicana, specimen from San Miguel Island (USNM 157611): A, Left 1st elytron from
segment 2, with detail ofborder and surface papillae; B, Left 3rd elytron from segment 6, with detail ofborder
and surface papillae. Scale = 0.1 mm.
amentous tip; lateral antennae withbulbous curved borders and entire tips; longer no-
ceratophores, inserted ventrally and nearly tosetae with spinous pockets basally and
hidden from view dorsally, styles short, su- more distally with smaller close-set spines
bulate, papillate. and bifid split tips. Neurosetae (Fig. 4D, F)
Tentaculophores of segment I (Fig. 4A) numerous, very long, forming fan-shaped
lateral to prostomium, projecting anterior- bundles; neurosetae slender, with basal spi-
ly, each with small projecting acicular lobe nous pockets or spurs, finely spinous dis-
and 2 curved notosetae on inner side, long tally, tapering to slender bifid split tips.
dorsal tentacular cirrus, similar to median Ventral cirri (Fig. 4D) on middle of neu-
antenna, and shorter ventral tentacular cir- ropodia, short, subulate, smooth.
rus; small rounded facial tubercle (Fig. 4B)
between bases ofceratophores oflateral an-
Acknowledgments
tennae. Segment II (Fig. 4A) with first pair
My
of large elytrophores, biramous parapodia, thanks go to Dr. Craig R. Smith and
and long ventral buccal cirri, attached ba- Hilary Maybaum of the Department of
sally lateral to ventral mouth, similar to Oceanography, University of Hawaii, at
ventral tentacular cirri. Manoa forthe polynoid specimens from the
Biramous parapodium (Fig. 4D) with no- Whale-fall site in the Santa Catalina Basin
topodium shorter than neuropodium, bul- and for the information packet on the
bous basally, with tapering acicular process Whale-fall research and for being a part of
on lower side; neuropodium subconical, this interesting study. Dr. Kenneth L. Smith
presetal lobe tapering to pointed acicular ofScripps Institution ofOceanography fur-
process, postsetal lobe shorter, rounded. nished information on the pelagic macelH-
Notosetae (Fig. 4D, E) numerous, forming cephalin polychaete from the Santa Catalina
radiating bundle, stouter than neurosetae, Basin. I thank Dr. Jean-Claude Dauvin of
shorter, curved to longer, nearly straight, the Museum National d'Histoire Naturelle,
and nearly as long as neurosetae; shorter Paris for the loan of the holotype of Pein-
notosetae with up to 15 spinous pockets on aleopolynoe sillardi. I thank Leslie Harris