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VENUS (Jap. Jour. Malac.)Rre - Vol. 57, No. 2 {199R>/ 75 84

OriginalArticles zag

A new species of Bathybuccinum (:) from the

Aleutian Islands

Yuri KANToR and M. G. HARAsEwycH

A.?VL Severtzov hrstitute of Problems of Evolution, Russian Academy of Sciences. Leninskij Prospec4 33, Moscaw 11ro71 Russia, and Department of invertebrate Zooiogy. Nittionat Museum of Nbturat History, Smithsonian institution. PVbshington, DC 2a560 USA

Abstract: Bathybuccinum (Ovulatibuccinunz) clarki new species, is described from bathyal depths off the central Aleutian Islands, This new species is provisienally assigned to the genus Batdybuccinum primarily en the basis of its distinctive triangular with terminal nuclcus, and large , which are rare features in Buccininae. Conchologi- cally, the new species most closely resembres (EpistobuccinumJ epistomium Dall, 1907, which, however, has a typical buccinid eperculum that is large, oval, with a subcentral nucleus.

Key words: , Buccinidae, Batlu,buccinum, North Pacific, new species.

Introduction

Neogastropods of the family Buccinidae comprise a diverse and abundant component

of the subtidal to abyssal fauna of carnivores and scavengers, especially in temperate and

polar regions. The rank and composition of this taxon has been subject to widely varying

interpretations (e.g. Boss, 1982; Ponder & Waren, 1988; Vaught, 1989), and is still far from resolved. Habe & Sato (1972) divided the northern Pacific Buccinidae into six subfamilies, including the nominotypical subfamily Buccininae. Golikov (1980) mono- graphed the Buccininae, subdividing it into 3 genera, 3 subgenera and 88 species. Tiba and Kosuge (1984) reviewed and illustrated 49 North Pacific species of the genus Buccinum. Most recently, Golikov & Sirenko (1988) proposed a new classification of the subfamily

Buccininae, recognizing 5 genera, 23 subgenera and I08 species, all from the boreal region. Among the buccinids collected during the National Marine Fisheries Service's Aleutian

Island Trawl Survey Cruise Number 971 were several specimens of a distinctiye buccinine

that could not be referred to any of the the 108 species listed by Golikev & Sirenko (1988), and only provisionally assigned to any of the genera or subgenera recognized by these

authors. This species is described as new, and tentatively assigned to the genus Bathybucci- num Golikov & Sirenko (1988). The nominotypical subgenus was erected to incorporate

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76 VENUS: Vol, S7, No.2(1998)

two species from bathyal depths off the southern Kurile Islands, while the subgenus

Ovulatibuccinum Golikov & Sirenko (1988),in which we include this new species, ranges from the Pacific coast of centraT Honshu to the eastern Aleutian Islands.

We are pleased to name this new species after Mr. Roger N. Clark, who collected the type material and brought it to our attention, in recongition of his many contributions

to the study of the invertebrate fauna of the Aleutian Islands.

Abbreviations

LACM - Los Angeles County Museum of Natural History, Los Angeles

USNM - National Museum of Natural History, Smithsonian Institution, Washington D.C.

ZIN - Zoological Institute, St. Petersburg

ZMMU - Zoological Museum, Moscow University, Moscow

Taxonomy

Family BUCCINIDAE Rafinesque, 1815 Subfamily Buccininae Rafinesque, 1815 Genus Bathybuccinum Golikov & Sirenko, 1988

Type species: Bathybuccinum bicordatum Golikov & Sirenko, 1988, by original designation.

"Type 7)'anslation of Originat Description: species Bathybuccinum bicordotum Golikov & Sirenko, bathyal zone of the southern Kurile Islands. Shell of small dimensions for the

subfamily (shell height not more than 25 mm), thin walled, covered by a developed periostra- cum that sometimes forms fringes. Axial sculpture represented only by thin growth lines.

Operculum small, oval, occupies not more than O.3 time the height of the , with

the nucleus situated at the lower edge of the operculum. In contrast to other genera in

the subfamily, in which the osphradium is less than half the length of the ctenidium, the

osphradium of Bathybuccinum is large, being only slightly smaller than the ctenidium.

The outer cusp of the lateral tooth of the is narrow, compared to the other cusps,

and relatively longer.

Based on the form of the whorls and the character of the shell sculpture this genus

is divided into 2 subgenera. The nominotypical subgenus, with type species Bathybuccinum

bicordotum Golikov & Sirenko, is characterized by angulate whorls and well developed spiral

sculpture, including keels.

In addition to the type species, Bathybuceinum unicordotum Golikov & Sirenko is also

assigned to this taxon."

Subgenus Ovutatibuccinum Golikov & Sirenko, 1988

Type species: Buccinum ovutum Dall, 1895, by original designation.

"The 1beanslation of Originat Description: subgenus Ovutatibuccinum Golikov & Sirenko

with type species Buccinum ovulum Dall, 1895 is characterized by the weak development

of spiral sculpture, by rounded, not angular whorls, and by the absence of keels. This

subgenus also contains Buccinum bombycinum Dall [1907] and Batirybuccinum fimbriatum

Golikov & Sirenko, 1988."

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Kantor & Harasewych: New Species of Bathybuccinum from Aleutian Islands 77

Bathybuccinum (Ovulatibuccinund clarki new species

(Figs. 1-23) '

Shell mot:phology: Shell (Figs. 1-3, 6-10) to 60 mm, thin, ovate-conic, with short siphonal

canal. Protoconch consisting of 2 low, rounded, chalky whorls, badly eroded in most speci-

mens. Transition to teleoconch marked by appearance of numerous, thin, spiral cords.

Teleoconch of up to 6 whorls, with sharply inflected periphery just below mid- becom-

ing less prominent in larger specimens. Whorls evenly rounded to weakly sinuated above and below periphery, Suture adpressed at or just below periphery of previous whorl. Axial sculpture limited to weak, opisthocyrt growth lines most prominent between spiral cords. Spiral sculpture of numerous, fine, closely-spaced spiral cords (37-58 between suture and

periphery, 30-38 between periphery and , and 15-24 on siphonal canal).

Aperture roughly hemi-elliptical, less than half the shell height. Outer lip rounded to weakly

angled, with narrow (3-4 mm) thickened band along margin of larger specimens. straight, deflected from shell axis by 5e, forming angle of 35-450 with parietal lip.

Siphonal fasciole weak, nearly axial, producing Iow, broad fold on the columella adjacent

to sharply keeled siphonal fold. Periostracum, outer shell layer resorbed from inductural

area exposing the purplish inner shell Iayer. Siphonal canal short, broad, open, slightly

deflected abaxially. Exterior shell surface olive brown, aperture purplish, except for white

siphonal fold and thickened band along outer lip. Periostracum thin, yellowish brown, finely lamellose. Operculum (Figs. 4, 5, 15, op) small (

triangular, weakly unguiculate laterally, nucleus terminal. Anatomy: Preserved (Figs. 15-16) consists of 3i12 whorls, digestive gland spans i14 314 2 wherls, kidney whorl, mantle cavity whorl. Mantle edge and roof thin.

Osphradium (Fig. 15, os) nearly as wide and long as ctenidium (Fig. 15, ct) in smaller specimens, becoming proportionally smaller in larger individuals. (Fig.

15, hg) as broad as opshradium and ctenidium combined, strongly transversely pleated,

overlaying the rectum and pallial gonoduct. Head medium-sized, tentacles short, stout,

eyes medium-sized, situated at small rounded lebes at base of tentacles. Foot short

(L/W==1.4), tapering posteriorly. Body color yellowish tan, siphon, head, and lateral regions of the foet densely speckled with black to produce dark gray tone. Digestive system - Proboscis (Fig. 17, pr) long (=tti3/4 aperture length), thick (LID s4.2), unpigmented. The powerful proboscis retractor muscles (Fig. 17, prr) are attached mainly to the left side of the rhynchodeum at mid-length. A circular muscle (Figs. 17, 18, cmr) rings the rhynchodeum near its anterior end, indicating the border of the evertible part of the proboscis. The mouth is wide, oval. The radula (Figs. 11-l4) is short (ntO.6 aper- ture length), consisting of 61-66 rews of teeth. Rachidian teeth are broad, with a nearly

rectangular basal plate and five cusps. The outermost cusps are broadest and laterally

buttressed. The central cusp is the weakest and shortest. The outer cusps of the lateral

teeth are long and narrow. The middle cusp is narrow, flanking the inner cusp. The

odontophoral retractor muscles extend from the rear end of proboscis and are attached

to the rhynchodaeum. The anterior oesophagus (Fig. 17, oe) is wide, flattened, and thick- walled, expanding to form the large, pyriform, valve of Leiblein (Fig. 18, vL), which is

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78 VENUS: Vol. S7, No.2(1998)

Figs.1-10.Bathyb"ccinum (Ovulatibuccinunij clarki n, sp, 1. Ventral, 2. right lateral, and 3. dorsal view of holotype, USNM 880225. 4. Inner

and 5. outer surfac ¢ s of Qperculum of holotype. Scale bar=5 mm. 6. Ventral, 7. rightdorsal Iateral, and 8. dorsal view of paratype 7, USNM 880227. 9. Ventral, and 10. view of paratype 1, USNM 880226, Scale bar=2cm for all shells.

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Kantor & Harasewych: New Speciesef Bathybuccinum fromAleutianIslands 79

Figs. 11-14. Radular morphology of Bathybuccinum (Ovulatibuccinum] clarki n. sp. 11. dorsal and 12. 0blique (45e) views of radular ribbon of holotype. 13. dorsal and 14. 0blique (4Se) views of radular ribbon of paratype 1. Scale bars=1oopm.

surrounded by the salivary glands (Fig. 17, 18, sg). The left salivary gland is elongated,

the right more compact and oval, their margins indistinct were they abutt. The nerve ring

(fig. 17, nr) surrounds the esophagus posterior to the valve of Leiblein. The gland of Leiblein (Fig. 17, 18, gL) is small, tubular, thin-walled and uncoiled, opening to the mid- oesophagus without constriction. The posterior esophagus forms a crop-like enlargement

before leaving the cephalic hemocoel. The stomach (Figs. 16, st, 19-21) is large (as long as retracted proboscis), with a long caecum (Figs. 20, 21, cae) or posterior mixing area. The digestive gland (Fig. 16, dg) is clearly separated into two lobes, each with its own duct (Figs. 20, 21, dd). One duct opens near the entrance of the esophagus, the other

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80 VENUS ： Vo1 ．57 ， No ．2 （1998）

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Kantor & Harasewych: New Species of Bathybuccinum from Aleutian Islands 81

near the middle portion of the stomach. Internally, the stomach is similar to that of other buccinid species. It has a single posterior sorting area and a poorly differentiated zone of compaction. The digestive gland duct pouches are deep. The typhlosoles (Fig. 21, typ)

are poorly developed. Mate reproductive system - A testicular duct runs anteriorly from the testis, which line

the right side of the digestive gland, becomes convoluted to form a seminal vesicle along the adapical surface of the kidney, before entering the mantle cavity, were it expands slightly into a narrow prostate gland atong the mantle wal1, before descending to the mantle floor and leading to the base of the penis. The penis (Fig. 22) is long, broad, and dorso-ventrally compressed, truncated anteriorly, with a small, conical papilla situated at its dorso-anterior edge. The papilla i$ surrounded by a shallow, circular fold. filemate reproductive system- The ovary (Figs. 15, 16, ov) overlies the right side of the digestive gland and gives rise to an oviduct that runs along the visceral mass, tangentially abutting the pericardium before entering the albumen gland adjacent to the kidney, The capsule gland (Fig. 15, cg) is long, cylindrical, extending nearly the length of the mantle cavity. A small, globular bursa copulatrix is anterior to the capsule gland. The female

opening, situated on the anterior-lateral wall of the bursa copulatrix, is anterior and to

the right of the rectum.

7)lpe material: Holotype, USNM 880225 (9, Length 58.2 mm), Seguam Pass, Aleutian Islands, Alaska, 52e16.46'N, 172055.89'W, in 291 m, F/V Vbsteraaien, 21 June 1997 (type

locality); Paratype 1, USNM 880226 (cr, Length 30.6 mm), Paratype 2 , LACM 2869 (empty shell, Length 48.5 mm), Paratypes 3-4, Clark Collection (cr, Length 37.7 mm, Lc 23226, W of Agattu 9 , Length 50.0 mm), Paratype 5, ZIN 59465, Paratype 6, ZMMU

Island, Aleutian Islands, Alaska, 52"13.50'N, 173027.80'E, in 169 m, black sand and gravel,

F/V Dominator, 6 August 1997; Paratypes 7-9, USNM 880227 (9, Length 50.0 mrn,

empty shells, Lengths 47.0 mm, 37.1 mm), S of Attu, Aleutian Islands, Alaska, 52e29.30'N,

172057.50'W, in 166 m, on sandlgravel, FIV Dominator, 2 August 1997; Paratype 10,

USNM 880228 (9, Length 48.2 mm) S of Herbert Island, Aleutian Islands, Alaska, 52e32.38'N, 170004.59'W, in 240 m, FIV J'lesteraaten, 19 June 1997; Paratype 11, USNM 880229 (9, Length 44.5 mm), Samalga Pass, AIeutian Island$, Alaska, 52065.60'N, 169e19.34'W, in 410 m, FIV Vesteraaten, 15 June 1997; Paratype 12, USNM 880230

Figs. 15-22. Anatomical features of the holotype of Bathybuccinum rOvulatibuccinunij ctarki. n. sp. 15. Left lateral and 16. dorsal views of animal. Scale bar == 10 mm. 17. Left lateral and 18. right lateral views of anterior alimen- tary system. Scale bar=5mm. 19. Dorsal and 20. ventral views of stomach. Scale bar=5mm. 21. Internal details of stomach, Scale bar=5 mm. 22. Penis, 2 views of distal end. Scale bar=5 mm. ao, anteri- or aorta: cae, caecum or posterior mixing area; cg, capsule gland; cmr, circular muscle of the rhynchodaeum; ct, etenidium; dd, ducts of the diges- tive gland; dg, digestive gland; gL, gland of Leiblein; hg, hypobranchial gland; ig, intestinal groove; n, nephridium; nr, nerye ring; odr, odonto- phore retractor muscle; oe, oesophagu$; op, operculum; os, osphradium; ov, evary; pr, proboscis; prr, proboscis retractor muscles; s, siphon; sd, salivary duct; sg, salivary gland; st, stomach; typ, typhlosoles; vL, valve of Leiblein,

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82 VENUS: Vol.57, No.2(1998)

(9, Length 62.9 mm) Seguam Pass, Aleutian Islands, Alaska, 52e16.26'N, 172e54.13'W, in 235 m, rocky bottom, strong current, F/V J'lesteraaien, 18 June 1997.

Remarks: In terms of shell morphology, this new species very closely resembles Buccinum

upistomium Dall, 1907, a species known only from the holotype, collected off the central Kurile Islands (Simushir) in 412 m. This species serves as the type species of the monotypic subgenus EPistobuccinum Golikov & Sirenko, 1988 [of Buccinum], which was distinguished "truncated on the basis of its conical shell with an angular periphery of the body whorl, covered with numerous flattened [spiral] cerds." Conchologically, Batlrybuccinum clarki can be distinguished from B. epistomium (see Golikov, 1980: pl. 31, Fig. 3; Tiba & Kosuge, 1984: 14-29) by its much thinner shell, broader inductura, presence of a siphonal fasciole, and absence of a thickened and deflected terminal varix. The operculum of the holotype of B. epistomium is large (O.6 Aperture length), oval, and has a subcentral nucleus, as is usual for the genus Buccinum. The presence of a large operculum with a central or subcentral nucleus was considered as one of the major diagnostic characters of Buccininae (Golikov, 1980). The operculum of the new species is small (

E 100 16oo 18oe 1600 w tttt/ttttt ./'tttt/ttltttttttt ' t:ttttttt/ttttttttttI･:1･-' ･1･ '//''1,'il'I/;/'/'''-'Il:';I//:1'''''i ttt.t/ttltittit.,.ltttt,I･･.It:tt:,,,/./,,,..tttt/t t ttte tttt// tttttttttttt/ttttt/tlttttt' /' tttttttt/t tttttttltttt ･=l/T/ttt ttt tt K> 'v''/I.,,,/,,[,,I..ttI/t/ttttt --:/,,,,///I,/ :･･:11･:: .Il,,=/i,l,/:/,,,,:-'ttttt'' ,Iiii/ttttttt::tttt/t/1,,,,:,t/t'tlt:t/tt::t/t/:tt 6rfN,1,I,''･:･:;:･::sv' ttttt/t::t:t/t/t･IIttttttt:t:tttt///..ttttttt'60 ,il;?tttttttltttttttttt:tt/i;III,1"e.'4･ss N :;I･,,,,IllI,II-Ili';l--1,1,,' '

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Fig. 23. Geographic and bathymetric distribution of Bathybuccinum (Ovulatibuccinuml ciarki n, sp, Star indicates type locality.

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Kantor ＆ Harasewych ： New Species of Bathy わuccinum from Aleutian Islands 83

with ＆ ： 7 11 13 16 ． This character ， together the of Sirenko ，1988 Figs，3， ， ， ， ） presence an osphradium that is nearly as large as the ctenidium ， a trait that is rare in Buccininae

us to tentatively assign this new species and diagnostic of Bathybuccinum， has prompted with to the genus Bath アbuccinum． The radu 且ar morphology of B ． cta 厂ki is also concordant that of Bathybuccinum ． Other anatomical features of B ． clarki are generally bucciniform ． Since there are very

of other species comparisons are difficult few published data on the anatomy Buccinum ， of B ．undatum and the generic assignment tentative ． The stomach anatomy is sim 量lar to that

and middendorffii Verkr 位zen 1882 （Medinskaya ， 1993 ． Linneus ， 1758 （Dakin ， 1912） B ． ， ） From the latterβ ． clarki differs in lacking an anterior sorting area ． The foregut of B ．

clarki is simi 且ar to that of most Buccinidae and lacks unique characters ． The rectum of with numerous sponge spicules diatoms and few paratype 2 contained sediments ， foraminiferans， Our placement of 8 ． ctarki in the subgenus Ovulatibuccinum is based on the absence of a keeled shoulder in this species ， and by the broader geographic range of this subgenus ・ mor − We recognize that Bathybuccinum （OvutatibuccinumJ clarki differs markedly in shell − especially initslargersize ， angular phology from all other members of this subgenus ， periph

fine spiral sculpture ． As additional anatomical data become available ， ery ， and prominent ， it is likely that the generic and subgeneric classification of the Buccininae will continue to be revised ．

ー ア リ ュ シ ャ ン 列 島産 Bathybuccinum の 1新 種

ー ・ Y ． カ ン ト ル M ．G ． ハ ラ セ ウ ィ ッ チ

要 約

一 ー エ バ の 1 フ ジ イ ロ バ イ Buccinum ア リ ュ シ ャ ン 列 島 の 陸 棚 h か ら採 集 さ れ る ゾ イ 科 種 は ， 見 い が 三 で が 端 位 で あ る 点 と ，嗅検 器 が 大 き い こ と で episthomizam Dall，1907 に 似 て る が ， 蓋 角 形 核

Bathyb ” ccinunt Golikov ＆ Sircnko，1988 に 置 か れ る 。

コ エ バ mm ： ア Bathvbuccinum （Ovulatibuccinum ）clarki n ． sp ．ソ ゾ イ （新和 名） は 殻 長 58、2 （摸 式 標 本 ー ロ バ が リ ュ シ ャ ン 列 島 シ グ ァ ム 海 峡 水 深 291m ） で ， フ ジ イ イ に 似 る が ，殻 は 非常 に 薄 く，滑 層 発 達 ． い が ら か で 殻 「1外 唇 の 縦 張 肋 に よ る 反 転 は 無 。 ま た 蓋 は 亜 三 角 形 で 核 は 殻 軸 寄 り で 端 位 し ， 縫 帯 明 ，

の エ ゾ バ イ と大 き な違 い は 無 い 。 の 点 で 異 な る 。 軟体 の 解 剖 学 的 特 徴 は他 類

Refe 『ences

20 ： 253 − 367 ． Dakin W ． J，1912． Buccinum （The ）． P 厂oc ． L ’verpoot Bio’． So‘． Golikov A ． N ．1980． Mo 〃usks Buccin ’nae q ブ the VMorld ． Fauna of the USSR ， new series

Mollusks VoL 5 No ．2 Nauka ，465 ．（in Russian ）． No ．12 且， ， ， ，Leningrad， pp Golikov A ． N ．＆ Sirenko B ．1．1988 ． New data to the creation of the system of the subfamily ZooL Inst， しrSSI 〜 Acad ．Sci． Buccininae （Gastropoda Pectinib匸anchia Bucciniformes ）． Proc ． ． − Lening厂a ｛ゴ 176 ： 85 104 （in Russian）．

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84 VENUS: Vol. 57, No.2(1998)

Habe, T,, & Sato. J. 1972. A classificatien of the family B"ccinidae from the North Pacific, Roe. Jdpanese Soc. S,stem, ZooL 8: 1-8, pls. 1, 2. Medinskaya A. I. 1993. Anatomy of the stomach of some Neogastropoda from the offshore zone ef the Japan Sea. Ruthenica 3(1): 17-24, Tiba, R, & S. Kosuge. 1984, Genus Buccinum, Linnaeus. NOrth PacijTc Shetls 14: 1-128.

[Received: FebruaTy 28, 1998; Accepted: April 2, 19981

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