On the morphology and relationships of sorne

16

A.A.lliHJJelliKeneaa; amt -

llzyflaJlbl(Cj

aog -

nepe.uHec MRHTHlfnoe

)lOITOJlHHTeJlhHRSl flH~CBOJt.Hast >KCJle3Rj

asg - .nononmnenhuan cJttoHHaH >Keneaa; be flO/IOCTh;

btn -

6yKK3JlbHast Macea;

Ka; C -- U..CKyM; CID HH)lHii; CU -

bt -

6yKKaJihHaR

6yKKaJibl!Ril Tpy6-

KOJIYMCIDH1pHbH1 M)'CKYJJ; Ct -

KTC-

K)'TMKyna; daS _;._ OpOTOK ,l\OflOJHHfTCJJbHOii

CJHOUHOif >KCJ1e3bi;

dd -

npoTOK nl1lll,CBapHTeJlbHOfi >KeJIC3bt;

dg - flHUI,CBBpHTeJibHaSI >IOTOK >KCJlC3bl Jlei16nefiua; e - rnaa; el - rnaanan nonacrb; f - roJmnuan nonacn.; g - rona~a; gf }KCJIC3HCTbiC CKJta)lKH mnu.euo.na; gl - )KeJie3fl JieH6nei1ua; h - cep)lu;e; ig - HtnecnmállhHbttí

Material for the study was partially collected by the author (Olivella borealis Golikov) but mainly .provided by different institutions and museums (Zoological Museum of Moscow State University; Institute of the Oceanology of the USSR Academy of Sciences, Moscow; Natal Museum, South Africa; Muséum National d'Histoire Naturelle, París; Brítish Museum (Natural History), London). In order to avoid any misunderstanding, the species studied are referréd lo the subfamilies, previously adopted by the authors until !he las! pari of the article: Subfamily Olivinae Oliva bulbosa (Ri:iding, 1798)

19

Morphology and relationships of oliviform gastropods

TI1llai

uoe

>KMo6oK;

ml - aa.nnHH

CCMenpHCMHHK; in ~ 11HTCC-

igl -

M3HTHHuan

KOJJhi..(O >KMy~Ka; fl -

nonacr&; mn -

HCpu:-

,UHH; f f - _peTpaKTOp paJzyJibli fS - pa.nyJISlpHblfi MCillOKi rw - OCTaTKH BH)'TpcHHCfi CTCHKH npe.I(nOCJIC~HCfO o6opom; S -

CHon;

_HhJe

sa-

copTHpyrorn;aSI

xpmuH; sd -

o6nacTb; _se-

nporoK cnrounoH

cy6pa)zyJISip-

>Keneahf; sg -

CJIIOn}faH

•

FIG. 1 (fronting page). 4.-F- Shells of the species s1udied: A-B- MelapitJm l(neatum (Lamarck, 1822} (A- female with 2 egg capsules, shelllength 24.0 mm; B ~ male, shelllength 25.5 mm); C- 0/lvella borealis Golikov, 1967, shelt Jength 9.0 mm; DOliva bulbosa (ROding, 1798), shelt length 22.7 mm; E- Pseudo/iva zebrinaA.Adams, 1853, shelllength 10.2·mm; F-GBenthobia tryoni Dall, 1889, shelllength 8.6 mm. PaKoamJbl HCCJICAOnat-mhlx »H~oa: A-B- Melapium lineatum (Lamarclt, 1822) (A- caMKa CJ1BYMR nHu.enwMH KancynaMH, 8biCOTa paKOBHHbl 24.0 MM; B- caMCII., DblCOTa paKOBHUbT 25.5 MM); e - Olivella borea/is Golikov, 1967. BbiCOTa

PMC. l. A-F-

paKODHHbl 9.0 MM; D- Oliva bulbosa (ROding, 1798), nr.1coTa paKonuuht 22.7 MM; E - Pseudo/iva zebrina A.Adams, 1853, nMcora pa~· .

B FIG.3. A- Crawllng 0/ivel/a borealis Golikov; B- positlon of the mollusc into the sediments PHC. 3. A- nonayu.tan: Oliveila boreaUs Golikov; B- nonomeuue MOJlJHOCKa n rpynTe.

B

FIG. '2 (frontirtg page). A- longitudinal section through the muscular bu lb of the accessory salivary gland of Belltlwbia tryoni, scale - 0.5 mm; B- sectiou through the oesophagus and accessory ocsophageal gland of Melapium lineatum, scale- 1 mm.

PMC. 2. A- npo¡¡:OJIDHMH cpca •tepea M)'CKYJlhHhlH: MClliOK J{OHOJ1HHTCJlbHofi CJlfOHHOft me.ne3hJ JJenthobia tryoni, r.tacuna6 0.5 MM; B - Cpe3ttCpe3

liHU~CUOl{ H f{OUOJJHt-fTCJibliYIO mmtCBOAIIY[{) >K8JIC3Y Me/apium fineatum,

MUCtuTaÓ- 1 MM.

22

23


Yu.I.Kantor

FIG 4. Morphology of the soft body of 0/ivella horealis Gollkov. A,B- body, removed from the shell; C- removed visceral mass; D - scheme of the positlon and attachment of the columellar muscle, the Jnner volume of the shell dotted, the remnants of the inner walls white; E- mantle. Scales 1 mm.

e-

TeJIO, M3BJIClJCHHOC H3 p8KOBHHbli om:eneHHbU~:f BHCL(CpMbHbtli MCIUOKj D - CXCM8 pacnoJIO>KCHlUI H npHKpefiJICHJUt KOJIYMM'JJHpHOI'O M)'CK)'JIR, BH)'tpCHHHSJ nOJIOCTh paKOBHIIbl 3aTOlJKomma, ocraswaHCst tJaCT& BH)'TJWHHHX CTeHOK paKO»HHbt 6ena~I; E- MI\HTHH. Macurra61 MM.

PJ{C. 4. Mop4JonornSI MSU'KOOO Tena 0/ive/la borealis Golikov. A,B -

)KeJie3aj Sh ~ raCTpH'lecKHli UI,HTOKj St -

>KeJ!Y,ll;OKi

t -

nujmooon«; tf- nonepettHafl CKJJap;Ka; tn - ronoott&ie uzynanbu,a; tr - cne.n.bl CmipMbHOÜ CKYJJbnT)'pbl¡ vl - KJJanau Jiel16neifna; vs -

vesicula semlnalls.

KEY TO ABBREVIATIONS IN FIGURES ag- anal gland; amt- anterior mantle tentacle; aog accessory oesophageal gland; asg- acccssory salivary gland; be - buccal cavlty; bm - buccal mass¡ bt - buccal tube; e

- caecum; cm

~

coiumellar muscle¡ ct - ctenldlum; cu -

cuticle; das - duct of the accessory salivary gland; dd duct of the dlgestlve gland; dg - dlgestive gland¡ di - duct of the gland of Leibfeln; e - eye; el - eye-lohe; f cephalic flap; g - gona~; gr ~ glandular foJds of the oesophagus; gl ~ gland of Leibleln; h - heart; ig ~ intestinal groove; igl - ingestlve gland; in - intestlne; mi -posterior mantle lobe; mn - muscular ring of the stomach; n - nephridium; nr - nerves and nervous ring; od ~ odontophore; odl - opening: of the duct of the gland of Leiblein; oe oesophagus; op -

operculum; os -

osphradium; ov -

ova-

ry; p - penis; pg - pallial gonoduct; pl - pedal Jobe; pmt - posterior mantle tentacle; pr ·- propodlum; prb -

probaseis; prr - proboscis retractors; r ~ rectum; rd radula; rdv - radular divertlculum; rn - rhynchostome; ro - renal openlng; rr - radular retractar; rs - radular sac; rw - remnant of hmer wall of the pénultlmate whorl; s - slphon; sa - sorting arca; se - subradular cartllages; sd - sallvary duct; sg- salivary gland¡ sh - gastlic shield; st - stomach; t - typhlosoles; tf - transverse fold; tn cephallc tentacles; tr - traces of the spiral sculpture; vt valve of Lelblein; vs - vesicula semlna/is.

DESCRIPTIONS OF MORPHOLOGY

Olivella borealis Golikov, 1967 MATERIAL STUDIED: 25 specimens, Vostok Bay, Japan Sea, depth S-6 m, sand, August 1988. 4 specimens sectioned, lO specimens dissected for gut content analysis. Description of living animals and their ecology. In Vostok Bay in the Japan Sea, the species is rather common at S-7 m depth on the

IliG. S. MoYphology of the digeslive system of 0/ivella borealls Golikov. A- scmidiagrammatic longitudinal section of the anterior p~rt ofthe dlgestive system, nervous rlnz not shown (scale 0.5 mm); B- scmidiagrammatic transvcrse section ofthc anterior part of the digestlve system at the leve!, indicated as 1 on fig. A; C- sernidiagrammatlc transverse section of the anterior part of the digestive system at the leve!, indlcated as 2 on fig. A (scale 0.5 mm); D - transverse section through ihc anterior part of the oesophagus (scale 0.1 mm); E- transvcrse sectlon 1hrough the posterior part of thc oesophagus (sea le 0.1 mm).

PHC. S. MoJXPonomu

muu:.enapmenhUOfi CffCTCMbl

0/ive/la borealis Golikov. A~

cxeMaTH3HpüB!\IHihJtf npOftOJTbHhiH

fiCp6AHIDJO l.I8C1h ni1ll.lCBapaTCJtbHOtf CHCTCMDt, OKOJTOrJIOTOtmoe HCpauoe KOJ1hi.J;O l-IC Hao6pa>KC!i0 (M8ClU'ffiÓ

0.5

cpca tmpea MM); B -

CXCMRTHSHpGBaHH&Iti: nOnCpet1HbltÍ CJ}C3 1fCpe3 nCpeJ:UUOID ~taCTb mHl(Cila¡JTCJlbHO-t:í CHCTCMbliJfi ypOBUC, OÓ03ti8t1CHHOM 1 Ha pHC. . A; C- CXCMRTI13Hpoll81Hlbli1' nonepe•IHh!tf Cpe3 •JCpe3 nepe;:tWOID ttaCTb llHlli.CllftpteJIMIOM CHCTCMI>t Ha ypOJJHC, o6o3H8'-ICIIIIOM

2 Ha puc. A (Macurra6 0.5 MM); D ~ nonepet.~Hb!Ü Cpe3llepea nepe;:tHroro tJRCTh mnu,CBOJJ.a épea llepea aa.nuwm ttaCTh nHrn.eoo.n.a (Macuna6 0.1 MM).

(MacmTa6 0.1 MM); E - nonepcLJHbiH


24 saHdy bottom. Most of the time these molluscs are buried in sand and are able to move rather rapidly through the sediments. In aquarium observa1ions the mean velocity of movement in the sediments is 20 cm/h (range 4-40 cm/h). Sometimes molluscs without apparent cause appeared on the sediment surface, where they can move more rapidly. The foot is broad, thin and semitransparent. The propodium is of crescent form and divided by a longitudinal cleft. The pedallobes are well developed and embrace the shelllaterally (Fig. 3). When the mollusc withdraws the pedallobes are greatly reduced in size due to the outflow of the liquid from broad !acunes of the lobes. The siphon during crawling is directed forward. The wac ter currents through the siphon and above the propodium inside the mantle cavity and outside the mantle cavity above the posterior part of the foot can be seen clearly. In aquarium observalions, molluscs with a shell length of less than a centimeter are usually buried in sand at a depth of 1-1.5 cm. The siphon is usually protruded through the sediment, although it can be pulled entirely under the sediment for long periods. Molluscs are usually orientated nearly parallel to the surface with the anterior part of the shell slightly raised (Fig. 3B). While crawling under the sediment a track in the form of a shallow groove is seen on the surface. When the mollusc is buried under sand, the pedallobes are greatly expanded and embrace most of the shell. There is a moderately large cavity in the sand below the spire. The water currents outside the mantle cavity above the posterior part of the foot are clearly seen. Sediment particles which have passed through the mantle cavity appear to be entangled with mucus to form long threads. During crawling the propodium plays the role of a wedge in moving the sediment parlides. Gut content analysis revealed that the mollusc swallows food and sediments particles without sorting. Thus sand grains and other inorganic particles are usually present in the stomach. Sometimes the size of the particles is surprisingly large. For instancc, the stomach of a mollusc with a shelllength of 9.0 mm contained a piece of bivalve shell 1.6 x 0.8 mm large, which occupied nearly the whole stomach volume. Remnants of different Arthropoda (Cladocera, Ostracoda, Cirripedia larvae, water mi tes), Foraminifera, Nematoda, and gastropods (Fartulum sp., Caecidae) were identified in the stomach contents. No remains of living bivalves were ever recorded. The analysis of the stabile carbon isotopes ratio was used for determination of the main source of income of the organic carbon for O. borealis. It is known, that the isotope ratio differs in different groups of plants and only slightly changes in the trophic web (for the review, see Kiyashko, 1987). The analysis allows lo state, that O.

borealis never feed on Bivalvia [Kantor, Kiyashko, 1990 ]. Thus rather different modes of feeding and diet was found amongst Olivella species. According to Marcus and Marcus [1959] O. verreauxii feed on bivalves, swallowing the prcy entirely. Thc strange feeding mechanism was described for O. columellaris [Seilacher, 1959]. The latter . species projects the head above the surface of sediments. Mucous "bags" are spun from the propodium and billow out in the swash of receding waves. Periodically, the nets are drawn forwards and probaseis reaches from behind to ingest them. ANATOMY. The shell is characterized by the resorption of the columella, and the inner walls of the spire. Only the inner wall of about half of the penultimate whorl remains (Fig. 4D). The columellar muscle has the form of a thick, slightly concave plate, which passes along the outer surface of the visceral mass and is attached lo the remnants of the inner wall of !he penultimate whorl. The only partly spirally eoiled visceral mass in its upper part above the stomach loses its spiral morphology and eorresponds in shape to the inner volume of the shell thatlacks columella and inner walls (Fig. 4 A-C). The head is absent. Two flaps triangular when contracted stage and pigmented at their tips, are placed at !he anterior end of the body. The rhynchostome opens below the right flap. The operculum is large, very thin, light yellow and transparent. It fills the entire aperture. It bears few growth lines, which are thread-like and slightly raised; in a specimen with a shell length of 10.6 mm, there are only three growth lines. Mantle complex (Fig. 4E): the mantle almost entirely covers the propodium when the mollusc withdraws in~o t~e shell. The dark gray osphradium is clearly seen through the mantle wall. The siphon is highly muscular with the wall formed of circular muscle.fibers and numerous bnndles of longitudinal muscles which are separated by radial fibers connecting the walls of the siphon. The mantle forms anterior and posterior mantle tentacles and a small posterior mantle lobe. The posterior mantle tentacle is derived from the right side of the mantle; it passes through the upper corner of the aperture and is situated in the channeled suture. It covsists of epithelium, a !ayer of longitudinal muscles, parenchymal and l.arge vacuolated ce!!¡; aqd bunqles of longitudinal muscle fibers. The thicll:nerve passes through the middle part of the tentacle, closer to the ventral side. The anterior mantle tentacle is situated near the siphon and, in the living mollusc, passes through the siphonal canal of the shell and along the dorsal side of the shell. Its histology is similar to that of the mantle wall. The small posterior mantle lobe is situated at the base of the posterior mantle tentacle. Its main

25

F!G. 6. Morphology of 1he sort body of Ollvella bor~alis Gollkov. A,B - stomach; C- stomach, opened mid-dorsally; D - transverso sectlon ofthestomach at the entrance ofthe duct of the digestlve gland; E- transverse section of the stomach in thearea of muscular ring; F- transversc sectlon of the caecum of the stomach¡ G ~ transveroo section of the posterior mantle Iobe; H- radula~ IdiagrammatJc transverse ooctlon of the radula in the radularsac; J ~ penls; K- vesicula semlnalis. Scale 0.05 mm for Flg. H and · O.S mm for aU others. PHC. 6. Moptfxmomu MiJfi(Qf() 'feM Oli-vella borealis Golikov. A-B ~ >KCJlYJWK; e - :>KCJty):{OK, BCJKeJIY.AKR B paitone MYCKyJt&Horo KOJI&u,a¡ F - norrepequwH cpea ueKyMa meny.n;~oROr.mJ Macurra6 0.5 CM,

MSH'KOI'O TeJia

Oliva bulbosa (ROding). A,B-

of the penis and opens at the tip of a long papilla . ~e >KeJie3bl e npoTOKRMH ue H306pa»eeu&t; B - MannHI (uaC1111'a6l MM); C - >KeJIYAOK (M8Cli1Ufi 1 MM).

pr FIG. 10. Morphology of the soft body of Pseudoliva zebrina A.Adams (A-E) and Amalda nwntrouzieri Souverbie (F,G). A,B,Fbody, re~ove.d from the shell (scale 0.5 cm); C- partof the visceral mass (scale0.25 cm); D- penis (scale 1 mm); E- viewof the crawlmg hve snail (from the sketch of S.Gofas); G- operculum (scate 0.25 cm). PHC. 10. MoJXPonornH

MSJf'Koro

te.n.a Pseudoliva zebrina A.Adarns (A-E) »Ama/da montrouzieri Souverbie (F-G) A,B,F- TCJIO, D- nemtC (MaCuiTa6

H3BJIClJCHHOC lt3 paKOBHHbl (M8CWT8Ó 0.5 CM); C- YlfRCTOK BHCl{Cpa:JlbHOI'O MCWKR (MRCUlTa6 0.25 CM); 1 MM); E- BH)l nonayll(ero MOJJJIIOCKa (e uaópocu S. Gofas); G- KpwruelfJ 33

hg

FIG. 12. Morphology of the soft body of PsJudo/iva anc/1/a Hanley. A- body, removed lrom the shell; B -anterior view of the head (scale 1 cm}; C- stomach; D ·- manthnA,C,D- in the same scale, scale 1 cm)

PHC. 12. MopclKlnomsr MSITKoro Tena Pseudo/iva ancilla Hantcy. A - reno MOJUJIOCKa 6e3 paKonHHM; B (MaCunafil CM); C- >KMYJ{OK; D- MftHTHil (A,C,D.- B O.AHOM M8CLUta6e, MRClliTI\61 CM),

.Museum Nl! E 2094; one bady dissected and part of the digestive system sectioned (female). ANATOMY: Body consists of 2.25 whorls in a specimen with a bady length of abaut 48 mm (Fig. l2A). The columellar muscle is very .thick and wide with very broad eavity. Its upper edge is turned outside. The muscle comprises abaut 1.5 whorls. The foot is broad, pedallobes absent. Propodium very narrow. The foot is pigmented with black spots. Mantle thick, ctenidium and osphradium are poorly seen through it. Siphon is very long and thick walled. Head small (Fig. 12B), well differentiated from the bady. Tentacles in fixed specimens very short, cone shaped, with eyes near the tips. In the live mollusc, it is seen, that the tentacles are elongate and the eyes are situated at the small lobes approximately in the middle of the tentacle [Kilburn, 1989: Fig. 2]. Mantle complex: Mantle (Fig. 12D) long, 1.5 times longer than its width. Siphon very long, without distributive valve. Ctenidium very long, occupying abaut 213 of the mantle length, and formed of high triangular lamellae. Osphradium narrow, symmetrical, equaling 1/z of the ctenidium Jength. Hypobranchial glaud well developed, forming distinct folds in the posterior part of the mantle. Rectum and pallial oviduct growing fused without distinct border. Anal opening and gonopore are close together. · Digestive system (Fig. 13): Proboscis short, flattened dorso-ventrally. Proboscis wall is formed of a thick !ayer of circular muscle fibers erossed by numerous irregularly spaced bands of longitudinal muscles. Odontophore very large, situ-

BH~ OOJIOBbl cnepe¡pt

ated at the base of the probaseis in the lower right side of the rhynchodaeum. Subradular eartilages paired, thick and fused anteriorly. Radular diverticulum opens into a poorly differentiated bucea! cavity at the probaseis base. 'l'he very thick-walled long bucea! tube leads from the mouth opening to the bucea! eavity; the walls of the bucea! tube are formc:d of circular muscle fibers. This tube occupies almos! the whole inner volume of the probaseis and is lined with cuticle, which in the posterior part is. formed of many layers of up to 0.2 mm thick. Rhynchodaeum very thick with numerous muscles attached to its anterior part by one end and to the skin by the other. Oesophagus with thick muscular walls and forms a S-shaped curve after leaving the probaseis. The valve of Leiblein large, cone-shaped. Small and compact acinous salivary glands are tightly attached to the oesophagus on both sides of the valve of Leiblein. Numerous muscle fibers, which are attached to the rhynchodaeum by one end, and to the oesophagus and valve of Leiblein by the other, penetrate the salivary glauds. The right salivary gland is situated below the odontophore, the left mainly above it. Ducts of the glands are short, and immediately after leaving the glands enter the walls of the oesophagus abave the valve of Leiblein aud pass iuside the walls. They open into the bucea! tube near the entrance to the radular diverticulum. The small unpaired accessory salivary gland is situated near the right salivary gland. Its (luct is lined with smooth epithelium and opens into the anterior part of the bucea! tu be near the mouth.

FIG.13.Pseudo/lvaancil/aHanley. A -semidlagramrnaticlongltudinalsectlon ofthe proboscis (scale 1 cm), sallvary ducts notshm;n; B~D- organsof the body haemocoel (scale 0.5 cm): B- from the ventral side. C ~ from the dorsal slde, D- from the rights1de (proboscis ls CUl'Ved to the lert to show the val ve of Lelblein). PHC. 13. Pseudoliva ancil/a Hanley. A- cxeMaru3wposaHublif npononr.uwtl epea xoúma (Macurra61 CM), npoTOKH CJIIOHHblX men~ He Hao6pa» ses through the nerve ring and joins~ the colu~ mellar muscle. Proboscis retractors are poorly

35


nr

H · · A bod removed from the shell (sea le- 0.5 cm); C -longitudinal FIG. 14. Morphology of the soft body of Bentlwbw. tryom Dan. ,B -· Y¡ th head (mantle removed) (sea le - 0.5 cm); E - mantle section of the val ve of Leiblein (seale- 0.5 mm); D - anterlodr re(~ le e OOS mm). H -lateral tooth in the different projection. (sca1e ~ o.s cm); F- form of the ctenldium lamellae; 0 ~ ra u a - · • . D n A B TeJIO H3.Meqe¡:moe H3 paKOBHHbl (Macurra6 0.5 CM); e PHC. 14. Mop$onornSJ MYrKOro Te11R Benthobw. tryoni a · • .--m; roJIOBhlcrtCpe]Vf,MaHTH$1YAMeua (r.tacurra60.5ct>ü; flpüAOJihHNÜ epea 1.fCpe3 KJianau Jieütineliua (Macurra6 0.5 MM) • D , G ~ mlrrvJia (Macurra6 0.05 MM); H - naTepanbH&tt:i ayO E _ MaHTHSI (Macmn6 0.5 cM); F - oPMa nenecn: The valve of Leiblein is pear-shaped, l!s diameter being twice tha t of the oesophagus. It is

covered wíth a very thin muscular !ayer (Fig. 14C). On the anterior part of the valve the epithelium is formed of very tall and ?arrow c~lls with oval basal nuclei. These cells stam gray Wtth nuclei yellow. They bear long cilia probably stuck together and having a cuticular cov~r. The base of the valve is formed of oval cells wtth ~ranulated cytoplasm staining dark blue. Nuclet rounded and yellow. Between the oval cells, there ar~ ~o metimes very small wedge-formed cells stammg dark yellow.

16


Yu.I.Kantor

37

rs

aog FIG. 16. Rcconstruction of the position of the organs of thc body hacmocoel of Bentlwbia tryoní Dall from the serial seclions. Nervous ring not shown. A- from the right si de; B - from the left si de. Columellar muscle indicated by dotled arca. Scal,e 0.5 mm. PHC. 16. PeKoHCTPYKU.HH noJfO>KCJHfH oprauou T)'JlOUHll.(noro reMOU.CJut y Bentlwbia tryoni Dall, nony•ICI:IHI'» e cepHt111biX cpcaou. Hepnuoe KOJtbU.O ue J.I306pa}l(euo. A- e npanoH cTopoHbl; B -e nenojf croponM. KoJryMeJmuptlb!H MYCKYJf3aTOliKOnau. Ma cm ra6 O.SMM

FIG. 15. A--: Semidlagrammatlc longitudinal section of the anterior part of the digestive system of Benthobia tryoni Dall (scale O.S mm)· Sahvary glands not shown, arrow indica tes the place of the opening of the salivary duct; B ~ mid oesophagus of Nucella heyseana (Dunker). opened ventrally (scale 0.5 cm). Arrows Jndlcate the direction of the food movement (drawlng of A.I.Medinskaya). PHC. 15. A-

cxeMaTHaHponamthtfi

npoJ,\OJibHbl~ cpea ttepea nepe~HIOIO

li8CTb nMll{euapJffeJlbHOit CMCTeMbf Benthobia

tryoni Dall

(Macrura(} 0.5 MM)· CJUOHHbte >KeJle3bt He uao6pa>KCHbl, CTpeJIKO~ OÓ
Analysis of the parsimonious trees revealed that only two basic topologies exist. The differenee in the topologies concerns the position of Melapium. A.nalysis with Nucella as an outgroup produced trees in which Melapium was included either in the same clade with Pseudoliva or in the clade with Oliva, Olivella, and Amalda. This results in the consensus tree, in which Melapium is placed in the separate clade (Fig. 19). Analysis with Alcithoe as an outgroup produced a single topology, the same as the second topology, obtained with Nucella as the outgroup. Below is the discussion of both cladograms. Discussion of the characters and clades is based on the consensus cladogram with Nucella asan outgroup. It is importan! to mention, that in al! the cladograms the taxa of the ingroup do not form a monophyletic taxon.

i:HSCUSSION OF THE CLADOGRAMS

CHARACTER ANALYSIS

l. Form of the shell suture. The reconstruction of the character evolution shows either the possibility of the origin of the channeled suture (state 1) from the suture, covered with the eallus (state 2) in clade 12 or both states 1 and 2 independently from the plesiomorphic state. The latter seems more probable to me.

2. Resorption o! inner walls of the shell is synapomorphic for the clade 11 while the complete resorption of the inner walls is the autapomorphic state for Olivel/a. 3. Presence o[ the pedallobes. Appearance of pedallobes is a synapomorphy of the clade 14.

46


Yu.J.Kantor

4. Form of the propodium. Appearance of crescent-shaped propodium is a synapomorphy for the clade 14.

S. Morphology of the head. The reconstruction of the character evolution shows the change of its states from plesiomorphic to 1 (clade 14) and independently from 1 to 3 (autapomorphy of Olivella) and from 1 to 2 (autapomorphy of the clade 12).

6. Operculum. Operculum is lost independently in Oliva and Melapium. 7. Presence of the posterior mantle lobe. The character is synapomorphic for clade 14 an4 appears independently in Benthobia. 8. Presence of the anterior mantle tentacle.. The character is synapomorphic for clade 11.

9. Presence o! the posterior mantle tentacle. The character is synapomorphic for cladc 11.

1O. Position of the radula. Although the reconstruction suggests the position of the radula

Moreover, although this marginal teeth are flat, they are well defined and there is a longitudinal fold of the radular membrane between the marginal and the lateral teeth. As such folds clearly define the marginal teeth from the lateral in taenioglossan radulas, I think that the plates in Olivella are true marginals. 14. Morphology of the salivary glands. According to the analysis the tubular salivary glands appeared independently from acinous in Melapium and clade 14. 1S. The length of the salivary tjucts. The réconstruction of the character evolution suggest the independent origin of the shortened salivary ducts in clade 13 and 12.

16. Accessory salivary glands. The reconstruction suggests the plesiomorphic condition of the state 1 of the character in comparison with the state 2. The Jast one is the apomorphy for Melapium and Olivella. Reduction of one of the accessory salivary glands is most probably synapomorphic for the ingroup.

a t the proboscis tip (state 0) to be plesiomorphic, this is in contradiction with our data on Benthobia anatomy (see description and discussion of the character 11). Thus, the radular position at the probaseis base should be considered as plesiomorphic for the clade 13. Nevertheless the cladogram shows a possibility of reversion of the character in Olivella. This reversion should be considered as an autapomorphy for 0/ivella. Position of the radula at the probaseis base in Olivella may be connected with the feeding mechanism (see Discussion of the morphology).

11. Connection of the radular retractar wíth the columellar muscle. According to the formal analysis the state 1 of the character should be considered as plesiomorphic. Nevertheless, the plesiomorphic condition is the state O (see description of the character). So, to my mind, losses of the connection occurred independently in clade 14, Pseudoliva and Melapium. 12. Connection of the radular refractor with the body wall. Reconstruction of the character evolution suggests that the presence of this connection is an apomorphic condition. So, the state O is an autapomorphy for the clade 12. 13. The number of radular teeth per transverse row. According to formal analysis the presence of marginal teeth in Olivella should be considered as an apomorphic condition. Pondcr [ 1973 J also stated, that additional plates appeared secondarily in Olive/la. Nevertheless, it seems to me, that the inGependent reduction of the marginal teeth in other clades probably more adequately describes the situation. Indeed, the general evolutionary trend in Neogastropoda is the reduction of the number of teeth in a row.

17. The gland of Leiblein. Reduction of the gland of Leiblein is an autapomorphy for Olivella. 18. Accessory oesophageal gland. Reconstruction suggests the possibilities of either independent origin of the character in Oliva, Melapium and clade 13, or reduction of the gland in clades 12 and Olivella.

19. Morphology of the stomac'h. Reconstruction suggests the independent origin of the tubular U-shaped stomach (type 3, autapomorphy for Amalda) and the type 2 stomach (autapomorphy for Olivella) from the plesiomorphic type 1 stomach. 20. Presence of the anal gland. The analysis shows a possibility of numerous reductions of the anal gland (in Olivella verreauxii, Amalda dimidiata, Melapium and clade 13).

As it was said in the description of the characters, state l of the character 21 is an autapomorphy for Melapium, while states 1 of the characters 22 and 23 are the autapomorphies for Olivella. CLADE ANALYSfS. During the discussion of the principal clades the character-state reconstruction advocated in the preceding section is used. Each clade is followed by included taxa and by a list of synapomorphies. Discussion is based on the consensus cladogram with Nucella as the outgroup. Each clade is characterized by its apomorphies (in squ-

47

are brackets), the character states are presented in round brackets.

PHYLOGENY AND CLASSIFICATION OF THE OLIVIFORM GASTROPODS.

Clade 14: Amalda, Oliva, Olivella [3(1), 4(1) 5(1), 7(1), 11(!), 14(1) J. The monophyly of the clade is supported by 6 apomorphies. The plesiomorphic state of the character 1 is unclear. In the cladograms produced with P AUP program, this character synapomorphic state for the dad e is 2 and in the cladograms produced by HENNIG86 program the plesiomorphic state may be either O, or 1 or 2. The channeled suture (state 1) is correlated with the presence of the posterior mantle tentacle (the apomorphic condition). So, it seems more likely that the plesiomorphic state of the character is Oor 2.

The cladistic analysis presented here could not confirm the monophyly of oliviforms. This is the evidence of the fact, that Olividae sensu lato is a polyphyletic group, including severa! families. The well documented clade 14 corresponds to the volume of the family Olividae adopted by Olsson [19S6]. As it was said in introduction, sorne authors expressed their opinion on the isolation of the subfamily Olivellinae as a separate family. Golikov and Starobogatov [1988] established the family Olivellidae and placed it into a new monotypical suhordcr Olivelloidei Golikov et Starobogatov, 1988, thus opposing it to ncarly al! other stenoglossan Neogastropoda. Their brief diagnosis of the subordcr lacks a lot of importan! feaJures: "Bucciniformes with smooth tun-eted shell. Head Jacks tentacles and eyes. Radula has outer pair of marginal teeth lacking thc bend and having the fonn of rectangular plates. Family Olivellidae Golikov et Starobogatov fam.nov. (Shell small, turreted-cylindrical. Foot large with broad lateral lobes. Central radular tooth broad and with many cusps)." (op.cit., p. 73). This point of view is disproved by my data. Dueto the numbcr of synapomorphies Olivella is closely related to Oliva, although differs greatly in possessing many autapomorphic chara~ters. In my opinion, the genus Olivella should be ¡solated as a separate family but its p1acement ínto a scparate from other Olividae subor~er (as proposed by Golikov and Starohogatov) ~s. dou~ tful. I clearly realize, that the rest of Olmdae·Is morphologically heterogeneous and complex group. Much more species should be studied, before the final decisions on the phylogeny and relationships of all olivid genera can be made. In this connection although I do not propose)he system of the whole group, it is worth to re.. establish the supcrfamily Olivoidea [as proposed by Olsson, 19S6] to include Olivellidae and Olividae. It should be emphasized, that the latter family probably is a paraphyletic group. The clade 13 corresponds to the subfamily Pseudolivinae, which was already isolated as a separate family [Golikov, Starobogatov, 1975]. In note 34 of the cited paper, the authors wrote: "The subfamily Pseudolivinae, being rather far from other Olividae asto shell characters and differing greatly from them in radula, is elevated to family rank ... On the basis of shell structure and radula we assign the family Pseudolividae lo the superfamily Buccinoidea." 1 agree with the neccssity of the isolation of Pseudolivinae into separaJe family. Cladistic analysis presented h~re did not finally resolve the problem of evaluatmg its position in the system of Neogastropo~a. As Pseudolividae and Olivoidea do not cons1ltute a monophylctic taxon, it is necessary to include more differcut groups of Neogastropoda iuto the

Clade 11: Oliva, Olivella [2(1), 8(1), 9(1) ]. Oliva [6(1), 13(1), 18(1) ]. The appearance of the glandular epithelium of the oesophagus is remarkab1e, but occurs also in clade 13 and Melapium. Clade 15: Olivella [2(2), S(3), 10(1), 16(2), 17(1), 19(1), 22(!), 23 (1) ]. The genus is well defined with 8 apomorphies, 6 of which are autapomorphies. Shift of the radula to the probaseis base is probably secondary and therefore apomorphic in comparison with Oliva. The intermediate morphological stage is found in Amalda and Melapium, in which the radula position is at the probaseis base, but the radular diverticulum opens near the probaseis tip. Characters 2, 22 and 23 are connected with each other. Clade 12: Amalda montrouzieri, A. dimidiata [1(2), S(2), 12(0), 13(1), lS(l), 19(?2) ]. The monophyly of this clade is supported with 5 apomorphies one of which - reduction of the marginal teeth [13(1)] occurs independently in other clades. (No information is available on the morphology of stomach of A. dimidiata.) So, the state · 2 of the character 19 may he either an apomorphy for the whole clade or autapomorphy of Ama/da montrouzieri. Only one character distinguishes the two genera, the absence of the anal gland in A. dimidiata. Clade 13: Benthobia, Pseudoliva [13(1),

IS (1), 18 (1), 20(1) ]. The monophy~y of the clade is supported by only 4 apomorph1es, all of which appear to be parallel in the other clades. Pseudoliva [11 (1) J is characterized by only one weak apomorphy. Benthobia [7 (1) J also is characterized by a single apomorphy which appears independently in ciad e 14. Clade S: Melapium [6(1), 11(1), 13(1), 14(1), 16(2), 20(1), 21 (l) J. The genus is characterized by 7 apomorphies with only one autapomorphy [21 (1) J.

::!:48~-----~----------Yu.I.Kantor

analysis. Genus Benthobia Dall, 1889 was only rccently included in Pseudolívinae [Bouchet, Warén, 1985], and my morphological data confirm thís point of view. The Pseudolividae is characterized by few apomorphíes and possesses many primitivo features. The most importan! of them are the plesiomorphic posítion of the radula at the proboscis base and the connection of the radular retractor with the co1umellar muscle which was found in Benthobia. The data on thc anatomy of Zemira [Ponder, Darragh, 1975] show, that Z. australis shares characters both with Pseudoliva and Benthobia. The general anatomy of the anterior dígestive system is very similar to the former genus, while the presenee of the cannection of thc radular retrae" tor with the columellar muscle is the symplesiamorphy wíth Benthabia. The mentíoned authors stated, that there are. no accessory salívary glands in Zemira. But in Pseudoliva the single aceessary salivary gland is so small, that it can easily be míssed during disseeting such a small animal as Z. australis. Zemira is the only representative of the family which passesses the small anal gland. Finally, the systcmatic pasition of Melapium should be discusscd. As was said abave, Melaplum forms a scparate clade, althaugh ít is documentcd wíth only 6 weak apomorphíes. Usually it is placed in the subfam]y Pseudolivinae [e.g. Kilburn, 1989]. Severa! importan! eharacters distínguish M elapium from the latter group: absence of the spiral sulcus an the body whorl, opening of the radular divertículum near the probaseis típ and the great development of the glandular epithelium of the oesophagus whích farms a distínct very large gland. From Olívoidea M elapium differs in the absence of the crescent-shaped propodium and metapodia, the importan! apomorphies of the dade. From my point of view, thesc significan! differences separa te M elapium as a family. DISCUSSION OF THE MORPHOLOGY. One of the most interesting features found is the morpholagy of the proboscis of Pseudolívidae and Olivella. Previously, the position ofthe radula sac and opening of the radular diverticulum at the proboscis base were known only in representatíves of the order Toxoglossa. The latter have a specialized intraembolíc proboscis type and feedíng mechanism, in whích the marginal teeth are removed fmm the radular membrane and used at the probaseis típ for stabbing and subsequent poisoning of the prey [Kantor, 1990 ]. It was supposed that the maín reasan for the origin of íntraembolic probaseis typ.: was the appearance of the poíson gland. On the contrary, ít ís diffícult ta say anythíng certaín an the appearance and functíaníng of the probaseis in Pseudolívidae. It is obvious from the morphalogy, that the position of

the radular sac at the proboscís base in Benthobia and Zemira is a plesiomorphic condition. The same situation occurs ín Pseudolíva. Ponder [1973] dístinguished 3 basic patterns of organization of the foregut ín the Neogastropoda, probably evolved separately and derived from a early neogastropod forerunner before the elongation of the proboscis. These groupings are: l. The rachiglossan group in which the dorsal wall of the bucea! cavity provided elongation of the oesophagus during the formation of the probaseis; 2. The cancellariids, in which the mid oesephagus is the site of elongation; 3. The toxoglóssans, in which the proboscis was brought about by the elongation of a bucea! tube. The 3 types of organization refcrrcd to 3 natural groups within the living Neogastropoda, which Ponder named as superfamilies Muricacea (= Rachiglossa), Cancellariacea (= Nematoglossa) and Conacea (= Toxoglossa). Thesc natural groups are well clefined by the major morphologicaltcndcncics wíth the differcnt changes of the midgut gland" among them. Thus, in Raehíglossa, there is the dcfinítion of the gland of Leíbleín by stripping off of the glandular folds. In Toxoglossa, the poison gl¡md ís formed ín the way similar to that of the formatíon of the gland of Leíblein, whíle in Nematoglossa 'there is no stripping off of the glandular folds. Follmyíng Ponder's log1c, Pscudolivioae should belong to Conacea, as the formatiun of their proboscis origínated ín the similar way by the elongation of the buecaltube. At the same time, they lack the most importan! distinguíshing character of Conacea, the poíson gland, and in general organization of the foregut Pseudo!ividae have many simílarítíes with Raehiglossa, the lllost importan! of whích is the presence of the derined gland and valve of Leibleín. Pseudolividae can not belong to the latter, due to the formation of the proboscís in quite different way. In this connectíon I must assume the fourth evolutíonary line among thc N eogastropoda and to define the fourth natural group among the order. Mor¡;hology of the proboscís of 0/ivella, in whích the radular sac is placed at the proboscis base probably origínated from a probosds with the radula at its tip. The posítion of the radula at the proboscis base in Olivella borealis may be an adaptation to the mode of feeding. The long bucea! tube in this genus is líned wíth epithelium whiI CUOCOÓOM l CJI!OHHasr lKCJIC3a ncnapna>I. Pa11y;Ia oópaaonana HIHpüllM "CHTpaJ!bHb!M 3yÓOM JlllOO C TPCMll KpynHhlMH 3YOl(aMH, JIIIOO MHoroqHCJICHHhlMH MaJICHbKHMH H 1\BY- lfJJH OIIH03Y0"0BhlM JlaTCpaJ!hHhiMH. Jinor¡¡;a HMCCTCll MaJleHbK35! 3HaJlbHaR )KCJ1C3a.

CeMeií:ci'BO nKJl!O'IacT pa¡¡;hl Pseudoliva Swaínson, 1840 (Tnnonai1 POli ccMclícTBa); Benthobia Dall, 1889" Zemira H. et A.Adams, 1853. CYJI" no Mo¡xjJoJlornH paKOBHHhl n pa¡¡;yJlhl, po~hl Naudoliva Kilburn, 1889 u Fulmentum P.Flscher, 1884 OTHOC>!TC5l K :JTaMy JKC CCMCHCTBy,

50

Yu.I.Kantor

Suborder Muricoidei Rafinesque, 1815

pacnOJIO)KC...

O'lieHb 3H3l.J:HTeJlbHOM p33BHTHH )(OITOJIHHTeirbHO:Ü

Shell suboval with vcry large and convex body whorl and small spire. Spiral sulcus on the body whorl absent. Siphonal canal short. Operculum absent. Head tentacles long and slcndcr without eye-lobes. Eyes present, or absent. Propodium narrow. Parapodia absent. Radula sac positions at the probaseis base in the probaseis contracted state but the radular diverticulum opens into the buccal cavity near the probaseis tip. Oesophagus betwecn the opening of the gland of Leiblein and the valve of Leiblein forms nearly a complete ring. in the frontal surface. Epithelium of this part forms a vcry Jarge acccssory gland, which consists of numerous Jarge glandular sacs opening into the ocsophagus. Acccssory salivary gland absent. Radula formcd of broad central tooth with threc large cusps and of unicuspidatc Jaterals. The family includes the single genus Melapíum H. et A.Adams, 1853 with two species. The new family differs from the family Pseudolividae, in which it was previously included, in thc absence of the spiral sulcus on the body whorl, in the absence of the opcrculum, in the absence of the acccssory salivary gland, in opening of the radular diverticulum into the bucea! cavity near the probaseis tip and in great development of the acccssory oesophageal gland. REMARKS: the exact position of Melapiidae among Muricoidei is unclear. PaKOBHHa ITOl.lTH OBaJibHaSI, e OliCHb BhiCOKHM

M BhlnyKJih!M IIOCJie):\HliM o6opOTOM ll KOpoTKl!M aaBHTKOM. CnupaJJbHh!H cyJihxyc na nOCJie¡:¡neM o6opzyre OTCyTcrnyeT. CmjJoHaJJhHh!H xana.n xopoTxnil. Kpb!IDC'lKa OTCYTCTByeT. ronoBHhle II1Y-

6e3

IIOJIHHTCJJbHOÜ CJHOHHOÜ %e.TIC3hl,

Hl!eM MCCTa OTKpb!TUll pa¡:¡yJillpHOro ):\HBCpTHKyJia B 6yKK3JibHYIO nOJIOCTh y BCplliHHbl XOÓOTa H B

Family Melapiidae fam. nov.

llaJlbl\3 Jl}IHJ-iHI":llC lf TOHKHC,

and

rJI33HbiX JIOTI3-

creii. rnaaa l!MC!OTCll HJIH OTCYTCTBYIO'r. ITporro):\llll yaxuil, ITapano¡:¡un OTCYTCTBYIOT. PanynllpHoe nJiaranHrn;e pacnoJiarae-rcsr y ocHonaHH.sr xo6oTa B ero COKparu;CHHOM COCT05IHHH, O):(H3KO pa-

AYJillpllhli.. ):\l!BCPTHKYJI OTKph!BBeTCll B 6yKKaJibnyro noJIOCTb y nepmumx xo6oTa. y,mcrox nu!IIeno¡:¡a Me>K¡:¡y MCCTOM OTKpb!Tllll )!(CJ!e3h! Jleft6neilHa n KJiananoM Jlcil6neil¡¡a ynnunen, ¡jlopMMpyeT TIOlfTU rronnoe KOJibu;o, pacnonaraiDmeec.SI no

IÍJpOHTBJlbHOlf IIJIOCKOCTII, M OopaayeT O'!CHb Kpynnyro ):\OnOJIHIITCJlbHyiO >KeJIC3y. )J(CJie3a o6pa30B3H3 MHOI'OlJHCJICHHbiMH KpynHhiMH CCKpe-

flHII(CBO.ll.HO:Ü: JKeJIC3bi,

3AME'IAHH51': OKOH'!aTeJibHOC IIOJIO>KCHHC Melapiidae cpe¡:¡n Muricoidei ocraercll ue>ICHhlM.

Superfamily Olivoidea Latreille, 1825 Shell usually glossy. Sutures usually narrow and channeled, but may be covered by the callus. Foot with parapodia and well developed crescentshapcd propodium, subdivided by longitudinal cleft. Salivary glands formed of ramifying tubes. The radula may have marginal teeth. The supelfamily included 2 families: Olivellidae and Olividae. REMARKS: Up to date the information on the anatomy of diffcrent "olivids" is too Jimited. This prevents the proposition of the new classification of the entire group. lt is very Jikely, that including additional taxa in the cladistic an~lysis would change the topology and thus, the op1mon on the subfamiliar and familiar classification. That is why, Olividae are treated as a single family, although the provisional cladistic analysis confirms the paraphyly of the group. PaKoBnHa 6JieCT51u¡aSI,

o6ñilJHo

e Y3KHM Kana-

JI&l.faThlM illBOM, lfHOr,[{a illOB nepeKphiT KaJIJiy~

coM. Hora e naparro,AHSIMU u xopomo

pa3BHTñiM

CepiTOBH):\Hb!M rrpOIIO):\HCM, llOAP33):\CJICHHh!M npo¡:¡oJibHOil 6opoa¡:¡oil. CnroHHhle xeJIC3h! cI Tpy6o'IK3MH. Panyna MO>KCT HMeTb MaprHHaJibHblC 3y6h!. HaJICeMeilcrno BKJIIO'laeT 2 ceMeilcTna: Olivellidae u Olividae. 3AME'-!AHH5f: .D:o HaCTO>III\el'O MOMCHTa J13HHDIC no anaTOMMH pa3JIHtiHbiX

11

0JIHBHJ.J;" OllCHb

Ce?oiCHcTno BKJIIOtiaeT

ennHCTBCHHñiH

po,n;

Melapium H. et A. Adams, 1853 CABYMll BUJIHMH. Honoe CCMCÜCTBO OTJIH1I3CTC5I OT CCMCiÍCTBa Pseudolividae, B xoTopoe ono rrpe)J(Jie BKJiro'IMn. Haó.nro)laercl! ana'lHTCJihHall reorpa4Jn'lecKaSI neo)lnOpoi\HOCTh KaK ncKO· naeMhiX,

TaK H COBpCMCHHDlX cPayH IIO COÚTHOilleHHIO "HeTOKCOrJIOCCHhiXn li

11

TOKCOrJIOC- .

B conpeMeHHHIX