Eleven New Species of Free-Living Marine Nematodes

30 Pages·1992·18 MB·English

by  Edwin J Keppner

GuifResearchReports.Vol.8,No.4,333-362.J992 ManuscriptreceivedSeptember7,1991;acceptedNovember6,1991
ELEVEN NEW SPECIES OFFREE-LIVING MARINE NEMATODES OFTHE
GENUS HALALAIMUS DE MAN, 1888 (NEMATODA: ENOPLIDA) FROM
FLORIDAWITH KEYS TO THE SPECIES
EDWIN KEPPNER
J.
306HibiscusAvenue,PanamaCityBeach,Florida32413
ABSTRACT. ThegenusHalalaimusisreviewedanddividedintofourgroupsbasedoncharactersofthemale. Characters
usedtoseparatethegroupsofmalesincludepresenceorabsenceofcaudalalacandthepresenceorabsenceofaprecloacal
sensillumand/orpKire. TennewspeciesaredescribedfromSt.AndrewBay,BayCounty,Florida,andH.gerltKhin.sp.is
proposedforH.gracilissensuGerlach,1967. NewspeciesfromSt.AndrewBayareH.thalassinus,H.tarjani,H.bayensis.
H.bulbocaudatus.H.variabilis,H.paracomatus,H.americanus,H.floridanus.H.brimi,andH.parafletcheri. Keystothe
speciesofeachgroupareprovidedbasedoncharactersofthemale. Akeytothefemalesofthegenusisalsoprovided.
Introduction doraCobb,1920;anddescribednewspeciesineachgenus.
HedescribedNuadaasliavingtwocirclesofsensillaclose
De Man(1888) erected the genusHalalaimus to ac- togetherintheheadregionandanamphidsimilartothatof
commodateaspeciesoffree-livingmarinenematodefrom Halalaimus. Hestatedreasonsforconsidering7/ and
theNorthSea. The genusHalalaimuswasdifferentiated TycnodoraassubgeneraofHalalaimusandsuggestedthat
fromothergeneraonthebasisoftheextremelyelongated Halalaimus pondcus Filipjev, 1922 represented a new
andlongitudinallyorientatedamphid. Theheadregionof subgenusofHalalaimusoranewgenus.
thetypespecies,HalalaimusgracilisDeMan, 1888,pos- Stekhoven(1935)placedNuadainsynonymywiththe
sessedthreecirclesofscnsilla. Thefirstcircleofsensilla gemsHalalaimus,andAUgen(1953)thenplacedNuadaas
containedsixsetae(innerlabialsensilla),diesecondcircle asubgenusofHalalaimus. Wieser(1953)summarizedthe
contained six setae (outer labial sensilla), and the third information regarding the genusHalalaimus, Herecog-
circlecontainedfoursetae(cephalicsensilla). Thecuticle nized two subgenera, Halalaimus s. str. and Tycnodora
wasthickandnottransverselystriatedexceptforthecaudal Cobb, 1920, and erected the third subgenus Pachydora
region of the male where there was a scries of coarse Wieser, 1953 in whichheplacedH. ponticus and anew
transverse striaiions restricted to the lateral fields. A species,HalalaimusclimactericusWieser, 1953. Heob-
buccal cavity was absent. The esophagus was long and served that the distinction between the subgenera Hala-
narrowanteriorlyandbroadposteriorly,anditfollowedthe laimusandTycnodora(distancebetweentheanteriorand
formoftheanteriorpartofthebodywhichtaperssignifi- posteriorcirclesofanteriorsensilla)isnotabsolutebecause
cantlyfromthecsophago-intestinaljunctiontotheattenu- transitionalspecieswereknown. Thedistinguishingcrite-
atedanteriorextremity. rion was that the posterior circle ofcephalic sensilla in
Southern (1914) erected the genus Nuada for the Tycnodorawasnofartherposteriorfromthecircleofouter
spQCiQSNuadaleptosomaSouthern.1914fromthecoastof labialsensillathantheouterlabialsensillawerefrom the
Ireland, ThegenusNuadawascharacterizedbyaslender anteriorend. InthesubgenusHalalaimuss.sir.,thecircle
body,thickcuticle,thin-walledheadregion,foursubme- ofcephalicsensillawasfartherposteriorfromthecircleof
diancephalicsetae(questionedbySouthern.1914),andthe outerlabialsensillathantheouterlabialsensillawerefrom
absenceofamphids. N.leptosomawasrepresentedbytwo the anterior end. Wieser (1953) provided a key to the
specimens, a male and a female. The four submedian subgeneraandthespecieswithineachsubgenus. Thekey
cephalicsetaeappearedtobepresentinonespecimenand emphasizedthelocationandlengthoftheanteriorcirclesof
wereabsentfromtheotherspecimen. sensillaandthelocationandlengthoftheamphid.
Cobb(1920)erecteddiegenusTycnodoraforaspecies Mawson(1958)discussedthegenusHalalaimus,de-
offree-livingmarinenematode.Tycnodorapachydermata scribednewspecies,andconstructedakeytothespeciesof
Cobb, 1920, fromKeyWest,Florida. Thisspecieshasa thesubgeneraHalalaimusand Tycnodora. Thekeysem-
circle of outer labial sensilla and a circle of cephalic phasizedthelengthandpositionoftheanteriorsensillaimd
sensilla(6+4)incloseproximitytooneanother,whereas theshapeofthetiiil. Basedonthespecimensavailableto
theinnerlabialsensillawereabsentornotobservable. her,Mawson(1958)concludedthatthelengthandposition
Filipjev (1927) recognized the three genera, Hala- oftheamphidswassufficientlyvariabletorenderimprac-
laimusDeMan, 1888;NuadaSouthern, 1914;andTycno- ticabletheuseofthesecharactersinakeyto thespecies.
333
334 Keppner
Mawson (1958) also stated that the anterior circles of fourspecies. Theystatedthat“Uiecuticleofsomespecies
sensilla were not clear in a number of the specimens canbeseentobefaintlystriated(perhapsallspecieshave
availabletoher,andsheitssumed thatlliesesensillawere striatedcuticlesbutsomearebeyondUieresolvingpower
presentinUieusualnumbers. ofUielightmicroscope.)”
Tijum (1961) described anumberofnew species of Thepurposeofthispaperistodescribediespecimens
Halalaimus,Twoofthesenewsp^ciQS,Halalaimusseiosus ofthegenusHalalaimuscollectedfromBayCounty,Flor-
and HalalaimusfiUcollis were described as having six ida and provide akey to the species ofthegenus Hala-
cervical (cephalic) sensilla. Rao (1989) redescribed 11. laimus. Inaddition,specimensofthegenuswereobtained
setosusandH.fiUcollisandconfirmedthepresenceofsix from Uie Smithsonian Institution through thecourtesy of
cervical(cephalic)sensillain thesespecies. Dr.W.DuaneHopeandfromDr.ArmenC.TarjanofUie
Viiiello(1970)describedanumberofnewspeciesof UniversityofFlorida.Additionalspecimenswereobtained
Halalaimusanddiscussedthecharactersuseduidifferen- from the LI. S. Fish and Wildlife Service Field Office,
tiat’mgthespeciesinthegenus. Hiscollectionsyieldeda PanamaCily,Rorida. Thesespecimenswerecollectedas
liirgenumberofspeciesofHalalaimus.butfewspecimens partofasedimentcontaminantstudy ofSt. AndrewBay,
ofeachspecies. Viticllo(1970)expressedtlieopinionthat Florida.
thedifficultyinidentifyingUiespeciesof was Collections of free-living marine nematodes from
duetotherathersubtledifferencesbetweenspeciesimdthe estuarineandmarinesedimentsfromBayCounty,Florida
incompletenessofsomeofthepreviousdescriptions. He yieldedalargenumberofspeciesofHalalaimus,buteach
observeddialthetxansversestriationsinthecuticlearcbest species is represented by very few specimens. This is
observedindiecaudalregionandtheareaoftheposterior similar to the reports by Mawson (1958) and Vitiello
end of the amphid. He also observed, as did Mawson (1970). ManyofthespecimensexaminedduringUiisstudy
(1958), the variability in the position of the amphid in arenotdescribedhereinbecauseUicywererepresentedby
relationtotheanteriorendofthebodyanddievariability asinglespecimenorjuvenilesUiatcouldnotbeassociated
inthelengthoftheamphid. Healsostatedthatdietailis wiUiadescribedspecies.
easily broken, and that often it is difficult to determine
whetherthetailiscompleteornot. Thisvariabilityandthe
subtledifferencesbetweenspeciesrendersspecificdeter- Materialsand Methods
minationdifficult. Healsoquestioned thevalidityofthe
subgenusPachydora. Sedimentsampleswereobtainedfrom shallowwater
Gcrlach and Riemann (1974) placed the subgenus in St. Andrew Bay with corers ofvariousdiameters to a
Tycnodora in synonymy with die subgenus Huada and depthof5-10cminthesediment. Sedimentsamplestaken
listed the species then known for the Uiree subgcnera. byUieU. S.FishandWildlifeServicefromdeepwaterin
Riemann et til. (1970) discussed the morphology ofthe St.AndrewBay,BayCounty,RoridawereobtainedwiUi
amphid inthegenusHalalaimus, Juario(1974)erecteda aPonargrab,andacorewastakenfromUiesurfaceofUie
newsubgenus,Nualaimus, forthosespeciesofthegenus grabsample. Sedimentsamplesfrom theGulfofMexico
Halalaimuswithadistinctcircleofiimerlabialsensillain wereobtainedwithSCUBAequipment. Nematodeswere
additiontothecirclesofouterlabialandcephalicsensilla. removedfromthesedimentsbyrepeateddecantationprior
Lorenzen(1981)didnotacceptthesubgeneraNuada tofixationinhotalcoliol-formalin-aceticacid,ortheentire
imdPachydora. He also did notrecognize thesubgenus sedunenlsamplewasfixedwith10%formalinin.seawater
Nualaimus. HeplacedNualaimusinsynonymywithHala- prior to removal of Uie nematodes. Nematodes were
laimusbecause thetypespeciesofthegenusHalalaimus mountedinanhydrousglycerolonCobbslides. Measure-
and subgenus Halalaimus s. str.,HalalaimusgracilisDe mentsweremadewithacalibrated ocularmicrometeror
Man,1888,possessedacirclcofinnerlabialsensillaaswell were obtained from drawings made wiUi Uie aid of a
astheouterlabialandcephalicsensilla* Juario(1974)had drawingtube. MeasurementsaregiveninpmunlessoUi-
notincluded//,gracilis\n submenusNualaimus.Tlicre- erwisestated,andmeasurementsaregivenasthemeanof
fore, die genus Halalaimus is not currently divided into thepopulationfollowedbytherangeofthepopulationin
subgeiiera. Halalaimuscontainsaratherlargenumberof parentheses. Observations were madewiUi aNikonOp-
species,andthereisapracticalreasonforsubdividingthe tiphot microscope wiUi Nomarsky Differential Interfer-
species into subgenera or groups to mtike identification ence Contrast and a Wild M-20 microscope wiUi an oil
easierduringecologicalstudies. However,thetraditioniil immersionobjectivewithanN.A.of1.30.
subgenerawifinotbeusedinthispaperinaccordancewitli Onlythosespecimenscollectedby theauthororpro-
Loren/cn(1981),norwillnew subgenerabeerected. videdbyDr.Hope,Dr.Tarjan,ortheU.S.FishandWiliife
Platt and Warwick (1983) discussed the species of Service were examined directly. OUierwise, the work is
HalalaimusfromUieBritishIslesandprovidedfiguresof basedondescriptionsofspeciesprovidedintheliterature.
NewSpeciesofHalalaimus 335
Results The cuticle of the conical pan of the tail may be
smooth or have fine transverse striations in both sexes.
TheNomarskyDICoptics madesensilla, lateralcu- Males may have a prominentpatternofbroad, elongate
ticularmodifications, transverse cuiicularstriations, and elaborationscalledvermiculations(Fig,2)whichhavenot
cuticularvermiculationsmoreeasilyobserved. However, beenobservedinfemales. Thesevenniculationsappearto
the same structures were adequately visible with bright beinternalandmayberesiricicdtotheventralsurfaceor
field microscopy, and they probably would not be over- may occurboth ventrally anddorsally to the lateral line.
looked. Thecylindricalpanofthetail mayhavetransversestria-
ThebodyofthemembersofthegenusHalalaimusis lions that extend almost to the tail tip (Fig. 2). These
broadest near the midpoint, and the anterior end tapers striationsaremoreprominentUianthetransversestriations
greatlyfromtheesophago-intestinaljunctiontothehead. ofthebodyorconicalpartofthetailandarereferredtoas
Thetailofmostspeciesalsotapersgreatlyfromtheanusto “coarse” striations.
thetailtip. Specimensmountedwithsupportsequaltothe Theappearanceofthelateralfieldoneachsideofthe
width at midbody often yielded specimens in which the body m some species may be modified to present the
headandtailendswerecurvedupwardordownward. This appeanmceofalae(Fig.2), Gerlach(1967)referredtodiis
oftenresultedinthelongouterlabialandcephalicsensilla modificationas“wings." Theexaminationofthismodifi-
followinga tortuouscourse. Accurate me<tsurements of cationinwholemountsandcoarsetransversesectionscut
theirlengthwasdifficulttodetermineunderthesecircum- witharazorbladedidnotrevealadistinctexpansionofthe
stances. Ifthe anterior end was turned up ordown, the cuticlethatischaracteristicofalae. Thiscuticularmodifi-
distanceoftheamphidfromtheanteriorend,tlielengthof cationappearstobeinternal,andmaynotbeanalainthe
theamphid,andthedistancebetweencirclesofouterlabial true sense of the term. However, until scanning and
and cephalic sensilla were difficult to determine accu- transmissionelectronmicroscopestudiescanbeperformed
rately. onthismodification,thetermalawillbeused.
Theanteriorendhastwoorthreecirclesofsensillatliat When present on the body, the somatic alae begin
arcdiscerniblewithalightmicroscope(Fig. 1). Tltecircle betweentheposteriorendoftheamphidandthenervering
ofinnerlabial sensillamaybepresentinall species, but overeachlateral lineand extend the lengthofthe body.
may not be discernible with the light microscope when Wlienpresentontheconicalpartofthetailoffemales,the
minute. Whendiscernible, tlie inner labial sensillavary alaeareextensionsofthesomaticalaeandhavenoelabo-
frompapilliformtosedform. Whensmallandpapilliform, rations. Thealaeontheconicalpanofthemaletailmaybe
theymaybedifficulttoobserveiftheothersensillaobscure presentintheabsenceofsomaticalae. Iftheyarepresent
them. Thecirclesofouterlabialandcephalicsensillamay inthemale,theselateralalaemayhaveanelaboratescale-
beclosetogetherorfarapart,andthelengthofthesensilla likepattern termed “ornamented” (Fig. 2). Iftheorna-
inonecirclemaybedifferentfromthatintheothercircle. mentationsareabsent, thealae are referred toas “unor-
In someinstances, itwasobvious that theouterlabial or namenied,” Whensomaticandornamentedcaudalalaeare
cephalic sensilla were broken at the junction with the presentinmales,thesomaticalaeterminatejustanteriorto
cuticle. thebeginningofthecaudalalae(Fig.2).
Ingeneral,thecuticleisthinfromtheanteriorendto ThetailintliespeciesofHalalaimusexaminedduring
thelevelofthecephalicsensilla. Thecuticleposteriorto thisstudyconsistsofaproximalconicalpartfollowedbya
thecephalicsensillaisgreatlythickenedandremainssoto cylindricalpanthatcanbefiliformorrelativelythick.The
thejunctionoftheconicalandcylindricalpartsofthetail. tailtipispointed,blunt(expandedornot),orverynarrow
Setiformcervical,somatic,andcaudalsensillaarepresent anddividedintotwo(bifurcate)smallterminalappendages
intwospecies,andsomespecieshavesmall,widelyspaced (Fig, 3). Caudal glands were observed inthespecimens
pitsinthecuticle(Fig. 1). Thesepitsarelocatedsublater- examined- Tliespinneretwasobservableinthosespecies
ally and begin just posterior to, or at the level of, the withablunttailtipbutwasnotobservableinthosewitha
posteriorendoftheamphidandmayextendthelengtliof bifurcatetaillip.
thebody, Anarrow ductpenetratesthecuticlefrom the Malesexaminedduringthisstudymayhaveasingle,
baseofeachpit. ventro-median,setiform, precloacal sensillum (Fig,2); a
Thecuticleofthebodymaybesmoothorhavevery single,ventro-median,precloacalpore;botlitliesensillum
finetransversestriations. Asstaledbyothers,thesestria- and the pore; or the sensillum and pore may be absent.
tions are often best observedat the posteriorend ofthe Whenpresent,theporehasaductthatpenetratesthecuticle
amphidorintheanalregionofthebody. Inafewspecies andtum.santeriorlyinthebody.Thesestructureshavebeen
observedduring thisstudy, thestriationsappearedtobe- describedinotherspeciesofthegenus,andthepresenceor
come minute punciaiions in die midbody or precloacal absence ofthese structures is valuable in differentiating
regionofthemaleorpreanalregionin thefemale. species.
336 Keppner
NewSpeciesofHalalaimus 337
Based ontheobservationsmadeduring thisstudy,it oftailwithorwithouttransversecuticularstriations. Caudal
appears that the males possess the best characters for glandspresent;sp'mneretpresentorundetermined. Species
differentiatingspecies. Thecharactersofthemaleempha- mostlymarineandestuarine. CoomansandJacobs(1983)
sizedhereinaretheshapeofthetailop(bifurcateornot), discuss those species not found in estuarine and marine
thepatternofcuiicularsiriationsonthetail,thepresenceor environments.
absenceofsomatictransversecuticularstriations,thepres- The specimens described and discussed herein are
enceorabsenceofcaudalalaeandtheirornamentation,the dividedinto groupsbasedonmale charactersinorderto
presenceorabsenceofamidvcniralprccloacalsensillum providesomedegreeoforganizationandpointsofrefer-
and/orpore, thepresence orabsence ofapatternofver- ence. Akey tothemalesofthe species ineachgroup is
miculaiionsinthecuticleinthecloacalregion theshapeof givenattheendoftheaccountofthespeciesinthatgroup.
thespicules,andtheshapeandpresenceorab,senceofthe Aseparatekeytothefemalesofallspeciesisgivenatthe
gubemaculum. The riistance of the amphids from the endofthetaxonomicsection,becausetheyarcnotaseasily
anterior end, the length ofthe amphid, thelengthofthe separatedintogroupsastliemales. Thosespeciesofthe
outerlabialandcephalicsensilla,andtheabilitytodiscern genus osinquirendainCerlachandRiemann,(1974)
thecircleofinnerlabialsensillawithalightmicroscopeare arenotincludedmthefollowingkeys. Alistofthespecies
alsousefulinidentifyingthespecies. Themethodoffixing included in the following discussions and keys to the
thespecimensdidnotappeartoaffecttheabilitytodiscern speciesofHalalaimusfollows.
thesomaticalae,ornamentedorunomamentedcaudalalae,
striations,orvermiculations. Thesecharacterswereequally KnownSpecies
visibleafterformalinoralcohol-formalin-aceticacidfixa-
tion. HalalaimusalaiusTimm, 1952
Tliecharactersofthefemalethatappearmostreliable HalalaimusalgeriensisCoomansandJacobs, 1983
arethepresenceorabsenceofcoarsetransversestriations HalalaimusamphidellusViiicllo, 1970
onthecylindricalpartofthetail,shapeofthetail lip,the HalalaimusamphistriusViliello. 1970
presenceorabsenceofsomatic transversecuticularstria- Halalaimusow/ieSergeeva, 1972
lions, the distance ofthe amphids from theanteriorend, HalalaimusbrachyauluxMawson, 1958
length ofthe amphids,theability todiscern thecircleof HalalaimusbrevispiculumSergeeva, 1973
innerlabialsensillawithalightmicroscope,andlengthof HalalaimuscapiiulatusBoucher, 1977
theouterlabialandcephalicsensilla. HalalaimuscaroliniensisChitwood, 1936
ThespecimensofthespeciesofHalalaimusexamined HalalaimusciliocaudatusAllgen, 1932
wererestrictedtothosementionedpreviously. Compari- HalalaimiscirrhatusGerlach, 1953
sonswithotherspeciesofthegenusHalalaimuswerebased HalalaimusclimactericusWicser, 1953
on the descriptions in the literature rather than actual Halalaimus Wieser, 1953
examinationsoftypespecimens. Thisrequiresthatsome HalalaimuscubanusAndrassy, 1973
assumptions be made. It was assumed that iimer labial HalalaimuscurvicaudaiusJuario, 1974
sensilla were not discernible, that transverse cuticular HalalaimusdelamareiViticllo. 1970
striations were absent, that the somatic and caudal alae HalalaimusdiacrosMawson, 1958
wereabsent,andthatapiecloacalsetiformsensillumand/ HalalaimusdiplocephalusFilipjev. 1927
or pore were absent unless they were mentioned in the HalalaimusfiUcollisTurm, 1961
descriptionorshownonthefiguresofthespecies. HalalaimusfilicorpusViliello, 1970
HalalaimusfilumGQTlnch, 1962
GenericDiagnosis-HalalaimusDeMan, 1888 HalalaimusfletcheriMawson, 1958
HalalaimusflarescensGerlach, 1%7
Enoplida,Oxystominidac,Typespecies:Halalaimus HalalaimusgracilisDeMan, 1888
gracilisDcMim,1888. Amphidgreatlyelongatedlongitu- HalalaimushorridusGerlach, 1956
dinally. Anteriorand posterior ends ofbody attenuated. HalalaimusisaiishikoviFilipjev, 1927
Sixirmerlabialsensillapresentorabsent(possiblypresent HalalaimusjaltensisSergeeva, 1973
inallspeciesbutnotdiscerniblewithalightmicroscopein HalalaimuslepiodermaPlatonova, 1971
some).SixouterlabialSensillaandfourorsix(twospecies) HalalaimusleplosomaSouthern, 1914
cephalic sensilla present. Cuticle quite Uiick, abruptly HalalaimuslineatoidesTimm. 1961
reducedinUiicknessatlevelofcephalicsensilla,anus,and HalalainuislineatusTimm, 1961
againatjunction ofconical and cylmdrical partsoftail; HalalaimuslongicaudaiusFilipjev, 1927
transversecuticularsiriationspresentorabsent. Tailconi- HalalaimuslongicollisAllgen, 1932
calthencylindrical;lipblunt,orbifurcate. Cylindricalpart HalalaimuslongisetosusHopper, 1963
i
338 Keppner
HalalaimuslongisiriatusTimm, 1961 Halalaimusstammer Schneider, 1940
HalalainmsluiarusViiiello, 1970 HalalaimusstriaiusGerlach. 1956
HalalaimusluiicolusTunm, 1961 HalalaimussupercirrhatusGerlach, 1955
HalalaimusnmcquariensisMawson, 1958 HalalaimustenuicapitatusFilipjev, 1946
HalalaimusmarriMawson. 1958 HalalaimusterrestrisGerlach, 1959
HalalaimusmeyersiWieserandHopper, 1967 HalalaimusturbidusViiiello, 1970
HalalaimusminisculusTchesunov, 1978 HalalaimuswodjanizkiiSergeeva, 1972
HalalaimusmonstrocaudalusViiiello. 1970 HalalaimuszenkeviishiFilipjev, 1927
HalalaimusnigrilapidariusBoucher,1977
HalalaimuspachydermaFilipjev, 1927 NewSpeciesDescribedHerein.
HalalaimuspachydermatusCobb, 1920
HalalaimuspachydoroidesViiiello, 1970 Halalaimusthalassinusn.sp
HalalaimuspapilUferGerlach, 1956 Halalaimustarjanin. sp.
HalalaimusparvusChiiwood, 1936 Halalaimusbayensisn.sp.
HalalaimusponticusFilipjev, 1922 Halalaimusbulbocaudaiusn.sp,
HalalaimusrectispiculatusPlatonova, 1971 Halalaimusvariabilisn.sp.
HalalaimusrelaiusGerlach, 1967 Halalaimusparacomatusn. sp.
HalalaimussarsiGerlach, 1967 Halalaimusamericanusn.sp
HalalaimussderaiusT\mm, 1952 Halalaimusfloridanusn.sp.
HalalaimussetosusTimm, 1961 Halalaimusgerlachin.sp.
HalalaimussimilisAllgen, 1930 Halalaimusbrimin. sp.
HalalaimussobakiniSergeeva, 1973 Halalaimusparafletcherin.sp.
ArtificialKeytotheGroupsofMalesof
theGenusHalalaimusDeMan,1888.
Themalecharactersusedtodefinethegroupsarethepresenceorabsenceofcaudalalaeandthepresenceorabsence
ofaprecloacalsensillumand/orprecloacalpore. Thesecharactersareusedincombinationtodistinguishfourartificial
groupsinthefollowingkey:
1. Caudalalae present 2
Caudal alaeabsent 3
2(1). Precloacal sensillum and/orpore present Group
1
Precloacal sensillum and/orporeabsent Group 2
3(1). Precloacal sensillum and/or porepresent Group 3
Precloacal sensillum and/orpore absent Group4
Group1 Wieser(1953)describedHalalaimuscomatuson Uie
basis of female specimens collected from the coast of
Malesofthespeciesinthisgrouphavecaudalalae,and Chile. Mawson(1958)describedthemaleofH. comatus
asetiformprecloacalsensillumand/orporeispresent. The fromtheAntarctic. Tliemalehasornamentedcaudalalae
known species and those described as new herein have and a single, ventro-median. precloacal sensillum. H.
ornamentedcaudalalae. However,twomalespecimensof comatuswas unique in the presence ofthese characters.
apparentlydifferentspecieswereexaminedthathadunor- However, the collections from Florida waters yielded a
namenied caudal alae, but they are not described here numberofadditionalspecieswitlithesecharacters.
because each is represented by asingle spcc'unen. Dis-
tinctly visiblecircleofinnerlabialsensillapresentornot Halalaimusthalassinusn.sp.
discernible. Outerlabialsensillamaybelongerorshorter Figs.4-9
thancephalicsensilla,and the twocirclesareofvarying
distancesapart. Speciesin thisgroupallhaveatailwith Cuticlewithfinetransversestriations. Lateralsomatic
bluntlipand visiblespinneret. alaepresent,beginjustposteriortoamphid, indistinctat
NewSpeciesofHalalajmus 339
Figs.4-9. Halalaimusthalassinusn.sp. Fig.4. Male,cloacalregion,leftlateralview. Fig.5. Male,anteriorend,leftlateral
view. Fig.6, Male,posteriorend,leftlateralview. Fig.7. Female,anteriorend,leftlateralview. Fig.8. Female,analregion,
leftlateralview. Fig.9. Female,posteriorend,leftlateralview. Scalebarsinpm.
1
340 Keppner
first then more evident, vermiculated anteriorly, smooth Cuticlewithfinetransversestriations.Lateralsomatic
overmostofbody,thenvermiculatedprecloacallyinmale. alae not observed. Ornamented caudal alae present in
Somaticalaeterminatejustanteriortothecloacainmale, male, absent in female. Inner labial sensilla setiform.
ornamented caudal alaepresent. Somatic alaeterminate Outerlabialandcephalicsensillasetiformandunequal in
postanallyinfemaleatjunctionofconicalandcylindrical length; cephalic sensilla longer; circles well-separated.
parts oftail,not vermiculated pieanally,andcaudalalae Excretorypore not observed. Lateral alaenot observed.
not ornamented. Setiform cervical sensillapresent from Maleswithprecloacalsensillum,poreabsent;ornamented
justposteriortoamphidtolevelofstronglydefinedlateral caudalalaepresent. Tailconicalthencylindrical. Cylin-
alaeinmales, becomepapilliform onremainderofbody, dricalpartoftailwithcoarsetransversestriations. Tailtip
thensetiformprecloacallyandcaudally. Setiformcervical clavatc;spinneretpresent.
sensilla present, somatic and caudal sensilla absent in Males(n=4); Length1.09mm(1.05-1.13). Widthat
females. Excretoryporenotobserved. Innerlabialsensilla midbody22,7(22-24). Headdiameter5.1(4.4-5.3)atlevel
papilliform. Outer labial and cephalic sensilla equal in ofcephalicsensilla. Outerlabialand/orcephalicsensilla
length,intwowell-separatedcircles. Maleswitliprecloa- werebrokenormissingonthreemales. Onemalewithall
cal setiform sensillum present; pore absent. Cylindrical sensillapresentwithouterlabials2.4 long,cephalicsen-
part of tail with fine transverse striations. Tail lip ex- silla 4,0 long. Cephalic sensilla in holotype 4.8 long.
panded,blunt;spiimeretpresent. Labia]surfacetoamphid8.6(7.8-9.6)andnervering186(182-
Male(n=l): Length2.24mm. Widthatmidbody22. 190). Amphid 38,8(38-40) long. Esopliagus371.8(353-
Headdiameter4.2atlevelofcephalicsensilla. Outerlabial 378)long. Tail159(154-165)long. Widthatcloaca19(19-
andcephalicsensilla11 long. Labialsurfacetoamphid22 19). Spicules39(38-40)long,alate. Gubemaculum10.(X9.6-
andnervering229. Amphid23long. Cervicalandcaudal 11.0) long, consists of a plate with keel-like extension
sensilla5long.Esophagus466long.Tail216long.Width betweenspiculesandcup-shapedextensionlateraltoeach
atcloaca20. Spicules30 long,alate. Gubemaculum9.6 spiculetip. Vemiiculationsnotobservedonconicalpartof
long;consistsofaplatewithkeel-likeextensionbetween tail, a = 46.5(46.7-48.2). b = 2.93(2.88-3.00). c =
spiculesandacup-shapedpartlateraltotipofeachspicule. 6.90(6.75-7.06).
a= 101.8. b=4.81. c= 10.4. Females(n=2): Ungth1.06mm(1.02-1.09). Width
Female(n=1): Length2.21 mm. Widthatmidbody atmidbody33(29-37). Headdiameter6.4(6.4-6.4)atlevel
27. Headdiameter4.8atlevelofcephalicsensilla. Outer ofcephalicsensilla. Outerlabialsensilla2.1(2.1-2.1)long.
labial and cephalic sensilla 10 long. Labial surface to Cephalic sensilla 4.3(4.3-4.3) long. Labial surface to
amphid24andnervering240. Amphid27long. Cervical amphid 10(10-10)andnervering 179(178-180). Amphid
sensillaSlong.Esophagus473long. Tail213long. Width 32(32-32) long. Esophagus 346,5(321-372) long. Tail
atanus 16. Reproductivesystemamphidelphic;reflexed. 176.5(171-182)long. Widthatanus15(14-16). Reproduc-
Vulva1.18mmfromanteriorend. a=81.9. b=4.67. c= tivesystemamphidelphic;reflexed. Vulva589(567-611)
10.4. V=53%. from anteriorend. a = 32.4(29.5-35,2). b= 3.06(2,93-
Specimens: Male holotype, USNM77260; female 3.V8). c=5.98(5.96-6.00). V=56%(56-56).
allotype, USNM77261. Specimens: Holotype male, USNM 77262; three
Locality: St.AndrewBay,BayCounty,Florida(85° paraiype males, USNM 77263-77265; allotype female,
42M3"W,30°08’33'’N)at the NationalMarineFisheries USNM77497;paratypefemaleUSNM77499.
ServiceLaboratory, from aseagrass bed {Thalassiates- Locality: St.AndrewBay,BayCounty,Florida(85°
tudinum)about I meterdeep. 39’46"W,30°08’34"N)waier13metersdeep,(85°38’52’W,
Etymology: fromtheGreekThaiass,thesea. 30°07’38"N) water7.5meters deep,and(85°39’46"W,
Remarks: Halalaimus thalassinus n. sp. is unique 30°08’40"N)water 12,2metersdeep.
amongthespeciesinGroup 1 inthepossessionofcervical, Etymology: NamedforDr.ArmenC.Tarjan,Univer-
somaticandcaudalsensillainthemaleandcervicalsen- sityofFlorida.
sillain the female. The only otherspecies in the genus Remarks: Halalaimus tarjani n. sp. belongs with
Halalaimus with distinctcervical and caudal sensilla is thosespeciesinGroup1 thathavediscernibleinnerlabial
HalalaimusdelamareiViiiello, 1970,whichhasbeenplaced sensilla,ornamentedcaudalalae,andthecylindricalpartof
inGroup3. H.delamareidoesnothavecaudalalaeinthe tailhascoarsestriations. H.tarjanin.sp.differsfromthe
male, thecervical andcaudal sensillaare veryshort,and onlyotherspecieswiththesecharacters,Halalaimusbay-
iimerlabialsensillaarenotdiscernible. ensisn.sp.(tobedescribednext),inthattheouterlabialand
cephalic sensillaaremuchshorter and unequal in length
(0,29-0.33&0.78-0.92versus2,8-3,0headdiameters),the
Halalaimustarjanin.sp. amphidbeginsmuchclosertotheanteriorend(1.7versus
Figs.10-19 5.3-6.0 head diameters), the spicules are longer(2.0-2.
NewSpeciesofHaimmmus 341
V\gs.10-19,Halalaimustarjania.up. Fig.10. Male,cloacalregion,rightlateralview. Fig.11. Male,anteriorend,rightlateral
view. Fig.12. Male,cloacalregion,rightlateralview. Fig.13. Male,anteriorend,rightlateralview. Fig.14. Male,posterior
end,rightlateralview. Fig.15. Male,anteriorend,leftlateralview. Fig.16. Female,anteriorend,leftlateralview. Fig.17.
Female,posteriorend,leftlateralview.Fig.18.Female,anteriorend,leftlateralview.Fig.19.Female,posteriorend,leftlateral
view. Scalebarsinpm.
1
342 Keppner
versus 1.7cloacaldiameters),andthegubemaculum isof cloaca 14(14-14). Spicules24(24-24)long,alate. Guber-
adifferentshape. naculum8(8-8)long,consistsofplatewithkeel-likeexten-
H. tarjanin.sp.isalsosimilartothosespeciesofthe sionbetweenspiculesandcup-shapedextensionlateralto
genus Halalaimus with a broad amphid, Wieser (1953) eachspiculetip. a=62.1(56.7-67.4). b=4.09(4.02-4.16).
placedthosespecieswithabroadamphid(40%ofcorre- c=6.49(6.30-6.67),
spondingbodydiameteratmidlengthoftheamphid)inthe Juvenilefemale(n=1): Length 1.10mm. Widthat
subgenusPachydora. Thissubgenuscontained twospe- midbody 16. Head diameter 3.6 at level of cephalic
cies,Halalaimus{Pachydora)ponticusFilipjev, 1922and sensilla. Outerlabialandcephalicsensilla11long. Labial
Halalaimus(Pachydora)cUmactericusWieser,1953. Vidcllo surfacetoamphid37andnervering 158. Amphid37long.
(1970)describedHalalaimuspachydoroidesanddiscussed Esophagus 265 long. Tail 160 long. Widlh at anus 11.
therelationshipbetweenamphidwidthandcorresponding Reproductive system amphidelphic; reflexed. Anterior
bodydiameteranddemonstratedthat therelationshipde- endtovulva536. a=68.8. b=4.15. c=6.88. V=49%.
creasesfromtheanteriortoposteriorendofdieamphidin Specimens: Holotypemale,USNM77498;allotype
H.pachydoroidesandH.ponticus. female,USNM77500.
H. tarjanin. sp. also demonstrates this relationship. Locality: St.AndrewBay,BayCounty,Florida(85®
The amphid is 29.8%(27-32) ofdiecorresponding body 39’46‘W.30®08’40'‘N and85®36’43"W,30®06’52"N).
diameteranteriorlyand24%(20-27)posteriorly.H.tarjani Water9.5and 12.2metersdeep.
n.sp. femalesdifferfromH, cUmactericusfemales(male Etymology: Namedforthegeographiclocality.Bay
unknown)inthepresenceofcoarsetransversestriationson County,Florida.
thecylindricalpartofthetail,presenceofdiscernibleinner Remarks: Halalaimusbayensisn. sp, belongs with
labial.scnsilla,andin thelongerouterlabialandcephalic Uioscspeciesin Group 1 thathaveadiscerniblecircleof
sensilla(2.1 &4.3 versus l.Oand2.0). //. tarjanin. sp. iimer labial sensilla, ornamented caudal alae, and the
differsfromH.pachydoroides{Gtx>up^)inthepresenceof cylindricalpartofthetailhascoarsetransversesuialions.
discernibleinnerlabialscnsilla,shapeofdietail(cylindri- //.bayensisti.sp.differsfromH.tarjanin.sp.asdescribed
calpartshort,bluntversuscylindricalpartlong,flagellate), undertheremarkssectionfor tarjanin.sp. H,bayensis
inthegreaterdistancebetweencirclesofouterlabialand n.sp.malesarealsosimilartomalesoff/, variabilisn.sp.
cephalicscnsilla(L1-L2versus0.4headdiameters),andin and H. jloridanus n. sp. (both described below), H.
the shorter length of the tail (males = 6.75-7.06, bayensis n. sp. differs from //. variabilis n. sp. in the
females “c” = 5.96-6.00 versus males "*c” = 4.7-5.0, presenceofaprccloacalseiiformsensillum,tlieabsenceof
females *‘c” =4.9-6.1). H. tarjanin. sp.differsfrom//. a prccloacal pore, and the pre,scncc ofdiscernible inner
ponticus in the presence ofa discernible circle ofinner labialscnsilla. //.bayensisn.sp.differsfromH.Jloridanus
labialsensilla,and in diepresence ofornamented caudal n.sp.intileshorterouterlabialandcephalicsensilla(2,8-
alaein themale. 3.0versus4.4-4.5headdiameterslong),distancefromthe
labial surface totheamphid (5.3-6-0 versus2.9-3.1 head
Halalaimusbayensisn.sp. diameters), length of the tail (13.5-13.7 versus 7.5-9.4
Figs.20-27 cloacaldiameterslong),‘‘a’’value(56.0-67.4versus78.0-
89.5),andthepresenceofdiscernibleiimerlabialsensilla.
Cuticlewithfinetransversestriations,appearpuncUitc
at midbody. Cuticular pits present, Lateral alae not Halalaimusbulbocaudatusn.sp.
observed. Ornamented caudal alae restricted to conical Figs.28-34
partofmaletail;absentinfemale. Cuticleinmalecloacal
regionfaintlyvermiculatedonventralsurfaceinholotype, Cuticlewithfainturnsversestriations,bestobserved
moredistinctinparatype. Innerlabialsensillapapillifonn. in prccloacal region in male. Lateral somatic alae not
Outerlabialandcephalicscnsillaequalinlengthwithinand observed. Omajnenicdcaudalalaepresentinmale,absent
betweencircles;intwowell-separatedcircles. Excretory in female. Innerlabial seasillapapillifonn. Outerlabial
porenotobserved. Maleswithsciifonnprccloacalsensil- and cephalic sensiUa equal in length, circles well-sepa-
lum; pore absent. Cylindrical part of tail with coarse rated. Ajnphidrelativelyshort,situatedwellposteriorto
transversestriations. Tail lipblunt;spinneretpresent. cephalicsensilla. Excretoryporenotobserved. Malewith
Males(n=2): Length 1.24mm(1.19-1.28). Widdial prccloacalsensillum;poreabsent. Cylindricalpanoftail
midbody20(19-21). Headdiameter3.6(3.6-3.6)atlevelof witiioulcoarsetransversestriations. Tailtipinbothsexes
cephalicseasilla. Outerlabialandccpliahcsensilla 11.5(11- withnearlyspherietdswellingat lip;spinneretpresent.
12)long. Labialsurfacetoamphid23.5(23-24)andnerve Male(n=1): LcngUi1.16mm. Widlhatmidbody20.
ring 184(182-186). Amphid48(46-50) long. Esophagus Headdiameter3.8atlevelofcephalicsensilla. Outerlabial
302(296-308) long. Tail 190.5(189-192) long. Widthat andcephalicscnsilla4.2long. Labialsurfacetoamphid2