Freshwater nematodes from Loch Ness, Scotland. Part 1. The orders Tylenchida Thorne, 1949 and Rhabditida Chitwood, 1933 (Nematoda, Secernentea)

24 Pages·2001·10.3 MB·

by  F R Wanless

)
K*£33*U"&-0
Bull. nat. Hist.Mus. bond. (Zool.)67(1): 1-24 Issued28June2001
Freshwater nematodes from Loch Ness,
Scotland Part The orders Tylenchida JUN 2001
I.
D
Thorne, 1949 and Rhabditida Chitwood, 1933
siL^rWTY
(Nematoda, Secernentea).
F. R. WANLESS AND R. HUNTER*
DepartmentofZoology, TheNaturalHistoryMuseum, CromwellRoad, London SW75BD, UK
CONTENTS
Introduction 1
Nematodefauna 2
Materia] andMethods 2
Abbreviations 4
Specieslist 4
Descriptionsofspecies 5
Acknowledgements 22
References 22
SYNOPSIS. DuringasurveyofthenematodesofLochNess.Scotland(Project Urquhart 1993-94)94nematodespecieswere
identifiedfrombenthiccoresamplescollectedfromtheprofunda!(90-211 m)andfromrivermouthareas(<0.5m).Thispaper
presentsataxonomicreviewofthenematodesofthetwoordersTylenchidaThorne. 1949andRhabditidaChitwood, 1933.Thirty
five species are described and figured; some morphological features are illustrated by Normarski interference-contrast
microscopy.
INTRODUCTION and sand (63-125 urn. 36.4%) (Smith B. D. etal, 1981).
Water levels remain relatively constant throughout the year al-
thoughstream levelsvarybecauseofsnowmeltinspring,butmore
This study isbasedon nematodescollected in LochNess, Scotland importantly because of fluctuations in rainfall. The loch has a
during Project Urquhart (1993-94). The first part presented here catchment areaof 1775 km: providing 84 m3 S"1 mean inflow with
dealswithspeciesthatbelongintheordersTylenchidaThorne. 1949 themajorityofthecatchmentbeingroughgroundorforest,andonly
and RhabditidaChitwood, 1933. The second part, now in prepara- 7.5 km: urbanized. Surface water is slightly acidic with an annual
tion, will cover species of the remaining orders. The results of mean pH 6.7; it has low conductivity 30 uS cm-1 at 20°C and is
ecological studies(R. David,1998-Ph.D. thesis)will be published stainedwithhumics.Lowconductivitylevelsinlakewaterareoften
elsewhere. The following briefprofile ofLoch Ness is essentially associatedwithdarkcolourationandahighconcentrationoforganic
basedontheliteratureMaitland(1981)andShine&Martin(1987). compoundsbecausetheyhavebeendrainedthroughswampy/peaty
LochNess is the largest body offreshwater in the United King- regions.Thetotalorganiccarbonconcentrationsofthesurfacewater
dom. It runs in a north-east/ south-west direction and is 39 km in is 3 mg Cl_l Maitland (1981). In many systems oflake classifica-
length,butonly 2.4kmat itswidestpointwithanaveragedepthof tion. Loch Ness falls within the nutrient-poor Spence (1967) and
132 m. A new maximum depth of 239.5 m was found during a oligotrophiccategoryVollenweider(1968). However,Baileyetal.,
Project Urquhart sonar survey. The loch basin has in most places 1981 debate whether Loch Ness along with Loch Awe should be
very steep, sometimesprecipitous shelvingsides,thus ithas avery described as dystrophic (acid), a category considered by Jarnefelt
smallshorezoneforitssurfaceareaMaitland(1981).Theflatbedof (1958)assupplementaryto.ratherthancomparablewitholigotropic
the loch is divided into two basins of 220 m depth as a result of andeutrophiccategories.
fluvial deposits of material opposite the entrance to the River The dissolved oxygen content of the Loch Ness water column
Foyers. The floor is extensively covered by black lake sediments was, along with other lochs studied, consistently found to be over
whichoccupiesover50%oftheareaofLochNessgreaterthan 150 80% saturated (often approaching 100%) even during periods of
m depth. Shine & Martin (1987) found that a 4 m core onlyjust stratification Smith, I. R. etal, (1981
penetratedtoclay,suggestingthattheorganicsedimentisatleastof UndertheclassificationsystemofYoshimura(1936),LochNess
thatdepth. Sedimentsanalysedfromasinglecoreobtainedfromthe isawarmmonomicticlakewhichmeansthatthetemperaturenever
profundal area of Loch Ness were found to consist of fine size falls below 4°C at any depth, there is one circulation ofthe water
fractions withclay (< 39 urn, 45.8%), fine silt (39-63 urn, 18.1%) column every year in winter and the loch is stratified during the
'R.HunterneeR.David.
©TheNaturalHistoryMuseum,2001
F.R.WANLESSANDR. HUNTER
summerMurray&Pullar(1910).Fromlateautumntothespringthe MATERIAL AND METHODS
lochisthesametemperaturethroughout,withprogressivedevelop-
mentofstratifiedconditionsfromMaytothefollowingautumn.The
temperaturerangeinmidsummeristypically 14.5°Catthesurfaceto Samplingand fixation
5.5°C at220m (Mackal & Love, 1969; Murray& Pullar, 1910). Profundal sampling: coresweretakenwithaBowersandConnolly
Maitland (1981) gives a detailed account of human activities Multicorer deployed from the research vessel Seol Mara. This
whichinfluencetheenvironmentalparametersinherentinscientific devicetakesfourcoretubes (eachof5.9cmdiametergivingacore
studieseffectingLochNess.Thelochisrelativelyunpolluteddespite surface area of 27.34 cm2), allowing sediments to be recovered
arable, tourist and urban influences. The Scottish Environmental withoutdisturbingthe sedimentwaterinterface.
Protection Agencyhas supplieddetailsofsewerage inputstoLoch Sediments were sampled at four stations: Fort Augustus Bay,
Ness which indicate that there are seven direct septic tank inputs DeepSouthBasin,FoyersPlateauandDeepNorthBasincoveringa
fromsmallcommunitiesorhotelsandtouristattractions,onlytwoof range ofdepths between 91 and 211 m (Fig. 1, Table 1). At each
which have monitored flows. Another septic tank inflow enters station samplingwasconcentrated within approximately 10-20m:
LochNessindirectlyviatheRiverMoriston.Therearetwoactivated between 10—13th July 1993, allowing for boat drift. Eight cores
sludge plants for full biological treatment, one at Drumnadrochit were collected from each station except for the Deep North Basin
and another at Fort Augustus. When maximum flow is reached, whereonlyfourcoresweretakenbecauseofpoorweatherconditi-
sewerage by-passes the treatment plant and discharges untreated ons.Oftheeightcorescollectedsixwereusedforfaunalanalysis;of
intothewatercourse. Seasonalinformationontheloadingvariation thesefivewere sectionedintotwo, onecentimeterlayers. One was
wasnotavailable. However, DrumnadrochitandFortAugustusare sectioned into five onecentimeterlayers i.e. 0-1 cm, 1-2cm, 2-3
knowntofrequentlybreachtheirconsentlimits.Thewaterregimeof cm, 3—4 and 4—5 cm. The seventh core was used to take redox
Loch Ness is affected directly by an hydro-electric pump storage potentialreadingsimmediatelyonrecovery.Thetoptwocentimeters
schemebasedatFoyersandindirectlybyfourmoreinthecatchment ofthe remaining core was placed in a cold box forcarbon content
area.Theseinfluencesmayhaveaneffectonthefloraandfaunaof analysis.
Loch Ness. Riversampling: sedimentswerecollectedbyhand withacoring
tube ofthe same dimensions as usedforcollecting profundal sam-
ples. The cores were sectioned as above. Three stations i.e. Rivers
NEMATODE FAUNA Oich, FoyersandMoristonwere selectedby surveyingtheareafor
soft sediment similarin grain size to the profundal samples where
So far as is known the only study ofnematodes from freshwater coretubescouldusedwithease.Sampleswerethentakenrandomly
lakes ofthe United Kingdom is that ofMartin et al., (1993) who within an areaof 10m2. All samples were sublittoral rangingfrom
publishedafulllistingofmacrobenthicandmeiofaunalspeciesfrom 0.08-0.39 m depth. Eighteen cores, six from each station were
profundal sediments of both Loch Ness and Morar. Their list of collectedfrom7-8thAugust 1994.
nematodesfromLochNessprofundalcores(>200m)althoughnot After slicing, all samples were immediately fixed using 8%
exhaustiveincludesIronustemiicaudatusdeMan, Tripylaglomerans formaldehyde,atambienttemperature,givingafinaldilutionof4%
grp, Tobrilus gracilis grp, Tobrilus cf. pellucidus and Dorylaimid after mixing. A trace of rose bengal was added to the fixative to
'A'. Additional species listed (Eumonhystera filiformis grp, temporarily stain the nematodes, thus making them easier to see
Eumonhystera cf. longicaudatula, Ethmolaimus pratensis grp, whencounting and sorting.
Aphanolaimus sp. andDorylaimus cf. stagnalis) were collected at In addition to the stations listed in Table 1, four sub-littoral
lesserdepths such as 50-170m. qualitativecoresweretakenfromasandybeachatBorlumBay,Fort
InadditionColes(1996)recordsChromadoritatenuisSchneider, Augustus (NH085 385)on 22July 1992fromdepthsof0.10-0.38
1906 andAphanolaimus ? aquaticus Daday, 1894 from 'trickle of m. Some ofthe nematode species founddid notreoccurduringthe
freshwater spring from beside footpath from Goyes Hotel, Foyers 1992-93surveys,sowehavetakenthisopportunitytoincludethem
Harbour, Loch Ness, Scotland'. inthispaper.They areidentifiedinthedescriptionsasBorlumBay
Table 1 Summaryofsamplingstations,coredepthsandsedimentcharacteristics.
Core Depth
Station No's Position Date (m) Sediment
FortAugustusBay(FA) 2-7 57"08.80'N4"39.45'W 10/7/93 91-105 Organicmatter(OM)floe,occasionallyferrugineousmixedwith
greysiliceoussand
W
DeepSouthBasin(DSB) 8-13 57°12.55'N4°34.55- 11+12/7/93 194-210 Asabovebutwithslightsulphuroussmell
W
FoyersPlateau(FP) 14-19 57"15.80'N4°29.60" 12+13/7/93 150-161 Asabove
W
DeepNorthBasin(DNB) 20,22 57°16.40'N4°29.10' 13/7/93 211 211 Asabove
RiverOich(RO) 31.32 NH094382 7/8/94 0.31 Sublittoral.Rivermouth.AlgaeandOMonsurface,coarsesandbelow
33,34 NH094382 7/8/94 0.20 Smallstonesandgravel
35 NH094382 7/8/94 0.33 Coarsesandandsmallpebbles
36 NH094382 7/8/94 0.17 Coarsesand
RiverFoyers(RF) 40^15 NH211 495 7/8/94 0.14-0.39 Stagnantsublittoral.50mfromrivermouth.OMandgreysiliceous
sandcontainingblackstreaks. Strongsulphuroussmell
RiverMoriston(RM) 50 NH211 495 8/8/94 0.15 100mfromrivermouthSandbetweenboulders
(accountoffulldataset 51,52 NH211 495 8/8/94 0.100.08 Coarsesandsmallpebbles
inprep.) 53 NH211 495 8/8/94 0.20 Sandandgravel,somepebbles
54 NH211 495 8/8/94 0.15 Coarsesand
55 NH211 495 8/8/94 0.16 Sandandgravel
.
FRESHWATERNEMATODESFROMLOCHNESS
R. Ness
200m contour
Farigaig
R. Foyers
200m contour
1 RiverOich (RO)
2. FortAugustus Bay (FA)
3. RiverMoriston (RM)
4. DeepSouth Basin (DSB)
Direction offlow 5. RiverFoyers (RF)
6. Foyers Plateau (FP)
7. Deep North Basin (DNB)
** Activated sludgetreatment
* Significantseptictank input
R. Tarff
Fig. 1 MapofLochNessshowingsamplingstations.
(1992collection).Also,theyhavenotbeenincludedintheecologi- amounts of organic matter of very similar density to that of the
cal part of this study which is based entirely on the 1992-93 nematodes.Inordertoreducesamplesortingtime,itwasdecidedto
samples. subsample the remaining 1 cm core slices usingthe 'Asko sample
splitter' Elmgren (1973). Twohundrednematodeswerepickedout
Extractionandslidepreparation fromeachcore; iflessthan200nematodeswerepresentinthefirst
Nematodes were extracted by the Ludox centrifugation-floatation subsample, further subsamples were extracted until the required
technique(Persmarketal., 1992).However,afterextractingthefirst number was found. Extracted nematodes were then dehydrated to
core it was found that the nematodes were still obscured by large glycerineby the Seinhorst method (Seinhorst 1962).
1
F.R. WANLESSANDR. HUNTER
Figures, photographs and measurements MiculenchussalvusAndrassy, 1959 +
Specimens were examined, figured and photographed with an Ol- Tylenchus rexAndrassy, 1979 - +
ympus BH-2 interference contrast microscope fitted with camera Tylenchinae sp. + +
lucida. The drawings areoriginal andbasedentirely on Loch Ness
specimens. Allabsolutemeasurementsofnematodesaregiven um.
FamilyANGUINIDAENicoll, 1935
Sedimenthorizon
Thiscanbetakenas0-1 cmunlessastatementismadetothecontary Ditylencluts sp. + —
in the descriptions.
Abbreviations used Family BELONOLAIMIDAEWhitehead, 1960
a = body length-fgreatestbody width
b = body length-fdistancefromanteriorendtojunctionof Geocenamuscf. nanus (Allen, 1955) +
esophagus and intestine Tylenchorhynchus sp. - +
b' = body length -f distance from anterior end to posterior
endofoesophageal glands
c = body length -ftail length Family HOPLOLAIMIDAE Filipjev, 1934
c' = tail length -fbody widthatanus
L = totalbody length Helicotylenchuspseudorobustus (Steiner, 1914) + +
MB = distance ofmedian bulb from anteriorend -r oesopha-
geal length x 100
R = total numberofbody annules Family HETERODERIDAEFilipjev, 1934
Roes = numberofannules in oesophagealregion.
Rex = number of annules between anterior end ofbody and Meloidogyneardenensis Santos, 1968 +
MeloidogynekralliJepson, 1983 - +
excretory pore
Rv = numberofannules between anteriorend andvulva
Rvan = numberofannules between vulvaandanus
Ran = numberofannules ontail Family CRICONEMATIDAETaylor, 1936
tail/V-a = tail length-fdistance betweenvulvaandanus Criconemaannuliferum (de Man, 1921) - +
VV = distanceofvulvafromanteriorend-rbodylengthx 100 Criconemademani (Micoletzky, 1915) + -
= distance ofvulva from anterior end -f distance ofanus Criconema sp. - +
from anteriorend x 100 Discocriconemella sp. - +
VL/VB = distance between vulva and posterior end of body -r Hemicydiophora sp. - +
body width atvulva Ogma sp. + -
SPECIES LIST FamilyTYLENCHULIDAE Skarbilovich, 1947
Paratylenchussp. -
ThesystematicclassificationoftheorderTylenchidaisbasedonthat
of Fortuner, Geraert, Luc, Maggenti and Raski (1987-1988) 'A
reappraisalofTylenchina(Nemata)'.ThatoftheorderRhabditidais FamilyAPHELENCHOIDIDAE Skarbilovich, 1947
afterLorenzen (1981).
Aphelenchoides sp. 1 +
Aphelenchoides sp. 2 +
OrderTYLENCHIDAThome, 1949 S* Aphelenchoides sp. 3 +
FamilyTYLENCHIDAEOrley, 1880
Aglenchusagricola (de Man, 1884) + OrderRHABDITIDA Chitwood, 1933
CoslenchuspolonicusBrzeski, 1982 + Family RHABDITIDAEChitwood, 1933
CCoosslleenncchhuuss sspp.. 21 -+ cf. Caenorhabditissp. +
Filenchuscf. discrepans (Andrassy, 1954) +
Filenchusfaeultativus(Szczgiel, 1969)
Filenchusthornei(Andrassy, 1954) + FamilyDIPLOGASTERIDAE Micoletzky, 1922
Filenchussp. 1 - Diplogasteritusnudicapitatus(Steiner, 1914) +
Filenchussp. 2 —
Filenchussp. 3 -
Lelenchusleptosoma (de Man, 1880) Family CEPHALOBIDAEFilipjev, 1934
Lelenchus sp. -
MalenchusacarayensisAndrassy, 1968 + Eucephalobusoxyuroides (de Man, 1876)
Malenchusbryophilus (Steiner, 1914) + Eucephalobussp.
Malenchuspachycephalus Andrassy, 198
Malenchuspressulus (Kazachenko, 1975) * S =. Sublittoral, P= Profundal.
FRESHWATERNEMATODES FROM LOCHNESS
DESCRIPTIONS OF SPECIES genitalbranch 123-146umlong;spermathecapartlyoffset,usually
poorly defined, ovoid to elongate-ovoid, sometimes appearing
double, length variable 20-25.6 um; postuterine sac lacking.
Aglenchus agricola (de Man, 1884) Andrassy, 1954
Males, (n=6). L=591.5 |jm (469-670); a= 38.9 (33^3); b (n
(Fig. 2) - 4) = 6.2 (5.6-6.7); c = 3.1 (2.9-3.3); c' = 17.5 (15.3-19);
Materialexamined. FortAugustus Bay: 92, 105 m;cores2, 3; gubernaculum(n=5)=6.4um(6.3-6.4);spicules(n=5)= 14.7um
29$. Foyers Plateau: 150-161 m; cores 14-17; 29946*6*. River (14-15.3); tail = 193.8 urn (153-219).
Foyers: 0.14-0.39 m; cores40, 43,45: 299, 266. Similartofemale.Annules 1.6-1.96umwideatmid-body. Spear
12-12.8umlong,withroundedknobsabout2.6umwide.Oesopha-
Horizon. Core 2 (2-3 cm), core 14(3^4cm), core40(2-3 cm). gus 81.6-101 um long; median bulb ovoid with usually distinct
F65.6e)6m;(a6Vl.e3s-=6,.797).;(6nc(==7653)...53-L(738=..246-)53;0.4tu)a;rinlc/'(V6=-2a51-4=.65617.(9)1:2(.1a7.-=71-235.1.08)():;26tV.a4i=l-3=545..1491)4;(5\b3i=m- aovsaclycvmuempseytiartnig4c6a2l^4;-—82b%u5r%osfaoofaedbsaoondpayhlal3gee2nga-tl3h8;l.ec4nlgoutahmc.alTleolsnitgpisswtiu1tb4eh4--ls1imk5oe3,o.ts6houmomerwlvhoeanrtgy
finely crenate margins.
(188-200).
Headcontinuous, notannulated. Body annules 1.6-1.8 urn wide Distributionandhabitat. Cosmopolitan,invarioussoils,lives
at mid-body. Lateral fields with three lines; outer lines sometimes on ornearplant roots, in mossesandfreshwater.
appear double, whereas the inner line which is usually weakly
expressed,couldbeinterpretedastwolinesverycloselysetasthey REMARKS. Morphometric measurements of this population fall
midwaybetweenthoseoftwovery similarspecies,A. agricolaand
aSpppeeaarrmaosdeeritahteerlygulrloybuosrt,ri1d1g.e0--li1k2e.8(duerpnenlodnegn,tboansaolptkincaolbssedtitsitnigns)c.t A. muktii Phukan & Sanwal, 1980. A. tnuktii, according to the
about3.2 urn wide. Oesophagus92.7-101.7 um long; median bulb originalauthors,isdistinguishedfromA. agricola 'inhavinganon-
ovoidwithusuallydistinctvalvesat44-50%ofoesophageallength. annulated lipregion, 3 incisures in the lateral field,andavery long
Vulva with flaps about 5.0 um long covering about three annules; filiform tail. (A. agricola has 3 annules in the lip region, 1 lateral
vagina curved anteriorly with swollen pyriform walls; anterior incisuresandatailwhichisnotasfiliformasinA.muktii).'Ofthese
charactersthefirsttwoaremistakenbecauseinA.agricolathehead
is not annulated and the lateral field is comprisedofthree lines. In
practiceA. muktiiisdistinguishedfromA.agricolaby itsverylong
filiform tail. Tail length inA. agricola rangesfrom 134to 179 um,
whereas in A. muktii the range is 178-276 um (Geraert & Raski.
1988). Femaletaillengthofthispopulationvariesbetween 153-197
um. Br/eski (pers. comm.) notestail lengthsofA. agricola varying
from 134-208um.Inmalesofbothspeciestherewouldappeartobe
adistinction between tail lengths and ratioc'. Tail length 140-169
um inA. agricola vs 178-330um inA. muktii:ratioc' 13-15 vs22-
25 in A. muktii. However the Loch Ness males bridge the gap in
respect of tail length 153-219 urn and fall between the range of
values in the caseofratioc', c'= 15.3-19.
Theoverlapintaillengthsandothermorphometricmeasurements
suggest that the specific status ofA. muktii is doubtful. This popu-
lation is therefore identifiedasA. agricola.
Coslenchuspolonicus Brzeski, 1982
(Fig. 3)
Material examined. Deep South Basin: 204 m; core 9; 1 9.
RiverFoyers: 0.22 m; core40; 1 9.
Horizon. Core40, (1-2 cm)
Females, (n=2). L=635, 744um; a=41.5,46.5; b=5.4,6.2;c
=5.8,5.4;c'=ll,12;V=65.8,64;V'=79.6,80;Rex=47,52;Roes
=62,63;Rv=203;Rvan-44.49; Ran=55,65;tail/V-a= 1.0;tail
= 110, 137.6 um.
Head more or less continuous with body contour, 6.4-6.7 um
wide with 4 very fine annules. Annules 2.3, 2.8 um at mid-body.
Lateral fields with4 lines, the two inner lines closely spaced, thus
sometimesappearingasasingleline.Cuticlewith 18-20longitudi-
nal ridges (difficult tocount) excluding lateral fields. Spearrobust
15, 13.4 um long; knobs rounded, 3.8, 3.2 um wide. Oesophagus
Fig.2 Aglenchusagricola(deMan, 1884).A-E,female.A,oesophageal 118, 120 um long; median bulb ovoid, valve at about 45% of
region;B,posteriorendofreproductivesystem;C.tail;D,lateralfield; oesophageal length. Vulva, with lateral vulval membranes, 6.4 um
E,habitus:F,malespicularregion.Scalebarsa=20|jm,b=40|jm,c= longorabout3annuleswide;vaginainclinedanteriorlywiththick,
100um. somewhat pyriform, walls; postuterine sac small; spermatheca
F.R. WANLESSANDR. HUNTER
Fig.3 CoslenchuspolonicusBrzeski, 1982.A-F,female.A,oesophageal
region;B,lateralfield;C,posteriorendofreproductivesystem;D,
habitus;E,tailtip;F,tail. Scalebarsa=20um,b= 100um.
Fig.4 Coslenchussp. 1. A-E.female.A.oesophagealregion;B.lateral
field;C,vulvalregion; D.habitus:E,tail. Scalebarsa=20um,b= 100
elongate, 38, 41 jam long, packed with sperms about 2.0 um in um.
diameter. Distance fromvulvatoanus 107-128 um. Tail tip finely
roundedwithannulesinonespecimen;roundedwithoutdiscernible sloping posteriorly, 2.6, 3.0 pm wide. Oesophagus 96.3, 94.7 um
annules inother. long; median bulb ovoid; valve well developed at about 46% of
Distribution and habitat. 'Collected in several places in Po- oesophageal length. Vulva with lateral vulval membranes 7.0, 7.6
urn or 3 adjacent annules long; vagina perpendicular or slightly
landandinAndreevskoe,Karelia,USSR,alwaysinlowpeatsoil,in
inclined anteriorly, with thick walls; postuterine sac not evident;
small numberofspecimens' (Brzeski, 1987).
spermatheca without sperm. Distance from vulvato anus 100, 120
Remarks. These nematodes were not originally identified as C. um. Tail tip finely rounded.
polonicusbecausetheyhavefewercuticularridges(18-20vs26in Remarks. UsingBrzeski's (1987) andGeraert & Raski's (1988)
C. polonicus). However, Brzeski (pers. comm.) recognized these
fareemalneos,otahnedrssuigggneisfticeadntthedyifafeprpeenacreesdbteotbweeeCn.ptohleosneicfuse.maAlessthaenrde ktheeysm,itdh-ebsoednyemanantuoldeessacroemmearcglionsaelltoyCt.ooanwdirdaess2.y6i,B2r.z7esvksi2,.11-928.75,buumt
in C. andrassyi, alsothe numberofannules betweenthe vulvaand
dtheesclroipwteironnsuomfbeC.rpooflocuntiiccuusla(rBrrziedsgkeis,l1i9es82w,it1h9i8n7)thietirsaansgesuomfevdartihaa-t theanteriorendofthebody aretoolow, 136, 138 vs 157-186in C.
andrassyi.
tionthatmightbe expected inthis species.
Coslenchus sp. 2
Coslenchus sp. 1
(Fig. 5)
(Fig. 4)
Material EXAMINED. Fort Augustus Bay: 92 m; core 4; 19. Materialexamined. RiverFoyers: 0.22m; core40; 1 9.
Foyers Plateau: 157 m; core 16; 19. Horizon. Core40, (1-2 cm).
FEMALES, (n=2).L=520,527umV; a=23.2,24.7;b=5.5,5.4;c FVemale. (n= l).L=546pm;a=24;b=4;c=5.4;c'=7;V=65;
-5.6,6.1;c'=7.2,6.9;V=64,65; =77,79;Rex=37,42;Roes =79.5;Rex=40;Roes=63;Rv= 152;Rvan=41;Ran=66;tail/
=42, 46; Rv = 136, 138; Rvan = 40, 37; Ran = 59, 53; tail/V-a= V-a= 1.1; tail = 102 pm.
0.92,0.93; tail = 93.4, 86.4 um. Head narrower than adjacent body; 7.7 um wide with 5
Head offset in one specimen; 7.0, 7.5 um wide with 4 annules. annules.Annules 2.7 pm wide at mid-body. Lateral fields with 4
Annules about 2.6, 2.7 urn at mid-body. Lateral fields with four lines. Cuticle with longitudinal ridges and additional short ridges
lines. Cuticlewith 14longitudinal ridges (excluding lateral fields). distributed irregularly, giving an estimated total of 15-16 ridges
Spearmoderatelyrobust11.5, 12.8umlong,knobsrounded,slightly excluding lateralfields. Spearslender, 13.5 pm long; knobs small,
FRESHWATERNEMATODES FROM LOCHNESS
A/1
1
ill
Fig.5 Coslenchussp.2.A-E,female.A,oesophagealregion: B. lateral
field;C,vulvalregion;D.tail;E.habitus. Scalebarsa=20pm.b= 100 Fig.6 Filenchuscfdiscrepans(Andrassy, 1954). A-E,female. A.
pm. oesophagealregion: B. lateralfield;C,reproductivesystem;D.tail;E,
habitus. F, malespicularregion.Scalebarsa=20pm.b= 10pm,c=
roundedabout2.6umwide.Oesophagus 136umlong;medianbulb 50pm.
ovoid,valvewelldevelopedat45.5%ofoesophageal length. Vulva
withlateralvulvalmembranes,7.6umlongorabout3annuleswide;
mid-body. Lateral fields with two lines. Spearslender, 6.0-7.6 pm
vaginaslightlyinclinedanteriorlywiththickenedwalls;postuterine
sac short; spermathecaempty. Distance from vulvato anus 91 um. longwithsmallbasalknobs,about 1.2pmwide.Oesophagus69-92
Tail damaged, but annules upto finely rounded terminus. pmlong;medianbulbsomewhatfusiform,valveweakat35-42%of
oesophageal length. Anterior genital branch 68-156 pm long.
Remarks. Although the tail of this specimen is damaged, it is Spermatheca axial, oblong with rounded sperms about 1.3 pm in
clearlydifferentfromtheotherspeciesofCoslenchusfoundinLoch diameter. Postuterine sac 7.0-13.4 pm long. Vagina more or less
Ness. Ratios effected by this damage are considered to be close to perpendiculartobody axis.
measurementsthatwouldhavebeenobtainedhadthespecimenbeen
undamaged. It keys out close to C. pastorAndrassy, 1982, but the MALE, (n = 1). L = 453 pm; a = 47; b = 5.0; c = 4.5; c' = 14.5;
morphometries are apoorfit. gubernaculum = 3.0pm; spicules = 13.8 pm; tail =101 pm.
Similartofemale,exceptbodymoreslenderwithnarrowerlateral
Filenchus cf. discrepans (Andrassy, 1954) Raski & fields. Testis 152 pm long, occupying 33% ofbody length. Bursa
Geraert, 1987 adanal, 19 pm long.
(Fig. 6) Distribution and habitat. Widely distributed in Europe with
additional recordsfromMexico,Russia,USA(terrestrial soils)and
Materialexamined. Fort AugustusBay: 98, 102m;cores5,6; New Guinea (terrestrial andfresh water).
299. Deep South Basin: 196, 204 m; cores 8. 10; 299. Foyers
Plateau: 158,-160m;cores 14, 15, 18;399.DeepNorthBasin:cores REMARKS. This population keys out to F. discrepans. The mor-
20,22;211 m.299.RiverFoyers:0.25-0.39m;cores41,42,44; 16, phology ofthe female reproductive system closely resembles that
399. figured forthe type specimen, especially in respect ofthe oblong
Horizon. Core 14, (1-2 cm). spermathecainfemales.However,thecephalicregionisnotmakedly
narrower than the adjacent body region as figured by Andrassy
Females, (n= 10). L=429 um(337-526);a=35 (27.0-45.8);b (1954) anddescribedbyTroccoli & Geraert (1995). Brzeski (pers.
=5.3V(5.0-6.1);c=3.8(3.4-4.5);c'= 14.1 (12.8-17.6);V=60(57- comm..)suggeststhatthesenematodesshowaffinitiestoF.misellus
64); = 82.3 (80.5-84); tail/V-a = 2.1 (1.7-2.5); tail = 109 urn (Andrassy, 1958),butinFmisellustaillength(28-71 pm)andratio
(91.4-140). tail/V-a (0.7-1.6) are different (Brzeski, 1979); tail shape also
Head3.8-5.0pmwideatbase.Annules 1.2um(0.8-1.6)wideat differs.
F.R. WANLESSANDR. HUNTER
Filenchusfacultativus (Szczygiel, 1969) Raski & Geraert, species of Filenchus, the same range is also given by Karegar &
1987 Geraert (1988) in their summary of characters distinguishing F.
facultativus from other very similar species, whereas Torres &
(Fig. 7) Geraert (1996) record spearlengths of7.5-9.0 um in apopulation
Material examined. Fort Augustus Bay: 91, m; cores 2, 5; describedfromArgentina.
3$?.
Horizon. Core 2, (2-3 cm). Filenchus thornei (Andrassy, 1954) Andrassy, 1963
Females. (n=3).L=515um(434-557);a=36(35-37.8);b=6.1 (Fig. 8)
V(6.0-6.3);c=4.0(3.9-4.1);c'= 13(11.6-14.5);V=63.2(62-64.6); Material examined. Deep South Basin: 161 m; core 19, 19.
=84.8.(83.7-85.6);tail/V-a=2.1 (2.0-2.2);tail= 127um(105- RiverFoyers: 0.22m;core40, 12. FoyersPlateau: 159m;core 14,
142).
1<J.
Head about 4.6 um wide at base with 2-3 annules. Amphids
sinuous. Annules 1.7 um(1.5-1.9) atmidbody. Lateralfieldswith Horizon. Core 14, (2-3 cm); core 19, (1-2 cm); core 40, (2-3
twolines.Spearslender9.0um(n=2)longwithsmallbasalknobs, cm).
baublobutov1o.id2,umvawlivdeew.eaOeksaotp3h9a^g1u2s%8o3f.8oeusomph(a7g3e.a6l-9l1e)ngltho.ngE;xcmreedtioarny F=e5m.a0,le4.s1,;c'(=n=142.)5..L18=; 9V97=,519,00536;uVm;=a=733,87,34.45.;7t;abil=/V6-.a9,=60..59;5,c
pore62.4,68.7um(n=2)fromanterior.Anteriorgenitalbranch 145 1.16; tail = 131.5, 191.5 um.
um (127-159) long. Spermatheca axial or slightly offset, elongate Head about 7.6, 8.0 um wide at base with 3-4 annules; height
23,26umlongwithroundedsperms(n=2).Postuterinesac7.7-12 about3.5 um. Amphidsnotobserved. Annules 1.3-1.6 um wideat
um long. Vagina 7.0-8.0 urn long, more or less perpendicular to mid-body. Lateral fields with four lines, inner lines very faint and
body axis. Tailtippointedtofinely rounded. notalwaysevident. Speardistinct,moderatelyslender, 13.4, 12 um
Distribution and habitat. A widespread species found inter- long with smallbasal knobs about 2.0 urn wide. Oesophagus 144-
restrial soils. 155 um long; median bulb more or less ovoid, valves moderately
distinct at 39.7, 42% of oesophageal length. Excretory pore
Remarks. F. facultativus is a variable species and these nema- sclerotized at 112, 122 um from anterior. Anterior genital branch
tdoedsecsriabreediwnitthheinlittehreatruaren.geHoowfevmeera,sutrheemsepneatrsatof9.o0tuhemrlpoonpgulisatatiotnhse 4la3r2tourbno(dny=a1xi);ssapbeorumtat1h3e.5cau4m2luomngl.onTagi,loftfispeft.inVealygipnoainpteerdp.endicu-
extreem range recorded for this species (6.0-9.0 um.). A range of
6.0-8.0 um is given by Raski & Geraert (1987) in their key to
-
F
Fig.7 Filenchusfacultativus(Szczygiel, 1969).A-G,female.A. Fig.8 Filenchusthornei(Andrassy, 1954).A-E,female.A,habitus;B,
oesophagealregion;B,headshowingamphid;C,posteriorendof posteriorendofreproductivesystem;C,tail;D,headregion;E,
reproductivesystem;D,lateralfield;E,reproductivesystem;F,tail oesophagealregion.F,malespicularregion. Scalebarsa=200urn,b=
terminus;G,habitus.Scalebarsa= 10urn,b=30um,c= 100um. 30urn,c=20um.
)
FRESHWATERNEMATODES FROM LOCH NESS 9
Male, (n= 1). L=960pm; a=44.2;b= 7.1; c =5.1; c'= 12.8; (56-73) from anterior. Oesophagus 85 pm (74-94.2) long; median
gubernaculum =6.0 pm; spicules = 22.6 urn; tail = 188 pm. bulb with poorlydevelopedvalvesat40.4% (35^15.6)ofoesopha-
Similartofemale;bodyslightlysinuousandcurveddistally,also geal length. Anterior genital branch 163 pm (115-198) long.
narrowed in region ofcloaca- possibly an artefact as the body is Spermathecaoffset,27.7pm(22.4-32)long.Postuterinesac8.9pm
slightly twisted in this region. Bursa 38 urn long, with crenate (8.3-9.6) long. Vagina7.0-7.7 pm long, gently inclined anteriorly
borders; cloacal lips protruding. Tail tip finely rounded. with thickened walls. Tail terminuspointedtofinely rounded.
Distribution and habitat. Cosmopolitan, found in damp soils Remarks. The specific identity of these females is uncertain.
and freshwaterhabitats. They show affinities with F.facultativus described above and may
REMARKS. ThisspecieswasrecentlyredescribedbyBrzeski(1997 bleoncgoenrsapencdiftihce.waHlolwsevofert,heivnatghiensaeanreemsaltioghdtelsy tthhiecksepneeadr.is slightly
and these specimens fall well within the range of measurements
presented forF. thornei. The heightofthe head is perhaps slightly Filenchus sp. 2
lower, butthis is notthought tobe ofany significance.
(Fig. 10)
Filenchus sp. 1 Materialexamined. Foyers Plateau: 157 m;core 14, 1 9.
Fig. 9
Female, (n= 1). L=625 pm; a=40.1; b=5.2: c=5.5;c'=9.0;
Materialexamined. FoyersPlateau: 159m;core 14.299.Deep V =65.8; V'= 80; tail/V-a= 1.0; tail = 108 pm;
North Basin: 211 m; core 22, 1 9. Head5.7 pm wideatbase. Amphidsnotobserved. Annules fine,
1.3 pm wide at mid-body. Lateral field with four lines, inner two
Horizon. Core 14, (1-2 cm; 3-4cm). faint.Spearindistinct,9.3pmlongwithsmallbasal knobsabout 1.3
Females, (n=3). L=531 pm(439-615);a=40.6(39.7—41.8);b pm wide. Excretory pore 82.5 pm from anterior. Oesophagus 119
= 6.0 (5.5-6.5); c = 3.4 (3.2-3.6); c' = 18.5 (15.8-20.2); V = 58.6 pm long; medianbulbovoid, valvesweakat40.7%ofoesophageal
V
(57-60); =83.3 (82.6-84.5); tail/V-a=2.5 (2.2-2.7); tail = 157 length. Anterior genital branch 175 pm long; spermatheca axial,
urn (132-191.5). about 22 pm long, with rounded sperms about 1.9 pm in diameter.
Head 5.0-5.7 urn wide at base with two annules. Amphids Postuterinesac6.4pmlong,occupying41%ofcorrespondingbody
sinuous.Annulesabout 1.6urnwideatmid-body.Lateral field(only diameter.Vaginaabout5.8pinlong,perpendiculartobodyaxis.Tail
evidentintwospecimens)withfourlaterallines,theinnertwobeing terminus finely rounded.
veryfaintandclosetoouters. Spearindistinct,slender,9.6urn long
withsmallroundedknobsabout 1.3urnwide.Excretorypore64urn
Fig.9 Filenchussp. 1.A-F,female.A.oesophagealregion;B.head Fig. 10 Filenchussp.2.A-E,female.A,oesophagealregion:B.habitus;
showingamphid;C,lateralfield;D,tailtip;E,habitus;F.posteriorend C.lateralfield:D,tail;E,posteriorendofreproductivesystem.Scale
ofreproductivesystem. Scalebarsa= 10pm,b= 100pm. barsa=20pm,b= 100pm.
10 F.R. WANLESSANDR. HUNTER
Remarks. ThisnematodeisclosetoF. butteus(Thorne&Malek,
1968) Brzeski, 1997,butthetail is longerand differs in shape.
Filenchus sp. 3
(Fig. 11)
Materialexamined. FortAugustusBay: 92 m; core 3, 16.
MALE, (n = 1). L=434 urn; a= 35.7; b = 6.4; c =4.4; c'= 10.3;
gubernaculum = 5.8 urn; spicules = 15 um; tail = 99 urn.
Head 5.0 um wide at base with 3-4 annules. Amphids not
observed.Annulesfineabout0.9umatmid-body.Lateralfieldwith
fourlaterallines,hardlyevident.Spearmoderatelyslender, 11.2um
long with small basal knobs 1.9 um wide. Excretory pore 61.4 um
from anterior. Oesophagus poorly preserved, about 68 um long;
median bulb ovoid, valves not observed, centre at about 59% of
oesophageal length. Testis 138 um long, occupying 32% ofbody
length,bursaadanal,about 19umlong,withfinecrenatedmargins.
Tail tippointed.
Remarks. Noconclusion canbe reachedon the specific identity
ofthis specimen. It is close to F.thornei, but differs by its shorter
body length, spicules andtail.
Lelenchus leptosoma (de Man, 1880) Raski & Geraert,
1985
(Figs 12, 36B)
Materialexamined. FortAugustusBay:92m;core3; 1 9.Deep
SouthBasin: 194m;core 13; 1 9. FoyersPlateau: 159, 160m;cores
Fig. 12 Lelenchusleptosoma(deMan. 1880).A-E.female.A,
14, 15; 399.
oesophagealregion: B.headshowingamphid;C.posteriorregion:D.
Females, (n = 5). L = 546 (487-583) um; a = 46.6 (40-49.8); habitus; E.reproductivesystem. Scalebarsa=20pm.b= 10pm.c=
b=5.5 (4.9-6.3); c = 3.1 (2.7-3.35); c'=24.8 (22-27.9); V =52 60um,d= 100um.
V
(48-54.8); =77.6(75.5-78); tail/V-a=2.2 (1.9-2.5);tail= 180
um (156-215).
Cephalic region narrowed dorso-ventrally. Cuticle smooth by
light microscopy. Amphids sinuous. Lateral field absent. Spear
slender, 7.7-9.3 um long with small rounded knobs about 1.4 um
wide. Oesophagus 88-108 um long; median bulb spindle-shaped
with valves at 41-43% of oesophageal length. Anterior genital
branch 96.7-121.5 um long. Spermatheca more orless bispherical
with rounded sperm (absent in one specimen) about 1.3 um in
diameter. Postuterine sac not evident in any specimen, possibly
collapsed. Vagina about 5.5 um long with thin walls, curved
anteriorly.
Distributionandhabitat. Cosmopolitan;soilsandfreshwater.
Remarks. These specimens, for the most part, agree with the
description andmorphometriespresentedinthe literature(Raski &
Geraert, 1985). Minor differences slightly extending the range of
severalratios are notconsideredtobe ofany significance.
Lelenchus sp.
(Figs 13. 36A)
Materialexamined. DeepSouthBasin: 195,204m;cores9, 11;
299. FoyersPlateau: 157, 159 m; cores 14, 16; lcJ, 1 9.
FEMALES, (n=3).L=620(512-763)um;a=47.4(42-54.5);b=
Fig. 11 Filenchussp.3.A-E,male.A,oesophagealregion:B,lateral 6.0(V5.5-6.5); c=3.5 (3.3-3.8); c'=22.8 (21.4-24); V=57.6(57-
field;C,spicularregion: D.habitus;E,tailandspicularregion.Scale 58); =81 (80-82);tail/V-a=2.1 (1.8-2.4);tail= 173 (154-200)
barsa=20pm,b= 100pm. um.