TWO NEW SPECIES OF AINURDRILUS (CLITELLATA TUBIFICIDAE) FROM SOUTH-WESTERN AUSTRALIA, WITH NOTES ON AINUDRILUS NHARNA PINDER AND BRINKHURST

7 Pages·2003·2.2 MB·

by  Adrian M Pinder

Recordsofthe WesternAustralian Museum 21: 1-7 (2002).
Two new species ofAinudrilus (Clitellata: Tubificidae) from south-western
Australia, with notes onAinudrilus nhama Finder and Brinkhurst
AdrianM.FinderandStuartA.Halse
DepartmentofConservationandLandManagement,P.O. Box51,Wanneroo,6946WesternAustralia,Australia
Abtsract-Twonew species ofAinudrilus are described fromsouth-western
Australiaand thedescriptionofA. nharnaisamended.Ainudrilusangustivasa
sp. nov., from Lake Logue near Eneabba, is characterised by simple
spermathecal ducts, thinvasa deferentia and lackofhairchaetae.Ainudrilus
ngopitchup sp. nov., from a swamp near Kojonup, has long spermathecal
ducts,broadvasadeferentiaandhairchaetae.
INTRODUCTION SYSTEMATICS
The freshwater representatives of the tubificid
genusAinudriluswererecentlyreviewedbyFinder SubfamilyRhyacodrilinae
and Brinkhurst (2000). Fourfreshwaterspecies, all GenusAinudrilusFinogenova,1982
fromAustraliaandnumerousmarinespecies,from
Australia and elsewhere in the Pacific and Typespecies
Caribbean, are currently recognised (Erseus, 1990, Ainudrilus oceanicus Finogenova, 1982 by original
1997; Finogenova, 1982). Two new species have designation.
recently been collected from freshwater wetlands
sampled during a biological survey of the Diagnosis
wheatbelt and adjacent coastal areas of south- Hairchaetae presentorabsent. Chaetae ofpenial
western Australia. Wetlands in this region are segmentmodified,chaetaeofspermathecalsegment
threatened by secondary salinisation and usually unmodified. Vasa deferentia usuallybroad
waterlogging resulting from rising groundwater and glandular, entering atria medially to
caused by replacement of perennial native subapically.Atriavariablyshapedbutusuallymore
vegetation by annual crops that use less water or less erect or directed posteriad, consisting of an
(George et al., 1995). The biological survey is ampulla, often constricted medially and with
designedtoprovide aframeworkforplarming the spacious lumen, often containing sperm, usually
conservationofregionalbiodiversityin theface of leading to well developed ejaculatory ducts.
this threat. Non-marine tubificids are particularly Prostate absent. Penes absent, though ejaculatory
sensitive to salinity and discovery of two new ducts often eversible. Spermathecae with distinct,
species in the south-west, which otherwise has and often complex ducts. Sperm loose in
only one endemic tubificid {Ainudrilus nharna spermathecal ampullae. Coelomocytes large and
Finder and Brinkhurst, 2000), is of conservation generallyabundant.
significanceinrelationtotheaboveenvironmental Included Australian freshwater species:
concerns.
Ainudrilusfultoni (Brinkhurst, 1982), A. billabongus
(Brinkhurst, 1984), A. stagnalis Erseus, 1997, A.
MATERIALSANDMETHODS nhama Finder and Brinkhurst, 2000, A. angustivasa
sp.nov.andA.ngopitchupsp.nov.
Thetwonewspecieswerecollectedinsamplesof
benthic invertebrates takenusingaD-frame sweep
netwithameshporesizeof250pmandpreserved AinudrilusnhamaFinderandBrinkhurst,2000
in ethanol. Specimens were stained with Figure1
Grenacher's borax carmine, cleared with methyl
salicylate and slide mounted in Permount®, either Ainudrilus nharna Finder and Brinkhurst, 2000: 55,
wholeorwiththegerutalsegmentsdissected.Type Figure3.
material is deposited with the Western Australian Materialexamined
Museum (WAM) with other material held by the
Department of Conservation and Land HolotypeandParatypes
Management(CALM). Franikland River at Roe Road ford, 34 km NNW
2 A.M.Finder,S.A.Halse
Figure1 Ainudrilus niiarna Finder and Brinkhurst: A, male genitalia of holotype; B, spermatheca of holotype; C,
WAM WAM
foldedvasadeferentiaof V4159andV4166;D,malegenitaliafrom 37-98;E,sectionthroughvas
WAM
deferensof V4156,showingglandularnatureofliningcells;F,ventral chaeta;G,dorsalchaeta.Scale
lines;A-D50pm;E-G,20pm.
of Walpole, Western Australia, 34°41’02''S SE of Corrigin, 32°27'29"S 117°59'53"E, 22 October
116°51'13"E,9September1996(WAM1-99to4-99). 1997; Hamersley River, Fitzgerald River National
Park, 33°53'25"S 119°5r39"E, 12 September 1998;
OtherMaterial Jimperding Brook at Lover's Lane, 31°35'32"S
Not previously listed. All specimens from the 116°2r43"E, 28 October 1997; Lake Bryde, 30 km
south-west of Western Australia, collected by the SW of Newdegate, 33°21’14"S 118'’49’26"E, 3
authors with D.J. Gale or J.M. McRae and held by October 1997; Lake Coomelberrup, 10 km SE of
CALM. Calyerup Creek, west of Fitzgerald River EXimbleyung, 33°24'36"S 117°47'01"E, 05 Nov 1998;
NationalPark,33°56’11"S119°03'56"E,12September Lake Dulbining, 40 km E of Narrogin, 32°54'24"S
1998; Dale River at Lupton's Bridge, 32°18'08"S 117°36'49"E, 24 October 1997; Melaleuca swamp 30
116°41'16"E, 29 October 1997; Dam on Gorge Rock, km NW of Hopetoun, 33‘='49'40"S 120°24‘20"E, 11
NewAustralianAinudrilus(Clitellata:Tubificidae) 3
September 1998; Melaleuca swamp in Paperbark records listed above show that the species is
Nature Reserve, 21 km SE of Corrigin, 32°24'58"S widespreadinthesouth-west,includingthecentral
118°05'51"E, 25 October 1999; Peenebup Creek, 10 andsouthernwheatbeltandsouth-coastandoccurs
km S of Ongerup, 34°06’02"S 118°32'12"E, 27 in a wide variety of wetlands. Pinder and
September 1998; Lake Pleasant View, Manypeaks, Brinkhurst (2000) noted thatA. nhama was present
34°49'51’'S118°10'59"E,29September1998. atLakeWalbyringwhenthiswetlandhadasalinity
Material listed in Pinder and Brinkhurst (2000) of 2.8 parts per thousand (ppt) (Halse et ah, 2000)
newly deposited with WAM. Thomas Spring, but was apparently absent at a later date when
south-west of Augusta, 34°21'00"S 115°09’35"E, 17 salinity was 20 ppt. However, the species was
September 1996 (WAM V4159); northern tributary subsequently collected at Lake Coomelberrup and
of Collier Creek on Cemetary Road, Walpole, Hamersely River at salinities of 22 and 20 ppt
34°58'30"S 116°45T2"E, 11 September 1996 (WAM respectively and is evidently tolerant of moderate
4160);FranklandRiveratRoeRoadFord,34°41'02"S salinity.
116°51'13"E,9September1996(WAMV4156-4158).
Remarks Ainudrilusangustivasasp.nov.
This species was described and illustrated in Figure2
Pinderand Brinkhurst(2000)butre-examinationof
new and previously documented material has Materialexamined
revealed some new features and intra-specific
Holotype
variation for some characters. Pinder and Dissected specimen. Lake Logue, 12 km SSW of
Brinkhurst (2000) noted 4-7 penial chaetae per Eneabbain Lake LogueNature Reserve, 29°59'20"S
bundle but up to 10 per bundle have now been 115°08'50"E, Western Australia, 27 October 1999,
boobstehrvoefd.thAessnpoetremdatfohrectahle tawmopunlelwaespoefciAes.,nohnaemoar S.A.HalseandD.J.Gale(WAMV4145).
sometimes lie in IX, though still with pores
anteriorly on X. The vasa deferentia ofthis species Paratypes
are ciliated, with the lining tissue consisting of a Fiveonslides(1 dissected,4whole-mounted)and
sIiEn)gliendliacyaetrinogfgtallalncdeulllsarfialclteidviwtiyt.hTvhaeculoulmeesn(Foifgutrhee csoelvleercatilonmdaattuaraessforahnodlotiympmea(tWurAeMsV4i1n47a-l4c1o5h3o)l.,
vasa deferentia is generally difficult to follow and
waswrongly interpreted asbeingfolded vertically Etymology
in the holotype (partly because of corrfusion with Fromthe latinangustus (narrow), referring to the
theovary,whichisnormallycloselyassociatedwith thinvasadeferentia.
thevasdeferens)butisactuallyonlyslightlyfolded
horizontally (Figure lA). The vasa deferentia vary Description
from fairly straight (Figure ID) to moderately Dimensions of preserved and slide-mounted
folded(Figure1C)indissectedspecimens.Theatria specimens: length 7.5-9 mm, width 0.45-0.5 mm.
ofthesectionedholotypeappearfairlyerect(Figure Number of segments 42-54. Prostomium rounded.
lA), whereas in dissected and slide mounted Pharynx in II and III, pharyngeal gland cells
specimens (e.g. Figure IE), including specimens abundant, mostly on pharynx and oesophagus
collected with the holotype, the atria appear more rather than post-pharyngeal septa. Oesophagus
squashed. This is probably due to compression from pharynx to IX, stomach in X-XII (type
under thecoverslip, althoughthe lowerpartofthe specimenswithnumerousparasiticciliatesattached
atrium and the ejaculatory duct appear to be tointeriorofstomach wall). Coelomocytespatchily
eversible (seen protruding from the male pore in distributed, particularly abundant in some pre-
some specimens) so the shape of the atria will clitellar segments, ovoid (10-15 pm) and
depend on the degree of contraction. Despite the granulated. Clitellum coveringposterior third ofX
real or apparent plasticity of the shape and and all ofXI and XII, least developed ventrally on
arrangement of the atrium and vas deferens, all XI.
specimens attributed to A. nharna have the Hair chaetae absent, all chaetaebifid with upper
characteristic short spermathecal duct with the teeth slightly shorter than lower, nodulus distal.
constrictionclose to thepore (Figure IB),andhave Ventral and dorsal chaetae from II, 65-75 pm, 6-9
chaetae of the same size and form (Figure IG, H) per bundle anteriorly, 3-5 per bundle posteriorly.
andsoareconsideredtobeconspecific. Penial chaetae of XI 4-8 per bundle, 65-87 pm,
ArecordofthisspeciesfromLakeWalbyringnear with simple bent ectal ends (som.e bifid on semi-
Narrogin (Pinder and Brinkhurst, 2000) was mature specimens) and indistinct distal nodulus.
considered to be a northern outlier from other Penialchaetae lying in aline parallel toeach other
records listed in the samepublication,butthenew and protruding through the body wall ventral to
4 A.M.Finder,S.A.Halse
Figure2 Ainudrilusangustivasasp. nov.: A, malegenitaliaofholotype; B,spermathecaofholotype;C,penialchaetae;
D,ventralchaeta;E,dorsalchaeta.Scalelines:A-B50pm;C-E,20pm.
male pores. Chaetae on spermathecal segment ejaculatory ducts narrowing between atria and
presentbutnotmodified. pores (everted in some specimens). Prostate tissue
Genitalia paired. Genital pores in line with absent.Femaleporesnotobserved.
somatic ventral chaetae, spermathecal pores
anterioronX,maleporesmedialonXI.Malepores Remarks
each a narrow slit within longitudinal depressions Thelackofprostatetissue,medialentryofthevas
either side of penial chaetae. Testes and ovaries into the atria and the bipartite atria are typical of
antero-ventralinXandXIrespectively.Spermsacs the genus Ainudrilus and the numerous parallel
to VIII and XVII, egg sacs to XV. Spermathecal penial chaetae are at least similar to the other
ampullae ovoid in IX and/or X, 210-225 pm long, freshwater forms (marine species generally have
containingloosesperm,cormectedtoporesonXvia fewer, exceptforthe typespeciesA. oceanicus). The
muscular ducts (130-150 x 65-80 pm). Ratio of narrowvasadeferentiaaretmusualbutalsoknown
length of spermathecal ampulla to duct length inthemarineAinudriluslutulentus (Erseus, 1984)of
about T.0.75. Ducts with lining tissue surrormded southernChina,whichwasattributedtothisgenus
by thick circular muscle, with sparse covering of by Erseus (1990)because it is 'otherwise similar to
peritoneal cells. Sperm funnels on 10/11 feed the type species' (i.e. itlacks prostate and thevas/
narrow (14-19 pm) non-glandular ciliated vasa atrial union is not apical). Rhyacodrilus simplex
deferentiawhichenteratriamedially.Atria115-145 (Benham, 1903) of New Zealand also lacks
pm wide, in two parts separatedby a ringofatrial prostates, which are normally present as a diffuse
muscle around the middle, upper part with thick coveringovertheatriainRhyacodrilus,andhasthin,
lining tissue aroimd broad ciliated lumen, lower non-glmdular vasa deferentia but the latter curl
part with thick lining tissue around narrower around the atrium and enter it more apically.
ciliated lumen, except for a more open unciliated Ainudrilus angustivasa differs from the remaining
areaectallynearejaculatoryducts.Atriallumennot two species from Western Australia in the lack of
containing sperm in type material. Eversible hair chaetae and can be distinguished from other
NewAustralianAinudrilus(Clitellata:Tubificidae) 5
Australian freshwater species, which all lack hairs, muscular ducts (245-330 x 50-75 pm), ratio of
by the thin vasa deferentia and the morphology of ampulla to duct about 1:1.3. Duct with narrow
the other chaetae, see Brinkhurst (1982, 1984) and lumen, surrounded by thick lining tissue then
Erseus(1997). circularmuscleandacontinuouslayerofperitoneal
Lake Logue is afre.sh tobrackish lake fringed by cells. Junction of duct and spermathecal ampulla
Melaleuca and Acacia trees. It usually dries particularlymuscularwithcircularmuscleforming
seasonally,althoughoccasionallycontainswaterfor a sphincter just ectal to duct-ampulla union.
several years. At the time of sampling the water Spermathecal ducts of paratype penetrating septa
was moderately coloured at280TCLf, pH was 7.83 9/10and 10/11, withoneampullainIXand onein
to8.18andsalinitywas1.1ppt. XI. Holotype with at least one ampulla in XI prior
to dissection. Sperm funnels on 10/11 feed broad
(up to 50 pm) ciliated, possibly glandular, loosely
Ainudrilusngopitchupsp.nov. folded vasa deferentia. Exact position of atrium/
Figure3 vas deferens union not visible but presumably
medial. Atria 85-120 pm wide, in two parts
Material examined separatedbyaringofmuscletissue,entalpartwith
Holotype thick lining tissue aroimd a broad ciliated lumen
Dissected specimen, Ngopitchup Swamp, in and ectal part with upper half filled with lining
Water Reserve 2184, 21.5 km south-west of tissuearoundnarrowciliatedlumenandlowerhalf
Kojonup,33°57'27"S117°20’32"E,WesternAustralia, forming a broad unciliated lumen. Atria without
coll.A.M.FinderandJ.M.McRae(WAMV4154). sperm in type specimens. Ejaculatory ducts
narrowing towards pores. Prostate tissue absent.
Femaleporesnotobserved.
Paratype
Whole-mounted specimen, collection details as
forholotype(WAMV4155). Remarks
Thelack ofprostate tissue,broad vasa deferentia
Etymology and the bipartite atria are all typical of the genus
Namedforthetypelocality. Acihnauedtraielusa.reThAe.onnlhyamotahearnAdinutdhrrieleusmtaoriponsesesspsechiaeisr
{Ainudrilus brendae Erseus, 1997,Ainudriluspiliferus
Description Erseus, 1997 and Ainudrilus taitamensis Erseus,
Both specimens with post-clitellar segments 1990). The marine species differ from both A.
mmiosusnmitnemgd ssopecliemnegntshatunIkXn0o.3w4n.mmWi(dhtolhotyopfe)slaindde tngwoopistmcahlulpastnrdaiAg.htnhpaenmiaalincthhaaettaAe. pbreerndbauenhdalseoannldy
0.46 (paratype).Prostomiumrounded.Pharynx has ventral chaetae with upper teeth much longer
in II and III, pharyngeal gland cells mostly on thanthelower,andtheothertwohavelongtubular
pharynx and oesophagus in IV-VI. Oesophagus atria. The long spermathecal ducts readily
frompharynxtoIX,stomachinX-XII.Coelomocytes distinguish the new species from A. nhama. The
sparse, ovoid (about 10 pm long) and granulated. chaetae of A. ngopitchup are also slightly shorter
ClitellumfromViXtoendofXII. thanthoseofA.nhama.
Anterior ventral chaetae 4-6 per bundle from II, The type locality, Ngopitchup Swamp, is a
85-100 pm, bifid with upper tooth thirmer and shallowperchedseasonalsedgeswampwithsandy
slightlyshorterthanupper,nodulusdistal.Anterior clay sediment. At the time of sampling the water
dorsal bundles each with 4-5 long (235-330 pm) wasmoderatelycoloured at280TCU,pHwas8.47
thinhairs and anequalnumberofcrotchetchaetae andsalinitywas0.58ppt.
of similar dimensions and form to ventral chaetae
but with fine pectinations on some. Penial chaetae
of XI 3-5 per bvmdle with simple bent ectal ends, DISCUSSION
aboutsamelengthassomaticventralchaetae,lying ApomorphiesunitingspeciesofAinudrilusarethe
inparalleltoeachotherandprotrudingthroughthe lack ofprostate (presumably lost independently in
body wall ventral to the male pores. Chaetae on Rhyacodrilussimplexandothergenera)andthenon-
spermathecalsegmentpresentbutnotmodified. apical entry of the vasa deferentia into the atria.
Genitalia paired. Genital pores in ventral chaetal The type species, A. oceanicus, has vasa deferentia
line. Spermathecalpores anterior on X, male pores lining cells that are clearly glandular, as in A.
medial on XL Male pores each a narrow slit in nhama, which suggested to Baker (1982) that this
depression lateral to penial chaetae. Testes and specieswasnotcloselyrelatedtoA.fultoni(thenin
ovaries antero-ventral in X and XI respectively. Rhyacodrilus) and Rhyacodrilus simplex, which he
Spermathecal ampullae ovoid, 210-260 pm long observed to have non-glandular vasa deferentia.
with loose sperm, connected to pores via long Rhyacodrilusfultoniwastransferred toAinudrilusby
6 A.M.Finder,S.A.Halse
Figure3 Ainudrilus ngopitchupsp. nov.: A, malegenitalia ofholotype; B,spermathecaofholotype;C,penialchaetae;
D,ventralchaeta;E,dorsalchaeta.Scalelines:A-D50pm;E-G,20pm.
Erseus(1990)onthebasisofitslackofprostateand west of Western Australia, where a large
non-apical atrial vas/union. Other species {A. proportion of freshwater wetlands are
lutulentus and A. gibsoni) with these features, but threatened or already affected by secondary
also with vasa deferentia that are not clearly salinisation and hydrological disturbance. The
glandular, have now also been included in the salinity tolerances of the new species are
genus (Erseus, 1990). In fact, A. fultoni has vasa unknown but both appear to be uncommon
deferentia with an amorphous appearance, due to compared toA. nhama, which has been found in
the thick lining tissue, and thus appears many wetlands and rivers throughout the south-
intermediateinformbetweenA.angustivasaandA. westand isknowntooccurinwaterup to22ppt.
nharna/A. oceanicus, whether glandular or not. Neither of the localities for the new species
BakersuggestedthatA. oceanicushasatriawiththin (Ngopitchup Swamp and Lake Logue) is
lining tissue because the glandular role normally threatened by salinity, as the former is perched
performed by the atrial cells was being performed above the surrounding landscape and the latter
by the vasa deferentia. However, A. nhama, which lies in a coastal sandplain with low salinity
also has clearly glandular vasa deferentia (Figure groundwater.However,thenewspecieshighlight
IF),hasatrialliningtissueaswelldevelopedasthat theconservationvalueofwetlands,suchas these,
of A. angustivasa which has a thin, non-glandular that are likely to maintain a diverse freshwater
vasa deferentia. This suggests that there is no faunainaregionbroadlyaffectedbysalinity.
correlation between the glandular development of
theatriaandvasadeferentia.
Both ofthenew species are known fromsingle ACKNOWLEDGEMENTS
freshwater localities in the agricultural south- The biological survey of the wheatbelt is part of
NewAustralianAimidrilus(Clitellata;Tubificidae) 7
the State Salinity Strategy. Field work was Erseus, C. (1997). The marine Tubificidae (Oligochaeta)
undertaken with Jane McRae and David Cale and of Darwin Harbour, Northern Territory, Australia,
samples were sorted by Jane McRae, Melitta with descriptions of fifteen new species. In Hanley,
Pennifold and Edyta Jasinska. We thank Ralph J.R., Caswell, G., Megirian, D. and Larson, H.K. The
BrinkhurstandChristerErseusforadviceaboutthe Marine Flora and Fauna ofDarwin Harbour, Northern
Territory,Australia.ProceedingsoftheSixthInternational
gutprotozoainA.angustivasa. MarineBiological Workshop99-132. Museumsand Art
GalleriesoftheNorthernTerritoryandtheAustralian
MarineSciencesAssociation,Darwin.
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