A new species of Schizotrema (Cumacea: Nannastacidae) from Moreton Bay, Queensland

9 Pages·1996·2.3 MB·English

A NEW SPECIES OFSCH1ZOTREMA (CUMACEA: NANNASTACIDAE) FROM
MORETON BAY, QUEENSLAND
DJ.TAFEANDJ.G. GREENWOOD
Tafe, D.J. & Greenwood, J.G. 1996:07:20: A new species of Schizotrema (Cumacea:
Nannastacidae)fromMoretonBay,Queensland.MemoirsoftheQueenslandMuseum39(2):
381-389. Brisbane. ISSN0079-8835.
Both sexes ofSchizotrema nudum sp. nov. aredescribed and figured. Itdiffers from other
species of the genus in lacking spines on the carapace and on the dorsal surface of the
abdomen.ThespeciesalsodiffersfromthecloselyrelatedS.leopardinumHale,intherelative
lengthsofexopod andendopodoftheuropod. Eleven speciesarenowknown in thisgenus.
Five(5.aculeatumHale,S. depressumCaiman,S. leopardinumHale,S. nudumsp. nov.and
S. resimum Hale) occur in Australian waters. Crustacea, Cumacea, Nannastacidae,
Australia, Schizotrema.
D.J. Tafe, Queensland Museum, P.O. Box 3300, South Brisbane, Queensland 4101,
Australia; J.G. Greenwood, Department ofZoology, University ofQueensland, St Lucia,
Queensland4072, Australia; received 20February 1996.
During a study ofcumaceans in Moreton Bay, FamilyNANNASTACIDAE
on the central east coast of Australia, a new Schizotrema Caiman, 1911
species of Schizotrema Caiman, 1911 was cap-
tured. The genus is one of 18 in the Nannas- SchizotremaCaiman, 1911:360; Stebbing, 1913:165.
tacidae. Schizotrema is differentiated from the
closelyrelatedSchizocumabythepseudorostrum DIAGNOSIS. Anterolateral angle of carapace
which forms widely spaced inhalent siphons. well developed; eyes divided into two separate
groups; pseudorostrum forming two widely
separated inhalent siphons; second to fifth
All specimens were taken using a sledge-
pereionites well developed, usually with plate-
mounted netof500 u,mmesh towedwithin 0.4m like lateral extensions; no pleopods and no free
ofthesubstratumatnight. Although700samples
telson.
were collected from 40 sites widely distributed Eleven species are now known in this genus.
withintheBayregiononlythreespecimensofthe Five (S. aculeatum Hale, S. depressum Caiman,
new species were taken, and all came from the 5. leopardinum Hale, S. nudum sp. nov. and S.
same location. One specimen of Schizotrema resimum Hale) occur in Australian waters and
aculeatum Hale, 1945, was also taken from the onlyS. aculeatum HaleandS. nudumsp. nov.are
same location. A male and female of the new known from Moreton Bay.
species weredissected, drawn anddescribed and
the other male used for S.E.M. study. Descrip- KEYTO SPECIES OFSCHIZOTREMA
tions were carried out with reference to Felgen- (Adapted from Hale 1949)
hauer (1992), Hale (1936, 1945, 1949), Jones
(1963) and Walling (1989). In descriptions of 1. Carapacebroadanddepressed. Peduncle of
uropod longerthan telsonic somite
appendages lateral refers to that margin of the depressumCaiman
appendage facing the lateral body surface and Carapacenotorlittledepressed. Peduncleof
medial refers to that margin directed toward the uropod much shorterthan telsonicsomite 2
. .
midlineofthebody. Longplumosenatatorysetae 2. Exopodofuropod atleast0.3 times aslongasen-
on thoracic appendages have been truncated in dopod(notincludingterminal spines) .... 3
some figures Exopod ofuropod at most0.25 times as long as
endopod 9
SYSTEMATICS 3. Last pedigerousand firstpleon somiteeach with
ClassCRUSTACEA onepairofoutstandingdorsal spines 4
SubclassMALACOSTRACA Such somites withclumpsofsmall spinesorno
SuperorderPERACARIDA spines 5
CUMACEA
Order 4. Spinesoncarapaceaculeate . . aculeatum Hale
382 MEMOIRS OFTHEQUEENSLAND MUSEUM
Spinesoncarapacespatulatc sakaiiGamo devoid ofspines. Two prominent ocular regions
. . .
5. Anterolateral angleofcarapace producedasa located anteriorly on dorsolateral margins, each
stoutcylindrical process 6 composed of 3 separate, hemispherical lenses
Anterolateral angleofcarapace not producedasa (Fig. 1C,D).
stoutcylindrical process 7 Pleural parts of second to fifth pedigerous
6.Telsonic somite widerthan longin dorsal view somites expanded (Fig. ID); pleural region of
bifronsCaiman second pedigerous somite almost as wide as
Telsonic somite longerthan wide indorsal view carapace, 3-5 gradually decreasing in width; ab-
atlanticum Bacescu& Muradian dominal somites not expanded laterally. Dorsal
7. Uropod with spine ofexopod notquitereaching region oftelsonic somiteflattened, approximate-
distal endofendopod (excludingterminal spine) ly as wide as long, and longerthan peduncles of
macrodactylusFage uropods (Fig. IE).
Uropodwith spineofexopod clearly reaching First antenna (Fig. 2A) with first segment of
beyond distal end ofendopod (excluding ter- peduncle longer than second and third segments
minal spine) 8 together, three large setae distolaterally, row of
8. Surfaceofcarapace with reticulate patternofin- short,simplesetaelaterally;secondsegmentwith
dentations; anterolateral cornerofcarapacean- two large setae distolaterally, tubercle with one
gularand without spine .... nudum sp. nov. plumose and two simple setae distomedially;
Surfaceofcarapace forthe most partsmooth;
anterolateral angleofcarapace producedasa third segmentsubequal in length tosecond, bear-
slenderspine sordidumCaiman ing 1 simple and 2 plumose setae distomedially,
andaccessory flagellumdistolaterally;accessory
9. Carapace withdorsal and lateral spines flagellum bearing 4-5 simple setae; main flagel-
resimum Hale
Carapace not spiny 10 lum 3-segmented, first and second segments
slenderandsubequal inlength,thirdsmaller,with
10. Carapace with mottled colourpattern,and with 2 long, annulated aesthetascs terminally and 2-3
anterolateral anglebroad, notatall down-bent fine setae subterminally.
leopardinum Hale
Carapace withoutmottledcolourpattern, and Secondantenna(Fig.2B)with3 shortproximal
withanterolateral angle producedand strongly segments; fourth segment longer than combined
down-bent btdensFage 1-3. Third and fourth segments with lateral mar-
gins setose. Flagellum elongate, multiarticulate.
Schizotrema nudum sp. nov. Mandible (Fig. 2C) molar process cylindrical
(Figs 1-4) with flattened masticating surface. Incisor with
3-4 teeth on inner edge; lacinia mobilis present
MATERIAL EXAMINED. HOLOTYPE on left mandible only; row of5-6 closely spaced
QMW20468,adult (S.L., 1.6mm),perm, slidemount, stiffsetae on inner margin ofmandible between
3H11o9,r°sCDe.wsTahatofeeer,Btae1ym7,.p6eP.re1ae9tl9u0r,Ies.2l-aPn3dA,mR2fA7sT°a3nY0dP',SE3,S41pQ5.p3M.°Wt2.22s'0aEl4,i6nis9tiyt,,e disFtiarlsttemeatxhiallnad (mFoilga.r2pDr)ocweistsh. 2 well developed
omvoiugn.t(;S.QL.M,W12.04m4m7)0,,saamdeuldtata(Sa.sLh.,olo1l.y7pem,mp)e,rmS,.Esl.iMd.e tneurmmbienarloefndhiatemsatcearsreytianeg; altartgheerirlodibsetawliethnds7-9a
mount, site34, otherwise samedata as holotype. setae, smaller 3-4 setae, with longest proximal,
slenderandpappose. Appendagewithbackward-
DESCRIPTION OFMALE. Standard length 1.6 lydirectedendopoditeposteriorly;palpunilobed,
mm, (measured from anterior end of pseudo- with 2 long, slender setae, each with fine setules
rostrum to posterior end of telsonic somite, ex- almost invisible at x400.
cluding spines and setae). Cuticle well calcified. First maxilliped (Fig. 2E) basis with a row of
Carapace with reticulate pattern of indentations; slender simple setae medially and a hamate seta
last three pedigerous and first three abdominal distomedially. Endopod 4-segmented; first seg-
somites with paired dorsal nodules but without ment short, with 3 setae distomedially; second
obvious spines (Fig. 1A, B). Carapace twice as segment rectangular with scattered setae; third
long as combined length ofexposed pedigerous segment shorterand narrower, with 3 strong dis-
somites, almost 1/3 total length of animal; talsetaeoneofwhichislongandserrulate, lateral
posterior margin ofcarapace slightly raised dor- margin of segment convex, with simple setae;
sally, producedposteriorlytocoverwholeoffirst fourth segment circular, with 2 fine subterminal
pedigerous somite and dorsum of second; setae.
anterolateral corner of carapace angular and Second maxilliped (Fig. 2F) basis subequal in
NEWCUMACEAN FROM MORETON BAY
383
FIG. 1.Schizotremanudum sp. nov.,adult male. A, lateral view. B,dorsolateral view.C,carapace, lateral view.
=D,1c0a0rna,pamce,anterolateral view.E,telsonicsomiteanduropods,dorsal view.SEMswithJEOL6400Scalebars
384 MEMOIRSOFTHEQUEENSLAND MUSEUM
01mm i r 0*5mm 1 r 0'1ram
AC D E F B GHI
FIG.2.Schizofremanudumsp.nov.,adultmale.A,firstantenna.B,secondantenna.C,rightmandibleandportion
ofleftmandible.D,firstmaxilla.E,firstmaxilliped.F,secondmaxilliped.G,thirdmaxilliped.H,firstpereiopod.
I, second pereiopod.
NEWCUMACEAN FROM MORETON BAY
385
length to merus, long, plumose setadistomedial- microspines laterally; segments 3-7 very
ly, setae on medial margin and ridge on lateral reduced, each bearing a pair of long, plumose
margin; ischium extremely short, without setae; setae.
merus geniculate, expanded centrolaterally, Third pereiopod (Fig. 3A) endopod segments
prominence bearing several long setae dis- slender, together at least 1.5 times as long as
tolaterally,singlelargeplumosesetaarisingfrom inflated basis. Endopodal carpus longer than
the central anteromedial surface; carpus slightly othersegments, almosttwicecombinedlengthof
shorter than merus, longer than propodus, with ischium and merus; dactylus arcuate, bearing 2
row ofplumose setae along medial margin, scat- setae. Exopod with 2 subequal proximal seg-
tered simple setae on lateral surface; propodus ments, first bearing 10 ridges with microspines
almostaswideaslong,with3stoutserrulatesetae laterally; segments 3-7 very reduced, each bear-
distally, with 3-4 slender setae subdistally; dac- ing a pairoflong, plumose setae.
tylus short with strong terminal seta. Fourth pereiopod (Fig. 3B) similarto third ex-
Third maxilliped (Fig. 2G) basis inflated, sub- cept terminal 5 segments of endopod together
equal in length to rest of limb; laterodistal lobe twice as long as inflated basis; exopod with 2
with 2 stout and 1 fine plumose setae, two subequal proximal segments, first naked and
plumose setae on distomedial region of basis; second bearing 7 pairs of minute ridges with
ischium of endopod reduced, with simple seta microspines; 4 reduced terminal segments each
distolaterally; merus broad witha stout, plumose bearing a pairoflong, plumose setae.
seta distolaterally, row ofshort setae on convex Fifth pereiopod (Fig. 3C), with slender basis
lateralmargin;carpussubequal inlengthtomerus and terminal segments, without exopod. Carpus
but narrower, long plumose seta laterally, scat- longer than other segments, 1.5 times length of
tered short setae distomedially; propodus longer propodus and twice combined length ofischium
than merus, carpus, and dactylus, simple seta and merus; dactylus arcuate as with third and
distolaterally, 3 plumose setae distally; dactylus fourth perciopods.
slender with 3 stout, curved terminal setae and 1 Tclsonic somite (Figs IE, 3D) as wide as long,
slender curved subterminal seta, 1 medial and 2 with 6 scattered setaeon each side ofthe dorsum
lateral simple setae. Exopod with basal segment but without spines. Dorsal profile as figured.
bearing 12 ridges with microspines, following Peduncle of uropod (Figs IE, 3D) with lateral
segment naked and elongate, 4 short distal seg- margin 0.6 times length of telsonic somite, 0.4
mentseach bearing 1 pairoflong plumose setae. times lengthofendopodexclusiveofitsterminal
First pereiopod (Fig. 2H) with inflated basis spine. Exopod at least as long as peduncle and
and 5 endopod segments. Endopod longer than 0.45 lengthofendopod,withitslongterminalseta
basis, terminal segments progressively longer reachingnearlytomidlengthofterminalendopod
from ischium to propodus, dactylus shorter than seta; 1 short distolateral terminal exopod seta.
propodusand subequal in length to terminal seta; Terminal seta of endopod about half as long as
setaeon all segments(exceptterminal seta) short ramus, with subterminal lateral setule; 2-3 short
and simple; propodus and dactylus with rows of distomedial endopod setae. Medial margin ofen-
fine setae on medial margins; terminal seta of dopod serrate, with microspines.
dactylus slightly curved with sctules on distal
medial margin, 2 smaller terminal setae and 2 DESCRIPTIONOFFEMALE.StandardLength:
subterminal setae. Exopodwith 2 basal segments 1.4 mm. Cuticle well calcified. Carapace and
ofsimilarlength,first broad and fringed laterally abdominal somites with reticulate pattern of in-
bearing 12 ridges with microspines; second dentations and paired dorsal nodules as in male.
naked and elongate; segments 3-7 reduced in First antenna (Fig. 3E) with first segment of
length,eachbearingapairoflong,plumosesetae. peduncle longer than combined length of seg-
Second pereiopod (Fig. 21) basis inflated, as ments2+3,3 longsetaedistomedially,rowoffine
longas restoflimb. Endopodal ischium reduced; setae medially; second segmentwith 2 longsetae
carpus subequal in length to dactylus, twice as distomedially, tubercle with 3 simple setae dis-
long as merus and propodus; terminal dactylar tolaterally; third segment subequal in length to
seta straight and longer than segment, 2 shorter second, with accessory flagellum bearing 3-4
terminal setae, 1 lateral and 2 medial setae; sur- setae; main flagellum 3-scgmented with 2 annu-
face of dactylus and propodus covered with latcd aesthctascs and 1 long seta mounted ter-
microspines. Exopod with 2 subequal proximal minally;combinedlength longerthan3segments
segments, first bearing 12 ridges with ofpeduncle.
386 MEMOIRS OFTHEQUEENSLANDMUSEUM
Mandible (Fig. 3F) molar process cylindrical row proximally, lateral margin convex, three
with flattened masticating surface. Distal end slenderplumosesetaedistomedially,rowofshort
with4teeth on inneredge; lacinia mobilison left setae on medial margin, 3-4 short setae on distal
mandibleonly;rowof5closelypackedspineson margin; dactylus slender, twice as long as wide,
inner margin of mandible between distal teeth with2largecurvedterminalsetaeand2-3smaller
and molarprocess. subterminal setae. Exopod with 2 proximal seg-
First maxilla (Fig. 4A) with 2 well-developed ments subequal in length; 2 reduced terminal
terminal endites bearing several hamate setae; segments each bearing a pair of long plumose
larger lobe with 8 distal setae and a subterminal setae.
seta laterally; smaller lobe with 4 distal setae, First pereiopod (Fig. 4F) basis inflated; 5
longest one proximal, slender and plumose. slender endopod segments; ischium subequal in
Posteriorly appendage with a backwardly length to merus with 1 medial and 2 lateral setae;
directedendopodite;unilobedpalpwith2slender merus with 3 setae on convex lateral margin and
distal setae. 2on medial margin;carpustwicelengthofmerus
Second maxilla (Fig. 4B) with 3 lobes, all with with 2 lateral and 3 medial setae; propodus sube-
setae along distal margins; largest, most distal qual in length to carpus and at least 1.5 times as
lobe with 13-14 setae, longest one plumose; long as dactylus, 4 setae laterally and 2 dis-
smaller innerlobe with 1 1-12 simple setae, outer tomedially, row of fine setae along medial mar-
lobe with 6-7 delicate, inwardly directed setae. gin; dactylus slender, with curved terminal seta
First maxilliped (Fig. 4C) basis with row of as long as dactylus, 2 shorter slender terminal
simple setae laterally and stout setae medially; setae and 2 subterminal setae. Exopod with 2
endopod 4-scgmented, first segment short, with proximal segmentssubequal in length; 3 reduced
onelongplumosesetaand 2 stoutsetaemedially; terminal segments each bearing a pair of long
second segment rectangular, with hamate setae plumose setae.
medially and slender setae laterally; third seg- Second pereiopod (Fig. 4G) basis inflated,
ment narrow, with 3 strong distal setae, one long longer than segments 1-4 of endopod, scattered
and plumose; lateral margin of third segment simple setae only; ischium reduced and naked;
convex, with simple setae; fourth segment cir- merus longer than ischium and propodus but
cular, with 2 fine subterminal setae. shorter than carpus and dactylus, 3 lateral and 2
Second maxilliped (Fig. 4D) basis longer than medial setae; carpus subequal in length to dac-
merus and ischium combined, long plumose seta tylus, twice as long as propodus, 1 long and 2
distomedially; row of short setae medially and short distolateral setae, row offine lateral setae;
shortsimplesetadistolaterally;ischiumrudimen- propodus short with row of fine lateral setae;
tary and naked; merus geniculate, lateral margin dactylus twice as long as propodus with major
convex, with several fine setae, single large terminal seta straight and longerthan segment, 2
plumose seta arising from the central shorter terminal setae, surface of dactylus
anteromedial surface; carpus longer than merus covered with microspines. Exopod with 2
and propodus, with 4 large plumose setae and proximal segmentssubequal in length, 2 reduced
numerous simple setae medially, row of simple terminal segments each bearing a pair of long,
setae midlalerally; propodus almost as wide as plumose setae.
long, 3 strong, serrulate and 5-6 slender setae Pereiopods 3-5 (Fig. 4H-J) with slender basis
distally, directed medially, medial margin with and 5 slender endopod segments; dactylus ar-
roundedsetuled lobe,3 midlateral setae;dactylus cuate with seta on inner margin; carpus longer
slender, shorterthan propodus,directed medially than propodus and nearly twice as long as merus
with strong terminal spine. Exopod with 5 long, and ischium together; no exopod.
plumose setae. Telsonic somite(Fig.4K)aswideas long, with
Third maxilliped (Fig.4E)basisas long as next 9-10short setaeon dorsal surface, with 2 slender
3 segments combined, tubercle with 2 long setaedistomedially.
plumosesetaedistolaterally,2 plumosesetaedis- Peduncleofuropod(Fig.4K)withoutermargin
tomedially; ischium short with plumose seta dis- more than halfas long as telsonic somite (0.65X)
tomedially; merus longer than ischium but and half as long as endopod exclusive of its
shorter than carpus, plumose seta distolaterally terminal seta, 1 slenderdistomedial seta; exopod
and small simple seta distomedially; carpus shorter than peduncle and about 1/3 as long as
shorterthan propodus, plumose seta distolateral- endopod, with its stout terminal seta reaching
ly, 3-4 small setae distomedially; propodus nar- beyond the distal end of endopod segment, 2
NEW CUMACEAN FROM MORETON BAY 387
FIG.3.Schizotremanudumsp. nov. A-D,adultmale. A,thirdpcreiopod. B, fourthpereiopod.C,fifthpereiopod.
D, telsonic somiteand uropods. E,F, ovigerous female. E, first antenna. F, rightand left mandibles.
388 MEMOIRS OFTHEQUEENSLAND MUSEUM
BCDEFGHI
A J K
FIG. 4. Schizotremanudum sp. nov., ovigerous female. A, first maxilla. B, second maxilla. C, first maxilliped.
DTsecondmaxilliped. E, third maxilliped. F, firstpereiopod.G,secondperciopod. H, thirdpereiopod. I, fourth
pereiopod. J, fifth pereiopod. K, telsonic somiteand uropods.
NEWCUMACEAN FROM MORETON BAY 389
small subterminal setae; endopod with 2 stout ETYMOLOGY. Latinnudumnaked; referringto
terminal setae, the outer one 2/3 as long as the the lack ofconspicuous body spines and striking
ramus and 3 times as long as the inner one, colourpatterns.
bearing a long subterminal setule laterally and
rowofmicrospinesmedially, 1 fineterminal seta, ACKNOWLEDGEMENTS
2 dorsolateral and 2 dorsomedial setae, and 3
distomedial ridges bearing microspines.
We gratefully acknowledge B. Koh and R.
DISCUSSION. Schizotrema nudum sp. nov. is aCrnuddPg.inMgattohnerfofrorascsoinssttarnuccetiivnetchoemfmieelnd,tsJ.aSnhdorP.t
distinguished within the genus by its lack of Davie,L. WatlingandG. Pooreforreviewingthe
spines on the general surface of carapace and
manuscript. Sampling and analytical equipment
abdomen,andbythepaired nodulesonthedorsal
was supplied by the Zoology Department,
surfaces ofmost free somites ofthe pereion and
University of Queensland, and funding of
pleon. The uropods also distinguish S. nudum fieldwork and electron microscopy was supplied
nfruodmumotihdedrisAtuisntgruiaslhieadn fsrpoemciSe.s.acSuclheiaztoutmr,emSa. by Reckitt & Colman Pty Ltd.
bifrons and S. sakai which have on spination
LITERATURECITED
alone. The latterthreespecieshavecharacteristic
spines on the carapace and free somites.
Specimens of S. aculeatum were also taken at CALMAN, W. T. 1911. On new or rare Crustacea of
night in Horseshoe Bay. the Order Cumacea from the collection of the
Copenhagen Museum. Part2. TheFamiliesNan-
Like S. nudum, S. leopardinum is completely nastacidae and Diastylidae. Transactions of the
devoid of stout spines on the cuticle. However, Zoological SocietyofLondon 18: 341-398.
therelativeproportionsofthe rami ofthe uropod FELGENHAUER, B. E. 1992. External anatomy and
enable thetwospecies tobeeasily distinguished. integumentary structures. Pp. 7-43. In Harrison,
The female of S. leopardinum has not been F.W. & Humes, A.G. (eds). Microscopic
describedbutthemaleuropodhasanexopodonly Anatomy of Invertebrates. Vol. 10: Decapoda
0.25x the length of the endopod, compared to Crustacea. (Wiley-Liss: New York).
0.45x inS. nudum. Alsothe differences in colour HALE, H.M. 1936. Cumacea from a South Australian
and surface texture make the two species readily reef. Recordsofthe South Australian Museum5:
404-438.
distinguishable. The bold pigment patches ofS.
leopardinum persist even in spirit preserved 1945. Australian Cumacea. No.9. The family Nan-
nastacidae. Records of the South Australian
material (Hale, 1949). Museum 8: 145-218.
nuSdcuhmizobtyreimtas rsemaslilmeurmsiiszed,isctionngsupiischueodusfrobmod5y. 194n9a.stAaucsitdraael.ianRCeucomradcseao.fNot.he16S.oTuhtehfaAmuisltyraNlaina-n
spination and very small exopod on the uropod. Museum9: 225-246.
The dorsum of its carapace exhibits rather large JONES,N.S. 1963.Themarine faunaofNewZealand:
spines, many of which bear a brush of minute crustaceans ofthe orderCumacea. New Zealand
setae distally. Oceanographic Institute Memoir23: 1-82.
Schizotrema depressum exhibits a broad, STEBBING, T.R.R. 1913. Cumacea (Sympoda). Das
&
depressedcarapacewhichdistinguishesitfromS. Tierreich, 39 (R. Friedlander Son: Berlin).
nudumandall othermembersofthegenus(Hale, WATL2I1N0pG., L. 1989. A classification system forcrus-
1949).
tacean setae based on the homology concept. Pp.
The new species was compared with type &
15-26. In Felgenhauer, B.E., Watling, L.
material of5. aculeatumandS. leopardinum, and Thistle,A.B.(eds).CrustaceanIssues6:Function-
non-type material of S. depressum, all in the al morphology offeeding and grooming in Crus-
South Australian Museum. tacea. (A.A.Balkema: Rotterdam).