DISCOVERYOF PARASTENOCARIDIDAE(COPEPODA, HARPACTICOIDA)IN INDIA,WITH THE DESCRIPTION OF THREENEW SPECIES OF PARASTENOCARIS KESSLER,1913, FROM THE RIVER KRISHNAA TVIJAYAWADA 1/ BY Y.RANGA REDDY 2/ Departmentof Zoology,Nagarjuna University, Nagarjunanagar 522 510, India 1/Thispaper is dedicatedto the fond memory of myelder brother ,YenumulaV enkataRanga Reddy, who,a towerof strengthto myfamily, passed away while this work was in progress . ABSTRACT Inatwo-yearstudy of thefamily Parastenocarididae in the River Krishna at Vijayawada,South India, vespecies belonging to the genus Parastenocaris Kessler,1913, have been met with. Of these,three are new to science: P. gayatri n. sp., P. savita n. sp., and P. sandhya n.sp.The rsttwo ofthesebelong to the brevipes-group,the last one to the sioli-group.This paper gives an illustrated descriptionof thesenew taxa, and also brie y discussestheir af nities and ecology. The other two species,viz., P.curvispinus Enckell,1970, and Parastenocaris sp.,will be dealtwith elsewhere. This isthe rstreport on Parastenocarididae from India. Incidentally,it has also been found that parastenocaridids constitute a ratherfavoured item in thediet of the postlarvae of a commerciallyimportant gobioid sh, Glossogobiusgiuris (Hamilton, 1822).A briefnote of this ndinghas been made. RÉSUMÉ Aucours d’ uneé tudede deux ans sur la famille des Parastenocarididae, provenant du euve Krishnaà Vijayawada,Inde du Sud, cinq espè ces appartenant au genre Parastenocaris Kessler, 1913,ont é térencontré es. Parmi elles, trois sont nouvelles pour la science: P. gayatri n. sp., P. savita n. sp. et P. sandhya n.sp. Les deux premiè res appartiennent au groupe brevipes,latroisiè me au groupe sioli.Cetravail donne une description illustré e deces nouveaux taxons, ainsi qu’ une brè ve discussionde leurs af nité s etde leur é cologie.Les deux autres espè ces, P.curvispinus Enckell, 1970 et Parastenocaris sp.seront traité es par ailleurs. Ceci constitue la premiè re é tudesur les Parastenocarididaede l’Inde. Parailleurs, il aétémis en é videnceque les Parastenocarididae constituent un é lément appré cié dansl’ alimentation de la post-larve d’ unpoisson d’ importancecommerciale, Glossogobiusgiuris (Hamilton,1822). Une note courte relative à cettetrouvaille est fournie. 2/ e-mail:[email protected] m c KoninklijkeBrill NV ,Leiden,2001 Crustaceana 74(8):705-733 ° 706 Y.RANGA REDDY INTRODUCTION Parastenocaridids are small harpacticoids (length0.2-0.6 mm), inhabiting the space betweensediment particles ofunderground and subsoil waters. Aidedby their minute,vermiform body and short limbs, theycan crawl orswim freely in the capillary system ofthe interstices betweensand grains. Thefamily Parastenocarididae contains about200 species in vewell-recog- nizedgenera: Parastenocaris Kessler, 1913, Forcatocaris Jakobi,1969, Parafor - catocaris Jakobi,1972, Potamocaris Dussart, 1979,and Murunducaris Reid, 1994. Of these, Parastenocaris is the most speciose genusand has aworld-widedistribu- tion,whereas all othergenera, containing few species, are exclusively Neotropical (Reid,1994). The family is ‘primarily freshwater’and only about a dozenspecies inhabit marine andbrackish coastal subsoil water (Wells, 1986).In the wholeof Asia, onlyabout 20 species haveso far beenrecorded (see Dussart &Defaye, 1990),but, surprisingly, none from India, as conrmed by H.K.Schminke(pers. comm.). Inthe courseof a two-yearstudy of parastenocaridids ofthe River Krishna at Vijayawada,I havecome across vespecies, viz., Parastenocaris gayatri n. sp., Parastenocaris savita n. sp., Parastenocaris sandhya n. sp., Parastenocaris curvispinus Enckell,1970, and Parastenocaris sp.The three newspecies will bedescribed below; accounts of the othertwo species foundwill bepublished elsewhere. STUDY AREA TheRiver Krishnais oneof the major rivers ofIndia. Originating near Mahabaleswarat analtitude of1360 m in the Western Ghatmountains, only about60 km from the ArabianSea, the river owsacross almost the entire peninsularIndia from the west to the east overa distance ofapprox. 1300 km beforedischarging into the Bayof Bengal. It enters the sea bytwoprincipal mouths andhas built upa large,very fertile delta continuouswith that ofthe Godavari River to the northeast.In the deltaic region,numerous arti cial habitats suchas tanks,ponds, canals, etc., are fedby the river.Theriver derives its water from the monsoonrains andhas several tributaries, ofwhich the Bhima (north)and the Tungabhadra(south) are the largest ones.It has acatchment area ofabout 233,229 km2. At the headof the delta at Vijayawada(16 ±310N 80±E)there is animportant barrage,named Prakasam Barrage,which was constructedin 1955for regulating the owof water in asystem ofirrigation canals, andwhich is situated 80km from the river mouth.The river narrowsbetween two hills ofgneiss andthen spreads PARASTENOCARIDIDAE FROMINDIA 707 overalluvial plains. Thechannel there is 1.2km wide.During summer, the river, downstreamof the barrage,becomes a narrowstream, with depthsbarely reaching 1.5m. Thedepth, however, rises to as muchas 13m during oodingtimes. Thesampling site at Vijayawadais located nearthe southernend of a road- bridgeacross the river,called KanakaDurga V aradhi,about 2.5 km downstream ofPrakasam Barrage.Here the river bedhas adeposit of nesand and detritus particles, butwith little ornoclay,andis almost devoidof macrophyticvegetation. Purefreshwater conditionsprevail throughoutthe year.During the present study, anunprecedented oodwas witnessed in the monthof October, 1998, which causedserious damageto the benthiccommunities. Thetemperature regime was: air 30-38±C,water 28-35 ±C. METHODS Coresamples wereregularly collected oncea monthfor two consecutive years, i.e.,January 1998 to December1999, using plastic tubes of70cm lengthand 4 cm diameter. Onafewoccasions, a metal corerwas also employed.Moist, exposedas well as submergedparts ofthe riverbedwere sampled. Each time, sampling was doneat vesites in c.100 m 2,andat eachpoint about ten cores weretaken from the sediment surface to adepthof 10-30cm, pooled into a bucketand vigorously stirred with ltered habitat-water.Thesupernatant was ltered througha plankton net madeof bolting silk (mesh size 70 ¹m).The ltrate was then xedin 10% formalin andpreserved in a5%formalin solution.A fewsamples werealso xed in 20%alcohol and preserved in 70%alcohol. The water collected in dug-out pits nearthe water’s edgedid not yield anyparastenocaridids. Specimens were dissected in lactophenol,using a Getnerstereoscopic microscopeat 90 ; the parts £ weremounted under cover slips andsealed with Araldite. All measurements of preservedanimals weremade with acalibrated eyepiecemicrometer, anddrawings weremade with acamera lucida mountedon a Meoptacompound microscope at magnications of270 , 450 or 675 .Someparatypes were largely dissected £ £ £ beforedrawing the appendages;lateral views weregenerally drawn in situ. Body lengthwas measuredfrom the base ofthe rostrum to the endof the caudalrami. All typematerial has beendeposited in TheNatural History Museum,London. 708 Y.RANGA REDDY DESCRIPTIVE PART Parastenocarisgayatri n.sp. ( gs. 1-4) Parastenocaris sp.:Reddy, 1977: 337-341, gs.1-10. Materialexamined. — Holotype(adult ,0.47mm), allotype (adult ),paratypes (25 , 25 ),allundissected and preserved in 70% alcohol, deposited in TheNatural History Museum, London;registration numbers: holotype 2000.1280; allotype 2000.1281; paratypes 2000.1282-1331. Severaldissected and undissected paratypes are kept at the Department of Zoology, Nagarjuna University.T ypelocality. River Krishna at Vijayawada, South India, 16 ±310N 80±E;closeto the southernend of KanakaDurga V aradhi,a road-bridgeacross the river, from nesand,about 10 m fromthe water’ s edgeat a depthof 10to 30 cm.11 February1999; water temperature 29 ±C. Description anddrawings are basedon the studyof the c.75 specimens that constitute the type-series. Adultmale. —Total length(excluding caudal setae) ofholotype 0.47 mm, of paratypes0.42-0.52 mm, average 0.47 mm ( N 30).Body elongate, subcylin- D drical, vermiform,about 9 times as longas wide,slightly taperingposteriorly andwithout ornamentation. Cephalothorax, excluding rostral projection,as long as next2 somites combinedand with somewhatspherical integumental window. Urosomites 2-5with 1distinct rectangular,integumental windoweach; window onurosomite 2relatively short andtrapezoidal. Anal operculum smooth, posterior borderstraight, notreaching end of anal somite. Caudalrami parallel and40% shorter thananal somite; eachramus 3times as longas maximumwidth, subcylindrical, distal third narrow.Armature consisting of7setae: dorsal seta inserted almost oppositeto agroupof 3poorlydeveloped, unequallateral setae, located behindthe middle ofoutermargin, and 1 posterolat- eral and2 terminal setae, outerterminal strongest and4.3 times as longas caudal ramus; posterolateral seta longerthan, and inner terminal seta as longas, caudal ramus. Rostrum (g. 1a, b) prominent,subcylindrical, not de ned at base,and tipped with stubby,modied seta (spine?); nosensilla discernible. Antennule( g. 2a)haplocer, 7-segmented; segment 2longest,segments 3and4 enlarged;segment 4with dentiform,lateral process,carrying 1 short seta; segment 6with strong,lateral, spinousprocess; segments 1-7with 0,5, 2, 3, 0, 0, and 7setae; segment 4with longaesthetasc, constricted at midlengthand reaching beyondtip ofantennule,segment 7with short aesthetasc. Antenna( g. 2b). Coxa small, unarmed.Allobasis 3.6times as longas max- imum width,with 2groupsof