CO\nRBJTONS TO TN STUDY OF THE REPRODUCTON, PROLFCTY AND DEVELOPMENT OF THE SPECTES LEUCAS. PU S DELNEATUS (HAECKEL) (PSCES, CYPRNDAE) GH. BREZEANU n this paper, the author describes the reproduction, the prolificity and the development of Leucaspius delineatus. Though Leucaspius ilelineatus is a very common species, itsbiology is but little known. Speciality literature particularly records certain dala in connection with faunistic and systematic dharacterisiics (BERG,1949; CARAu$u, 1952; nanannscu, i964), PAVLOV. P. and SMrRNov A. r. (1965, studied Leucaspius population from the middle Dnlepe_r basin, making a detailed analysis of mcriitic characteristics accompanigd by data concer' ning reproduction and nutrition. Previously, BALON (1956) dealt with the appearison and development of scales. Though considered as an economically valueless species? its occurencein numeroius akeso marsheso ponds and rivers is important both in regard of composition of the fish fauna in the respective basin, as well as in regard of tie position of this species in the trophic chain. From this point of ^view it maybe considered haimful as competing in the food ofthg youngof cer' tain ipecies of economic valueo or usefuf as forage fish food. Therefore, at least fiom this point of view, the study of its biology is of im,portante. A species iittle exigent of environm,ental conditions, it feeds particulgly on zooplanktonic organiims (Rotatoria, Copepoda, Cladoce_ra) but also on larvae of simuliidae, C6leoptera, Tendipedidae and bentonic Culicidae or on perimacrophytic ones (PAVLOV and SMRNOY' 1965). Ourinvestigations on the reproduction and development were carried out in the carp reaiing ponds fromthe Dridu commune (a) in 1964L967' and' in 196? in the SutG[iol lake in the zone where the latter extends into a stagnant water channel. The ponds are characterized by shallow water reduced transparency, silty substratum, stony development of aquatic, macrophytic vegetat_ion, profure phytoplankton and zooplinkton. The are supplied with water! numning Srom fne alomila river. Both river and ponds Contain large quantity of solute
510 GHEORGE BREZEANU salts (1144rl9p.qlt)j1 whigh_1h!o1_ne ie the dominant element (3201060 mg/l chlorine)(busntta and BREZEANU, l96s). rn summer, a tendency appears in ponds ofincreaeing salts concentration in noticeable due to a atroni mascu0 fenele Lt J,4 46 J.6 4,0 1.2 4.4 +,6 18,t0 62,t,+ [,6,t.E 6.0 cm Fig. 1. Percent variation of the Leucaspius females and males length in ponds. water evapor3tion. The poseibility of regulating and directing the water supply regime^imp_edes however the occurrence of phenomena which may becomdioxious for the life of fishes. The SiutGhiol lake offers, in the zone of our observationso were caried out somewiat particular conditions. Thus, the water transparency ie highn depth reaches up to 23 metres, while the bottom is sandysilty. On tf,is,
REPRoDucToN,PRO,FOTYANDDEYELoPilENToF'E]0ASPaSDE'NEATaS 511 an abundant macrophytic vegetation develops. salts concentration is much smallerchlorine *it;.h not exceeding 47 mgll. po"ar the lake" areo hiwevero particularll biotopes ""tl ^flograble for the'deielopment of the studied n august 1961, for inatance' up species. i" fzo kgiha ivere Liicospius in ponds,. ihit" io SiutGhiol, though oo *"otii.tive data are'available] "._..ghi nomeious shools were obeerved. 5h;il;"otpiit population from the ponds calme}ere^from the alomila rivero with the'watelr pumped frog' the river. The Siu'Ghi"l p.p"l,.],t^t1^l: soecihc to the lakes comil"*of the Black Sea littoral. From the morphological Jnalysis of the materiai collected in April 19641967, the. following results *""J.la"f"J; th" population from the ponde is made up of specimens whose leneth (L) is comprised^ between 3,45,5 cm in males, and betweem 4'3507 cm il?;;;#: ; 4. l, the presence of fogt felghts classes was recordeil. The dominant class ii comptis"ld between 4,64,8*cm, females being generally larser than maleso a chiracter which likewige results from weight relationshrp (1,50 gr average weight in maleso l,b0 gr. i1 fery3l^es)' ''Ti" ii^itr'"rt.uyished by u6are sotewhat diffegeng from those set down by other authors (BERC, rptg; CAnAU9U, 1952, BANARESCU, 1961) wbich ;;r ;il.; popjitio". of diff"t"ot o, biotopes are not similar. The four lengths to as many "oo"..g" gtoopi, recorded by "l"si".'correspond h"j.li!91vr* gnhc (1949). n thi'e respect PAVLbV"ao SnlfnnOv (1965) _show that the span of'life is of 4 y"q.l and that sexrla! maturity is reached at o 4e y_ear. Ti".verag" proporri;n between males and females ii of 39o/o respectively 61o/o. REPRODUCTON, PROLFCTY, DEYELOPMENT During the three years of observationo it was recorded tbat reproduction takes place in April\iay the water temperature playing a determinant role in setfing it off.'n 19641965, for inetanceo repioductio" JlT_t"g in Ponds on April"23, in 1967 on April 222m while in the SutGhiol lake in the midtill of Mayo when the timperature reached 819'C. n this respect it is intereiting to note that in the northern_regigl1 Pf the USSR., repioduction begins in June and last!till4fggt! (!,PRG, L964), while in the miaile Dnieperlasin, PAVLOV and S]{FNOY (1965) show that in May gonads are in th;4th development stage? which confirms the ecological variability of thie species. Lewcaspius is a foecies with portioned asynchronou8_reproducture (prne' GHN, cit.'from 7). ir in the caie of other cyprinids with similar reproduction (PAPADOPOL, 1958, f963) in during in thbsparonirig pe,riodo in_ the lyary: eggs in different development stagedare to befound. Analy_sing_.their dlmen; ei;oal variation, PAVLoV and Sil{RNOV (f965) determined 5 "generations" of eggs, among which the first three were dominant. :fir" n".r" iecorded a variation of much.greater amplitude: 31 dimensional groups of eggs (Fig. 2). On the basis of structural characters (TROSO.V' 1947) irui"l.y"f," irlit""a under the microscope on the fixed material (4o/o for' mol) these were included in the following development stages: '3rcl stage (fig. 3, il) Ovocytes of a more o1 less spherical shape, very often polyh"edric: or ovoid. fransparent, they Present a central oval nucleus
512 GHEORGHE BREZEANU in which small vacuoles are observed. within the cytoprasmatic mass a variable member of vitellus r?":j::*uy be discerned. ThJ d;_;; ;i ovoc)rtes varies between 90290 u. the most numerous being those with a diameter of 2s0_270 6,r (Fig. 2). The 4th unaccomplished slage (Fig. 3. v). ovocytes with rikewise undefinedo spherical, ovoid,polyhedrii rh'"pe,less transparent, with an eccentrically 271 241 0vocie stadrut^zf 0rocte stadrul Enedesdvthsrt 0 v o c te st alr u! E desa'ybst t 2^ re1 RNN BTF R RR Ss \ NN RR N\ RR F s s.* R ks N FFR* RRRS F ss EN R $s Fig' 2. Dimensional variation of ovocytes in divers development stages. FS, R s ss situated nucleus. The vitellus formatio: process is advanced, the cytoplasmatic mass comprjsing a great number of vitellinle vacuolee. Their diameter is &mprised between 300800 u the highest percentage being that or tnor","ith a 450500 u ' diameter. The atl accompliahed. stage (Fig. 3. v). ovules ready to be evacuated. The quantrtyot vrtellus is compriaed within the cytoplasmaiic spece which became opaque. The nucleus ca_n no longer be observei. Th" of the ovule is whitishyellow, and its shape sphelricar, with a diametei "Lfo'"i between "opiir"a 900 080 u. Those r with a io+o'rogo u diameter.""doil.ot..the stagedevelopment of eggso.their structural and size deveropment are an important infi""1or in deteriiining the degree of development of sonads gl.,h:'lp,'.d."t.j:l process (TRUSo_v;t947). oin tnis t".i, itrilr (;i.";";;: ding to 9) established a proportionalitlindex by whichthe degree of'r"p"od,r" lt^t:. p^ytrlionality may be inferred. The_ higher this index, il the greit", "r" both the duration of reproduction and the degree of proportiooaliiy. fn.carp a'..d, bream,for instance, the indexis of lio/o,,'rie"pectiveiy 22.60/0, occupying_ in this respect ln intermediate place.s ajiiost'other ;ypri,,i,fi. f1,lary9gius, Scardinius, Alburnus, Rhodeus it e*c"ej ioy" 1faf.l,bbpOi, 1958, 1963). rn Lewaspins the index varies between 67,74_.g9,07 (Table l) which means a long, reproduction period and a large number of poriions. Judging by the
0,5 mm Fig. 3. Ovocytes and eggs in divers development stages, ovocytes in stage 3 of development; Y ovocytes in stage 4 imperfected; V bvocytes in stage 4 perfected; V egg ovocytes in morule stage; V 48 hours embryo; Y 5 days embryo.
6L4 GHEORGHE BR,EZEANU Tdh w. 7 Proportion of egga in different development gtadea and proportiotrauy index in o/o Nr. Total nr. of eggc Ovocytes 3rd etade o/ /o Ovocyteg 4rd etade o/ /o Ovocytes etade fv % nder of n'*f;*tt 3 4 5 6 n 9 l0 1.700 r.040 2.300 1.400 1.590 t.2t2 604 740 914 t.074 55,?5 65,71 60,99 46,30 44,54 58'90 39,82 15,75 11,49 3?,39 27,50 34,28 26,08 33,42 3?,33 34,29 33,33 29,52 32,27 30,36 16,75 13,04 20,28 18,13 6,81 26,85 24,73 26,24 32,25 tt,ru 86,95 79,85 83,86 99,0? 72,84 75,00 73,74 67,71 diensional variation of egge (fig. 2) which refecte the heterogenous development of eggs in the reproduction period, it would result ttiat Lerrcespins spawns approxinat"ly 20 portions.r fn fact, ae we ehowed before, apawning lasts more Fig. 4. Reproduction areal of the Leucaspiws speciee in Sutghiol lake. ) n a firturc article we shall present some critical observations on the notion of portion.
REpRoDucToN, PRO/FCTy AND DEVET OPXDNT OF 'DACASPAS DE'NEATAS than one month, in which period the female in laye many tir"es quite few eggs. To thie effect, eertain ooologicd observations are interesting. During reproduction period, the ehoale of apawning epecimene occnr esp ' cially in tf,e glailow zoneie where water is quickly warmed up an the young Fig. 5. The development of genital pepillae in' annotpiut fomales during the reproduction period. Fig. 6. Occurcnce of. in l*ucatpius maleg during the reproduction period.
516 GHEORGHD BREZEANU vegetation is already developed (fig. a). The prjference^for certain plant speciei is noticedo namely: Scirpus, Phragmitcs, Typha, Carex' /ris. The zones with Potamogeton and'ceratoihylum ore avoided. 1 this period n'lptill tuber cles appear in in rales, while fbmales fimales develop genital genital_ papillae (fig. 5,!). M?ing Matrng Mliiro takes place nlace wh.en when water is rs calm; calm: small shoals snoa$ of or males and females swim amid"st stemi of aquatic plants on which then spawn. During o1e. day the same shoal lays sev6ral poitions of 2030 eggs eich. These are laid at depths of 1020 cm. Within the deptlr limits of water is transparent, the quantity of oxygen is above saturation limit, and_ temperature reaches sooner fgtg'c. 1819"C. At g;;ter, greatero depths where temperature is rs by23'lower, byjrt'_lower, and oxygen below saturation linrrit, f,eucaspius no longer spawns. Reproduction is ge^nerally interrrrnted interrupted if water temperature temoeratirre drops below Selow 17l 1718"C. t amy amv therefore be said that from these points of view is thermophilouso phytophilous said thit from these points of view leucaspius is tht and oxyphilous. Temierature oscillations have a negative effect on laid eggs. lhusa in April wh6nnig hts are usually colder alod wate_r temperature drops^by 45" at th'e surface, tf,e eggs which are in this horizon die. Suipe.ding at different depths stems of Typha iid Sdrprr on which spawns were io be foundo it was found that incubltion develops in optimum conditions the depth of 1520 cm where water temperature is constant at 1920'C. at Referring to'prolificity and its appreciation criteria the following ar,e resulting: being a ipecies of a sm.ll sized, _Leucaspius has an absolutely.^llll prolificiiy. The"totai suantity of eggs in the ovaiy varies between 6042300 lpec. (t.il" 2) and is'directiy related to the length and weight o{ th9 bo_ily. C'omplrtine thl absolute prolificity bv WLSON J formula modified by PA' PAdOPOL llg62\ valuei appearvery close to those obtainde b_y direct deter' minations, constituting a reiiible verifrcation of the data obtained. Date on the prolificity of Leucaspius Tabb nr. 2 Nr. Length (L) cm Body weight mg Gonad weight mg Gooo.ro Absolute rnn matic prolifi city lraport %l city lcoeficient'l Prolificity relat. Obs., 3 4 ) 6 1 B 9 l0 5,7 502 5,9 5,4 5,6 6,5 502 6,6 5,6 6 2, 420 045 500 r50 440 820 640 000 550 500 200 160 r50 435 400 618 420 300 350 240 14,10 15,30 10,00 37,00 21,00 22,00 26,00 17,00 22,00 16,00 2r2 604 740 944 014 700 040 300 400 590 251 418?50 944 1 050 723 066 2 613 364 600 853 Jt r 493 820 745 602 634 150 903 060 colect. 14.V. 1965 colect. 4v. 67 ' Computed by Wilson's formula, moilifiecl by Papadopol'
REPn,oDUcToN, PRoLF0TY.AND DEVELOPUENT of 'Ea 1ASPU S DD'N EATa S 6t7 Relative prolificity places Lewcaspius species with fecundity; aylong.high the number of p"r g" of body weight being thrice, as.big ae i" carp or "gg. ;;;; 17, C1,1finJ sade timeo.s. c6nrequenie of the fact that it breede "i t[" id",if one year, and the reproductive cycle nas a!is! intensivity in ;h"4;;;. ;t. dstimated life (roi Lernospius'has also a high specific prolificitv.'these conditione, to which, according to u6' a high Percentageot sur ;i;i"dh;rpi.*" in tle incubation and laivae periode,ls tb be added, gene' rally ensure ilense and ubiquitorrs populations. 'Th; embryonic and larial deveiof"'ent lasts about 20 days' within this time egg fivision, embryo formation ind the,accomplishq:"t larval stage oi take pfile. n the first stage of embroynic development, 4050' atter lay_ingo ^at p' rt is A; 'g; ilefied increaiing tlreir ii""t"" frtm 1000 p!9 1700 *11 foo*or part of the membrane surrounding the,egg(follicula_r epithelium and radiary zone (11, 12) moves away frgni vitellus, formjng the previ' ;ilil rpace nula with a fluid resulted'from the melting of shiny drops (sreopoe, L967). ' Also at the same time egg esgmentation (formation_of blastomeres and gas' ttd.iflg. 3. V) likewise U"?fr,"rg that at about 24 hours after fecundation the cuiliie of th'e embryo *"ly l" discerned (fig. 3. V). ts development, lasts 6? days. n the 3 days emlryo_ t!'e slightly pigmented eye6? the mouth' heart' blood ciiculation, mot6chard and alimentary iaial may bl discemed_. The body i"i".orp"r"nt, unpigmented, surrounding 3/a of the vitelline eaco whose shape is spherlcal (Fig. 3. VD. 'Hatching 6""o", on the 6u 7th day from fecundationo if water temperature at 222"C. As in the caie of other species (6), the duration if incubation ""irrc can be ehortened or lengthenedo depending ol water tempera' 1.l days. n ture. Thus, below 20o the duration of"incubation increuses!v even after ihis time hatching did not take place the embry_o dies. n such ceses death is induced by the i',cipacity of the lmbryo to break egg membrane the and thus to free itself from it. Ti this effect it is recorded that at the tempe' rature of 1718" the movemente of the embryo within the egg are slower. The rupture of the membrane is determined by the powerful movements of the embry6. Even younger embryos 45 days oo_6. n.y brak this membrane when eggs ire kept at higher ternperatures (2_526'). n connectioo iith this'facto glbunfd[a and BUZNCOV (cit. by lt) show that before hatching the embryo secretes the hatchjng ferment whjch diminishes the resistance ot the snttonodiog membrane. t therefore seems that in conditions of a low water temperature th"is ferment is no longer secreted and the resistance of the membrane is not modified. At hatching (fig.?. ), a moment which marks the end of theemhryonic period and the f,"gfioiog of the larval one (6), the la_rvae arc.44,5 mm longo Leing characterize"d by irongly pigmented "y"so. spherical rritelline sac and a transparent body. On the dorsal part, from head to tail, there are two rows of bla'ck chromaiophores under the form of small stars. On the hinder part of the body, on the dorsal and ventral part the swimmi.q_nembrana is observed, better developed in the caudal,oo". Th" swimming 5!,aaer has begun to e formedo whicl permits the larvae to swim easilyo and float at various depths, as against othei species (carp, crucian, bream) whose larva connat swin at this
GHEOBOHE BREZEANU stage (6). They live solidarily in the carm zonee hear the shores where water gets warm guicker. At the age of 3 days, the vitelline sac is reduced to half and the lanrae pass to aixed nutrition, uei'rg both vitelline reserves, ae well ae nutritional elements from water, partioulaily the phpoplankton. ftis is abgorled simultaneously. with the water which penetiatee inlo the ponth, \ysghing tl" rr.rchiae, being the elirninated thro:ugh opercula. At thie stale the ti""." hr"1 1 Fig.?.Larve in diverg development atages. 24 hours larvae aftcr eclosian; l0 days larvae after eclosian. $9*iq9 a mixed.respiration: the exchange of gases ie made at the level of bran 9$ae_(in formation) ald epidermis, especially in the zone of the viteiline gac (6). The body ie 66,5 mm long and of a supple spindle rike shape. Body pigmentation is aecentuated, and a characterigti" featio" ie that in the doreil and anal fins.rays b"gl" to be formed. rt swi'rrs with greater facility though without forming shoals. the,age.ag of l0 days (fig.?l.), vitelline reserves are completely resorbed. Their length varies between lll2 mm, and the chromatoplorous pigments are spread over theentire surface of the body. The transparent fine h'av"e their rays formedbut etill retain their gwimming membrane. TLe body is still trangparent which Plrmits the observation o internal organs. Characteristic is the canalwh_oee llieot""y lengtl is.3/4 of rle body let'grh, being curved opposite tbe swi'nming bladder and having the larger i..m"i in the To"" purt. ^rj"tt" the.previoue.etage^, they now feedonly 91 aqu_atig,nicroorganiems'which they actively "gather'o from the water. Alongside w:ith the transitiin to active nouriement, the larvae develop much quicker. Thus,.at the age of 1516 days, tleir length is doubled reaching 1316 r,. The body isno longer transpareni and ie of i whitishyellow colorir on the doreal side and white on the ventral side. This is the iransition period to the "young" stage, eo that external morphology changes. rn this respicto the disap,
BBPRODUCTON, PRO,FCTY AND DEYE'OPUENT OF LEA C ASPA S DE'N EATA S, 619 peafance of the swimming Tembrane and the formation of all the fine are near the shoree in zonee with ""JiaJ in.j g"o"p in eilall shoals t*i;i"; *T;;il; macrophytic vegetaibn ric! in plankton' "rf fefla1fr,ihe featur_ee specificto the larval stage dieap' p"*,iil"i"*,ifuaif"di "g" aii i"i"s l720"'l, and the body etill of a narrow Fig. 8. 20 ilaye iniliviiluale of Leucatpius in conparison with the ailulte' epindle like shape resembling to a cwrtain extent to that of the adult. At thie r[[" ga.r,dn "r trq56) ;;t;tk"' sealee begin to be formed ond the lateral id"t;j"dl;;;",i.culv swim ruth great r?pidityanq form shoals of 5940 ;""t;. &'Z0_.25dale, the doby i"s cover6d, with whitieh ecales forming. a ;f;;h:ad;"t coloured Jfi;;;hra6"r"l and lateral parts.the shape of the itr;fiilil;;il;;i".1.. "r;;l Tlii is already the sate of "young". td"t stightb comp'essed laterallv' CONCLUSONS From a 3 years stutly (1964 \961), it was establiehed' that Leucasph'n lr""a.oa tlerjlop tr;;fialf" "*logjc'j conditions. Reproductionbegins in AprilMay, wheo w"t* t"f"i.t""" o? tgtgo and lasts ii1 the end of June' fr""'*#; il;ll p *ior"t"'..5rmchrooous, hav in g a portionality h$"* :i_ 9i:11 S9.02.";the ieproduction period, in ovaryr eggs in various developme*
520 GHEOR,GHE BREZEANU stages are to be.found, which differ both in size and in structure. They sparun on vegetation, at depths of 1020 cmo in optimum temperature, oxygen and light conditions. Embryonic development (egg division, embryo formation and development) lasts 67 days. Larval development lasts about 15 days. At hatching, larvae arc 44,5 mm long, and after 1819 days 1720 mm long. The vitelline sac is resorbed at 6_7 days, when they pass over to an exclusivily planktonic nourishment. The larval development stage comes to an end at the age of 20 days, simultaneously with the appearance of seales. CONTRBUT LA STUDUL REPRODUCER, PROLFCTAT $ DESVOLTAR SPECE LEUCASPUS DELNEA"US (HAECKEL) (PSCES, CYPRNDAE) REZUMAT Studiinduse timp de 3 ani (L9641967), sa constatat ci Leucaspius se reproduce gi dezvolti in condilii ecologice variabile. Reproducerea incsps in luna apriliemai, cind temperatura apei are l$o19o gi dureazi pini la sfirsitul lunii iunie. Tipul de ponti este porlionat asincron, avind indicele de porlionalitate de 67,7489,07. n perioada reproducerii in ovar se glsesc icre in diverse stadii de dezvoltare care se deosebesc atit ca mirime cit gi ca structuri. Depune icrele pe vegetalie la adincimi de 1020 cm in condi$i optime de temperature, oxigen gi lumind. Dezvoltarea embrionari (diviziunea oului, formarea si dezvoltarea embrionului) dureazi 67 zile. Dezvoltarea larvari dureazi cca 15 zile. La eclozare larvele au lungimea de 44,5 mm iar dupn lb19 zile de L720 mm. Sacul vitelin se resoarbe la 67 zile, cind larvele trec la o hrani exclusiv planctonici. Stadiul larvar de dezvoltare ia sfirqit la virsta de 20 zile odati cu aparilia solzilor. BBL.OGRAPHY l. BALON, E. 1956. Zakladanie lusak u Proei Rutilus rutilus (L.) j ovsiankii (Leucaspius delineans (Haeck.) Polskie Archia Hidror. 3, 16. 2. BANARESCU, P. 1964 Fauna R.P.R. Pisces Osteichthyes 13: 362365, Ed. Acarl. R.P.R. Bucuregti. 3. BERG, L. S.1949 Ribi presnih vod S.S.S.R., i soprodelnih stran. fsz. Akad. Nauk SSSR 3 vol., MoscouaLeningrail 4. BU$NTA" TH." BREZEANU, GH. Hidrochemische fsos und lidrobiologische Bedingungen in Fischteichen die mit FluBwasser gespeist werden sowie deren Produktivitet. Zeitschr. fiir Fisch. 13, 3, 4: 269283, 5. CARAU$U, S. f 952 iratat de ihtiologie. Ed. Acad. R.P.R., Bucuregti. 6. KRJANOVSK, S. G. 1949 Ecologomorfologhiceskie zakonomernost razvitia karpovih viunovih i somovih rib. Tr. nst. morf. jioot. 7: 27129.?. PAPADOPOL, M. 1958 Contribulii a studiul fecunditetii, cregterii gi ecologiei crapului (Cyprinus carpio) din Delta Dunirii 9i citeva din bblfle zonelor inundabile. Anal, Uniu. Parhon ser. st. nat. 16: f 31139.
REpnoDUcTON, PROLFCTY AND DEVELOPDNT OF LEACASPAS DE'NEAUS 621 L, peecuitl. in S. PAPADOPOL, M. 1962 Deapre prolificitatea pllticii Abrerqra brgna Delta Dunrrii ji enaliza dinamicii ei in ontogenezi' Anql' rlom"sott' ger' Dtol' 3, 7$90. 9. papadoilol ftf.f968despre carsctcrul pontei pl[ticii Abramig brama danubii ' [pr"io"lper"uitl in Deita Dunlrii. Srud. gi ceic. de bial. ser. biol. anim:4' 15' 465476. Verhovka ili ovgeanca Lqnasoiut ihlircotus r0. payloy, i. p. i..c,. ' 'lh;;"[iti1."."i".. SMRNOV 1965 aredneva tecenia' t;;pr;. zool. Jurn, lcad. Noulc. sssr 4, lo 15741577. rf. STEOpOE,'1.tgOi histologie, ernbriologie. Ed. ilidact. 9i petlagog. Eucu' re4d: 3l?330. Ciiotogie, 12. TRUSOVJ'V. Z.lg4iGhietologhiceekii analiz tak nazvaemoi, Ystadiizrelostiiaici' nikov eudaka. Tt, labor. oz,no ribeuta' 1: 15516?'