IARCHIVES

FISHERIES RESEARCH BOARD OF CANADA

Translation Ser3esA No. 181

ON THE SCALE PATTERN OF SOCKEYE OF DIFFERENT LOCAL POPULATIONS

By F. V. Krogiusa Doctor of Biological Sciences, Kamchatka Branch9 Pacific Research Institute for Fisheries and Oceanography (TINRO)

Original titles 0 stroenii cheshui Kamchatskoi krasnoi raznykh lokalnykh stad

Froms Materialy po biologii morskovo perioda zhizni dalnevostochnykh lososeie pp. 52-63, 1958. Published by Vsesoiuznyi Nauchno-Issledovatelskii Institut Morskovo Rybnovo Khoz.iaistva 3 Okeanografii (VNIRO)9 Moscow

Translated by R. Eo Foerster

Distributed by the Fisheries Research Board of Ganada9 Biological Station9 Nanaimoq B. C.

1958 [b. 521 In connection with studies of the distribution and routes of migration of salmon in the northwest portion of the Pacific Ocean, conducted by the Kamchatka Division of `fllüE?.0, it became necessary to ascertain if it is possible to determine9 by some method other than tagging, from what spawning river basins the sockeye ( nerka Walb) caught in the ocean origlnateo

Conditions during the residence of sockeye in the spawning-nursery areas of Kamchatka and during the ocean period of their life on the routes of migration, and probably also in the marine feeding areas, are dissimilar for different stockso Thus differences arise in the periods of residences of the young sockeye in different nursery areas and in the ocean, i.e., variations occur in the rate of maturity and growth of sockeye of separate stocks. All these characteristics of life and growth of the sockeye are reflected in the pattern of their soaleso Long age.^ it was established that the scales of sonkeye, reared in different spawningGnursery a,reas, had dissimilar patterns (Gilbert, 1914m1925-, Foerster, 1929? Krogius and K.•okhin, 1956? Gerry Kiddq 19^°^6)o

Howeverf, not baving a sufficiently representative knowledge of the patterns of scaleWp by which the fish, c•aughi, in the ocean, could be related to thd particular stocks produced in the different rivers, much confusion existed. With a view to investigating this question, there was undertaken, in 1955, a comparative study of the scales of sockeye originating from those different spawning areas of the Kairi,.;hatka pe^insssla, which were the best known or which were of greatest :>a gnifüoance in t.h^.^ reproduction of these salmono

The length of life of young s4,ckeye, prior to descent to the sea, in different spawning.._,nut.ses`:1 areas comprises from a few months to three or sompm, times four yea.t•E.o From the r:â.ver::, and sprengs the young migrate downstream u..^^ually as yearlings and rarely a und.wx`yC,-'rrliSlgs and t?iUo°yenr°oldso In the lakes the young :ï el'!s"kin not l es4.5 than one yGar<, in many of the lakes of the

K6'•mehat,ka p11Y7in;',ilrl: a ',ti.h W, young continue to feed for two to three yearso

Differences in hydrological and feeding conditions in the different lakes, rivers and springs, lead to dissimilar growth of the young and, c;onse® quently9 to different scale patternss in some areas the young sockeye may have in a year only a few solerites, in others the number of sclerites may range from 15-20o However in mono-typ3o rearing areas the conditions of life cannot always cause substantial differences in rate of growth of the young and consequently in the pattern of the central part of the scaleo Such differences are not deteoted, for example, in comparing the lazabaciva°°, produced in the springs of the Kamchatka, Paratunka, V^.^rovski river systems and the sockeye from Kurile Lake (Càzernaya River system) and from Lake Azabachi (Kamchatka River system). In such cases it is necessary to base the recognition of sockeye preferably on the differences in the pattern of the ocean zone of the scaleo

^po 50 The seaward migration of young sockeye in different areas of the ocean takes place in dif fer ent months ? in some cases even prior to the commencement of spring growth, in others - not until after the resumption of new spring growth of the youngo In the latter seaward migration the freshwater zone of growth of the scales terminates in several wider scr erites, laid down after the narrow °°winter°° oneso It may terminate with narrow 00winter'° scleritesa if the seaward migration takes place before the commencement of intensive summer growtho For early seaward migrations the °°winteb °° sclerites can even be absent slnce, according to the calendar, they develop usually in the spring or even at the beginning of the sunmero - 2 - .

All these features in the scale pattern can occur among young sockeye in a single area or can be noted in different yearso But9 in general9 certain characteristic scale patterns usually predominate in sockeye of any single stock, Their understanding or recognition requires observation of material over several. ,. yearso

In order to differentiate the patterns of scales we have. used the following indices or criterla.-

1o A count of the number of sc5erites, laid down during each year of life of the fish in fresh water or in the seao In the ocean zone of the scale the wide ("summer°°) and narrow ("winter") sclerites were counted separatelyo

2. A determination of the size of the scale at the end of each period or year of life (from the beginning to the end of the band of narrow fi1win-kert9 sc ^.er^,tes) 0 This made it possible to estimate the mean w^.dth of the sclerites (measurements made by ocular micrometer with constant magniflcatzon)o

3o A notation of the character of the scierites9 which can have either straâght, cr.ooked, broken or forked formo In the ocean zone of growth the transition or change from wide sclerites to narrow and again to wide can be sudden or gradual. It was sometimes difficult to determine the narrowest Bclerites. The presence or absence of "winter" sclerites or sclerites of second summer growth in the freshwater zone region of the scale was also notedo

4o The shape of the sockeye scale 5._= not always the samee it can be either oval or more _ezrcealara It is necessary to consider this feature carefully since the form of the scale-changes vary considerably even a short distance from that place on the body of the fish where the scales are usually collected ( from the left side of the fish above the lateral gâ.ne, somewhat anterior to the dorsal fin).

Our studies have included sockeye sGales from the following river vystemss Kamch,atka, Py^.ga (Apuka river system) and Parattanka (east coast)9 Ozernayag Bolshaya and Palana (west coast) and also Kukhtua,(north coast of Okhotsk Sea)o The characteristic features of the sockeye scales of the Rivers 4zernayag Bolshayas Kamchatka and Paratunka and of Lakes Dalnee and Blizhnee have been determined on the basis of studies of material collected over several recent yearso The characteristics of the sockeye scales from other rivers (Palana9 Kukhtua9 Pylga) were revealed from a collection of only one year for each river, but the collections were made in different yearso

The material examined is still insufficient for a complete understanding of the characteristic features of the scale pattern of sackeyea produced in these various river systems,but it does give an idea of the chief types of different patternso

Some idea of the differences are shown in the following tableso With reference to the fish caught in the ocean9 belonging to one or other of the stocks9 it is necessary to use both tableso In the tables we do not at present include the data on the dimensions of the scales since these datag with rare exceptions9 do not reveal sufficiently the real dlfferences9 except with the use of statistical methods of vari.ationo However even the information contained in the tables and in the description of the scales is still insufficient for all cases of determ?.natlono For this purpose an atlas is required of photographs of sockeye scales from different areas of the penznsula9 ïncà.udzngfl for each of themg samples for all age groupso 3

[p° 56] Let us summarize briefly the characteristics of the scale J patterns of sockeye from some of the main KamGhatka River spawning groundso

Kamchatka Rûvero The Kamchatka River system occupies the greatest areaô its spawning-nursery basins, in which sockeye are reared (riversa springs and lakes) are very dlversifledo It is apparent that in this river system are produced several local stocks of sockeye whose characteristic differences are found not only during the freshwater period of life but also during the ocean pe.riodo

A large part of the sQckeye population migrates to the Karnchatka system at an age of 41+ years, l.oea9 has one year of freshwater lifeo Moreover9 a considerable part of the population remains for 2 years in fresh water9 for the most part - these sockeye are reared in the lakeso They return to spawn at ages 42+ and 52¢o These sockeye consist of two typess one with a fast growth^, the other with a delayed growth.

For Kamoha`cka River sockeye typical scales have an elongated oval form with uniform9 continuous sclerltes9 rarely Wplit or irregular (orooked).

On the sockeye scales from the Kamchatka Rivero as distinct from sockeye from the rivers on the west coast of the Peninsula (©zernaya9 Bolshaya9 Palana), the first sclerites laid down after seaward migration from the rivers are poorly distinguished in width from the remaining sclerites laid down in the first summer spent in the oceano They are auite narrower than in the scales of sockeye from the rlv-ers on the west coast of Kamohatka, in which the first ocean sclerites are wider than the suwsequent, oneso 0°Wis3ter" sclerlt.es, which are considerably narrower than 20siummer°° sc'l^erites are sharply separated off from the latter. In fish of the chief age group (41+) dr^rl,a^g the first ocean yea:, there are laid down several more sclerites than in the following years (12-16 °'summer", 5-6 Nlnt,er°°)o In k,he other age gy^oupd, the relation of numbers of solerltes, laid down in dlfferent, ^,earsq is not -.onstanto

In those fish remaining in fresh water for one year there occur at this txmes 10-16 soleriteso Fish in fresh water for two years have at least two types of soaless first - when, during both surtimers, there are laid down from 5®10 scleritesq second = when there are produced 9m14 sclerltes ( see Figso 19 3A 7 and 3)0

BQlsha^a Rjver., In the Bolshaya River systemy as with the Kamohatka, the sockeye spawn not only in the rivers and springs but also in the lakeso Hbwever9 the majority of the young migrate seaward after one year°s residence in fresh water and only an insignificant portion remain for two. seasonso

On the scales of the sockeye from the Bolshaya River system the sclerites are not as regular as on Kamchatka River sockeyeÿ they often run together or spllt9 in places they have broken oontourso The transition from wide to narrow sclerites 3s gradual9 theréfore it is difficult to determine the boundary of one or the othero In the first year spent in the ocean there is laid down a large number of sclerites (11R-20 wi& ones and 3-7 narrow)o I A characteristic feature of the sockeye scales of the Bolshaya River system is the pattern of growth zone in the second ocean yearo It is difficult to determine whether there were laid down in the second year a smaller number of sclerites (4m9 wide and 2-3 narrow) than in the third year (5m11 wide and 3-6 narrow) or whether in the middle of this growth zone there occurs an - 4 m accessory ring (band) of narrow sclerites. If the latter is correct, then for the second ocean year in the ocean it is necessary to allow for a total of 14m30 scleriteso This/feature of the scale pattern for sockeye from the Bolshaya River was observed each year (Fig. 6)0 L Sr

flzernay^, River. In the Ozernaya River system the sockeye spawn in Kurile Lake and its tributaries and in the outlet of the Ozernaya Rivero The young remain in the lake for 2-3 years.

For the Ozernaya sockeye the scales are usually wider and more circular than for the Kamchatka sockeyeo The soierites both in the fresh water and ocean zones of growth are, in large part, fused,, broken, split or running togethero The "winter" sclerites are considerably narrower than the "summer" and usually are sharply separated from the lattero Sometimes, especially in the second and third zones of orjeaas gr_owth"9 there are many narrow sclerzteso

In the first year in the sea the scales show 14-19 very wide and 4®9 narrow scleriteso

During the freshwater period of life the fishq in the first yearg lay down 5-8 and in the second 7=10 sclerz,tes. For fish remaining in fresh water for a third year there are formed 59 6 or 8 sclerites in each yearo Usually the zone of the freshwater period of growth ends with narrowed scierztes (see Figso 12 & 15)0

Kukhtua River. (North coast of Okhotsk Seao) For sockeye reared in the Kukhtua River systemg the scales are of the same type as for Ozernaya sockeyeo They differ from the latter in having more regular soleriteso During the first ocean year the sclerites are wider and there is a greater numbers 16m23 wide and 6-11 narrow (see pig, 13)a

Py1ga River. (Apuka River system m east coast of Kamchatkao) The sockeye migrate from the Pylga River in the spring, in June9 therefore for them to the time of escape from the river there is really no summer growth9 on the border of the scales there appear narrow "winter" scleriteso The sclerites9 laid down during the life of these sockeye in the sea, have regular markings9 fused and split solerites are seldom notedo In the first year in the sea there are laid down 21m23 scleriteso The annual rings are made up of a few narrow solerites, sharply distinguishable from the wide oneso

In the freshwater period of life there are formed regular unbroken sclerites9 having many narrow sclerites they are readily distinguished from the scales of the fish which stay in fresh water for one or two yea.rso Usually the freshwater zone of growth of the scales ends with a band of narrow sclerites (see Figso 5 and A)o

ParatunkaRivero In the Paratunka River system there are known to be three stocks of sockeyes one - reared in the springs9 flowing into the river, and two - reared in Dalnee and Blizhnee i.akeso The sockeyeQ originating in - 5-

. each of these9!are distinguishable from representatives of the two other stocks by a seiies^o.f characteristic features9 among them the pattern of the scales. d The young,sockeyeg native to the springsq stay in the river less than a year9 but sometimes for several moriths9 in the latter cases the freshwater period of life is reflected in their scales only by a few scleriteso

InLake Dalnee9 which is distinguished by a high abundance of food, the young sockeye have an exceptionally fine growth; they remain in the lake for from one to three yearsa On the scales are laid down many wide, uniform sclerites9 and the freshwater zone of growth occupies a considerably greater area than on the scales of sockeye from other areasb

In the first year of ocean life there are laid down 17°27 sclerites. In the second year9 1Om15o All the sclerites are very regular in contour9 not ft3sed9 broken or split (see Figso 10 and l4).

In Blizhnee Lake the food conditions are much poorer than in DaZnne 00 62-1 Lake and the young grow very much more slowly there; furthermoreq at the end of the first summer, growth is retarded and around the centre of the scale there is found ^n accessory ring of narrow sclerites (see Fig. 11)0

The oc an zone of growth on the scales of sockeye from the Paratunka Lakes does not have characteristic differenceso In the first year ther.e are . laid down 14G20 wide sclerites, in the second, 8d16 scleriteso t On the scales of sockeye from Blizhnee Lake the annual ocean rings always appear to be very indistincts the wide sclerites gradually narrow and then gradually wideno For sockeye from Lake Dalnee this peculiarity is not as strongly shown and in some years the "winter" sclerites are clearly separated from the "summer" oneso The majority of the sclerites have regular markingso

The described types of scale patterns have been used by us for discernm ing the origin of the various local stocks of sockeye taken in 1955 and 1956 in the northwest Pacific Ocean expedition of the Kamchatka Division of TINRO, for a study of the distribution and migration of salmono

In the period dune 10 to July 199 1955, in the area lying east of the coast of the and the north Kurile Islands9 between 500 and 55o N. and 1750 E.9 there were examined 137 specimens of sockeye (Birman, 1957)o pf.these the fish of the Ozernaya River stocks constituted about 25%9 nevertheless the Ozernaya River stocks of sockeye were9 in 1955, the most numerous of all the stocks rep'roducing in the rivers of the Kamchatka Peninsulao

In the most easterly part of the area9 around 1700 Eo9 in the period from June 10 to 18, at the same timeg there were caught fish with scales typical of Ozernaya River sockeye9 and with scales typical of sockeye of the Kamchatka River and several other rivers on the east coast of Kamchatkao In the northern part of the area examined, around the Komandorsky Islandsq in the June 18 to 30 periode Ozernaya River sockeye were not encounteredo Here, in the catches9 there predominated fish with scales typical of Kamchatka River sockeyeo there were found also sockeye originating in the more northerly rivers (among themg Pylga River) and from the rivers of the Avachinaya Gulfo From July .10 to 19 around the north Kurile Islands there occurred, in the catches, Ozernaya River sockeye and sockeye from the Bolshaya Rivero On the 9th of July around the southwest coast of Kamchatka there were taken sockeye from the river systems of-the east coast of Kamchatka. 6

Among all the sockeye examined 52% were fish_resident in fresh water for either one year or several months? the remaining 48% were fish which had been In fresh water for 2m3 yearso Among these9 14 specimens had been caught in the northern part of the region where Ozernaya River sockeye had not been , encountered, the remainder9 however9 were composed of Ozernaya River sockeye 11 (around'65%)0

In May-June 19569 studies were made of the migrations of sockeye from the area between 1600 E. and 1720 E. and 460 N. and 490 N. Here there were examined 57 specimenso Among these the fish with scales, typical of Ozernaya River sockeye, constituted not more than 20%o Many of the fish had scales similar to the scales of Bolshaya River sockeye9 the othersa apparently, origi- nated in the Palana River and9 finallyg some of the fish had scales similar to the scales of Kamchatka River sockeyeo Almost onemhalf of all the fish examined had stayed in fresh water for two to three years. Of these9 in turn, half could be considered as Ozernaya River sockeye, but the majority of the remainder originated, undoubtedly, in the Bolshaya Rivero This assumption seemed quite probable since around the mouth of the Bolshaya River in 1956 there were caught an unusual number of sockeye and, among them9 as compared with the usual situa- tion, there were caught more fish which had remained in fresh water for two yearso It is not out of the question, howevers that these fish belonged to the Ozernaya stock and migrated past the mouth of the Bolshaya River southward to the Ozernaya Rivero

[p. 631 In the period from the 4th to 27th of August, 1956, between . 48036' and 530 R. east of the Kamchatka coast and the north Kurile Islands there were examined 132 sockeyeo More than 40% of these fish were juveniles and in the second stage of maturity of the sexual productss, ioeofl.would not be taking part in the 1956 spawningo Among them about 45% were Ozernaya River sockeye9 About 25% Bolshaya River and about 30% sockeye from east coast of Kamchatka River, Among the mature sockeye, caught in the region of Cape Shipunski at the end of Ay.agusts, there were many fishg s].m11ar in scale pattern to the sockeye of Lake Blizhneea several specimens had scales typical of.sockeye from Dalnee Lake (Paratunka River system); and there were found sockeye from the Kamchatka Rivero Of the mature fish caught south of 520 N. around 80% were Ozernaya River sockeye; among the remaining fish there predominatedsockeye belongingfl apparently9 to the Bolshaya River stockso In the catch of August 4th, off the southeast coast of Kamchatka there were detected several specimens of sockeye bound for adjacent rivers on the east coasto

In our opinion the first attempts to assign9 from the scales, the origin of sockeye caught in the ocean to the different stocks indicated that the method described ultimately could aid the study of the routes of migration of the separate stocks of sockeyeo In order to improve this method it will be necessary to make very detailed studies of the scales of sockeye from a much greater number of spawningmnursery Kamchatka River systems9 if possible, and to study the connection between the scale pattern and the conditions in the places of residence of the fisho - 7 -

Literature

I. B. Birman. On the distribution and migration of Kamchatka salmon in the northwest part of the Pacific Ocean. 1957. F. V% Krogius and E. M. Krokhin. Results of a study of the biology of spawning sockeye, the status of their stOcks and the fluctuations in their numbers in Kamchatka waters. "Ichthyological Problems", Paper No. 7 9 1956. C. H. Gilbert, 1913-1924. Contributions to the life-history of the . Papers 1-10. Annual Reports, B.C. Fish.Dept. R. E. Foerster. 1929. An investigation of the life-history and propagation of the sockeye salmon at Cultus Lake, B. C. Introduction and the run of 1929. Contrib. Can, Bio1. 9 5(1), pp. 1-35. Kidd, Gerry. 1956. Scale ring counts pinpoint sockeye races. Western Fish- eries, Vol. 52 9 No. 6, September. V The photographs for the following figures not reprodaaeÿbleo Please refer to 11 original text.

W

57] Fig. 1. Sockeye scale from the Kamchatka Riverg age 4oo

Fig. 2o Sockeye scale - azabachi from the k'ara^.,unka Rzver9 age 31+.

Fig. 3. Sockeye scale from the Kamchatka River, age 31+o

Fig. 4. Sockeye scale from the palarta River„ age 4g+o

(N.B. The Russian system is to designate the ac t tua é years of gx awth , fhus r "31+"9 herein9 is eqaa-1-valent to a"42""" in Our systerno)

[po 58] Fig. 5•, Sockeye scale from the Pylga RiveAg age 4g+.

Fig. bo Sockeye scale from the Bolahayw River_, age 41+ or 51t

Fig. 7. Sockeye scale from the ICamohatka River ,age 51+0

[po 59] Fig. 8. Sockeye scale from Lake Anabachi (Kamohatka, R. basin), age 52 0 Fig. 9" Sockeye scale from the Pylga River,, .^ge 6

Fig. 10. Sockeye scale from Lake Daflnee (Paratunka R. basin),, age 15 2 c.,

Fig. fl1o Sockeye scale from BA.iûhnee Lake (Paratunka R. basin), age

1po 60] Fig. 12o Sockeye scale from the Ozernaya Riverg age

Fig. 13. Sockeye scale from the Kukhtya River, age 52

Fig. 14o Sockeye scale from Lake Dalnee (Paratunka R. system), age 4 3

Fig. i5o Sockeye scale from the Ozernaya Rxver9 age 6 3¢a T f r C s

Lp. 54) 'Fable 1, Zone of freshwater period of growth.

2Zumber of seasona Less than spent in fresh water one year One year Two years Three years

Spawning area "Spring" Kamchatka R. Pylga R. Dalnee Bolshaya R. Blizhnee Kamchatka R. Dalnee Blizhnee Ozernaya R. Dalnee Kamchatka Ozernaya H. sockeye Palana R. (Apuka Lake (Fig. 6) Lake ylga R. Lake Lake Kykhtya R. Lake Yykhtye. R. (azabachi) (Fig. 3 & 4) system) (Fig. 7 & 9) (Fig. 10) (Fig. 11) (Fi,-. 12 & 13) (Fig. 14) (Fii. 15) Kamchatka (Fig. 5) Paratunka other rivers (Fig. 1 & 2)

Contour of sclerites reo•v].arl/ regular regular regular irregu].a O irregular regular regular irregular irregular regular regular irreFu].ar wide

Number of 1 year L,-8 10-16 10-16 12-23 5-10 9-15 5-10 6-23 9-13 5-8 5-15 5-°- 5-8 sclerites 2 year ------10-24 10-24 5-9 9-13 5-15 5-8 5-8 3 year ------5-15 5-8 5-8

rmi i, ea v z Characteristic to 00 features ô rs ^ ^ ô w 0 m O ID ' N • O ! N W L4 a o O C N G Da O •V 1 N N ('. N O ^ ^ U U O O U .rt N•O m O • N U U U O O N N N U p^ (r ^.{ y.y^ N N ^ U p U U

'I -^V m O A rNl D GO f^•^ N 7^{ cOa N^ O • O • C • C j O N G N A •O N N e N N O N 0 O W O t^ ^^ N rl ri O N 0 Ç TS f. ^ C O N^ N O O W O.O U ,ÿ f^ ^ G1 O•r1 O•rl rl ^ rl N F r1 .C N 3 O. 4 CO• N N b U • .G 'O W +. 9 N .Ç N N M N ri LIS ri N N•1-^ N^ü N d 7 N rl r 7 ^{ N N O S-i O0 .C a0 -C i. ri r^ N W 1r0"-I .G U rl rJ m rl rl F ^-rl +- C +^ O O O F•3 -N U N •p O G O U' O O 3 U 3 b N N 7 N F N N O ^^ § U 3^ •^ t^i^ ^ 3 N 3 . F. N O ^ ^J ^^ W N U U Y U ^ O U O O •+W 0 .N S-r ô^ •+ N O N ••N •^ N ô N O N Si Y.. fr N d O Sr G M W Sa IS N I ^ . N N T•^ 1+ r{ f. .V F b i. N Ç f+ .^Ti{ N+^ N b^{ W b W t+ W £. N 1* C W G.: ^3Nc,Ô O F O F aUi N O N4^ N •C y^ ÿ N1i2 N W U'^ ^ L^ N O N Ô N Ô N W ' d âC O W N N^`-1 41 +> f• O U t0 N o U ^C N o 0^ N N N O 4- O 4- .•M•I v.^ + -H .C v ON ^ ^i ^ ^i 2¢ •0 7 ô •^rl l•d ^rl -o -H v S• ! a F U2 f+ i. •Vt i. N+- ^ f. O O N L. fy f. ç7 F O Ii ^ •^C rl r^1i ri ri ri Ô o Û^ rl M1 ol- H ^ rl ^ rl O rl I t m ? F. M R e rA N [A m C W o v] ^ v] 0 6 r^n co co v) m co R r/] ri

"The expression "Contour of sclerites reoga].ar" means that the sclerites have an equal, uniform spacing and are continuous, normal ovals,

2/The expression "Contour of sclerites irregular" means that the sclerites are broken and crooked and the spacings are of irregular widths with crooked margins. (

LP. 551 Table 2, Zone of ocean period of growth.

Pylga R. (Apuka R.,) Ozernaya R. Paratunka R. Palana R. Holshaya R. Kykhtya R. Sra..rin€ Dalnee Lake Blizhnee Lake Kamchatka R. (Fig. 2 , (Fig . 4) (Fig. 6) (Fig. 12, 13, 15) area (Fir, 10, 14) (Fig. 11) (Fig. 1 , 3 , 7) 5 , 9)

not irregular but irregular, Contour of sclerites regular regular regular regular not irregulam but split or split or 'using discontinuous fusing

é.umLer of First year 10-18 16-23 14-19 zone - 10-20 10-2U 17-25 scleritec zone small zone small zone small zone large zone small zone large Second year 7-17 zone - 7-10 10-18 10-15 5*-16 -

"Winter" sclerites sclerites 2 or-3 narrow "vrinter" sclerites ^arecteristic features usually not a usually not a "v(inter" sclerites sclerites , si*^ilar to clearly separated clear boundary clear boundary clearly separated clearly separated from not clear an accessory ring from "swmner° between "winter" between "winter" from "su^.mer" "sutmaer" lying between the and "summer" and "summer" sclerites sclerites first and following clearly marked ring of "winter" sclerites

oval oval circular Sh?re of scale oval, elongated circular oval, elongated circular