In e eb a e Zoology, 2024, 21(1): 67–80 © INVERTEBRATE ZOOLOGY, 2024
S a ocys s o cephalopods can unc ion wi h asymme ic
s a oli hs: on he disco e y o an anomali y in s a oli h
on ogene ic de elopmen in squid Be y eu his
sep emden a us (Coleoidea: Gona idae)
V.R. Zimina
In e eb a e Zoology Depa men , Lomonoso Moscow S a e Uni e si y, Leninskie Go y 1-12, Moscow
119234 Russia. E-mail: zimina@ ni o. u
Vic o ia Zimina: ORCID 0009-0006-4902-5921
ABSTRACT: The a icle p esen s a desc ip ion o he i s disco e ed squid Be y eu his
sep emden a us wi h an asymme ic pai o s a oli hs. One s a oli h om a pai had h ee
ini ial c ys alliza ion poin s, wo o which ga e ise o he de elopmen o wo sepa a e
pa ala al s a oli hs du ing squid on ogenesis. These pa ala al s a oli hs we e loca ed in
one s a ocys chambe a he ime o ha ching, and me ged in o single s a oli h only on he
ou h day a e pa ala a ha ching. The s a oli h ha appea ed a e me ging, e ained an
abno mal modi ied o m un il he adul hood. The second s a oli h o he pai had no mal
shape o his species. The inding sugges s he p esence o unknown mechanisms ha
may compensa e asymme y in he s a oli h-s a ocys sys em unc ioning and allow a squid
wi h de ec s in es ibula appa a us o su i e and each adul hood. Appa en ly, on ea ly
s ages o pa ala ae on ogene ic de elopmen he s a ocys s do no play a i al ole, which
may be ela ed o a he inac i e, plank onic li es yle o pa ala ae. Da a on mo phome y
o s a oli hs is p esen ed o he commande squid Be y eu his magis e om he Be ing
Sea and Paci ic Ocean and he p e iously conside ed o i s subspecies B. sep emden a us,
inhabi ing he Sea o Japan. Mo phome y o adul and pa ala al s a oli hs o hese wo
species is compa ed. The pa ala al s a oli hs a e la ge in B. sep emden a us han in B.
magis e . This is due o he ac ha pa ala ae o B. sep emden a us ha ch om he la ge
eggs han pa ala ae o B. magis e .
How o ci e his a icle: Zimina V.R. 2024. S a ocys s o cephalopods can unc ion wi h
asymme ic s a oli hs: on he disco e y o an anomali y in s a oli h on ogene ic de elop-
men in squid Be y eu his sep emden a us (Coleoidea: Gona idae) // I e . Zool. Vol.21.
No.1. P.67–80. doi: 10.15298/in e zool.21.1.03
KEY WORDS: Be y eu his sep emden a us, Be y eu his magis e , asymme ic s a oli hs,
pa ala al s a oli h, nuclei, mo phome y.
The a icle p esen s he ma e ials o he scien i ic wo k o V.P. Zimina awa ded he “In e eb a a” p ize o he bes
bachelo ’s hesis (h p://in e .bio.msu. u/ u/educa ion- u/baccalau ea e/92-in e eb a a-p emium).
В статье представлены материалы работы В.Р. Зиминой, удостоенной премии «In e eb a a» за лучшую
бакалаврскую диссертацию (h p://in e .bio.msu. u/ u/educa ion- u/baccalau ea e/92-in e eb a a-p emium).
V.R. Zimina68
In oduc ion
S a ocys s a e he pai ed equilib ium o gans
loca ed in ca ilaginous c anium o cephalopods
(Budelmann, 1988). Se ing as accele a ion and
g a i y ecep o s, he s a ocys s o squids and
o he decapod cephalopods (cu le ishes, bob ail
squids and Spi ula) ep esen he mos complex
balance o gans o all in e eb a es and a e simila
in s uc u e o he es ibula appa a us o ishes.
The simila i y wi h ishes is due o he simila i y
in ecology, high maneu e abili y and he need o
complex o ien a ion in space in bo h squids and
ishes (Packa d, 1972). Di e en ypes o loco-
mo ion de e mine he s uc u e o he s a ocys s,
which e lec s animal’s way o li e (Budelmann,
Wol , 1976; Maddock, Young, 1984).
Basing on mo phological di e ences, he
s a ocys s in cephalopods a e classi ied in o h ee
ypes: nau ilus ype, oc opod ype and decapod
Статоцисты головоногих моллюсков могут работать
с несимметричными статолитами: об обнаружении
аномалии онтогенетического развития статолитов
кальмара Be y eu his sep emden a us (Gona idae:
Coleoidea)
В.Р. Зимина
Кафедра зоологии беспозвоночных, Московски государственны университет им. М.В. Ло-
моносова, Ленинские горы 1-12, Москва 119234 Россия. E-mail: zimina@ ni o. u
РЕЗЮМЕ: В работе представлено описание впервые обнаруженного кальмара
Be y eu his sep emden a us с ассиметричной парой статолитов. Один из статолитов был
с тремя точками кристаллизации, две из которых в процессе онтогенеза кальмара дали
начало двум независимым статолитам. Эти статолиты личинок-параларв располагались
в одной камере статоциста, и лишь на четвертые сутки после выклева слились в один
общий статолит, сохранивший у взрослого кальмара уродливую видоизмененную
форму. Второй статолит из пары сохранил нормальную форму, присущую кальмарам
этого вида. Находка позволяет предположить наличие неизвестных пока механизмов
компенсации асимметрии в работе системы статолит-статоцист, позволивших выжить
кальмару с дефектами в развитии вестибулярного аппарата и достичь дефинитивных
размеров и половой зрелости. По-видимому, на ранних стадиях онтогенетического
развития личинок-параларв работа статоцистов не играет жизненно важную роль,
что может быть связано с их малоподвижным, планктонным образом жизни. Пред-
ставлены данные морфометрии статолитов кальмаров рода Be y eu his, включающие
командорского кальмара Be y eu his magis e из Берингова моря и Тихого океана и
ранее считавшегося его подвидом Be y eu his sep emden a us, населяющего Японское
море. Приведены сравнения морфометрии статолитов взрослых животных, а также
статолитов личинок-параларв этих двух видов. Статолиты личинок-параларв на мо-
мент выклева у B. sep emden a us больше таковых у B. magis e . Это связано с тем,
что личинки-параларвы Be y eu his sep emden a us вылупляются из более крупных
яиц, чем у командорского кальмара.
Как цитировать эту статью: Zimina V.R. 2024. S a ocys s o cephalopods can unc ion wi h
asymme ic s a oli hs: on he disco e y o an anomali y in s a oli h on ogene ic de elopmen
in squid Be y eu his sep emden a us (Gona idae: Coleoidea) // I e . Zool. Vol.21. No.1.
P.67–80. doi: 10.15298/in e zool.21.1.03
КЛЮЧЕВЫЕ СЛОВА: Be y eu his sep emden a us, Be y eu his magis e , asymme ic
s a oli hs, pa ala al s a oli h, nuclei, mo phome y.
S a ocys s o cephalopods can unc ion wi h asymme ic s a oli hs 69
ype (Budelmann, 1988). Decapod s a ocys s
a e he mos complexly de eloped, being an i -
egula ly shaped ca i y due o he ca ilaginous
p o usions called an ic is ae and con aining cal-
ca eous s a oli h. The s a ocys ca i y is pa ially
sepa a ed in o h ee chambe s: an e io , pos e io
and en al. Wi hin he s a ocys he e is a senso y
epi helium called macula o which he s a oli h
is a ached (Young, 1960; Budelmann, 1988).
The senso y cells o macula se e as a pa o
g a i a ion- ecep ion sys em, while he senso y
epi helium o he c is a p o ides ecep ion o
endolymph mo ion unde angula accele a ion;
each o he ecep o a eas has i s own p ojec ion
in he animal’s b ain (S ephens, Young, 1982;
Budelmann, 1988, 1990). The s uc u e o he
g a i a ional sys em consis s o he h ee lami-
nae o he senso y epi helium (macula) and wo
s a oconial laye s. These laye s a e comple ely
adjacen o macula neglec a supe io (MNS)
and macula neglec a in e io (MNI), while he
s a oli h is a ached o maculae s a ica p inceps
(MSP) only in he wing a ea called he spu
(Budelmann e al., 1973; A khipkin, Biziko ,
2000). Typically, s a oli h o decapod cepha-
lopods consis s o he ou main pa s: wing,
os um, do sal dome and la e al dome.
The angula accele a ion ecep ion sys em
in decapod s a ocys s consis s o abou a dozen
o inge -like ca ilaginous p ocesses inside he
s a ocys ca i y (cu ed hamuli and s aigh
an ic is ae) as well as low ca ilaginous idges
co e ed wi h sensi i e hai cells called c is ae,
which un along he an e io , pos e io and la e al
walls o he s a ocys (Dilly e al., 1975; A khip-
kin, Biziko , 1998). The c is ae a e di ided in o
4 sec ions: he an e io ans e sal c is a (c a),
longi udinal c is a (cl), pos e io ans e sal
c is a (c p) and e ical c is a (c ). The inge -
like ca ilaginous p ocesses p o uding in o he
chambe o s a ocys (cu ed hamuli and s aigh
an ic is ae) s uc u e he inne s a ocys ca i y
o ming channels ha di ec he endolymph low.
All c is a ha e a anspa en sail-like s uc u e
called cupula, a ached o hei idge. De ia ion o
he cupula unde he endolymph low may exci e
hai cells o he senso y epi helium p o iding
ecep ion o angula accele a ion (S ephens,
Young, 1978; A khipkin, Biziko , 1998, 2000).
The mos de eloped, almos comple ely closed
ho izon al channel in s a ocys s is associa ed wi h
he c is ae esponsible o ecep ion o angula
accele a ion, p oduced by yawing (S ephens,
Young, 1978).
Du ing he animal’s mo emen he s a oli hs
a ached o he an e io wall o s a ocys s by
he macula, oscilla e on i , gene a ing di ec ed
lows o endolymph in he s a ocys s chambe s.
The mo phology o he s a oli hs is unc ion-
ally de e mined: each pa o he s a oli h while
oscilla ing di ec s he low o endolymph o
co esponding pa o he senso y epi helium
(A khipkin, Biziko , 1998).
Thus, mo phology o he s a oli h is de-
e mined by he unc ional ole o each o i s
pa s ha oge he wi h complexly s uc u ed
inne space o s a ocys s comp ise es ibula
appa a us o decapods ensu ing hem e ec i e
di ec ion and accele a ion con ol du ing je ing
swimming. As he mo phology o he s a oli h
is closely ela ed o i s unc ion, i is impo an
o no e ha he s a oli hs o squids wi h di -
e en li es yles di e . Two ypes o s a oli hs
a e dis inguished: deme sal (nea -bo om) and
pelagic. Typical ea u es o deme sal s a oli hs
a e he p esence o la ge usually paddle-shaped
os um ha is mos ly ee om wing, and well-
de eloped la e al and do sal domes sepa a ed by
a dis inc g oo e. Do sal and la e al domes o he
pelagic s a oli h a e poo ly sepa a ed om each
o he and unc ion as a uni ; os um is sho and
wing is long, ex ending almos o he os um
dis al end and o e lapping mos o he do sal
dome. S a oli hs o deme sal squids a e wo o
mo e imes la ge han hose o pelagic squids
among animals o he same size class (Cla ke,
Maddock, 1988; A khipkin, 1997; A khipkin,
Biziko , 2000). Taking in o accoun he s a oli h
unc ioning model desc ibed abo e, he mo e
massi e and s uc u ally di e en ia ed s a oli h
o deme sal ype ensu es be e sensi i i y o
angula accele a ions and p o ides accu a e
mo emen s such as oll and yawing, in highly
s uc u ed space o nea -bo om en i onmen ,
while pelagic ype s a oli hs a e mo e adop ed o
moni o accele a ions in he wa e column whe e
he e a e no obs acles o he je ing swimming
(A khipkin, Biziko , 2000).
S a oli hs a e widely used as egis e ing
s uc u es o age squids and cu le ishes. Thei
slides bea g ow h ma ks (inc emen s) wi h e i-
ied daily pe iodici y (Rosenbe g e al., 1981;
Dawe e al., 1985; Lipinski, 1986; Jackson,
2004; A khipkin e al., 2018). These inc emen s
V.R. Zimina70
s a o o m ei he du ing la e emb yogenesis
be o e ha ching (loliginid squids) o a he mo-
men o ha ching (oegopsid squids). The i s
сheck (ha ching ma k) is loca ed ou side he
ocus (nucleus), which is he poin o s a oli h
g ow h (A khipkin, Biziko , 1997; A khipkin,
2005). G owing h oughou he li e o an animal,
s a oli hs con ain in o ma ion abou indi idual
li e e en s such as s ess, ma ing, spawning and
so on. These e en s may be seen as s ess-ma ks
on he s a oli h sec ions (A khipkin e al., 1999;
A khipkin, 2005). In gene al, s a oli h g ow h in-
c emen s consis o c ys als o a agoni e (CaCO3)
lying in a p o ein ma ix consis ing mainly o
acidic p o eins. S a oli hs con ain la ge amoun
o aspa ic acid, which can se e as a ca alys o
he p ecipi a ion o calcium ca bona e (Rad ke,
1983). The p o ein ma ix can induce and di ec
c ys alliza ion p ocess (Weine , T aub, 1984).
On he o he hand, inhibi ion o g ow h may
occu h ough he in e ac ion o p o eins wi h
he axes o c ys al, so s e eochemical con ol
akes place (Addadi, Weine , 1985). Diu nal
inc emen s a e ela ed o he peculia i ies o he
biomine aliza ion p ocess: he calcium-p o ein
a io in he s a ocys s endolymph changes du ing
he day. In his case he p esence o calcium-
binding p o eins can block ca bona e deposi ion
e en a e c ys alliza ion has begun (W igh ,
1991). Thus, a ia ions in he o ganic/calcium
a io in s a ocys s endolymph h oughou he
day p oduce al e na ing ligh and da k g ow h
inc emen s ha may be obse ed on sec ions o
s a oli hs (Cas o, Gue a, 1989; Saue , Lipiński,
1991). The ligh e g ow h inc emen s con ain
mo e calcium and he da ke ones con ain mo e
p o ein. The concen a ion o magnesium ions
p obably a ec s he deposi ion o calcium, as
he e is mo e magnesium han calcium in he
endolymph du ing he day and ice e sa du ing
nigh . As a esul , mo e o ganic ma e wi h less
calci ica ion may be deposi ed in he day ime. The
isibili y o g ow h inc emen s on he os um
is also ela ed o biomine aliza ion: i becomes
di icul o dis inguish g ow h lines because less
o ganic ma e is deposi ed as he animals ge s
olde (Be encou , Gue a, 2000). I has also
been ound ha s a oli hs do no s a o o m a
all in he absence o s on ium in he wa e : he
p esence o his ca ions is i al o cephalopods
no mal g ow h (Hanlon e al., 1989).
Ma e ial and me hods
COLLECTION DATA AND BIOANALYSIS.
Squids Be y eu his sep emden a us Sasaki, 1915
we e collec ed om awl ca ches o R/V “Bukho o”
(expedi ion o “TINRO” — Paci ic b anch o Russian
Fede al Resea ch Ins i u e o Fishe y and Oceanog-
aphy (“VNIRO”) ca ied ou on 11.07.2014 and
18.07.2014 a he con inen al slope in he Pe e he
G ea Bay in he Sea o Japan (P imo sky K ai). The
squids we e sampled on July, 11, 2014 in posi ion
42°24′5″ N 131°34′9″ E and on July, 18, 2014 in
posi ion 42°27′8″ N 132°30′0″ E. A o al o 97 squids
we e collec ed (51 specimens o July, 11 and 46 speci-
mens o July, 18). Bioanalysis was conduc ed o all
squids wi h de e mina ion o sex, s age o ma u i y,
man le leng h and body weigh ; o emales he leng h
o nidamen al glands was eco ded. In all analyzed
squids a pai o s a oli hs we e ex ac ed om he
s a ocys s h ough a en al incision a he base o
he head behind he unnel. Sampled s a oli hs we e
s o ed in ubes con aining 96% e hanol. All in all, he
s a oli hs om 39 squids (19 specimens caugh on July,
11 and 20 specimens caugh on July, 18) we e used in
his s udy. Man le leng h o squids anged om 141
mm o 203 mm, in his a ea a e mainly indi iduals
in 3–5 s ages o ma u i y wi h domina ion o 3 s age.
Fo compa ison, 65 pai s o s a oli hs om squid
Be y eu his magis e Be y, 1913 (commande squid)
we e also analyzed: 30 pai s om squids caugh in
he Be ing Sea (61°18′30″ N; 175°11′59″ E) du ing
TINRO expedi ion in he end o No embe 1996
and 35 pai s om squids caugh in he Paci ic Ocean
(Middle Ku il Islands, 49°44′42″ N; 155°14′6″ E) in
TINRO expedi ion in he end o Decembe o 2006.
All s a oli hs o B. magis e we e accompanied by
bioanalysis da a o he specimens om which hey
we e ex ac ed. Squids om he Be ing Sea we e 188-
258 mm in man le leng h and om 2 o 5 ma u i y
s ages wi h domina ion o s age 2 and Paci ic Ocean
specimens we e 158–231 mm in man le leng h and
in 2-3 ma u i y (only one specimen in 4 s age) s ages
wi h domina ion o s age 2. S a oli hs om hese squids
we e s o ed d y, wi hou ixa ion o a long ime (27
and 17 yea s, espec i ely).
MORPHOMETRY AND GRINDING. S a oli hs
we e measu ed simila ly o he scheme used in Lish-
chenko & Lishchenko (2017) (Fig. 1), whe e he leng h
o do sal dome is ddl, ee pa o os um leng h is
p l, leng h o la e al dome is ldl, os um base wid h
is bw, os um leng h is l; s a oli h wid h is sw, o al
s a oli h leng h is sl and he wing leng h is wl. Mea-
su emen s we e aken wi h an ocula ule , con e ing
he alues ob ained o millime e s wi h ounding o
he nea es housand h. A o al o 133 s a oli hs we e
measu ed: 77 s a oli hs o B. sep emden a us (38 pai s
om specimens sampled 11.07.2014 and 39 pai s om
S a ocys s o cephalopods can unc ion wi h asymme ic s a oli hs 71
Fig. 1. Scheme o s a oli hs measu emen s.
Abb e ia ions: ddl — leng h o do sal dome; p l — ee pa o os um leng h; ldl — leng h o la e al dome; bw — os-
um base wid h; l — os um leng h; sw — s a oli h wid h; sl — o al s a oli h leng h; wl — wing leng h (Lishchenko,
Lishchenko, 2017 wi h changes).
Рис. 1. Схема промеров статолитов.
Обозначения: ddl — длина дорсального купола статолита; p l — длина свободной части рострума; ldl — длина
латерального купола статолита; bw — ширина основания рострума; l — длина рострума; sw — ширина статолита;
sl — общая длина статолита; wl — длина крыла статолита (Лищенко, Лищенко, 2017, с изменениями).
specimens sampled 18.07.2014); 56 s a oli hs o B.
magis e : 28 pieces om wo TINRO expedi ions
o 1996 and 2006 yea s. All s a oli hs we e g inded
on bo h sides acco ding o he s anda d me hodology
(A khipkin, Shche bich, 2012; A khipkin e al., 2018)
(Fig. 2A). Be o e g inding, he s a oli hs we e moun ed
on C ys albond 509 esin. The esin was mel ed using
an elec ic cooke . Each side o he s a oli h was g inded
wi h 1000 o 1500 g i sandpape and hen polished
wi h 3000 g i sandpape . A o al o 108 s a oli hs
we e g inded. Mo phome ic da a we e ob ained om
95 s a oli hs. Low quali y o o e g inded slides we e
no used in he s udy.
The sec ion wi h a d op o glyce ol was co e ed
wi h a co e slip and obse ed a 40X magni ica ion
(Fig. 2B). Pa ala al s a oli hs we e also mo pho-
me ically measu ed: leng h and wid h o he nea es
housand hs in mic ome e s using a measu ing ule
in ToupView so wa e. Op ical images we e ob ained
using came as moun ed on Olympus mic oscope
(Olympus Co po a ion, Tokyo, Japan), Zeiss (Zeiss
Axioplan2 mic oscope equipped wi h an AxioCam
HRm digi al came a), Leica mic oscope (Leica Mi-
c osys ems, We zla , Ge many), Olympus binocula
and so wa es such as ToupView, AxioVision, Helicon
Focus and Adobe Pho oshop CC 2019. STATISTICS:
S a is ical da a p ocessing was pe o med in Mic oso
Excel and Numbe s using a wo-sample - es wi h di -
e en a iances, calcula ing co ela ion coe icien s,
coe icien s o de e mina ion and end line unc ions.
To analyse how s a oli h p opo ions change wi h
g ow h we s udied co ela ions be ween di e en
s a oli hs pa ame e s. In all cases hese co ela ions
could be desc ibed in i s app oxima ion by a linea
eg ession unc ion (Y = a + b*X, whe e ‘a’ and ‘b’
a e linea eg ession coe icien s).
Resul s
STATOLITHS’ MORPHOLOGY AND
MORPHOMETRY. Gene al mo phology o
he s a oli h o B. sep emden a us om he Sea
o Japan is p esen ed on Fig. 3. A e age o al
leng h o he s a oli hs was 2.56±0.11 mm in B.
sep emden a us om he Sea o Japan; 2.48±0.10
mm in B. magis e om he Ku il Islands a ea,
and 2.65±0.16 mm in he B. magis e om he
Be ing Sea.
P opo ions o s a oli hs pa s we e sligh ly
di e en in wo species. The a ios sw/ sl, bw/
sl and bw/ l in B. magis e we e lowe han in
B. sep emden a us (Table 1). To es he alid-
i y o he di e ences in hese h ee indices, he
B. magis e da a om he Ku il Islands and he
Be ing Sea we e combined in o one sample
and a - es wi h unequal wo-sided c i e ion
was pe o med: o sw/ sl he signi icance le el
was p=0.01, o bw/ sl p=0.0003 and o bw/
l p=0.0006. Thus, di e ences a e eliable and
sw/ sl, bw/ sl and bw/ l indices can be used
as diagnos ic ea u es o dis inguish hese wo
squid species.
V.R. Zimina72
Fig. 2. Scheme o s a oli h g inding (A) and gene al p inciple o sec ion obse a ion (B), (A khipkin, Shche -
bich, 2012, wi h changes).
Рис. 2. Схема шлифовки статолита (А) и общий принцип анализа шлифа (В), (A khipkin, Shche bich,
2012, с изменениями).
Index
B. sep emden a us B. magis e
Sea o Japan Paci ic Ocean Be ing Sea
n=39 n=28 n=28
m±sd m±sd m±sd
l/ sl 0,459±0,02 0,470±0,03 0,460±0,04
sw/ sl 0,527±0,040,515±0,03 0,510±0,02
bw/ sl 0,259±0,020,246±0,02 0,240±0,02
ldl/ sl 0,443±0,05 0,439±0,03 0,437±0,02
l/ldl 1,045±0,11 1,075±0,09 1,053±0,09
p l/ sl 0,275±0,05 0,273±0,03 0,279±0,04
ddl/ sl 0,125±0,020,126±0,01 0,128±0,02
ddl/ldl 0,284±0,04 0,289±0,03 0,288±0,03
wl/ sl 0,594±0,05 0,599±0,040,591±0,03
bw/sw 0,492±0,05 0,480±0,05 0,472±0,03
bw/ l 0, 565±0,05 0,525±0,04 0,526±0,06
Table 1. Mo phome ic indices de e mining he main p opo ions o B. sep emden a us
and B. magis e s a oli hs.
Таблица. 1. Морфометрические показатели, определяющие основные пропорции статолитов
кальмаров B. sep emden a us и B. magis e .
Man le leng h o B. sep emden a us was 141–203 mm, ma u i y s age — 3–5; Man le leng h o B. magis e was
158–258 mm, ma u i y s age — 2–5.
Abb e ia ions: m — mean alue; n — numbe o s a oli hs; sd — s anda d de ia ion; ddl — leng h o do sal dome;
p l — ee pa o os um leng h; ldl — leng h o la e al dome; bw — os um base wid h; l — os um leng h; sw —
s a oli h wid h; sl — o al s a oli h leng h; wl — wing leng h.
S a ocys s o cephalopods can unc ion wi h asymme ic s a oli hs 73
Fig. 3. S uc u e o B. sep emden a us s a oli h, ligh mic oscopy. Le — iew om he pos e io side,
igh — iew om he an e io side.
Abb e ia ions: dd — do sal dome; ds — do sal spu ; ld — la e al dome; — os um; s — spu ; w — wing. Scale ba : 500 µm.
Рис. 3. Строение статолита кальмара B. sep emden a us, световая микроскопия. Слева вид с задней
стороны, cправа вид с передней стороны.
Обозначения: dd — дорсальный купол; ds — дорсальная шпора; ld — латеральный купол; — рострум; s — шпора;
w — крыло. Масштаб: 500 µm.
Reg ession coe icien s o di e en s a oli hs
indices we e p ocessed o he pu pose how
s a oli hs change du ing i s g ow h. Low nega-
i e co ela ion was ound be ween he g ow h
o bw/ sl, bw/ l indices wi h he g ow h o he
s a oli h o bo h squid species indica ing ha
he s a oli hs become mo e s eamlined as he
squid g ows. Low posi i e co ela ion o g ow h
indices in all samples was obse ed o p l/ sl,
l/ldl and bw/sw indica ing o a change in shape
o he s a oli h ha becomes mo e elonga ed and
slende e as i g ows. On he con a y, p opo -
ions o he wing (wl) and he la e al dome (ldl)
do no change du ing he g ow h o s a oli h. In
wo o he h ee cases, a low posi i e co ela ion
is no ed o he sw/ sl and l/ sl indices, con i m-
ing “s e ching” o he s a oli h, while he ddl/ sl
and ddl/ldl indices in wo o he h ee samples
do no change wi h s a oli h g ow h, indica ing
ha he do sal dome g ows p opo ionally wi h
he g ow h o he s a oli hs.
PARALARVAL STATOLITHS’ MOR-
PHOMETRY. S a oli h nucleus and i s check
ma k a e dis inguished clea ly on he g inded
s a oli h (Fig. 4) The mo phome ics o pa ala al
s a oli hs we e measu ed acco ding o scheme
on Fig. 5. In a e age, he pa ala al s a oli hs
o B. sep emden a us we e 242.3 µm in leng h
and 121.9 µm in wid h. The wid h o leng h a io
was 0.5. Mo phome y was pe o med o 38
specimens. In B magis e , he ollowing alues
we e ob ained: a e age leng h o he pa ala al
V.R. Zimina74
Fig. 4. Bila e al sec ion o B. sep emden a us s a oli h body, ligh mic oscopy. Scale ba : 100 µm.
Рис. 4. Двухсторонний шлиф тела статолита кальмара B. sep emden a us, световая микроскопия.
Масштаб: 100 µm.
Fig. 5. Scheme o pa ala al s a oli h mo phome y, ligh mic oscopy.
Abb e ia ions: l — leng h; w — wid h. Scale ba 100 µm.
Рис. 5. Схема морфометрии личиночного статолита, световая микроскопия.
Обозначения: l — длина; w — ширина. Масштаб: 100 µm.
S a ocys s o cephalopods can unc ion wi h asymme ic s a oli hs 75
w, mm (a e age) l, mm (a e age) w/l n
B. sep emden a us 0,122±0,01 0,242±0,01 0,503±0,03 38
B. magis e 0,106±0,01 0,197±0,01 0,540±0,04 40
-s a is ics 7,842 14,733 5,16
P(T<= )
wo-sided 2,38*10-11 7,68*10-24 2,39*10-6
Table 2. Mo phome y o pa ala al s a oli hs o squids B. sep emden a us and B. magis e .
Таблица 2. Морфометрия личиночных статолитов кальмаров B. sep emden a us и B. magis e .
Abb e ia ions: l — mean leng h o pa ala al s a oli h; w — mean wid h o pa ala al s a oli h; n — numbe o s a oli hs.
s a oli h was 196.5 µm; a e age wid h: 106 µm.
The wid h o leng h a io was 0.54. All in all,
hin sec ions o 40 B. magis e s a oli hs we e
analysed. Resul s and -s a is ics a e p esen ed
in Table 2.
ABNORMAL STATOLITH. Du ing ou
s udy one pai o s a oli hs ex ac ed om ma-
u ing emale B. sep emden a us wi h a man le
leng h o 198 mm and age o 191 days was ound
o be asymme ic: he le s a oli h had no mal
shape speci ic o his species, while he igh
s a oli h had abno mal shape due o de elop-
men anomalies: i ini ially appea ed as h ee
c ys alliza ion poin s (Fig. 6A) loca ed a 169,
46 and 215 µm apa om each o he . Fi s wo
c ys alliza ion poin s (Fig. 6A) ep esen he
nuclei o wo anomalous emb yonic s a oli hs. In
he la ge emb yonic s a oli h (Fig. 6A) he i s
g ow h ma k co esponding o pa ala a ha ching
is loca ed a 49, 100, 74, 53 µm om he nucleus
(measu emen s 104 clockwise on Fig. 6A). In he
smalle emb yonic s a oli h he dis ances om
he nucleus o he i s (ha ching) g ow h ma k
a e 47, 61, 23 and 45 µm (clockwise). The la ge
emb yonic s a oli h is 169 µm in leng h and 120
µm in wid h, o smalle emb yonic s a oli h
simila meanings a e 107 and 72 µm. Wid h o
leng h a ios we e 0.71 and 0.67 o bo h s a oli hs
espec i ely. A he momen o ha ching, each
o hese s a oli hs did no ha e ea -d op shape
ha is cha ac e is ic o he genus Be y eu his.
The hi d c ys alliza ion poin (Fig. 6A) o med
a bubble-like s uc u e on he smalle emb yonic
s a oli h (Fig. 6B). The wo sepa a e pa ala al
s a oli hs me ged in o a single s a oli h only on
he ou h day a e ha ching (Fig. 6B), he leng h
o his s a oli h was 337 µm. Me ging o wo
pa ala al s a oli hs esul ed in o ma ion o a
single anomalous dumbbell-shaped s a oli h. I
is impo an o no e ha his anomaly esul ed
in he o ma ion o an ugly s a oli h in adul -
hood wi h an al e ed gene al shape (Fig. 7B). In
adul s a oli h, an abno mal con exi y is isible
in he a ea o ansi ion o he s a oli h’s body
in o os um, while in no mal s a oli hs o his
species such con exi y is absen . This modi ied
zone is ma ked by 3 longi udinal su u es lines
o igina ing om he bounda y o wo pa ala al
s a oli hs, he dis ance be ween hese su u es is
274, 565 and 136, 177 µm o la ge and smalle
s a oli hs espec i ely (Fig. 6C). Thus, anomali y
in he appea ance o h ee g ow h poin s and wo
pa ala al s a oli hs o modi ied shape induced
o he change in he c ys alliza ion p ocess o
his de ec i e s a oli h as a whole. As can be seen
om he g ow h pa e n o abno mal s a oli h,
his squid o he i s 4 days a e ha ching had
wo s a oli hs in he igh s a ocys chambe and
one s a oli h in he le chambe . Such anomali y
esul ing in appea ance o asymme ic s a oli hs
wi hin one pai has ne e been desc ibed ye in
coleoid cephalopods.
The s a oli h in he le chambe o s a ocys
had no anomalies in i s de elopmen (Fig. 7A),
bu a i s sigh i seems ha pa ala al s a oli h
in his specimen was mo e ounded han usual
o B. sep emden a us (Fig. 8). The leng h o his
pa ala al s a oli h was 242 µm and he wid h
was 131 µm. Thus, he wid h o leng h a io was
0.54, while in he es 38 B. sep emden a us speci-
mens s udied he wid h o leng h a io a e aged
0.5. Dis ances om nucleus o i s -check ma k
we e 49, 125, 58 and 118 µm. I can be no ed
ha he dis ance om he c ys alliza ion poin
o he ha ching line in di ec ion o la e al dome
in all he e pa ala al s a oli hs om his pai o
s a ocys s is almos iden ical: 49 µm and 47 µm
o he de ec i e one and 49 µm o he no mal.
