In e eb a e Zoology, 2024, 21(1): 81–93 © INVERTEBRATE ZOOLOGY, 2024
A new species o he genus P oasellus (C us acea:
Isopoda: Asellidae) om he Abin Ri e basin,
wi h he p elimina y da a on he di e si y o he genus
in he sou hwes e n oo hills o he Russian Caucasus
I an N. Ma in1*, Se gey Yu. Sinelniko 2
1 A.N. Se e so Ins i u e o Ecology and E olu ion, Russian Academy o Sciences, Leninsky p ospek
33, Moscow 119071 Russia. E-mail: [email p o ec ed]
2 Papanin Ins i u e o he Biology o Inland Wa e s, Russian Academy o Sciences, Bo ok, Ya osla l
Region 152742 Russia. E-mail: [email p o ec ed]
* co esponding au ho
I an Ma in: ORCID: 0000-0003-0552-8456
Se gey Sinelniko : ORCID: 0000-0003-4188-4589
ABSTRACT. A new s ygobio ic species o he genus P oasellus Dudich, 1925 (C us acea:
Isopoda: Asellidae), P oasellus abini sp.n., is desc ibed om he hypo heic habi a s and
g oundwa e o he Abin Ri e basin, loca ed in he sou hwes e n oo hills o he Caucasian
Ridge. The new species is mo phologically and gene ically close o P oasellus linea is
Bi š ein, 1967, known om he E s a ie Sсhel (=Ashamba Ri e ) nea Gelendzhik. Da a
on phylogeny, ecology and eeding o he species and o he SW Caucasian species o he
genus a e also p esen ed in he pape .
How o ci e his a icle: Ma in I.N., Sinelniko S.Yu. 2024. A new species o he genus
P oasellus (C us acea: Isopoda: Asellidae) om he Abin Ri e basin, wi h he p elimina y
da a on he di e si y o he genus in he sou hwes e n oo hills o he Russian Caucasus //
In e . Zool. Vol.21. No.1. P.81–93. doi: 10.15298/in e zool.21.1.04
KEY WORDS: C us acea, di e si y, P oasellus, new species, hypo hea, s ygobio ic, sou h-
wes e n Caucasus, Russia.
Новый вид рода P oasellus (C us acea: Isopoda:
Asellidae) из бассейна реки Абин,
с предварительными данными по разнообразию рода
из юго-западных предгорий российского Кавказа
И.Н. Марин1*, С.Ю. Синельников2
1 Институт проблем экологии и эволюции им. А.Н. Северцова РАН, Ленинский проспект, 33,
Москва 119071 Россия. E-mail: [email p o ec ed]
2 Институт биологии внутренних вод им. И.Д. Папанина РАН, Борок, Ярославская обл. 152742
Россия. E-mail: [email p o ec ed]
* Автор для переписки
РЕЗЮМЕ. Новый стигобионтный вид рода P oasellus Dudich, 1925 (C us acea: Isopoda:
Asellidae), P oasellus abini sp.n., описывается из гипогейных биотопов и подземных
вод бассейна реки Абин, расположенной в юго-западных предгорьях Кавказского
хребта. Новый вид морфологически и генетически близок к P oasellus linea is Bi š ein,
1967, известному из Евстафьевской щели (= река Ашамба) близ Геленджика. В статье
также представлены данные о филогении, экологии и питании этого вида и других
представителей рода с юго-западных предгорий Кавказа.
I.N. Ma in, S.Yu. Sinelniko 82
In oduc ion
G oundwa e ecosys ems a e among he mos
unde s udied habi a s o ou plane (Saccò e al.,
2023). Cu en knowledge on he di e si y o
sub e anean and hypo heic c us aceans o he
Caucasus is s ill agmen a y, despi e he ac
ha qui e a lo o publica ions wi h a desc ip ion
o s ygobio ic di e si y ha e appea ed ecen ly
(Ma in, 2017, 2019, 2020; Ma in, Pala o , 2019a,
2023a, b; G ego e al., 2020; Pala o , Sokolo a,
2021; Ma in e al., 2021b, 2022, 2023; Rendoša
e al., 2021; Anis a enko e al., 2022; Pala o
e al., 2023). Mos likely he eason is ha
Caucasus is he second egion o he Wes e n
Palea c ic (a e he Balkan Peninsula) in e ms
o he size o ka s a ea, he a ie y o landscapes
and clima ic condi ions (Mye s e al., 2000;
K e e e al., 2001), as well as g oundwa e -
adap ed biodi e si y is mainly composed o
sho - ange species wi h es ic ed dis ibu ions
(T on elj e al., 2009; Eme e al., 2018). Mos o
he hypo heic c us aceans o he Caucasus a e
na owly endemic (Ma in e al., 2021; Pala o ,
Ma in, 2021). I is also impo an ha he s udy
o g oundwa e o ganisms is hinde ed by he
inaccessibili y and complexi y o hei collec ion.
The genus P oasellus Dudich, 1925 (C us-
acea: Isopoda: Asellidae) is one o he mos
di e se and mos widely dis ibu ed gene a o
g oundwa e c us aceans in he wes e n Pa-
laea c ic, cu en ly including abou 125 alid
species (Boyko e al., 2023). The unde s udy
in he Caucasus is also ue o his g oup o
c us aceans, especially in he wes e n pa o
he Caucasus Moun ains. Cu en ly only 7 spe-
cies o he genus P oasellus a e known om
di e en locali ies in he Caucasus, mos ly
desc ibed by J.A. Bi š ein (1936, 1967) (a e
Pala o , Sokolo a, 2021; Pala o e al., 2023).
A he same ime, only one species o his genus
has been desc ibed, namely P oasellus linea is
Bi š ein, 1967 om he wes e n oo hills o he
Caucasus, exac ly om he E s a ie Sсhel nea
Gelendzhik (Bi š ein, 1967). This loca ion mos
likely e e s o he sou ces o he small moun ain-
ous i e Ashamba (Yashamba), o igina ing on
he sou he n slope o he Ma kho h Ridge and
lowing in o he Black Sea in he Blue Bay a ea
(Gelendzhik). The endemism o his a ea has
al eady been shown on ano he g oup o hypo-
heic c us aceans, ep esen a i es o he genus
Nipha gus Schiöd e, 1849 (C us acea: Amphi-
poda: Nipha gidae) (Ma in e al., 2021a) and
ep esen a i es o he genus Lyu ella De zha in,
1939 (C us acea: Amphipoda: C angonyc idae)
(Ma in, Pala o , 2021b).
Recen sampling o ep esen a i es o he
genus P oasellus ha e shown ha hey a e much
mo e di e se han p e iously hough , inhabi -
ing he hypo hea o all la ge i e s in he a ea.
In his a icle we p esen da a on he molecula
di e si y, dis ibu ion, ecology o ep esen a-
i es o he genus in he wes e n oo hills o he
sou hwes e n Caucasus, as well as desc ibe a new
species om he Abin Ri e basin and nea by
small moun ainous i e s.
Ma e ial and Me hods
SPECIMEN SAMPLING and MORPHOLOGI-
CAL STUDY. G oundwa e isopods we e collec ed
by hand ne in sp ings and wells in he oo hill a ea o
he sou hwes e n Caucasus (see Fig. 1). All specimens
we e ixed in 70–90% solu ion o e hanol. The ype
ma e ial is deposi ed in he collec ion o Zoologi-
cal Museum o Moscow S a e Uni e si y, Moscow
(ZMMU) and au ho ’s collec ion in A.N. Se e so
Ins i u e o Ecology and E olu ion o Russian
Academy o Sciences, Moscow, Russia (LEMMI).
The body leng h (bl., in mm), he do sal leng h om
he an e odo sal ma gin o he head o he ma gin o
he pleo elson, wi hou he leng h o u opods and
an ennas, was used as a s anda d measu emen . Line
d awings we e made using came a lucida a ached o
Olympus SZX10 ligh s e eomic oscope.
MOLECULAR STUDY. A agmen o he mi-
ochond ial gene coding o cy och ome c oxidase
subuni I (COI m DNA) gene ma ke was ampli ied
wi h he help o he uni e sal p ime s LCO1490
Как цитировать эту статью: Ma in I.N., Sinelniko S.Yu. 2024. A new species o he genus
P oasellus (C us acea: Isopoda: Asellidae) om he Abin Ri e basin, wi h he p elimina y
da a on he di e si y o he genus in he sou hwes e n oo hills o he Russian Caucasus //
In e . Zool. Vol.21. No.1. P.81–93. doi: 10.15298/in e zool.21.1.04
КЛЮЧЕВЫЕ СЛОВА: ракообразные, разнообразие, P oasellus, новые виды, гипогея,
стигобионтный, юго-западный Кавказ, Россия.
A new P oasellus om he Abin Ri e basin 83
Fig. 1. Map o collec ion si es and phylogene ic ela ionships o P oasellus abini sp.n. Boo s ap suppo o
all nodes is epo ed.
Рис. 1. Карта мест сбора и филогенетические взаимоотношения P oasellus abini sp.n. Поддержка узлов
(клад) представлена.
(5’-gg caacaaa ca aaaga a gg-3’) and HC02198
(5’- aaac caggg gaccaaaaaa ca-3’) (Folme e al.,
1994). The ob ained sequences o he new species
a e deposi ed in he GenBank (NCBI) da abase o
he u he gene ic s udies. The aligned sequences o
COI m DNA gene ma ke s, 658 base pai s in leng h,
we e analyzed o pai wise sequence di e gence
(unco ec ed p–dis ances) wi h he sequences o he
ela ed species, deposi ed in GenBank (NCBI) da-
abase using MEGA 7.0 (Kuma e al., 2016). Only
Caucasian species o he genus P oasellus we e used
o he phylogene ic analysis. The bes e olu iona y
subs i u ion model was de e mined using MEGA 7.0.
and jModel es 2.1.141 (Diego Da iba, Uni e sidade
da Co uña as pa o he Compu e A chi ec u e G oup
(GAC), Co uña, Spain) on XSEDE ia he CIPRES
(Cybe In as uc u e o Phylogene ic Resea ch) Sci-
ence Ga eway V. 3.3 (h p://www.phylo.o g/, accessed
on 10 Sep embe 2023). Phylogene ic analysis was
pe o med using PhyML 3.0 (Guindon e al., 2010)
using GTR+G+I model o Maximum-Likelihood
analysis (ML).
Unco ec ed pai wise gene ic di e gence (p-
dis ances) was calcula ed using MEGA 7.0 wi h
he Kimu a 2‐Pa ame e (K2P) model o e olu ion
(Kimu a, 1980).
STABLE ISOTOPE ANALYSIS. Ma e ial o he
analysis o s able iso ope (δ13C/δ15N) was collec ed
in sp ings o No o ossiyskaya Schel, 44°44′27.39″N
37°54′03.71″E. The muscles issues o collec ed
animals we e o en-d ied a 50 °С o 4–5 days, and
hen we e w apped in in oil (1200–1500 µg and
400–600 µg, espec i ely). The iso opic composi ion
was de e mined using a The mo-Finnigan Del a V
I.N. Ma in, S.Yu. Sinelniko 84
Table 1. Pai wise gene ic (COI m DNA) dis ances (p-dis ances) (subs i u ions pe 100 nucleo ides) o P oasellus adegoyi sp.n. and congene s
om he Russian Caucasus.
Таблица 1. Попарные генетические (COI мтДНК) расстояния (p-дистанции) (замены на 100 нуклеотидов) P oasellus adegoyi sp.n.
и родственных видов с Российского Кавказа.
P oasellus abini
sp.n. (Abin
Ri e Basin) P. linea is Pshada
Basin Mezyb
Basin Vulan
Basin P. lio uschkini Vo on so ka
сa es P. i ys onicus P. p ecaspicus
P. linea is 0.086
P oasellus sp.
Pshada Basin 0.112 0.089
P oasellus sp.
Mezyb Basin 0.120 0.93 0.087
P oasellus sp.
Vulan Basin 0.124 0.103 0.110 0.091
P. c . lio uschkini 0.153 0.132 0.127 0.103 0.141
P oasellus sp.
Vo on so ka сa es 0.170 0.180 0.199 0.171 0.187 0.196
P. i ys onicus 0.145 0.144 0.139 0.099 0.154 0.147 0.188
P. p ecaspius 0.151 0.149 0.133 0.141 0.137 0.169 0.181 0.154
P oasellus sp.
Ka achae o-
Che kessiya 0.128 0.130 0.121 0.111 0.125 0.122 0.175 0.131 0.101
A new P oasellus om he Abin Ri e basin 85
Plus con inuous- low mass spec ome e (The mo
Elec on GmbH, B emen, Ge many) coupled wi h
an elemen al analyze (The mo Flash 1112, The mo
Elec on) a he Join Usage Cen e a he A.N. Se -
e so Ins i u e o Ecology and E olu ion o he Rus-
sian Academy o Sciences. The iso opic composi ion
o N and C was exp essed in he δ-no a ion ela i e
o he in e na ional s anda d (a mosphe ic ni ogen
o VPDB): δX(‰) = [(Rsample/Rs anda d) − 1] ×
1000, whe e R is he a io o he hea ie iso ope
o he ligh e iso ope. Samples we e analyzed wi h
e e ence gases calib a ed agains IAEA (Vienna,
Aus ia), e e ence ma e ials USGS 40 and USGS
41 (glu amic acid). The d i was co ec ed using
in e nal labo a o y s anda ds (ace anilide, casein).
The s anda d de ia ion o δ15N/δ13C alues in a e
labo a o y s anda ds (n=8) was <0.15‰.
S anda d abb e ia ions: A — an enna; Ep —
epime al pla e; Gn — gna hopods; M — maxilla;
Mx — maxilliped; P — pe eo pod; PL — pleopod;
Pp — pe eopods; T — elson; U — u opod; U —
u osomi e.
Resul s
PHYLOGENETIC DATA. The in e speci ic
gene ic di e gence o he new species is he low-
es compa ing wi h P. linea is om Ashamba,
ep esen ing abou 0.086 subs i u ions pe 100
nucleo ides (8.6%), while he di e gence om
o he Caucasian congene ic species eaches mo e
han 10% (see Table 1), which indica es p o-
longed isola ion and he absence o a gene low.
Phylogene ically he new species is also close
o P. linea is, p obably being i s sis e species
(see Fig. 1). A he same ime, all SW Caucasian
species o he genus P oasellus ep esen he
monophyle ic clade, wi h he species inhabi ing
hypo hean and unde g ound habi a s in he basins
o di e en local moun ainous i e s, such as
Ashamba, Abin, Pshada, Mezyb, Vulan, which
we e sepa a ed du ing las 2 Mya in he esul
o moun ain g ow.
TROPHIC POSITION BASED ON ISO-
TOPIC ANALYSIS. The s udied new species,
P oasellus abini sp.n., is si ua ed in he low opic
posi ion (–22.67±0.12 o δ13C and 4.40±0.32
o δ15N) close o p ima y he bi o ous animals
in he gene al scheme o iso opic alues o δ13C
and δ15N o mac ozooben hos (see Ma in e al.,
2021a). The simila ophic posi ion is cha ac e -
is ic o he bi o ous c us aceans co-occu ing in
he sp ings o he No o ossiyskaya Schel, such
as undesc ibed species o he genus Nipha gus
om he “ au icus” species complex (Amphi-
poda: Nipha gidae), Synu ella adegoyi Ma in
e Pala o , 2022 (Amphipoda: C angonyc idae)
(see Ma in & Pala o , 2022) and Gamma us c .
koma eki Schä e na, 1923 (Amphipoda: Gam-
ma idae), which a e p obably eed on p ima y
o ganic ma e , like he emains and oo s o
a ious o es plan s ha all in o he hypo hea
and g oundwa e (pe s. obse .; unpublished).
Taxonomic accoun
Isopoda La eille, 1817
Subo de Asello a La eille, 1802
Family Asellidae Ra inesque-Schmal z, 1815
Genus P oasellus Dudich, 1925
P oasellus abini sp.n.
Figs 2D–F, 3–5.
MATERIAL EXAMINED. Holo ype: ♀ (bl. 6.2
mm), ZMMU Mc-1458, Russian Fede a ion, sou h-
wes e n Caucasus, K asnoda K ai, Gelendzyk a ea,
he uppe s eam o he Adegoy Ri e , No o ossiys-
kaya Schel, 44°44′27.39″N 37°54′03.71″E, in he i e
hypo heic habi a s, hand ne sampling, coll. I. Ma in,
S. Sinelniko & S. Ma ina, 8 No . 2021.
Pa a ypes: ♀ (bl. 5.5 mm), ♂ (bl. 6.0 mm),
ZMMU Mc-1459, Russian Fede a ion, sou h-wes e n
Caucasus, K asnoda K ai, K ymsky dis ic , he
uppe s eam o he Shids Ri e , 44°48′09.03″N
37°59′26.54″E, inside a small well, coll. I. Ma in, S.
Ma ina, 24 July 2021.
O he ma e ial: Russian Fede a ion, sou h-wes e n
Caucasus, K asnoda K ai: 2♀♀, 6♂♂, LEMMI, Abin
a ea, he uppe s eam o he Abin Ri e , 44°43′32.3″N
38°10′04.5″E, coll. I. Ma in, S. Ma ina, 12 Aug.
2021; 5♀♀, 7♂♂, LEMMI, he uppe s eam o he
Adegoy Ri e , A onka, 44°42′53.2″N 37°58′27.1″E,
in he i e hypo heic habi a s, hand ne sampling,
coll. I. Ma in, S. Ma ina, 18 July 2021; 2♀♀, 4♂♂,
LEMMI, Abin a ea, Adegoy Ri e , nea Shapsugskaya
illage, 44°43′31.8″N 38°02′13.8″E, in he i e hy-
po heic habi a s, hand ne sampling, coll. I. Ma in,
S. Ma ina, 19 July 2021; 5♀♀, 6♂♂, LEMMI, Abin
a ea, Abin Ri e , Shapsugskaya illage, 44°45′30.2″N
38°04′50.0″E, in he i e hypo heic habi a s, hand
ne sampling, coll. I. Ma in, S. Ma ina, 19 July 2021;
3♀♀, 6♂♂, LEMMI, Abin i e , 44°43′43.6″N
38°06′35.6″E, in he i e hypo heic habi a s, hand
ne sampling, coll. I. Ma in, S. Ma ina, 3 Aug. 2021.
ETYMOLOGY. The new species is named a e
he Abin Ri e (SW Caucasus), in he basin o which
he new species was disco e ed.
DIAGNOSIS. Medium-sized, depigmen ed spe-
cies. Head bisinua e, medially conca e, abou 1.4
I.N. Ma in, S.Yu. Sinelniko 86
Fig. 2. Gene al iew and na u al habi a o P oasellus abini sp.n.: A — a o es well, Shids, gene al iew;
B, C — indi iduals o he new species on he bo om and walls o he well; D, F — gene al do sal iew o
ali e indi idual o he new P oasellus abini sp.n. and i s la e al iew (E).
Рис. 2. Общий вид и природные местообитания P oasellus abini sp.n.: A — лесной колодец, Шидс,
общий вид; B, C — особи нового вида на дне и стенках колодца; D, F — общий дорсальный вид живой
особи P oasellus abini sp.n. и ее вид сбоку (E).
A new P oasellus om he Abin Ri e basin 87
Fig. 3. P oasellus abini sp.n., ♂ om he hypo hean habi a s o he uppe s eam o Adegoy i e ( igh ibu-
a y o Abin i e ), No o ossiyskaya Schel: A — bo h an enna I and II; B — an enna I; C — dis al lagellum
o an enna I; D — labium; E — lab um; F — igh mandible; G — pa s incisi a (inciso ) o igh mandible;
H — maxilla; I — maxillula; J — maxilliped.
Рис. 3. P oasellus abini sp.n. ♂ из гипогеи верхнего течения реки Адегой (правого притока реки Абин),
Новороссийская щель: A — антенны I и II; B — антенна I; C — дистальный жгутик антенны I; D —
лабиум (нижняя губа); E — (лабрум) верхняя губа; F — правая мандибула; G — резцовый отросток
правой мандибуды; H — максилла; I — максиллула; J — максиллипед.
I.N. Ma in, S.Yu. Sinelniko 88
Fig. 4. P oasellus abini sp.n., ♂ om he hypo hean habi a s o he uppe s eam o Adegoy i e , No o os-
siyskaya Schel: A — pe eopod I; B — dac ylus o PI; C — pe eopod II; D — dac ylus o PII; E — pe eopod
III; F — dac ylus o PIII; G — pe eopod IV; H — dac ylus o PIV; I — pe eopod V; J — dac ylus o PV;
K — pe eopod VI; L — dac ylus o PVI; M — pe eopod VII; N — dac ylus o PVII.
Рис. 4. P oasellus abini sp.n., ♂ из гипогеи верхнего течения реки Адегой, Новороссийская щель: A —
переопода I; B — дактилус PI; C — переопода II; D — дактилус PII; E — переопода III; F — дактилус
PIII; G — переопода IV; H — дактилус PIV; I — переопода V; J — дактилус PV; K — переопода VI;
L — дактилус PVI; M — переопода VII; N — дактилус PVII.
A new P oasellus om he Abin Ri e basin 89
Fig. 5. P oasellus abini sp.n., ♂ (A–C, E, F, G, H) and ♀ (D, I) om he hypo hean habi a s o he uppe
s eam o Adegoy i e , No o ossiyskaya Schel: A — pleopod I; B — e inacula on medial ma gin o p o-
opodi e o PLI; C — pleopod II (♂); D — pleopod II (♀); E — pleopod III (♂); F — pleopod IV and V (♂);
G — pleo elson; H, I — u opod.
Рис. 5. P oasellus abini sp.n., ♂ (A–C, E, F, G, H) и ♀ (D, I) из гипогеи верхнего течения реки Адегой,
Новороссийская щель: А — плеопода I; B — ретинакула на медиальном краю протоподита PLI; C —
плеопода II (♂); D — плеопода II (♀); E — плеопода III (♂); F — плеопода IV и V (♂); G — плеотельсон;
H, I — уропода.
