Redescription of Ethmolaimus multipapillatusParamonov, 1926 (Nematoda: Chromadorida: Ethmolaimidae)

2011·0.46 MB·

by  S. Ya. Tsalolikhin

ZOOSYSTEMATICA ROSSICA, 20(1): 3–10 28 JULY 2011
Redescription of Ethmolaimus multipapillatus Paramonov, 1926
(Nematoda: Chromadorida: Ethmolaimidae)
Переописание Ethmolaimus multipapillatus Paramonov, 1926
(Nematoda: Chromadorida: Ethmolaimidae)
S.YA. TSALOLIKHIN
С.Я. ЦАЛОЛИХИН
S.Ya. Tsalolikhin, Zoological Institute, Russian Academy of Sciences, 1 Universitetskaya Emb., St Petersburg 199034,
Russia. E-mail: [email protected]
The neotype of Ethmolaimus multipapillatus Paramonov, 1926 is designated from Inder Lake,
Kazakhstan. Taxonomy, zoogeography and biology of the genus Ethmolaimus are discussed. A
key to species of the genera Ethmolaimus, Paraethmolaimus and Trichethmolaimus is given.
Выделен и описан неотип Ethmolaimus multipapillatus Paramonov, 1926 из озёра Индер
в Казахстане. Обсуждается таксономия, зоогеография и экология рода Ethmolaimus.
Приведен ключ для определения видов родов Ethmolaimus, Paraethmolaimus и Tricheth-
molaimus.
Key words: free-living nematodes, brackish waters, zoogeography, Kazakhstan
Ключевые слова: свободноживущие нематоды, солоноватые воды, зоогеография,
Казахстан
INTRODUCTION (Ethmolaimus cf. multipapillatus Paramonow,
1929 (sic!) in Gerlach, 1957). Therefore, of
Species Ethmolaimus multipapillatus
great interest is the material from brackish
was described by A.A. Paramonov (1926)
lakes of north-western Kazakhstan: Chelkar
from brackish waters near the Kinburn Spit (50°28´N 51°40´E), Alzhan (50°16´N
(Black Sea, Dnieper-Bug Liman). Even
50°41´E) and Inder (48°28´N 51°50´E),
though this species was recorded by this au-
where a large number of males, females and
thor as frequently occurring and abundant,
larvae of E. multipapillatus were found.
it was described by one male specimen and
The morphological characters and mor-
two female specimens only (Paramonov,
phometric data for the western Kazakh-
1926, 1929). Ethmolaimus multipapillatus
stan specimens conform completely to the
was discovered for the second time in the
original description of the species (Table
Black Sea near the Varna coast where three
1 and 2). Unfortunately, the type material
females and one male were collected (Ger-
collected by A.A. Paramonov has not been
lach, 1951). No other reliable records of the
species have been reported since it descrip- preserved. The neotype is designated here
tion done 85 years ago, except for a num- with the purpose of clarifying the taxonom-
ber of publications where E. multipapillatus ic status of Ethmolaimus multipapillatus in
was either just mentioned (e.g. Platt, 1982, accordance with conditions of Art. 75.3 of
1985) and no morphometric data were given the International Code of Zoological No-
(Jensen, 1994; Platt, 1985) or no reference mencalture (International Commission on
to males was made (Decraemer & Coomans, Zoological Nomenclature, 1999) as dis-
1978), or species identification was doubtful cussed in detail below.
© 2011 Zoological Institute, Russian Academy of Scienсes
4 S.YA. TSALOLIKHIN. REDESCRIPTION OF ETHMOLAIMUS MULTIPAPILLATUS
Ethmolaimus multipapillatus Paramonov, terms of both zoogeography and autecology.
1926 It should be remembered that a number of
(Figs 1–8) identifications are insufficiently reliable, as
has been mentioned above. Thus, a species
Neotype of E. multipapillatus: male; Ka-
similar to E. multipapillatus was identified
zakhstan, Inder Lake, 24 May 2010, coll.
by one female found in mangrove thickets of
L.Ya. Borkin; slide No A-7175 (Zoologi-
the Brazilian coast (Gerlach, 1957). How-
cal Institute, St. Petersburg, Russia). Ad- ever, species identification of this genus is
ditional material: 33 males, 61 females, 18 based primarily upon male genital structure,
juveniles from Inder Lake, Alzan Lake and and therefore, the absence of males in the
Chelkar Lake, same date and collector. material reduces reliability of this identifi-
Together with E. multipapillatus the fol- cation. The same is true for the discovery of
lowing species were found: a male and a 49 females and 16 larvae (not a single male!)
female of Penzancia flevensis (Stekhoven, of E. multipapillatus in mangrove thickets
1935), a larva of Tripyla tenuis Brzecki, of the Lizard Island, which is a part of the
1964, and a larva of Alaimus sp. Great Barrier Reef in Northern Australia
Description of neotype. L=1026 μm, (Decraemer & Coomans, 1978). The au-
a=38, b=8.6, c=15.8, spic. 35 μm, suppl. 22. thors have provided neither morphometry
Cuticle finely annulated, punctuation fine. nor drawings. Few males and females (with-
Cephalic diameter 13 μm. Cephalic setae out morphometric data, but with good mi-
about 1 μm long. Buccal cavity consists of crophotographs) have been reported in the
two parts: anterior part cup-shaped with work based on material from the hypersaline
weakly sclerotized walls, and long cylindri- lake (270‰) in Africa on the Namibia coast
cal part 19 μm with well sclerotized walls; in the region of Lüderitz Town (Platt, 1985),
at junction between the two parts curved and also from waters with similar salinity in
teeth inserts: one dorsal tooth and two sub- the estuary of the Murray River in Australia
ventral teeth, dorsal tooth being slightly and in the region of Malaga in Spain (Jensen,
more sclerotized then subventral ones. Am- 1994). Salinity of the Kinburn lakes, where
phid 4 μm in diameter, centre of amphid E. multipapillatus was found for the fist time,
situated in 13 μm behind front end. Oe- is 9–12‰; salinity of Western Kazakhstan
sophagus 120 μm long, bulbus 29 × 19 μm, lakes varies depending on the season and
NR=54%. Cardia small. Renetta fairly can reach 318‰.
outstretched (“tubular” sensu Paramonov, Revisions of the genus Ethmolaimus de
1929) and situated in 30 μm behind bulbus Man, 1880 including an analysis of species
and opening through a pore behind nerve composition were carried out repeatedly,
ring. Testes: T =245 μm, T =136 μm; sper- beginning with the work of Micoletzky
1 2
mia diameter about 7 μm. Spicules broad (1921). Hirschmann (1952) reduced all the
and sickle-shaped, 35 μm along axis (along species that had been described by that time,
the arc) and 27 μm along chorda (from tip except for E. multipapillatus, to synonyms of
to tip). Supplements 22, length of supple- the type species Ethmolaimus pratensis de
ments row 270 μm. Tail 65 μm long; caudal Man, 1880. Later, validity of the majority
glands well developed. Measurements of of the synonymised species was restored
others specimens see in Tables 1 and 2. (Gerlach & Riemann, 1973; Tsalolikhin,
1985). At present, the genus is considered
to include 12–14 valid species (Andrassy,
Comments to the redescription of
Ethmolaimus multipapillatus 2005; Decraemer & Smoll, 2006), of which
four species have been described based on
Literature data on distribution of Eth- females only, that casts some doubt upon
molaimus multipapillatus are of interest in their validity.
© 2011 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 20(1): 3–10
S.YA. TSALOLIKHIN. REDESCRIPTION OF ETHMOLAIMUS MULTIPAPILLATUS 5
Figs 1–8. Ethmolaimus multipapillatus. 1, entire body of male; 2, head lateral view, 3, head dorsal
view; 4, tail of male; 5, tail of femail; 6, posterior end of male lateral view; 7, posterior end of male
ventral view; 8, vulvar section and mature eggs. Scale bars: 60 μm (1), 15 μm (2–7), 40 μm (8).
Ethmolaimus bothnicus Jensen, 1994 and brackish and hypersaline waters should be
Ethmolaimus hailuotoensis Turpeenniemi, placed in a distinct taxon. There are few ex-
1995 can be considered to belong to brack- amples of nematodes with such a wide range
ish water (“semi-marine„) species, and E. of salinity tolerance, this is, primarily, Chro-
hirsutus (Gerlach, 1956) Jensen, 1994, to madorita leuckarti (de Man, 1876), a species
marine species. Before the revision of Jen- occurring in both brackish and saline (20‰
sen (1994) the latter species was placed in and higher), and freshwater lakes and even
a separate genus Trichethmolaimus Platt, in rivers (Tsalolikhin, 1985).
1982 (syn. Spiliphera hirsuta Gerlach, 1956) It is worth mentioning that the great
(Platt, 1982), a conclusion that is quite jus- majority of species of the order Chromador-
tified and should be supported at present. ida are marine nematodes, and only a rela-
The others are freshwater species. Ethmo- tively small portion of those occur in fresh
laimus multipapillatus, occurring in both waters. This demonstrates a tendency in the
© 2011 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 20(1): 3–10
6 S.YA. TSALOLIKHIN. REDESCRIPTION OF ETHMOLAIMUS MULTIPAPILLATUS
Table 1. Morphometric charaters of males of Ethmolaimus multipapillatus
Inder, Alzan and Black Sea, Black Sea,
Characters Chelkar lakes, Kinburn Peninsula (n=1) Varna Town (n=2)
Kazakhstan (n=15) (Paramonov, 1926, 1929) (Gerlach, 1951)
839–1053
L, μm 907 1230–1233
(943±18)
27.1–39.5
a 28 19.8–27.4
(31.9±1)
7.3–9.5
b 8 6.8–9.4
(8.2±0.2)
11.9–17.1
c 13.5 11.2–19.3
(13.9±0.4)
c´ 2.6–3.3 3 2.1
(3±0.1)
104–124
Oesophagus, μm 113 130–181
(115±2)
59–77
Tail, μm 67 64–110
(68±1)
T= 137–250
1
(204±17)
Gonads, μm ? T  T  250
T= 79–193 1 2
2
(132±13)
19–28
Supplements, n 22–24 (n=?) 24
(22±1)
204–290
SR, μm* – –
(253±7)
23–30
SR/L,% – –
(26±0.6)
Along axis: 30–36
(33±1)
Sp, μm Along chord: 32 Along chord: 32
Along chord: 23–29
(27±0.5)
Along axis: 10–16
(13±1)
Sp/SR,% – –
Along chord: 9–14
(11±1)
10–15
Cephalic diameter, μm 13 16
(14±0.3)
16–19
Stoma (cylindrical part), μm 15–20 (n=?) 16
(17±0.5)
12–18
Stoma/oesophagus, % 12 12
(15±0.5)
Amphid diameter, μm 4–5 4 6
*SR – length of supplement row.
© 2011 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 20(1): 3–10
S.YA. TSALOLIKHIN. REDESCRIPTION OF ETHMOLAIMUS MULTIPAPILLATUS 7
Таble. 2. Morphometric characters of females of Ethmolaimus multipapillatus
Inder, Alzan and Black Sea,
Black Sea,
Chelkar lakes, Kinburn Peninsula
Characters Varna Town (n=4)
Kazakhstan (n=2) (Paramonov,
(Gerlach, 1951)
(n=6) 1926, 1929)
935–993 830–990
L, μm 837–902
(961±10) (919)
23.1–31.6 17–19.6
a 22–25
(27.8±1.3) (17.9)
8.4–8.8 7.4–8
b 7.5–8
(8.6±0.1) (7.6)
10.3–11.1 8.2–11.3
c 11.2–11.7
(10.5±0.1) (10.1)
c´ 4.2–5 2.8–3.3 2.6–3.3
(4.4±0.1) (3.1)
106–114 112–128
Oesophagus, μm 108–115
(112±2) (120)
89–93 84–95
Tail, μm 75–77
(91±1) (88)
Q=182–210
1
(200±9)
Gonads, μm ? QQ200
Q=182–193 1 2
2
(186±7)
49–52
V% 51 47–50
(51±0.5)
Cephalic diameter, μm 13–14 14–15 19
15–19
Stoma (cylindrical part), μm 17–20 16
(17±0.5)
14–17
Stoma/oesophagus, % 16 13
(15±0.5)
Amphid diameter, μm 3–4 4 5
order for adaptation to a new habitat (Tsal- phological character as head setae, “…in Eth.
olikhin, 1989). Paramonov’s (1929) point multipapillatus head setae disappeared, but
of view of freshwater origin of E. multipa- this can hardly be regarded as proof of the
pillatus is not sufficiently convincing. In the impact of saline waters <…> head setae are
context of the question of the origin of the by no means a “marine” character, and no
genus Ethmolaimus in general and species pattern at all can be formulated here …”.
E. multipapillatus in particular, Paramonov I suppose E. multipapillatus appears to
(1929: 122) wrote with regard to such mor- be originally marine, and it then settled in
© 2011 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 20(1): 3–10
8 S.YA. TSALOLIKHIN. REDESCRIPTION OF ETHMOLAIMUS MULTIPAPILLATUS
coastal regions of Gondwana and gradu- 4(1). Head with lip region not set-off.
ally adapted to high salinity in water bodies 5(6). Cephalic setae very short, not more than
that had separated from the sea. This is the 2 μm; supplements not less than 18 . . . . . Eth-
molaimus multipapillatus Paramonov, 1926
only explanation that can be applicable for
6(5). Cephalic setae well developed; supple-
the presumed wide distribution of the spe-
ments not more than 17.
cies that is observed at present.
7(8). Amphids are situated below the level of
Tchesunov (1983, 1983а) noted the re- stoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Eth-
semblance between the nematode fauna of molaimus hailuotoensis Turpeenniemi, 1995
the Dnieper-Bug Liman (where the Kin- [Baltic Sea, Bothnian Gulf, salinity 5‰,
burn Spit, a type locality of E. multipapil- depth 12–22 m, sand, mud (Turpeenniemi,
latus is located), and that of the Caspian (1995)]
8(7). Amphids situated on level of stoma or at
Sea. However, the genus Ethmolaimus is
boundary of stoma and oesophagus.
absent in the list of the Caspian nematodes
9(10). Excretory duct of rеnеttа opening at level
(Tchesunov, 1983). Reliable data on nema-
of stoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
tode communities of saline lakes of the Cas- . . . . . Ethmolaimus derisorius Shoshin, 1998
pian Depression and the Caspian Sea are [Lake Baikal, depth 3–4 m, weakly muddy
extremely scanty; these are the data given fine sand (Shoshin, 1998)]
in the present work and in the description 10(9). Excretory duct of renetta opening in re-
of Oncholaimus bajulus Paramonov, 1937 gion of nerve ring.
11(14). Somatic setae are numerous, 20–50 to
from saline Lake Takhtaral in the drainage
200 μm in length.
of the Emba River (Paramonov, 1937). It
12(13). Somatic setae up to 200 μm; supple-
is noteworthy that another species of the
ments not more than 10 . . . . . . . . . . . . . . . . . . . . .
same genus, Oncholaimus hyrcanus Tchesu- Trichethmolaimus hirsutus (Gerlach, 1956)
nov, 1979 that is not closely related to the [North Sea, Kiel Bay and Clyde Sea (north-
species from Takhtaral (Tchesunov, 1976, western Scotland), salinity up to 35‰ (Jen-
1979, 1983а) inhabits the Caspian Sea. sen, 1994)]
Based on the limited data on the range 13(12). Somatic setae 20–50 μm; supplements
12–14.
of E. multipapillatus it can be assumed that
14(15). Cephalic setae 15 μm; spicules 32–34 μm
the Black Sea and Kazakhstan populations
. . . . . . . . . Ethmolaimus pilosus Shoshin, 1998
could have comprised a single (macro)
[Lake Baikal, depth 3–4 m, weakly muddy
population inhabiting the Ponto-Caspian fine sand (Shoshin, 1998)]
basin. I suppose that, taking into account 15(14). Cephalic setae 25 μm; spicules 28 μm . . . .
the absence of available specimens from the . . . . . . . . Ethmolaimus lanatus Shoshin, 1998
Black Sea basin, the designation of the neo- [Lake Baikal, depth 3–4 m, weakly muddy
type as it is done above from a Kazakhstan fine sand (Shoshin, 1998)]
16(11). Somatic setae short, very short or absent.
lake does not contradict Art 75.3.6 of the
17(18). Only dorsal tooth developed . . . Ethmo-
Code because the neotype came as nearly as laimus zullinii Eyualem & Coomans, 1996
practicable from the original type locality.
[Africa, Ethiopia: Lake Tana, depth 0.5 m,
mud (Eyualem & Coomans, 1996)]
Key to species of genus Ethmolaimus, 18(17). All three teeth developed, the dorsal be-
Paraethmolaimus and Trichethmolaimus ing as a rule larger, sometimes much larger
than subventral ones.
1(4). Head with lip region set-off. 19(20). Spicules slender and sickle-shaped, 25–
2(3). Supplements 20–28 . . . . . . . . . . . . . . . . . . . . . . . 27 μm along chord . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . Paraethmolaimus dahli (Gerlach, 1953) . . . . . . . Ethmolaimus bothnicus Jensen, 1994
[coastal brackish waters of South America [Baltic Sea, Bothnian Bay (Jensen, 1994)]
(Jensen, 1994)] 20(19). Spicules not slender (massive), arcuate.
3(2). Supplements 15–17 . . . . . . . . . . . . . Paraeth- 21(24). Oesophageal bulb is weakly developed.
molaimus appendixocaudatus Jensen, 1994 22(23). Amphid situated in upper part of stoma .
[brackish waters in Australia (Jensen, 1994)] . . . . . Ethmolaimus intermedius Jensen, 1994
© 2011 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 20(1): 3–10
S.YA. TSALOLIKHIN. REDESCRIPTION OF ETHMOLAIMUS MULTIPAPILLATUS 9
[Austria: Attersee, Finsterlatersee (Jensen, lung der der Academie der Wissenschaften
1994)] und der Literatur in Mainz, Mathematisch-
23(22). Amphid situated at base of stoma . . . . . . . Naturwissenschaftliche Klasse, 5: 131–176.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ethmolaimus Gerlach, S. & Riemann, F. 1973. Bremerhafen
parapratensis Alekseev & Naumova, 1979 Checklist of Aquatic Nematodes. Veröffent-
[Russia, Far East, Lake Khasan (Alekseev et lichungen des Instituts für Meeresforschung in
al., 1979)] Bremerhaven, Suppl. 4 (1): 296–298.
24(21). Oesophageal bulb strong. Hirschmann, H. 1952. Die Nematoden der Was-
25(26). Amphid diameter about 1/3 of head sergrenze Mittelfrankische Gewässer. Zoo-
width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . logische Jahrbücher, Abteilung für Systematik,
. . . . Ethmolaimus foreli (Hofmaenner, 1913) Geographie und Biologie der Tiere, 81 (4):
[lakes of Switzerland (Hofmänner & Menzel, 313–407.
1913)] International Commission on Zoological No-
26(25). Amphid diameter about ½ of head width. menclature. 1999. International Code of
27(28). Dorsal tooth much larger than subven- Zoological Nomenclature adopted by the In-
tral ones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ternational Union of Biological Sciences, 4th
Ethmolaimus revaliensis (Schneider, 1906) edition. The International Trust for Zoologi-
[freshwater lakes of Europe (Gerlach & Rie- cal Nomenclature, London. xxix + 306 p.
mann, 1973); freshwater lakes of Mongolia Jensen, P. 1994. Revision of Ethmolaiminae
(Tsalolikhin, 1985); Lake Baikal (Shoshin, with description of one new genus and three
1998)] new species. Hydrobiologia, 286: 1–15.
28(27). All teeth approximately similar . . . . . . Paramonow, A.A. 1926. Anatomische und sy-
. . . Ethmolaimus pratensis de Man, 1880 stematische Beiträge zur Kentniss der frei-
(syn.: E. tatricus Daday,1897; E. lemani Hof- lebenden Nematoden. Russkiy Zoologicheskiy
maenner, 1913; E. alpinus Micoletzky, 1914; Zhurnal, 6(2): 44–56.
E. americanus Cobb,1914; E. gracilicaudatus Paramonov, A.A. 1929. Die freilebenden Nema-
Cobb,1915; E. maduei Micoletzky, 1922; E. toden der Kinburnsense und der Angrenzen-
caudatus Alekseev et Dimina, 1979) den Gewässer. Arbeiten der Staatlichen Ich-
[widespread in moist soils, mosses and fresh thyologischen Versuchs-Station, 4 (1): 59–130.
(more rarely) brackish waters of Europe, Paramonov, A.A. 1937. Oncholaimus bajulus
Asia and North America (Hirschmann, 1952; sp.nova. Zapiski Bolshevskoy biologicheskoy
Gerlach & Riemann, 1973)] stantsii, 10: 119–124.
Platt, H.M., 1982. Revision of the Ethmolaimi-
ACKNOWLEDGMENTS dae. Bulletin of the British Museum (Natural
History, 43(4): 185–252.
I am very grateful to L.Ya. Borkin for collect- Platt, H.M., 1985. Further observations on Eth-
ing the valuable material used in the paper. molaimidae. Journal of Natural History, 19:
139–149.
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Received February 10, 2011 / Accepted June 7, 2011
© 2011 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 20(1): 3–10