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A new species of Dynoides Barnard, 1914
(Crustacea, Isopoda, Sphaeromatidae) from
Canada, with notes on geographic distribution of
the north-eastern Pacific Ocean species
Valiallah Khalaji-Pirbalouty & Jean-Marc Gagnon
To cite this article: Valiallah Khalaji-Pirbalouty & Jean-Marc Gagnon (2021) A new species of
Dynoides Barnard, 1914 (Crustacea, Isopoda, Sphaeromatidae) from Canada, with notes on
geographic distribution of the north-eastern Pacific Ocean species, Marine Biology Research, 17:1,
12-20, DOI: 10.1080/17451000.2021.1892766
To link to this article: https://doi.org/10.1080/17451000.2021.1892766
© 2021 The Author(s). Published by Informa
UK Limited, trading as Taylor & Francis
Group
Published online: 18 Mar 2021.
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MARINE BIOLOGY RESEARCH
2021, VOL. 17, NO. 1, 12–20
https://doi.org/10.1080/17451000.2021.1892766
A new species of Dynoides Barnard, 1914 (Crustacea, Isopoda,
Sphaeromatidae) from Canada, with notes on geographic distribution of the
north-eastern Pacific Ocean species
Valiallah Khalaji-Pirbalouty
a
and Jean-Marc Gagnon
b
a
Department of Biology, Faculty of Science, Shahrekord University, Shahrekord, Iran; bBeaty Centre for Species Discovery,
Canadian Museum of Nature, Ottawa, Canada
ABSTRACT
ARTICLE HISTORY
Dynoides canadensis sp. nov. is described from the south-western coast of British Columbia, Canada.
This species differs from its closely related species, D. elegans (Boone, 1923) ), by the presence of a
smooth pleotelson without prominent rounded tubercle on the basal part of the pleotelsonic sinus,
its sinus wall lacking crenulation; in having the penial processes length 7.7 × basal width and acute
distal apex instead of 2.3 × basal width and rounded and blunt distal apex in D. elegans. This new
species also has an appendix masculina with the distal apex extending somewhat beyond its
base, instead of not reaching the base as is the case for D. elegans. A map of the distribution for
the north-eastern Pacific species of Dynoides Barnard, 1914 (D. elegans (Boone, 1921);
D. crenulatus and D. saldanai Carvacho & Haasmann, 1984; and D. dentisinus Shen 1929) in the
north-eastern Pacific is provided. The new species is abundant in the western coastal zone of
British Columbia. A revised generic diagnosis is provided for the genus Dynoides.
Received 23 September 2020
Accepted 13 February 2021
Published online 18 March
2021
SUBJECT EDITOR
Saskia Brix Elsig
KEYWORDS
Isopoda; Sphaeromatidae;
Dynoides; new species;
British Columbia; East Pacific
Publication LSID: lsid:http://zoobank.org:pub:ADF85BE9-C307-43EA-B270-1B2DB2F61883
Introduction
The genus Dynoides Barnard, 1914 has 18 accepted
species (Boyko et al. 2008 onwards), which mostly
occur in the Pacific Ocean from the north-eastern to
the western Pacific intertidal and shallow water habitats. However, three species are known from the
Indian Ocean: Dynoides serratisinus Barnard, 1914
from South Africa; Dynoides indicus Müller, 1991 from
Sri Lanka; and Dynoides amblysinus Pillai, 1954 from
India. Only Dynoides castroi Loyola and Silva, 1960 is
reported from the South Atlantic Ocean (Brazil).
In the north-eastern Pacific, four species are known:
D. crenulatus Carvacho and Haasman 1984, D. saldanai Carvacho and Haasmann, 1984 both from the Pacific Coast of
Mexico; D. elegans (Boone, 1923) from the California coasts;
and D. dentisinus Shen, 1929 from San Francisco Bay, which
was originally described from the coast of North China.
Additionally, Dynoides sp. also occurs in Mexico, Baja California Sur, Bahia de Concepcion (Wetzer et al. 2018).
During the present study specimens of Dynoides collected
along the west coast of Canada, off British Columbia, either
CONTACT Valiallah Khalaji-Pirbalouty
incorrectly identified as Dynamenella perforata or only
identified at the genus level (i.e. Dynoides), were reexamined. The specimens are morphologically distinct from
any of the already described species of Dynoides. A new
species of Dynoides is described herein.
Materials and methods
All specimens examined for this study are from British
Columbia (Figure 1), and were deposited in the Crustacea Collection of the Canadian Museum of Nature
(Natural Heritage Campus, Gatineau, Quebec, Canada).
Drawings were made with the aid of a camera lucida
on Olympus BX51 compound microscope and illustrations were electronically inked with Corel Draw
(version X6). Colour images of the specimens were
taken using a Zeiss AxioCam ERc5s camera mounted
on a Zeiss stereo microscope (Stemi 508).
Terminology of the morphological characters
broadly follows Wetzer & Mowery (2017). Abbreviations: CMNC – Canadian Museum of Nature, Canada;
khalajiv@yahoo.com
© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Published online 18 Mar 2021
MARINE BIOLOGY RESEARCH
13
Figure 1. Map of the geographic distribution of the genus Dynoides Barnard, 1914, in the north-eastern Pacific. A, species distribution on the north-eastern Pacific coast; B, locations of Dynoides canadensis sp. nov. distribution; C, location of D. dentisinus distribution; D, location of D. elegans (red circle) and Dynoides sp. (blue square); E, D. crenulatus (red circle) and D. saldanai (green
square).
RS – robust seta/e; SPS – sensory palmate setae; PMS –
plumose marginal setae.
Type species: Dynoides serratisinus Barnard, 1914 from
Natal and Mozambique (by monotypy).
Systematics
Generic diagnosis
Family Sphaeromatidae Latreille, 1825
Genus Dynoides Barnard, 1914
The full synonymy for the genus was provided by Li
(2000).
Body dorsal surfaces smooth, covered with small
tubercles and setosed in some species. Head longer
than broad, with small median rostral process. Pereonites 2–7 without coxal plate sutures. Pleon with or
14
V. KHALAJI-PIRBALOUTY AND J.-M. GAGNON
without median prominent dorsal process, posterior
margin with two separate sutures on either side. Pleotelson wider than long, posterior margin with a slit,
sinus, notch, or foramen. Epistome anteriorly and posteriorly rounded. Maxilliped palp articles 2–4 medial
margins slightly extended. Maxillula mesial endite
with four long comb setae. Maxilla with four 4
curved pectinate RS on middle and lateral endites.
Left mandible incisor and lacinia mobilis with 3–4
cusps, spine row present; palp articles 2 bearing two
biserrate setae on distolateral margin in most of
known species. Pereopods 1–7 ambulatory, inferior
margins of merus to propodus bearing dense fine
setae fringe. Penial processes long, entirely fused
along the basal third to half of their length. Appendix
masculina elongate, about twice the length of the
endopod; distal third to more than distal half-length
doubled back on proximal part. Pleopod 3 exopod
without transverse suture. Pleopods 4 and 5 endopods
bearing thickened transverse ridges, exopods
thickened transverse ridges absent. Uropods with
both rami broad and lamellar, subequal in length.
Dynoides canadensis sp. nov.
(Figures 1–5)
Material examined
Holotype. ♂ (4.2 mm), Canada, British Columbia, Barclay
Land District, Cape Beale, coll. Bousfield, Edward L., 19
July 1970 (CMNC 1985-0667.1).
Paratypes. 4 ♂♂(up to 4.2 mm), 18♀♀ (up to 4.3 mm),
1 ovigerous♀ (4.5 mm), same data as holotype, (CMNC
1985-0667.2). 2♂♂ (up to 5 mm), 2 ovigerous ♀♀
(3.5 mm); 2 ♀♀ (3.5 mm), British Columbia, Sooke Land
District, Sooke Harbour, Whiffin Spit, coll. Bousfield,
Edward L., 17 August 1955 (CMNC 1990-0064). 3 ♀♀
(up to 5 mm), British Columbia, Rupert Land Distr., Vancouver Island, Cape Scott, coll. Bousfield, Edward L., 18
July 1959 (CMNC 1990-0066). 20 ♂&♀, British Columbia,
Renfrew Land Distr., Vancouver Island, Port Renfrew,
coll. Bousfield, Edward L., 1 August 1970 (CMNC 19900068). 1♀ (3 mm), British Columbia, Queen Charlotte
Islands Land Distr., Graham Island, 27 July 1957
(CMNC 1990-0067). 5 ♂♂ (up to 4.9), 6 ♀♀ (up to 4.2),
British Columbia, Barclay Land District, British Columbia,
Barclay Land Distr., Trevor Channel, Tzartus Island, coll.
Bousfield, Edward L., 21 July 1970 (CMNC 1985-0664). 4
♂♂ (up to 4.5 mm), 5 ♂♂ (up to 4.2 mm), British Columbia, Metchosin Land Distr., Sooke Basin, Becher Bay, coll.
Bousfield, Edward L., 31 July 1970 (CMNC 1990-0057).
4♂♂ (up to 4.5 mm), 2 ♀♀ (3 mm), British Columbia,
Nootka Land Distr., Nootka Island, coll. Bousfield,
Edward L., 20 August 1959 (CMNC 1990-0059). 1 ♂
(4.2 mm), 1 ♂ (3.5 mm), British Columbia, Rupert Land
Distr., Hope Island, coll. Bousfield, Edward L., 22
August 1959 (CMNC 1990-0060). 1 ♂ (5.1 mm), 5 ♂♂
(up to 4 mm), 1 juvenile, British Columbia, Range 2
Coast Land Distr., Goose Island, coll. Bousfield, Edward
L., 6 August 1964 (CMNC 1990-0061). 6 ♀♀ (up to
3 mm), British Columbia, Range 2 Coast Land Distr.,
Hunter Island, coll. Bousfield, Edward L., 8 August
1964 (CMNC 1990-0063). 8 ♂♂ (up to 5 mm), 20 ♀♀
(up to 4.1 mm), 10 juveniles, British Columbia, Range
3 Coast Land Distr., Princess Royal Island, coll.
Bousfield, Edward L., 20 July 1964 (CMNC 1990-0065).
Description (based on holotype male)
Body smooth, 1.84 times as long as greatest width,
widest at pereonite 5 (Figure 2A). Head with small
rostral point. Pereonites 2–7 coxal plates fringed with
small marginal setae; coxae of pereonite 6 reaching
as far back as to overlap lateral parts of pereonite
7. Pleonite 1 with 2 anterolateral visible sutures
(Figure 2B). Pleon without median dorsal process. Pleotelson about 1.6 times as long as width, with a clear
dorsal dome, pleotelsonic sinus with straight-sided
margins, and slightly raised.
Epistome (Figure 2C) with rounded anterior and
posterior margins; lateral margins concave.
Antennula (Figure 2D) not extending to posterior of
pereonite 1; peduncle article 1, 2.6 times as long as
article 2, inferior distal margin with 1 palm setae; peduncle article 2 inferior distal margin with 3 palm and
some simple setae; peduncle articles 3 longer than
article 2, inferior distal margin with 2 palm and 3
simple setae; flagellum with 9 articles, articles 2–8
each bearing an aesthetasc.
Antenna (Figure 2E) extending to posterior of pereonite 1; peduncle articles 1 and 3 and peduncle
articles 2 and 4 sub-equal in length; peduncle article
5 longest, with some palm setae on distal margin;
flagellum with 14 articles.
Maxillula (Figure 2F) lateral endite with 10 simple
and serrated RS; mesial endite with 4 long comb and
1 small simple setae, 1 submarginal simple seta
present.
Maxilla (Figure 2G) lateral and middle endites each
with 4 curved pectinate RS; mesial endite with 4 long
rarely plumose and 3 long robust comb and 2
slender simple setae.
Left mandible (Figure 2H) incisor with 4 cusps;
lacinia mobilis with 3 cusps; spine row of 6 curved,
serrate spines; molar process with serrate teeth; palp
MARINE BIOLOGY RESEARCH
15
Figure 2. Dynoides canadensis sp. nov., holotype (CMNC 1985-0667.1); A, dorsal view; B, lateral view; C, epistome; D, antennula; E,
antenna; F, maxillula; G, maxilla; H, left mandible; I, palp of mandible; J, maxilliped; K, ovigerous female (CMNC 1985-0667.2).
16
V. KHALAJI-PIRBALOUTY AND J.-M. GAGNON
Figure 3. Dynoides canadensis sp. nov., holotype (CMNC 1985-0667.1); A–G, pereopods 1–7.
articles 2 with 2 biserrate setae, palp article 3 with 13
biserrate setae (Figure 2I).
Maxilliped (Figure 2J) endite lateral margin sinuate,
distomesial margin with single coupling hook, distal
margin with 4 long circumplumose, 2 densely circumplumose and 2 simple RS; palp articles 2–4 with weak
distally lobe; palp article 4 with single long seta on
superiodistal angle.
Pereopod 1 (Figure 3A) basis about 2.5 times as
long as greatest width, superior margin fringed with
short, acute scale-setae; ischium, merus and propodus
superior margin fringed with acute scale-setae; merus
superodistal angle with single long RS; carpus triangular, inferodistal angle with single long RS; propodus
2.4 times as long as wide, inferodistal angle with 2
long RS, superodistal corner with single sensory
palmate seta; dactylus inferior margin with cuticular
scales, secondary unguis simple, with 2 simple setae
at base, distal margin with 2 simple sub-marginal
setae.
Pereopod 2 (Figure 3B) basis about 3.2 times as
long as greatest width, with 2 small SPS; ischium,
merus, carpus and propodus superior margin fringed
with acute scale-setae; ischium about 3.6 times as
long as width; merus subequal in length to carpus,
superodistal and inferodistal angles with 1 long
simple seta; carpus inferodistal angle with a long
SPS, superodistal angle with a long simple RS; propodus about 1.5 times as long as carpus, inferodistal
angle with a long SPS; dactylus inferior margin with
cuticular scales, secondary unguis simple, with 3
simple setae at base, distal margin with 2 simple
sub-marginal setae.
Pereopod 3 (Figure 3C) basis about 2.25 times as
long as greatest width, with 3 small SPS; merus
longer than carpus, inferodistal angles with 1 long
MARINE BIOLOGY RESEARCH
17
Figure 4. Dynoides canadensis sp. nov., holotype (CMNC 1985-0667.1); A, penes; B–F, pleopods 1–5; G, uropod.
serrated RS; carpus inferodistal angle with 1 SPS, superodistal angle with a long simple RS; propodus about 2
times as long as carpus, inferodistal angle with a long
SPS; dactylus inferior margin with cuticular scales, secondary unguis simple.
Pereopods 4 and 5 (Figures 3D and E) are similar to
pereopod 3 as illustrated.
Pereopod 6 (Figure 3F) basis about 3 times as long as
greatest width, superior margin with 3 SPS; ischium,
merus, carpus and propodus superior margin fringed
with acute scale-setae; merus superodistal margin with
1 biserrate RS, inferior margin with 2 RS; carpus superodistal margin with 1 biserrated RS and 1SPS, inferior
margin with 1 biserrate RS, distomedial margin with 4
robustacute scale-setae; propodus 1.6 times as long as
carpus, superodistal corner with 1 slender and 1 SPS.
Pereopod 7 (Figure 3G) basis about 4 times as long
as greatest width, superior margin fringed with
cuticular scale; ischium, merus, carpus and propodus
are similar to pereopod 6 as illustrated.
Penial processes (Figure 4A) about 7.7 times as long
basal width entirely fused along basal 0.42 of length,
distal margin bearing setules on most of surface
except on apical parts, proximal lateral margin with
some scale setae.
Pleopod 1 (Figure 4B) exopod and endopod with 25
and 17 PMS respectively, endopod shorter than exopod;
exopod proximal lateral corner with single biserrated
seta. Sympodite mesial margin with 2 coupling hooks.
Pleopod 2 (Figure 4C) exopod and endopod subequal in length, with 27 and 25 PMS respectively;
appendix masculina proximally slightly swollen, distally narrowing, extending beyond endopod apex,
more than distal half length doubled back on the proximal half and extending somewhat beyond its base;
distal half bearing setules on most of surface medially,
18
V. KHALAJI-PIRBALOUTY AND J.-M. GAGNON
Figure 5. Dynoides canadensis sp. nov.; A, male, anterior dorsal; B, male, posterior dorsal; C, male, paratype, pleotelson; D, Ovigerous female, paratype, pleotelson; E, Dynoides elegans, male, pleotelson (after Wetzer & Mowery, 2017); F, Dynoides elegans, female,
pleotelson (after Wetzer & Mowery, 2017). Red arrows show a prominent rounded tubercle on the base of pleotelsonic sinus.
apex with some setules laterally; sympodite mesial
margin with 2 coupling hooks.
Pleopod 3 (Figure 4D) exopod and endopod subequal in length, with 34 and 16 PMS respectively; sympodite mesial margin with 2 coupling hooks.
Pleopod 4 (Figure 4E) both rami subequal in length,
exopod wider than endopod, with transverse suture,
transverse folds absent.
Pleopod 5 (Figure 4F) exopod with 3 scale patches,
lateral margin with slender simple marginal setae.
Uropodal rami (Figure 4G) extendingjust beyond pleotelsonic apex, fringed with dense small marginal setae.
Female: Similar to male except in sexual characters;
body smooth, 1.9 times as long as greatest width;
(Figures 2K, 5D). Uropod not extending to posterior
margin of pleotelson.
MARINE BIOLOGY RESEARCH
Etymology
The specific name is an adjective referring to the
country of the type locality.
19
distributed along the western coasts of British Columbia from Victoria area to Graham Island (Figure 1B).
Acknowledgements
Remarks
Dynoides canadensis sp. nov. is most similar to
D. elegans from California and D. saldanai and
D. crenulatus from Mexico, Oaxaca. Based on the redescription of D. elegans given by Wetzer et al. (2018), this
new species differs from D. elegans, in having the
penial processes length 7.7 × basal width and acute
distal apex (instead of 2.3 × basal width and rounded
and blunt distal apex), the doubled back part on the
proximal half of the appendix masculina extending
somewhat beyond its base (instead of not reaching
the base). The pleotelson of D. elegans is covered
with small tubercles, has a pleotelsonic sinus with a
prominent rounded tubercle on the base of sinus
and the sinus walls are finely crenulated (Figure 5E,
F). Conversely, the new species has a pleotelson
without small tubercles on dorsal surface, lacking a
prominent rounded tubercle on the basal part of the
pleotelsonic sinus and its sinus wall has no crenulation.
Dydoides crenulatus is readily distinguished from this
new species by its highly setose and more slender
body. The other species from Mexico, D. saldanai, can
be easily recognized by the heart-shaped slit on the
pleotelson apex.
The analyses of 16S rDNA by Wetzer et al. (2018)
clearly support the existence of two distinct Dynoides
species along the coastal zone of California area;
Dynoides elegans from Southern California, USA, and
Dynoides sp. from Baja California Sur, Mexico. Based
on distribution report of Dynoides species in the
Mexican Pacific by Espinosa-Pérez and Hendrickx
(2001), Dynoides sp. could be D. crenulatus or its sympatric species, D. saldanai.
Comments on the geographic distribution
Based on the previous studies, four species of Dynoides
are distributed in the north-eastern Pacific:
D. crenulatus is sympatric with D. saldanai in most
localities and distributed in the coastal zone of the
south-west of Mexico from Oaxacan to near the Gulf
of California (Figure 1E); D. dentisinus occurs in
San Francisco Bay, Western California (Figure 1C);
D. elegans reported from Cedros Island in Baja California Norte to Santa Cruz Island in Santa Barbara County,
Southern California (Figure 1D). The new species is
We are particularly grateful to Dr Robert Anderson for provision of the laboratory and to Mr. Philippe Ste-Marie for is
assistance facilities during the first author visit to the Canadian Museum of Nature, Ottawa, in 2019. Dr Niel Bruce
(Queensland Museum), Dr. Saskia Brix (Senckenberg
Research Institute, Germany) and Dr Brenda Doti (Universidad de Buenos Aires, Argentina) are thanked for their constructive suggestions and comments that improved the
manuscript. Financial support for this study was provided
by Canadian Museum of Nature Visiting Scientist Awards
2019, and Shahrekord University, Iran.
Disclosure statement
No potential conflict of interest was reported by the author(s).
ORCID
Valiallah Khalaji-Pirbalouty
http://orcid.org/0000-00020892-7463
Jean-Marc Gagnon
http://orcid.org/0000-0003-2778-4215
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