Table Of ContentZOOLOGICAL SCIENCE 8: 793-804 (1991) ! 1991 Zoological Society ol Japan
The Hyperbenthic Calanoid Copepod Paramisophria
from Okinawa, South Japan
SUSUMU Ohtsuka1 Audun FOSSHAGEN2 and Akio Go1
,
Faculty ofApplied Biological Science, Hiroshima University,
Higashi-Hiroshima 724, Japan, and 2Department of fisheries and
Marine Biology, University of Bergen, Thonnohlcns gt. 55,
N-5008 Bergen, Norway
ABSTRACT—Two species of the genus Paramisophria T. Scott. 1897 (Copepoda: Calanoida:
Arietellidae). one of which is new to science, were collected from near the bottom off Zamami ami
Kume Islands. Okinawa. SouthJapan anddescribed here. The findingofParamisophriajaponka n sp.
synonymizesthetwocloselyrelatedgeneraParamisophriaand ParapseudocyclopsCampancr. 1977.and
the \alid name ofgenus is Paramisophria, based on the principle ofpriority. This new species has the
most plesiomorphiccharactersofthegenusas follows: 22-segmented antenna 1 offemale; inner lobe ol
maxilla 1 with fivespinesandoneprocess:endopodofmaxilla 1 bearingthreesetae:endopodofleg5 ol
female having two plumose setae apically.
pseudocyclops and the closely related Paramis-
INTRODUCTION
ophria T. Scott, 1897 is reconsidered.
Although most calanoid copepods are generally
thought to be pelagic, many species of hyperben- MATERIALS AND METHODS
thic calanoids. however, have been collected from
lower intertidal zone todepthsover 1800m [1-13]. The specimens were collected off Kume Island
In Japan, one ofthe authors (SO) has intensive- (Stn. 1. 26°17.9'N, 126°54.2'E1 170 m. sandy bot-
ly been investigating shallow water hyperbenthic tom. 23 May 1989) and Zamami Island (Stn. 2.
calanoid copepods [2-6]. and recently obtained 26°15.9'N, 127°21.4'E, 120 m. sandy bottom. 23
numerous hyperbenthic species belonging to the May 1989), Okinawa by an originally designed
families Aetideidae. Arietellidae, Pseudocyclopi- sledge-net (mouth area: 1450 mm in length
dae. Pseudocyclopiidae and Stephidae from the mm in width; last net mesh size: 0.33 mm). The
Nansei Islands. South Japan. During the course of sledge-net was towed along the bottom at a speed
the taxonomic study, two species which have mor- of two knots by the T/RV Toyoshio-maru ol
phological characters unique to the genus Para- Hiroshima University for about five mm. The
pseudocyclops Campaner. 1977 (Arietellidae). distance between the sledge-net and the bottom
have been found first time in the Indo-Pacific was measured by a remote-sensing system (Funi-
region. One of them is new to science and both no-denki. Color net recorder CN-8). The speci-
adult females and males were collected. The mens were fixed in 10'y neutralized formalin
monotypic genus Parapseudocyclops accommo- sea-water immediatck after capture. Ihe ventral
dates P. wselaeCampaner. ofwhich only two adult side of the genital segment of the niu species w.i^
females were collected from the Brazilian con- observed with a SEM (Jeol JSM-T20). Contents m
tinental shelf [1]. By the record of the new species prosomal guts of 10 adult females ol tin
from Japan, the relationship between Para- species were examined with .1 differential inl
ence microscope. The detailed pi
Accepted March 7. 1991 content analysis was shown in th<
Received (161.
794 S. Ohtsuka, A. Fosshagen and A. Go
All the type specimens and one dissected speci- Body length. Female. Stn. 1 (one individual): 1.99
men of another species are deposited in the US mm. Stn. 2 (21 individuals): range (r)=1.85-2.08
National Museum of Natural History, USNM mm; mean+standarddeviation (m±s.d.)=1.95±
Smithsonian Institution, Washington, D.C., 0.05 mm. Male. Stn. 1 (one individual): 1.62mm.
U.S.A. Stn. 2 (seven individuals): r=1.41-1.64mm; m±
s.d.=1.56+0.08 mm.
Paramisophriajaponica n. sp.
Description. Female (holotype). Body (Fig. 1-A,
(Figs. 1-5) mm
B) compact and robust, 1.98 long; cephalo-
Types. Holotype: £, collected at Stn. 2 some and pediger 1 separated; pedigers 4 and 5
(26°15.9'N, 127°21.4'E, 23 May 1989), dissected fused. Prosome nearly symmetricalin dorsalview.
and mounted on glass slides, USNM250568; Para- Rostrum (Fig. 1-C) with a pair of subterminal
types: 2-¥--¥-and3^^, collectedatStn. 2, dissected filaments. Each side of pediger 5 with pointed
andmountedonglassslides; 3^^and3££ taken dorsolateral process and round lamellous medial
,
at Stn. 2, whole specimens, USNM 250569. and ventrolateral lobes, formerlobe reachingtwo-
Fig. 1. Paramisophriajaponica n. sp. Female (holotype: A, B, D, H, I; paratypes: C, E-G, J, K). A. Habitus,
dorsal view; B. Habitus, lateral view; C. Rostrum, lateral view; D-F. Pediger5, left lateral view; G. Pediger5,
right lateral view; H. Genital segment, ventralview; I. Anal segment and caudal rami, dorsal view;J. Urosome
with spermatophore, lateral view; K. Genital segment with spermatophore, ventral view.
1
Hyperbenthic Calanoids from Okina 795
Fig. 2. Paramisophnajapomcan sp. Female (holotype). A. Leftantenna 1; B. Right antenna 1: C. Antenna 1
Mandibular cutting edge: E. Mandibular palp. F. Maxilla 1; G. Maxilla 2; H. Maxillipcd
796 S. Ohtsuka, A. Fosshagen and A. Go
Fig. 3. Paramisophriajaponica n. sp. Female (holotype: A-F; paratype: G). A. Leg 1, anteriorface; B. Terminal
segment ofendopod ofleg 1, anteriorface; C. Leg2, anteriorface; D. Leg3, anteriorface; E. Leg4, posterior
face; F. Leg 5, anterior face; G. Leg 5, posterior face.
thirds the length ofgenital segment (Fig. 1-A, B). eachside throughfinetube. Analsegment(Fig. 1-
Urosome 4-segmented, one-third the length of I) small. Caudal ramus (Fig. 1-1) with four ter-
prosome. Genital segment (Fig. 1-H) with a pair minal and one subterminal setae and one dorsal
of ventrolateral gonopores anteriorly; two small inner setule. Left antenna 1 (Fig. 2-A) longer
copulatory openings located closely together at than right (Fig. 2-B); both antennae 1 22-
middle partofventral surface (see Fig. 5-A, B, C) segmented; segments 3-19 each furnished with
and connecting with sigmoid seminal receptacle of two setae and one aesthetasc, segment 7 bearing
,
Hyperbenthic Calanoids from Okinawa 797
Ck X
EE 1 O
I
o EE Ee *4
O
-; o
o
o
Fig. 4. Paramisophriajaponica n. sp.Male (a paratype: A-I; anotherparatype: J, K). A. Habitus, lateral view; B.
Rostrum, lateral view; C. Pediger5. right lateral view; D. Pediger5andurosome,dorsalview; E. Leftantenna 1
all setae omitted: F. Right antenna 1. all setae omitted; G. Segments 16-20 of left antenna L, dorsal view; H.
Segments 16 and 17 of left antenna 1. ventral view; [. Leg 5. anterior faee. short, thick spinule on outer proeess
indicated by arrowhead: J. Terminal segments of right leg 5. posterior face; K. Endopod of left leg 5.
extremely long seta: terminal segment with 10 fused, terminal segment with one medial seta, and
setae and three aesthetascs; segments 1-X posses- two setae and one minute setule terminally. Man-
sing long hairs along posterior margin. Antenna 2 dibular gnathobase (Fig. 2-D) with three teeth,
(Fig. 2-C): endopod 2-segmented. slightly longer dorsalmost bifurcate, and two patches of d
than exopod: apical segment shorterthan proximal like spinules. Mandibular palp (Fig. 2-E): 1-
one. bearing three setae of unequal lengths at segmented rudimentary endopod bearing two
midst length of inner margin: exopod consisting of setae of unequal lengths terminally; exopod 5-
six segments, proximal two segments incompletely semented. each of proximal four segments having
798 S. Ohtsuka, A. Fosshagen and A. Go
Fig. 5. Paramisophriajaponica n. sp. SEM-microphotographs ofgenital segment offemale. A. Genital segment,
ventralview,gonopore(g),copulatorypore(c), X619;B,C. Copulatorypores, X6188(B), X8840(C);D. Right
gonopore, X2652; E. Left gonopore, X2652.
one seta; apical segment with two setae. Maxilla 1 lobe furnished with one naked strong spine; en-
(Fig. 2-F): first inner lobe (gnathobase) with five dopod segments bearing seven large pectinate
spines and one process; second inner lobe with setae. Maxilliped (Fig. 2-H): basipod segments
rudimentary minute setule on tip; first outer lobe elongated; segment 1 being at right angle to seg-
bearing eight setae; inner margin of basipod 2 ment 2; endopod 5-segmented, segments 1, 2, and
bearing two rows of hairs and one minute middle 3, 4bearing four and three innersetae, respective-
seta; endopod 1-segmented, bulbous, and having ly; terminal segment having four setae. Legs 1-4
three terminal setae of unequal lengths; exopod each with 3-segmented endo- and exopods. Leg 1
fused, with basipod segment 2, bearing three plu- (Fig. 3-A, B): basipod segment 1 produced out-
mose setae terminally. Maxilla2 (Fig. 2-G) stout, wards into subterminal blunt process, segment 2
with six weakly developed inner lobes; fifth inner finelyserrated alongbase ofendopod, andbearing
Fiyperbenthic Calanoids from Okinawa 799
medial outer seta and inner seta near base oi an angle of about 60°; middle inner margin of this
endopod: endopod segments 2 and 3 produced fused segment bluntly produced inwards and bear-
outwards into terminal acute process. Legs 2 and 3 ing patches of minute hairs on posterior face; two
(Fig. 3-C, D) similar in structure, acute inner subterminal crest-like cuticular structures present
terminal process longer in latter than in former; on posterior face, inner one with six prominences,
endopod segment 2 produced outwards into acute outer one with 9-12 prominences; two triangular
terminal process, nearbase ofwhich a small prom- lamellous projections present terminally, outer
inence is present. Leg 4 (Fig. 3-E) furnished with one with a small setule. Left leg: basipod segment
small plumose seta on posterior face of basipod 2 broad, with 1-segmented bulbous endopod and
segment 2. Leg 5 (Fig. 3-F): basipod segments 1 short plumose seta near outer terminal end on
fused to intercoxal plate to form a common base; posterior face; exopod segment 1 triangular, bear-
basipod segment 2 completely fused with endopod ing small outer naked seta terminally; exopod
segment; endopod produced terminally and bear- segment 2 located on inner side of segment 1,
ing two plumose setae, one terminal and one elongated, furnishedwith outermiddle nakedseta;
subterminal; exopod segment 1 and basipod seg- exopod segment 3 small, with two stout pectinate
ment 1 separate; exopod segments 2 and 3 fused processes of unequal lengths and minute outer
incompletely, and its fusion line clearly visible on setule; outer process bearing minute projection
anterior face; exopod segment 3 bearing two ter- directed slightly outwards (indicated by arrowhead
minal and one subterminal large serrate spines; in Fig. 4-1).
terminal process with two minute prominences at
its base. Structure of female genital segment. An SEM-
examination of the female genital segment re-
Male (a paratype: Fig. 4-A-I; another paratype; vealed that the gonopore (Fig. 5-A, D, E) has an
Fig. 4-J. K). Body (Fig. 4-A) slenderer than in operculum with its anteriorpartopen, and that the
female. 1.56 mm long. Rostrum (Fig. 4-B) with copulatory pores (Fig. 5-B, C) open closely in a
two subterminal filaments as in female. Pediger 5 shallow common hole located centrally on the
(Fig.4-C. D) reaching middle of urosome seg- ventral side. A paratypicfemale hasa sausage-like
ment 2. Urosome (Fig. 4-D) 5-segmented; seg- spermatophore on the ventral side of its genital
ment 5 small. Left antenna 1 (Fig. 4-E, G. H) segment, which covers the copulatory pores (Fig.
geniculate. 21-segmented; segments 18 and 19 1-J, K).
incompletelyfused; segment 16 (Fig. 4-G, H)with
cuticular ridge along anterior margin, and bearing Variation. Dorsolateral lobe and dorsal process of
large spine anteroterminally; segment 17 fur- pediger 5 (Fig. 1-B, D, E, F, G) are slightly
nished withcleft alonganteriormargin, andcuticu- variable in shape: smoothly rounded (Fig. 1-B, D,
lar ridge along proximal half anterior margin; E, F) or bluntly pointed lobe (Fig. 1-G); sharp-
segment 18 (Fig. 4-G) also having two cuticular ness in dorsal process. A fusion line between the
ridges along anterior margin; segment 19 (Fig. 4- endopod and basipod 2 of leg 5 is not visible from
G) with anterior terminal end produced into a both sides in the holotypic female (Fig. 3-F),
blunt process which reaches middle length of next whereas it isclearly visibleon the posteriorsurface
segment. Right antenna 1 (Fig. 4-F) 22-seg- in a paratypic female (Fig. 3-G). In right leg 5 of
mented. shorter than left. Mouthparts and legs 1- male, the outer lamellous projection on the ter-
4 similar to those ofthe female. Leg5 (Fig. 4-1. J, minal segment is triangular in one paratype and
K): basipod segments 1 fused to form a common smoothly rounded in another paratype.
base. Right leg: basipod segment 2 produced at
inner terminal end; exopod segment 1 triangular, Examination ofgui contents. Half the individuals
bearing small outer naked seta at apex; exopod preyed on benthic cyclopoid or harpacticoid COpe-
segments 2 and 3 incompletely fused, expanded podids. One female fed on a chactognath. 1 our
like a fan. and jointed with preceding segment at individuals had empty guts. The gut-content
800 S. Ohtsuka, A. Fosshagen and A. Go
analysis indicated that P. japonica is a strong 2 of Parapseudocyclops are in plesiomorphic state
carnivore feeding mainlyon epibenthicorganisms. comparedwith those ofParamisophriaby Sars [7]:
reduction generally occurs in Paramisophria.
Remarks on new synonymy. The genus Paramis- The present new species has parts of the above
ophriawas established and brieflydefined by Scott diagnostic characters of both Paramisophria and
[15]. Later, the definition of the genus was given Parapseudocyclops: endopod of leg 5 of female
more exactly by Sars [7], and partly revised by separates from basipod 2, and has two setae on it;
Krishnaswamy [9]. The revised generic definition maxilla 1 bears five spines and one process on the
of Paramisophria is as follows: rostrum with two firstinnerlobe andthree setae onitsendopod, and
filaments; pediger 5 with two conspicuous subdor- eight setae on its outer lobe; one seta on the
sal projections; antenna 1 21-segmented; inner second inner lobe of maxilla 1 is rudimentary;
corner of basipod 2 of legs 2-4 produced, and there is only one seta on the first inner lobe of
endo- and exopods 3-segmented; legs 5 of female maxilla 2. These characters which are unsuitable
and male 3- and 5-segmented, respectively; basi- to the diagnosis of the genus Parapseudocyclops
pod 2 of female leg 5 with inner projection; belong to those of the genus Paramisophria. Pre-
basipod 2 of leg 5 of male with or without en- viously known species ofthe genus Paramisophria
dopod; right and left terminal segments ofleg5 of have an endopod ofleg 5 offemale with none (P.
male spatulate and unguiform, respectively. platysoma Ohtsuka & Mitsuzumi, 1990) or one
The following definition of the closely related seta (P. cluthae T. Scott, 1897; P. spooneri Krish-
genus Parapseudocyclops is given based on only naswamy, 1959; P. cluthae sensu Tanaka; P.
two adult females of the monotypic P. giselae [1]: ammophila Fosshagen, 1968; P. itoi Ohtsuka,
rostrum with one filament; left antenna 1 22- 1985; P. variabilis McKinnon & Kimmerer, 1985),
segmented; maxilla 1 with six spines on first inner and a maxilla 1 with four or five spines and one
lobe, one setaon secondinnerlobe, three setaeon processonthefirstinnerlobe [4,6, 7, 9-12, 15]. A
endopod and nine setae on first outer lobe; both reexamination of Paramisophria species collected
endo- and exopods ofleg5 coalescedwith basipod from Raunefjorden, Norway by Fosshagen [11],
2; endopodwithtwo longsetae; exopodwiththree however, revealed that this species has five spines
lateral and two terminal spines. and one process on the first inner lobe and
Although Campaner [1] didn'tmentionmorpho- rudimentalsmallsetuleonthesecondinnerlobeof
logical differences between two genera Paramis- maxilla 1, and one seta on endopod of leg 5 of
ophria and Parapseudocyclops in detail, he might female, and that the genus Paramisophria shares
have thought that the most important characteris- morphological characters with the genus Para-
ticto distinguishbetweenthese twogenerawasthe pseudocyclops. In male, the present newspeciesis
structure of leg 5 of adult female: in Paramis- morphologically similar to congeneric species ex-
ophria, exopode separate from basipod 2, and cept the crest-like cuticular structure of terminal
endopod with or without one seta, while in Para- segment of right leg 5 unique to the new species.
pseudocyclops, both endo- and exopodsfusedwith Therefore, we have come to a conclusion that the
basipod 2, and endopod bearing two setae [1, 14]. genus Parapseudocyclops should be synonymous
Although Sars [7] and Krishnaswamy [9] did not with the genus Paramisophria. Accoring to the
mention in their definition of the genus Paramis- rule of priority (International Code of Zoological
ophria, the structure of maxilla 1 and maxilla 2 of Nomenclature, Article 23), Paramisophria is a
Paramisophria is also distinguishable from that of valid name.
Parapseudocyclopsin: maxilla 1 havingfourorfive
spines and one process on first inner lobe, no seta Comparisons. The genus Paramisophria accom-
on second inner lobe, two setae on endopod and modates 11 species including the present newly
eight setae on first outer lobe; maxilla 2 with only described species, seven speciesinthe Indo-Pacific
one seta on first inner lobe [4, 6, 7, 9-12]. The region and four species in the Atlantic [1, 4, 6-12,
characteristics of antenna 1, maxilla 1 and maxilla 15; Greenwood personal communication]. P.
Hyperbenthic Calanoids from Okina 801
japonica and P. giselae are in the most plesiomor- female separate in P. japonica, and fused in P.
phic state among congenerie species in the Indo- giselae.
Pacific region and the Atlantic, respectively, he- Although Campaner [1] mentioned that P. gise-
cause these two species have such characters com- lae has only one rostral filament, another filament
bined as 22-segmented antenna I, leg 5 of female might have been detached during collection or
with two setae on endopod. and maxilla 1 with five dissection, because arietellids usually bear two
spines and one process on the first inner lobe, one rostral filaments [7]. In Campaner'sdescription [1)
seta on the second inner lobe and three setae on (see p. 816, Fig. 19), one seta on the posterior
endopod. while counterparts of other congeneric surface ofexopod segment 1 of leg 4 is illustrated,
species are in an apomorphic state: 20- or 21- but this is not mentioned in the text. Considering
segmented antenna I; endopod of leg 5 of female other arietellids and the unlikely position of this
with or without a seta: maxilla 1 with four or five seta, this may be incorrectly described.
spines and one process on gnathobase. one or no These two plesiomorphic species, P. japonica
seta on second inner lobe and two setae on en- and P. giselae might be mainly distributed at a
dopod. depth of 100 to 200 m on continental shelves, while
P. japonica ismost similarto P. giselae in having other congeneric species have a wide distribution,
a 22-scgmented antenna 1, two setae on endopod from lower intertidal zone (P. platysorna) to 240 m
offemale leg5, and five spines and one process on depth {P. cluthae from Raunefjorden. Norway) [1.
first inner lobe and three setae on endopod of 4. 6. 9-12. 17]. The species- and habitat-
maxilla 1. However, the new species is distin- relationships in the genus Paramisophria will be
guished from P. giselaein the followingcharacters: revealed by a cladistic analysis in a forthcoming
(1) rostrum with two filaments; (2) pedigers 2 and paper.
3 not produced on posteroventral ends: (3) dorso- The genus Rhapidophorus Edwards, 1891 is
lateral lobe of pediger 5 not as produced as in P. monotypic, comprising R. wilsoni Edwards of
giselae: (4) genital segment of female wider than which only the male is known [11. 14, 18], and is
long. In addition, the appendages of the new suggested to be related to the genera Paramis-
species are different from those of P. giselae: (1) ophria and Parapseudocyclops [1. 11, 18]. Cam-
dense hairy row along posterior margin of left paner [1] mentioned that "until the male of Para-
antenna 1 present on segments 1-8 in P. japonica, pseudocyclops is found or until the species R.
and on segments 1-11 in P. giselae: (2) six seg- wilsoni is reencountered, it is better to maintain
ments of exopod of antenna 2 in P. japonica, and the genera apart". Edwards [18] incompletely
seven in P. giselae: (3) rudimentary 1-segmented described only left leg 5 but not right leg 5.
mandibular endopod present in P. japonica and Comparing the legs 5 of the males of R. wilsoni
absent in P. giselae: (4) dorsalmost mandibular and P. japonica, their terminal segments are diffe-
tooth divided into two tips in P. japonica, but rent: in R. wilsoni the segment has only one seta.
undivided in P. giselae: (5) seta on second inner while in P. japonica the segment bears two stout
lobe of maxilla 1 reduced in P. japonica, but processes and a minute setule. The terminal seg-
developed in P. giselae: (6) the numberofsetae on ment of R. wilsoni is more similar to that of genus
outer lobe of maxilla 1 is eight in P. japonica, and Metacalanus in the Arietcllidae rather than to that
nine in P. giselae: (7) first inner lobe of maxilla 2 of P. japonica [2. 14|.
bearing one seta in P. japonica, and two in P.
giselae: (8) setal number of endopod segments 1
Paramisophria sp.
and 5 of maxilliped are respectively four and four
in P. japonica. and two and three in P. giselae; (9) (Fig. 6)
inner terminal end of basipod segment 2 of leg 3 Body length. Copepodid [V stage, female. Stn. I
with only one pointed tip in P. japonica and two in (26'17.9'N. 126°54.2'E, 23 May 1989) (two indi-
P. ziselae: (10) basipod segment 2 and exopod viduals): 2.05mm, dissected. 1.87mm, whole
segment 1. and exopod segments 1 and 2 ofleg5 of specimen. The specimen collected at Sin. I is
802 S. Ohtsuka, A. Fosshagen and A. Go
Fig. 6. Paramisophria sp. Copepodid IVfemale. A. Habitus, dorsalview; B. Rostrum, dorsalview; C. Pediger5,
left lateral view; D. Pediger 5, right lateral view; E. Segment 3 of urosome and caudal rami, dorsal view; F.
Antenna 2; G. Mandibular palp, rudimentary endopod indicated by arrow; H. Mandibular cutting edge; I.
Maxilla 1;J. Leg4,anteriorface;K. Innerterminalendofbasipod 1ofleg4,minutesetuleindicatedbyarrow;L.
Leg 5, anterior face.
