Collocherides bleptus n. sp. (Copepoda: Siphonostomatoida) associated with an intertidal ophiuroid in Madagascar

7 Pages·1993·0.58 MB·English

by  Humes, Arthur G

Bijdragentot deDierkunde, 63 (2) 121-127 (1993)
SPBAcademie Publishingbv, The Hague
Collocherides bleptus n. sp. (Copepoda: Siphonostomatoida) associated
with an intertidal ophiuroid in Madagascar
Arthur G. Humes
Boston University MarineProgram, MarineBiological Laboratory, Woods Hole, Massachusetts 02543,
U.S.A.
Keywords: Copepoda, Siphonostomatoida, Madagascar, ophiuroid, associate, Collocherides
Abstract A new species of Collocheridesassociated with
an ophiotrichid ophiuroid in Madagascar is herein
Collocherides bleptusn.sp.isassociatedwithabrittlestar,Mac- described.
rophiothrixsp., atNosy Bé, in northwestern Madagascar.The
newcopepoddiffersfromitstwocongeners byitslargersizeand
by having leg 5 in the female with anelongatedistal segment
Taxonomicpart
bearingonly two setae.
Siphonostomatoida Thorell, 1859
AsterocheridaeGiesbrecht, 1895
Résumé
CollocheridesStock, 1971
Collocherides bleptusn.sp.est associéed’une Ophiure,Macro-
phiothrixsp.,àNosy Bé,aunord-est deMadagascar.Le Copé-
podenouveaudiffère de ses deux congénèrespar sataille plus Collocheridesbleptus n. sp.
grandeetparlacinquièmepattedelafemelleayantundeuxième (Figs, la-i, 2a-j, 3a-i)
segment allongéportant deux soiesseulement.
Type material. - 520 specimens from 20ophiuroids,Macro-
phiothrixsp.,intertidal,underdead coral, Befefika,Nosy Bé,
Introduction northwestern Madagascar, 7 October 1964. Holotype 9
(USNM 259327), allotype cr (USNM 259328), and 380 para-
The siphonostomatoid genus CollocheridesStock, types (265 9 9, 115 cr cr)(USNM259329)depositedin the Na-
tional Museum of Natural History, Smithsonian Institution,
1971, iscloseto CollocheresCanu, 1893,butdiffers
Washington, D.C.; 20 paratypes (10 9 9, 10 cr cr) in the
in having reducedarmature onthethird segmentof Zoölogisch Museum, University ofAmsterdam (ZMA Crust.
theexopod inlegs 1-3.Two species arerecognized Co200415);and theremainingparatypes and 27 copepodidsin
in Collocherides. Collocherides astroboae Stock, the collection ofthe author.
1971, isassociatedwithAstroboanuda(Lyman) in
theGulfof Aqaba and intheDahlak Archipelago Female. — Body (Fig. la, b) slender. Specimens
in the Red Sea (Stock, 1971) and in northwestern preserved in 70%ethanol, seenin lateralview,with
Madagascar (Humes, 1973). This species has also urosome at 60° angle with prosome.Length 0.77
beenreported fromAstroboaalbatrossi Döderlein mm (0.75-0.78 mm) and greatest width 0.18 mm
inIndonesia(Stock, 1971). Collocheridessingularis (0.17-0.20 mm), based on 10specimens in lactic
Humes, 1986, is an associate ofAstroboa nudain acid. (Length and widthmeasuredonspecimens in
the Moluccas (Humes, 1986). depression slidewith cover glass exerting minimal
122 A.G. Humes - Collocheridesbleptus n. sp.
Fig. 1a-i.Collocherides bleptusn.sp., ￿:a,habitus,dorsal,foreshortened (scaleA);b, lateral(A); c,urosome, dorsal (B);d,urosome,
lateral (B); e, central part ofsecond postgenitalsomite showingsmallsurficial spines,ventral (C); f,anal somite and caudal ramus,
dorsal (C); g, caudal ramus, ventral(C);h,egg,ventral (D); i,antennule,antero-outer (E).
Bijdragen tot deDierkunde, 63 (2) - 1993 123
pressure.) Greatest dorsoventralthickness of pro- with minuteteeth; palp 1-segmented withlong seta.
some at level of ventral prominence 0.20 mm. So- Maxillule(Fig. 2d) with broadouter lobebearing 3
mitebearingleg 1 fusedwithcephalosome. Ratioof setae,more slender innerlobe having 2unequal se-
length to widthofprosome 2.2: 1. Ratiooflength tae. Maxilla(Fig. 2e) 2-segmented with slenderter-
of prosome to thatof urosome 1.14 : 1. minal claw. Maxilliped (Fig. 2f) slender, syncoxa
Somitebearing fifthpair oflegs (Fig. lc)65 X 86 and elongate basis without setae; endopod 3-seg-
/mi. Genital doublesomiteelongate, 120 /xm long, mented, each segmentwith 1 seta; terminalslender
86 wide anteriorly, and 70 nm wideat level of claw with bluntrecurved tip.
slight median dorsal transverse line of division. Appendages ofcephalosome arranged as in Fig.
Genitalareas located laterally(Fig. Id) in anterior 2g. Ventral areabetweenmaxillipeds and first pair
thirdofgenital somite, each areabearing 2 minute of legs with median protrusion (Fig. 2g, h).
setae. Three postgenital somites from anterior to Legs 1-4 (Figs. 2i, j, 3a, b)biramouswith 3-seg-
posterior 55 X 57, 36 X 47, and 26 X 44/xm. mented rami. Formula for armature as follows
Caudalramus (Fig. If, g) elongate, 55 X 20 (Roman numeralsindicating spines, Arabicnumer-
als representing setae):
ratio 2.75 : 1. Outerlateralseta,setsomewhatdor-
sally, 50/im, dorsalseta 15pun, outermost terminal
P, coxa 0—0basis 1—1 exp I—1; I—1; 111,2,2
seta52 2long terminalsetae 122/»m(outer)and
enp 0-1; 0-2; 1,2,3
51238/i/m*m,(winintherl)a,tearllaslmseotuoltehs.,Inthnoesremoonstitnenrmerinmaalrsgeitna P2 coxa 0-0 basis 1-0 exp I—1; I—1; 111,1,4
enp 0-1; 0-2; 1,2,3
longer. Distal end of caudal ramus with ventral
P3 coxa 0-0 basis 1-0 exp I—1; I—1; 111,1,3
roundedprotrusion (Fig. lg).
enp 0-1;0-2; 1,1,3
Body surface with few refractile points (sensil-
P4 coxa 0-0 basis 1-0 exp I—1; I—1; 111,1,3
la?). Ventralandlateralsurfaces of genital double
enp 0-1;0-2; 1,1,2
somite and first2postgenital somites with numer-
ous scalelike spines (Fig. Id, e). Basis of leg 1 with small innerseta. Endopods of
Egg sac (seen on 10 females) containing single legs 1-4with second segment having 2 setae.
relatively large egg 220 X 132 (Fig. lh). Leg 5 (Fig. Id, 3c) with elongate unornamented
Rostral areaslightly raisedin lateralview (Fig. distalsegment44 x 16 bearing 2terminalsetae
lb),butweakly defined.Antennule(Fig. li)258/xm 18/xmand 26/xm. Proximalsegment ofleg 5 trian-
long, 20-segmented (though separation ofsegments gular with subacute tip, seta 22 /an. All setae
2-5is incomplete and indistinct). Aestheteon seg- smooth.
ment 18.Armature: 1,2, 0, 2, 1, 1,0, 2, 5, 1, 1, 1, Leg 6represented by 2 smallsetae on genital area
1, 0, 1, 1, 0, 1 + aesthete, 1, and 4, respectively. (Fig. lc, d).
Lengths ofsegments(measured along theirposteri- Color of living specimens in transmitted light
ornonsetiferousmargins): 14(27 /*malonganterior opaquegray, eye dark red, egg sacs gray.
margin), 17.5(comprising segments 2-5), 5.5, 6,
16.5, 10, 8, 12, 14, 14, 15, 15, 15, 16, 22, 13, and Male.- Body (Fig. 3d)resembling femaleingener-
27 Segments 2-5 distinctly separated on al form. Length 0.71 mrri (0.68-0.77 mm) and
anterior margin but united on posterior margin. greatestwidth 0.17mm(0.15-0.18 mm), based on
Antenna(Fig. 2a) 156 long, basis elongate with 10specimens in lactic acid. Greatest dorsoventral
exopod having minutefreesegmentbearing 2 very thickness 0.17 mm. Ratios similar to those of
smallsetae. Endopod 2-segmented, both segments female.
with 1 seta, and terminal claw 39 /xm long with Somitebearing leg 5 (Fig. 3e) 44 X 75/xm. Geni-
slightly recurved blunt tip. tal somite75 x 91 /xm,widerthanlongwithslightly
Oral coneprominent in lateralview(Fig. lb) but rounded lateralmargins. Four postgenital somites
relatively short, 104 /xm long (Fig. 2b). Mandible fromanteriortoposterior 55 X 65,44 x 56,31 X
(Fig. 2c)with long stylet(65 armed terminally 47, and26 X 42jum.
124 A.G. Humes - Collocheridesbleptus n. sp.
Fig.2a-j.Collocherides bleptusn.sp., ￿:a, antenna, outer(scaleE);b, siphon,posterior(E); c,mandible,posterior(C); d,maxillule,
posterior(C);e, maxilla,posterior(E); f,maxilliped,posterior(F); g,cephalosome,ventral(B); h, outline ofareabetweenmaxillipeds
and first pairoflegs,lateral(C);i,leg 1 andintercoxal plate,anterior (F);j,leg2 and intercoxal plate,anterior (F). A1 = antennule,
MXPD = maxilliped,P1 = leg1.
Bijdragen tot deDierkunde, 63 (2) - 1993 125
Fig.3a-i. Collocherides bleptusn.sp. (a-c ￿, d-i ￿): a,leg3 andintercoxal plate,anterior (scaleF);b, leg4 and intercoxal plate,
anterior(F);c,leg5,ventral(C); d,habitus,lateral(A);e,urosome, ventral(B); f,antennule,inner (E);g,leg5,ventral (C);h,segment
bearingfifthpairoflegsand genitalsegment, showingleg6,ventral (B); i,segmentbearingfifthpairoflegs andgenitalsegment, show-
ingleg 6, lateral(B).
126 A.G. Humes Collocheridesbleptus n. sp.
Table I.Comparisonofthe three species ofCollocherides.
C. astroboae C.singularis C. bleptus
Lengthoffemale 0.61 mm 0.64mm 0.77 mm
(0.56-0.63mm) (0.63-0.65mm) (0.75-0.78mm)
Lengthofmale 0.52 mm 0.53 mm 0.71 mm
(0.50-0.53mm) (0.52-0.54mm) (0.68-0.77mm)
Posteroventral
prominenceon spiniform absent rounded
caudal ramus
Antennule, entirely entirely notseparated along
segments2-5 separated separated posteriormargin
Antenna,exopod 1 setule 1 seta minutewith 2 setae
Leg5, distal
segment, female suboval oval, 34 x 21fim elongate,44 x 16ftm
Leg5, number of
setaeon distal
segment 4in Ç, 5 in cr 4in 9, 5in a 2in 9. 5in cr
Leg5,proximal
segment, female acutelypointed bluntlyrounded subacutelypointed
Caudalramus resembling that offemale, dimen- Although all three species of Collocheridesare
sions 52 x 20(im. associated with Ophiuroidea, the new species, un-
Rostrum likethatoffemale. Antennule(Fig. 3f) like its two congeners living with subtidalbasket
19-segmented, segment 16 apparently representing stars, is found on an intertidalbrittle star. The
fusion of 2 segments seen in female. Last 2 seg- several features ofC. bleptus listedinTableImay
ments incompletely separated. Armature: 1,2,0,2, be a reflection of the differences in host and
1, 1, 0, 2, 5, 1, 1, 1, 1,0, 1,2, 1 + 1 aesthete, 1, habitat.
and4.Lengths ofsegments: 18(26 /imalonganteri- Unfortunately, thespecimens ofthehost ophiu-
or side), 19 (comprising segments2-5),5, 7, 17, 9, roid on which C. bleptus was found, although
9,14,21,21,20,19, 29, 65,10, and25/xm.Antenna preserved for identificationat the time of collec-
as in female. tion, have, with thepassage ofa quarterof a cen-
Oral cone, mandible, maxillule, maxilla, maxil- tury,beenlost.However,basedonfieldnotesmade
liped, and legs 1-4 like those of female. when the brittle stars were collected, the host has
Leg 5(Fig. 3g) withdistalsegment 41 x 16/un, been determinedto be Macrophiothrix sp.
its 5 terminalsetae from outer to inner20, 26, 23,
17,and35fim.Lateral setaon proximal segment24 Acknowledgements
jtm. All setae smooth.
Leg 6 (Fig. 3h, i) posteroventral flap on genital Thecopepods werecollected duringthe United States Program
somitebearing 2 veryunequal setae, longer seta 33 in Biology of the International Indian Ocean Expedition,
1963-1964,when the author was chief scientist at Nosy Bé,
jtm.
Color as in female. Madagascar. The study ofthe copepods was aided by agrant
(NSR 88 21979)fromthe National Science Foundation of the
United States.
Etymology. - The specific name bleptus is from a
Greek word meaning worthseeing.
References
Remarks. - Collocherides bleptus may be distin- Canu,E., 1893.Notesdebiologiemarine,fauniquesouétholo-
guished from both its congeners by features sum- giques,I. Un Copépodeascomyzontidesurunealguepéla-
marized in TableI. gique.Annls. Stn.aquicole Boulogne, 1: 100-108.
Bijdragen tot deDierkunde, 63 (2) - 1993 127
Giesbrecht, W., 1895. Die Asterocheriden des Golfes von Stock, J.H., 1971. Collocherides astroboae n. gen., n. sp., a
Neapel und der angrenzenden Meeres-Abschnitte. Fauna siphonostome cyclopoidcopepod living in the stomach of
Flora Golfes Neapel,25: 1-217. basket stars. Bijdr. Dierk.,41: 19-22.
Humes,A.G., 1973. Cyclopoidcopepodsassociated with the Thorell,T., 1859. Till kannedomen om vissa parasitiskt lef-
ophiuroidAstroboa nuda in Madagascar. Beaufortia, 21: vande Entomostraceer. Öfvers. K. svenska Vetensk. Akad.
25-35. Forh.,(ny följd)3(2): 1-84.
Humes,A.G., 1986. Two newspeciesofCopepodaassociated
with the basket star Astroboa nuda (Ophiuroidea)in the
Moluccas. ZoologicaScripta, 15:323-332. Received: 24February 1993