A New Species Of Excorallana Stebbing (Crustacea : Isopoda : Corallanidae) From The Pacific Coast Of Mexico, And Additional Records For E-Bruscai Delaney

11 Pages·1998·3.1 MB·English

by  M E Hendrickx

PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
111(2):303-313. 1998.
A new species ofExcorallana Stebbing (Crustacea: Isopoda:
Corallanidae) from the Pacific coast ofMexico, and additional
records forE. bruscai Delaney
Michel E. HendrickxandMa. del CarmenEspinosa-Perez
EstacionMazatlan,ICML,UNAM.P.O. Box811,Mazatlan,Sinaloa, 82000,Mexico
—
Abstract. The genus Excorallana Stebbing is represented in the Mexican
Pacific by four species. A fifth species, E. conabioae is recognized among
material collectedoffshore fromadepthrange of28-70 m. Excorallana con-
abioae is readily separated from Atlantic and Pacific species of this genus
without horns on cephalon and/orpereonite 1. Among the "horned" species,
E. conabioae mostclosely resembledE. bruscai, fromwhich itdiffersby the
size and orientation ofcephalic horns-like processes, the presence of 3 pairs
ofsmall horns-like processes ortubercles onpereonite 1, its muchlongeran-
tenna, andthepresenceofasub-lateralclusteroftuberclesoneachsideofthe
telson. Newrecords ofE. bruscaiindicate thatitis distributedthroughoutthe
GulfofCaliforniaareafromthe intertidalto atleast55 m.
The genus Excorallana Stebbing, 1904, additiontothefourabove-mentionedMex-
belongs to the family Corallanidae (Bruce ican species, onlyoneothermemberofthe
etal. 1982).ItisrepresentedintheMexican genus is known from the East Pacific: E.
Pacific by four species (one as a subspe- meridionalis Carvacho & Yanez, 1971,
cies): E. truncata (Richardson, 1899), E. fromChile.
tricornis occidentalis Richardson, 1905, E. Recent collection of invertebrates along
bruscaiDelaney, 1984andE. houstoniDe- thePacificcoastofMexico(Espinosa-Perez
laney, 1984. In addition to this, Brusca & Hendrickx, 1997, Hendrickx & Espino-
(1980) reported specimens of an unde- sa-Perez, 1998) led to the capture oflarge
scribedspeciesofExcorallanafromtheen- series of intertidal and sub-tidal isopods,
tire GulfofCalifornia. Brusca (1980) also amongwhichanewspeciesofExcorallana
reported E. kathyae Menzies, 1962, from was recognized. The new species is close
the GulfofCalifornia, butthis species has to E. bruscai, yet it contains distinctive
since been synonymized with E. truncata characters that separateitfromthis species
(Delaney, 1982). Initsreviewofthefamily and from any otherpreviously known spe-
Corallanidae, Delaney (1989:32) reported cies ofExcorallana.
18species(onewithtwosubspecies)ofEx- Abbreviationsusedinthispaperare: St.,
corallana. In all, the genus Excorallana samplingstation;TL,totallength;coll.,col-
contains 22 species, including those cited lector;EMU,EstacionMazatlanUNAMIn-
by Delaney (1989), E. bicornis Lemos de vertebrates Reference Collection; USNM,
Castro & Lima, 1976, E. yamamuroaeNu- UnitedStatesNationalMuseum, Smithson-
nomura, 1988, and E. delaneyi Stone & ian Institution, Washington D.C., U.S.A.;
Heard, 1989. Except for one record ofE. SEM, Scanning Electronic Microscope;
oculata (Hansen, 1890) atAnnobonIsland, CEEMEXP4,researchcruiseintheGulfof
WestAfrica, thegenusisknownonlyfrom Tehuantepec (1991); CORTES 1, 2 and 3,
the coasts of America (Delaney 1989). In research cruises in the Gulf of California
PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
(1982 and 1985); BBMAZ C, monthly re- 111°58.07'W),BajaCaliforniaSur,Mexico,
searchcruisesintheBayofMazatlan,Mex- 4 May 1982, 6 females (TL 8.1-12.4 mm)
ico (1979-1981). All specimens reported (EMU-4947). CORTES 3 Cruise, St. 19,
hereinwerecollectedbythestaffoftheLa- San Miguel Cape (28° 06.04'N,112°
boratorio de Invertebrados Bentonicos, Es- 47.01'W), Baja California, Mexico, 1 Aug
tacionMazatlan, ICML, UNAM. 1985, 1 ovigerous female (TL 10.6 mm)
(EMU-4948) (all specimens collected
CorallanidaeHansen, 1890 aboardthe R/V—ElPuma).
Excorallana Stebbing, 1904 Description. Male.Bodyelongate,with
Excorallana conabioae, new species nearlysub-parallelmargins,about3.3times
Figs. 1-5 as long as wide. Anteriormarginofcepha-
— lon slightlyproducedindorsalview, form-
Type material. Holotype, 1 male (TL ing a very small rostral point. Cephalon
10.0 mm), CORTES 2 Cruise, St. 8, San with a pair of conspicuous, anterior horn-
Marcial Point (25°02.03'N, 108°30.08'W), likeprocessesbetween eyes, asmallerpair
Baja California Sur, Mexico, 11 Mar 1985 betweenanteriorpairandanteriorborderof
(EMU-4942). Paratype, 1 female (TL 11.4 pereonite 1; distance between tubercles of
mm), CORTES 1 Cruise, St. 8, CarmenIs- second pair about Vi distance between tu-
land (25°34.06'N, 111°58.07'W), BajaCal- bercles ofanteriorpair. Eyes large,extend-
ifornia Sur, Mexico, 4 May 1982 (EMU- ing somewhat obliquely over the entire
4943). Paratypes, 1 male (TL 13.0 mm), length ofcephalon (Fig. 1C). Antennule (3
CORTES 3Cruise,St. 8,SanMarcialPoint pedunculararticles)containing7-9flagellar
(25°33.04'N, 110°59.08'W), Baja Califor- articles, almostreachinganterolateralangle
nia Sur, Mexico, 30Jul 1985 and 1 female ofpereonite 1 (Fig. 2A). Antennawith29-
(TL 9.0 mm), CORTES 1 Cruise, St. 8, 34 flagellararticles, allwithfringeofshort
CarmenIsland (25°34.06'N, 111°58.07'W), or long setae; fiagellum long, reaching
Baja California Sur, Mexico, 4 May 1982 about midlength of fourth pereonite (Fig.
(mounted for SEM photography) (EMU- 2B). Frontal lamina with anterior margin
4944).Paratypes, 1 male(TL 10.0mm)and narrowingtoroundedapex(Fig. 1A).Right
1 female (TL9.8 mm), CORTES 1 Cruise, mandible withelongate incisor, with 1 api-
St. 8, Carmen Island (25°34.06'N, cal and 1 shorter sub-apical cusps; lacinia
111°58.07'W),BajaCaliforniaSur,Mexico, reduced, represented by a small 2-spined
4 May 1982 (EMU-4945). Paratypes, 1 lobe. Left mandible with elongate incisor,
male (TL 10.4mm)and 1 female(TL 12.4 with one apical and two shorter sub-apical
mm), CORTES 1 Cruise, St. 8, CarmenIs- cusps; lacinia reduced, represented by a
land (25°34.06'N, 111°58.07'W), BajaCal- small 2-spined lobe; small molar process
ifornia Sur, Mexico, 4 May 1982 (EMU- present on left mandible only; middle and
4946). Paratypes, 1 male (TL 10.5 mm), distal articles of palp of both mandibles
CORTES 3Cruise,St. 8,SanMarcialPoint with few plumose (right) and non-plumose
(25°33.04'N, 110°59.08'W), Baja Califor- (both) setae. Maxillawithtrilobed, spinose
nia Sur, Mexico, 30 Jul 1985 (USNM apex. Maxilliped with a 5-segmented fia-
239375), and 1 female (TL 11.7 mm), gellum; last 3 articles ofpalp with numer-
CORTES 1 Cruise, St. 8, Carmen Island ous setae, antepenultimate article longer
(25°34.06'N, 111°58.07'W), Baja Califor- than the combined length oflast two arti-
nia Sur, Mexico, 4 May 1982 (USNM- cles (Fig. 3).
239374)(allspecimenscollectedaboardthe Pereonite 1 with 2 pairs ofdorsal horn-
R/VElPuma). like processes, seton transverse line, inner
Additional material—CORTES 1 pair larger, of about same size as anterior
Cruise, St. 8, Carmen Island (25°34.06'N, cephalic, outer pair considerably smaller;
VOLUME 111.NUMBER2
(T^f)
Fig. 1. Excorallana conabioae, new species, male holotype (EMU-4942). A, frontal lamina, clypeus and
labrum;B.lateralview;C.dorsalview;D.pleotelson.(Totallength, 10.0mm).
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Fig. 2. Excorallanaconabioae, newspecies, maleholotype(EMU-4942).A,rightantennula;B,rightan-
tenna;C,rightpereiopod 1;D,rightpereiopod2;E,rightpereiopod7.Scalebar=0.25mm.
VOLUME 111,NUMBER2
Fig. 3. Excorallanaconabioae, newspecies,maleholotype (EMU-4942).A,rightmandible;
dible;C,rightmaxilla;D,rightmaxillula;E,rightmaxilliped.Scalebar=0.1 mm.
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pair of closely set smaller, median tuber- other dorsal tubercles on pereonite 1 are
cles,just beyond 2 pairs ofanteriorhorns. wanting. Ornamentation of pereonites 6-7
Anterolateral angle of pereonite 1 pro- and of pleotelson similar in male and fe-
duced, partly covering posterior part of male,tuberclessomewhatsmallerinfemale
eyes. Posterior margin of pereonites 2-5 (Fig. 5D, E,—F).
without conspicuous ornamentation; poste- Remarks. Excorallana conabioae is
rior margin ofpereonite 6 crenate, that of readily separated from most Atlantic spe-
pereonite 7 with a crenate section over- cies ofthegenusandfromE. houstoniand
hanging a lower margin with sub-marginal E. truncatabythepresenceofcephalicpro-
row oftubercles (Fig. 5A, B, C). cesses. Among the "horned" species, E.
Pleonites 1 and4withsub-marginalrow conabioae mostcloselyresembledE. brus-
oftubercles, medianandsub-mediantuber- cai, from which it differs by the following
cles slightly larger on pleonite 1, largerin characteristics:inE. conabioaethecephalic
posterior segments; sub-median tubercles processes are pointing upwards, and the
fused in 2 large posteriorly produced sub- pereonite 1 hornsarenotstronglyproduced
medialcluster. Asecondrowofsmallertu- forwards (with upturned apex) as in E.
bercles visible close to anterior margin of bruscai; the anterior median cephalic mar-
eachpleonic segment (Fig. IB). Pleotelson gin of E. bruscai is strongly produced,
triangular, apex rounded; deep, large notch while E. conabioae features a smallrostral
ataboutmidlengthoflateralmargin; arow point; numberofflagellararticlesinanten-
of 6 (3 pairs) sub-basal tubercles, median nula and antenna ofE. bruscai is 6-8 and
pair much larger than other 2; a cluster of 22-25, respectively, 7-9 and 29-34 in E.
tubercles above the insertion ofuropods; a conabioae;inE.conabioaepereonite 1pro-
sub-triangularclusterofstrong sub-median cessesaresmalleryetmorenumerous(three
bifidsetaeextendinglongitudinallyoneach pairsinsteadofone, verylarge, inE. brus-
halfoftelson, frombase oflargestsub-ba- cai); the antenna is much longer and with
sal tubercle to posterior margin; a sub-lat- more numerous flagellular articles in E.
eralclusteroftuberclesbetweeneachpatch conabioae; thereisno sub-lateralclusterof
of setae and lateral margin oftelson (Fig. tubercles on each sideofthedorsal sideof
ID). telson in E. bruscai; females ofE. bruscai
Uropods slightly longer than pleotelson, lacks horns, whileinthenew speciesthese
fringed with long setae. Uropodalendopod features are reduced, yetdistinguishableas
broad,posteriorlysub-truncate,distallateral tuberclesoncephalonandonfirstpereonite
angles rounded with lateral spines, easily (one pairon each).
lost on preserved specimens. Uropodal ex- Other "horned" species of the genus
opod less than halfwidth ofendopod, also have twolarge (E. bicornisLemos deCas-
with easily lostmarginal spines (Fig. ID). tro & Lima, 1976) or three horns on ce-
Pleopods 1-5 fringedwithplumosemar- phalon [E. berbicensisBoone, 1919, andE.
ginal setae, except endopod ofpleopod 5. tricornis (Hansen, 1890)], no lateral inci-
Appendix masculina rodlike, with simple siononpleotelson{E. longicornisLemosde
pointed apex (Fig. 4). Castro, 1960), orpresentedfouror6horns
Female. Relatively wider than male on the cephalon [E. meridionalis, E. quad-
(about 2.5 times as long as wide). Anterior ricornis(Hansen, 1890),E. mexicanaRich-
pair of cephalic horn-like processes less ardson, 1905, and E. sexticornis (Richard-
than half the size of males, posteriormost son, 1901)]. —
smaller pair wanting. Largest sub-median Etymology. The new species is named
pair, clearly visibleonanteriorhalfofmale forCONABIO (ComisionNacionalparael
first pereonite, reduced to an obsolete pair Conocimiento y Uso de la Biodiversidad,
of small conical tubercles in female; the Mexico), in recognition of the support re-
VOLUME 111,NUMBER2
Fig.4. Excorallanaconabioae, newspecies,maleholotype(EMU-4942).A,rightpleopod rightpleo-
pod2;C,rightpleopod2;D,rightpleopod4;E,rightpleopod5.Scalebar=0.5mm.
ceived during our study of isopods ofthe 70 m. Environmental data available at the
Pacific coas—t ofMexico. moment of sampling indicate epibenthic
Habitat. Excorallana conabioae was temperaturerange from 14.2to 19.8°C and
taken in grab and dredge between 25 and dissolved oxygen concentration always
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Fig.5. Excorallanaconabioae, newspecies,male(A-C)andfemale(D-F)paratypes(EMU-4944).A-D,
dorsalviewofpleotelson;B,dorsalviewofcephalonandpereonite 1;C,frontalviewofcephalonandpereonite
1;E,dorsalviewofcephalonandpereonites 1-2;F,fronto-lateralviewofcephalonandpereonite 1 (SEM).
—————
VOLUME 111,NUMBER2
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Table 1. EnvironmentaldataavailableforthecapturesofExcorallanaconabioaeandE.bruscai.Dissolved
oxygenandtemperaturemeasuredatbottomlevel.S,sand;L,lime;C,clay;VFS,veryfinesand;FS,finesand;
MS,mediumsand.
Sediments
Cruise Station Depth(m) 2(ml/1) Temp.(°C) SIX Gramsize
E. conabioae —
CORTES 1 8 55 2.5 16.0 GRAVEL
CORTES2 8 64-70 3.5 17.5 99 FS
CORTES3 8 42 3.4 19.5 97 FS
CORTES3 19 28 3.5 14.2 100 MS
E.bruscai — — — —
BBMAZ-C14 8 8 — — — —
BBMAZ-C16 10 4 —
CORTES 1 8 55 2.5 16.0 GRAVEL —
CORTES2 47 37 1.5 1—3.5
CORTES3 16 22 4.5 87 VFS
CORTES3 47 28 4.0 29.4 9—6 F—S
CEEMEX-P4 10 23-24 4.8 27.5
hmiogshtelry tshaanndy,2.w4itmhl/o1ne2c;apsteudriemeanstssociwaetreed B1amjaaleCa(liTfLor5n.i7amSmur),(MEeMxUi-c4o9,542)M.aByB1M9A82Z,
with gravels (Table 1). — 16 Cruise, St. 10, Bay of Mazatlan
Geographic distribution. The new spe- (23°13.00'N, 106°27.00'W), Sinaloa, Mex-
ciesisrestrictedtothecontinentalplatform ico, 27 Nov 1980, 1 female (TL 7.5 mm)
alongtheeastcoastofBajaCaliforniaPen- (EMU-4953). BBMAZ 14 Cruise, St. 8,
insula,betweenCarmenIslandandSanMi- Bay of Mazatlan (23°13.00'N, 106°27.00'
guel Cape. W),Sinaloa,Mexico,27Nov 1980,2males
(TL 6.9-7.0 mm) and 7 ovigerous females
Excorallana bruscaiDelaney, 1984 (TL 6.8-9.6 mm) (EMU-4954). CEEMEX
P4 Cruise, St. 10, Boca de San Francisco
Excorallana sp. Brusca, 1980: 229. (16°10.00'N, 94°58.09'W), Oaxaca, Mexi-
Exc11o9-,r4a,2l11l,4a-n21a47.b,r—2uW2se;cta1zi9eD8r—e9:leat8n,aely.3,1,191399318,:4:f2ig55s,..fIigDs,. c((o2E,0M°U34-70.40M94a5'5rN,).1190951°,E3n11s.0ef9ne'amWad)la,eN(aTydaLeri9t.,0LiMmteimxg)-u
Materialexamined. CORTES 3Cruise, ico, 9 Apr 1996, 1 male (TL 7.6 mm)
St. 16, Punta Arboleda (26°52.02'N, (EMU-4633). PlayaelTesoro (24°18.00'N,
110°01.05'W), Sonora, Mexico, 31 Jul 110°19.00'W),BajaCaliforniaSur,Mexico,
1985, 3 males (TL 5.2-7.4 mm), 1 female 17Jul 1996, 6males(TL5.7-8.2mm)and
(TL 5.9 mm) and 2 ovigerous females (TL 16 females (TL 4.7-8.2 mm) (EMU-4634)
7.4-7.5 mm) (EMU-4949). CORTES 2 (CORTES and CEEMEX Cruises speci-
Cruise, St. 47,EsteroTastiota(28°17.08'N, mens collec—ted aboardtheR/VElPuma).
111°37.03'W), Sonora, Mexico, 18 Mar Remarks. The present records extend
1985, 1 male (TL 10.4mm) and2 females the distribution ofthis species from Punta
(TL 10.5-11.4 mm) (EMU-4950). COR- Lobos (27°20'N, 110°40'W), Sonora, to
TES 3 Cruise, St. 47, Estero Tastiota Boca de San Francisco (16°10.00'N,
(28°20.08'N, 111°41.04'W), Sonora, Mexi- 94°58.09'W), Oaxaca, along the east coast
co, 6 Aug 1985, 1 male (TL 8.6 mm) oftheGulfofCaliforniaandwesternMex-
(EMU-4951). CORTES 1 Cruise, St. 8, ico, and from Concepcion Bay (26°50'N,
Carmen Island(25°34.06'N, 111°58.07'W), 1H°55'W), Baja California, to the area of
— ———
PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
La Paz, Playa el Tesoro (24°18.00'N, Bruce,N.L., R. C. Brusca,&P. M. Delaney. 1982.
110°19.00'W), BajaCaliforniaSur. Collec- The status oftheisopodfamiliesCorallanidae
tion ofisopods were also made in the area Hansen, 1890 and—Excorallanidae Stebbing,
1904(Flabellifera). JournalofCrustaceanBi-
ofColima,JaliscoandMichoacan,inwest- ology2:464-468.
ernMexico,duringthissurveybutnospec- Brusca,R.C. 1980. CommonIntertidalInvertebrates
imens ofE.—bruscaiwere found. oftheGulfofCalifornia.UniversityofArizona
a1n98dH9a)bs,ihtaEal.tl.obwrusAsuccbca-oitriiddsailnfgobuennttodhiDicnelhtaahbneietiyantts(e.r1t9Oi8du4ar,l CarvachdPcroioeos,sntsaaA,l.id,Tseul&—cns.PoCan.cs,ip.fYiAacfrPoiirezizsom.uneadr.19oE2r7xin1ecd.no.trEaaelxdl.cl,(oaIrn5sai1oldp3laoeadpnapa,p.amrCeiarriol--a
records for this species, however, indicate lanidae). RevistadeBiologfaMarina14:129-
thatE. bruscaiis alsofoundin deeperwa- 134.
ter, on the continental shelf, at least to 55 Delaney,P. M. 1982. ThesynonymyofExcorallana
m,thussharingasimilarlowerbathymetric kathyaeMenzies, 1962,withExcorallanatrun-
loicmciatsiwointahllyE.scyomnpaabtiroica.e.TBhoetyhcsop-eocciceusrraerde ctdahaeet)a.s—(pReiJccoihuearsrndasl(oCnro,ufs1tC8ar9cu9e)sa,t,awcieItashnopaoBrdieaod,leoscgCroyirpa2tli:lo2an7n3io--f
in one sample, obtained in the Carmen Is- 280.
land area(CORTES 1, St. 8). Environmen- . 1984. Isopods of the genus Excorallana
tal conditions indicate an epibenthic tem- Stebbing, 1904 from the Gulf of California,
perature range of 13.5-29.4°C and dis- MBuelxlietciono(fCrMuastraicneea,ScIiseonpcoedsa,34C:o1r-a2l0l.anidae).
solvedoxygenconcentrationsquitevariable . 1989. Phylogeny and biogeography ofthe
(1.5 to 4.8 ml/1). Sediments werepredomi- marine isopodfamily—Corallanidae (Crustacea,
nantly sandy (Table 1). Isopoda, Flabellifera). NaturalHistoryMuse-
umLosAngelesCounty409:1-75.
Acknowledgments Espinosa-Perez,C, &M. E. Hendrickx. 1997. New
geographicrecordsoftwospeciesofCirolani-
The authors would like to thank the dae(Crustac—ea:Isopoda)fromtheeasterntrop-
CONABIO, Mexico, for the financial sup- UicaNlAPaMcif6i8c:.175A-n1a8l5e.sdelInstitutodeBiologfa,
port (Project HI70) obtained during our Hansen,H.J. 1890. Cirolanidaeetfam—iliaenonnullae
study oftheIsopodaofthe Pacific coastof propinquae Musei Hauniensis. Videnskaber-
Mexico. The fieldwork was partly support- nesSelskabSkrifter,6Raekke,Naturvidenska-
pCerdXoNjbeAcy-t0CP2O1C9NM2AA6C,NyTAC,LOR7MT9e0Ex0iS1c,o2Ba(BnprdMojA3eZcctrucIirsuCeiEss-;- HendricbnSkepexlhwi,ageMsrop.ogemcaEiM.tea,istd&haoeefmM:aC.taCsiaCsss.iskdiEidAsnifpindiidenneloaaisean)H-gaPae5nnr:sde2ez3n.f9i-r(s41It29s69ro8ep..codoarA:d
es) and the European Economic Commu- ofth—e subfamilyfrom the easterntropicalPa-
nity (projects TS2.0312 and CI1.0431E, cific. ProceedingsoftheBiologicalSocietyof
CEEMEX P4 cruise). We also thank Rich- Washington 111:295-302.
ardBruscawhofirstcalledourattentionon Lemos de Castro, A. 1960. Quatro especies novas,
thenewspeciesandBiol.YolandaHornelas ABrraqsuiiliveorsosd,odMeusExecoorNaalcliaonnaalSdteobbRiinog,de1J9a0n4e.iro
Orozco,oftheInstitutodeCienciasdelMar 50:61-77.
y Limnologia, UNAM, Mexico, for taking ,&I.M.Lima. 1976. OcorrenciasdeExcor-
theSEMpicturesofspecimens. Staffmem- allana subtilis (Hansen), Excorallana oculata
bers and students who helped during the (Hansen), Excorallana warmingii (Hansen) e
collection of material aboard the R/V El descricaodeumaespecienovaE—xcorallanabl-
Puma andin the fieldare also thanked. cMoursneisuddoelHitiosrtaolrinaortNeatduroalB,rasBiell.o HAorrqiuziovnotsed1o:
135-142.
LiteratureCited Menzies.R.J. 1962. ThemarineisopodfaunaofBa-
hfadeSanQuintin,BajaCalifornia,Mexico.
Boone,P.L. 1919. Descriptionsoftennewisopods. PacificNaturalist3:337-348.
ProceedingsoftheUnitedStatesNationalMu- Nunomura, N. 1988. DescriptionofExcorallanaya-
seum54:591-603. mamuroesp.nov.(Crustacea,Isopoda)prelim-