Two new species of Dendrobrachia Brook, 1889 (Cnidaria: octocorallia: dendrobrachiidae) from the north-eastern Atlantic and western Mediterranean

Two new species o Dend ob achia B ook, 1889 (Cnida ia: Oc oco allia: Dend ob achiidae) om he no h-eas e n A lan ic and wes e n Medi e anean PABLO J. LÓPEZ-GONZÁLEZ1 and MARINA R. CUNHA2 1 Biodi e sidad y Ecología de In e eb ados Ma inos, Depa amen o de Fisiología y Zoología, Facul ad de Biología, Uni e sidad de Se illa, Reina Me cedes 6, 41012 Se illa, Spain. E-mail: [email p o ec ed] 2 Cen o de Es udos do Ambien e e Ma (CESAM), Depa amen o de Biologia, Uni e sidade de A ei o, Campus de San iago, 3810-193 A ei o, Po ugal. E-mail: [email p o ec ed] SUMMARY: Examina ion o ecen ben hic ma e ial collec ed du ing se e al c uises in he Gul o Cadiz (NE A lan ic) and he S ai o Sicily (Medi e anean) has allowed he axonomic eassessmen o some p e iously iden i ied specimens belong- ing o he monogene ic go gonian amily Dend ob achiidae B ook, 1889. Dend ob achia allax B ook, 1889 is he ype spe- cies o he single genus in his amily, and was o iginally desc ibed om Ascension Island (Sou h A lan ic). Subsequen ly, o he au ho s epo ed he p esence o his species in Cape Ve de Islands (no h-eas e n A lan ic) and some Medi e anean locali ies (Albo an Sea and he S ai o Sicily). The s udy o he specimen om he P ince o Monaco collec ions in Cape Ve de Islands, and ecen ly collec ed ma e ial om he Gul o Cadiz (no h-eas e n A lan ic) and in he sou h o Mal a (Medi e anean), ma e ials p e iously conside ed as D. allax, allow us o ecognize wo undesc ibed species in his genus. All p e ious eco ds o D. allax om he no h-eas e n A lan ic and Medi e anean should be conside ed inco ec . Op esko and Baye (1991) added wo addi ional species o Dend ob achia. Two new species a e desc ibed he e and compa ed wi h hei congene s. Keywo ds: Cnida ia, Oc oco allia, Dend ob achia, no h-eas e n A lan ic, Medi e anean, new species. RESUMEN: Dos nue as especies de DenD ob achia B ook, 1889 (Cnida ia: Oc oco allia: Dend ob achiidae) del A lán ico no es e y del Medi e áneo occiden al. – El examen de ma e ial ben ónico ecolec ado ecien emen e en di e en es c uce os en el Gol o de Cádiz (A án ico no es e) y es echo de Sicilia (Medi e áneo) ha pe mi ido el eemplaza- mien o axonómico de algunos especímenes p e iamen e iden i icados pe enecien es a la amilia monogené ica de Go gona Dend ob achiidae B ook, 1889. Dend ob achia allax B ook, 1889 es la especie ipo del único géne o de es a amilia, y ue o iginalmen e desc i o de la isla Ascensión (A lán ico su ). Pos e io men e, o os au o es ci a on su p esencia en las islas Cabo Ve de (A lán ico no es e) y algunas localidades medi e áneas (ma de Albo án y es echo de Sicilia). El es udio del especimen de la colección del P íncipe de Mónaco en las islas Cabo Ve de, y ma e ial ecien emen e ecolec ado del gol o de Cádiz (A lán ico no es e) y su de Mal a (Medi e áneo), ma e ial p e iamen e conside ado como D. allax, nos pe mi en econoce dos especies no desc i as en es e géne o. Todas las ci as p e ias de D. allax en el A lán ico no des e y Medi e á- neo deben se conside adas inco ec as. Dos especies adicionales al géne o ue on añadidas po Op esko y Baye , 1991. Dos nue as especies son desc i as aquí y compa adas con su congéne es. Palab as cla e: Oc oco allia, Dend ob achia, A lán ico no es e, Medi e áneo, nue as especies. Scien ia Ma ina 74(3) Sep embe 2010, 423-434, Ba celona (Spain) ISSN: 0214-8358 doi: 10.3989/scima .2010.74n3423 INTRODUCTION The amily Dend ob achiidae B ook, 1889 is a s iking example o di icul axonomic placemen in go gonians. A gene al e iew o he in o ma ion pub- lished on he single genus Dend ob achia B ook 1889, ini ially aligned among he An ipa ha ia due o he s uc u e o he axis, has al eady been summa ized and discussed by Op esko and Baye (1991). In ha pape , he au ho s also desc ibed wo addi ional species in his 424 • P.J. LÓPEZ-GONZÁLEZ and M.R. CUNHA SCI. MAR., 74(3), Sep embe 2010, 423-434. ISSN 0214-8358 doi: 10.3989/scima ,2010,74n3423 genus om o he sou he n coas o Aus alia and he S ai o Flo ida. The ype species o he genus Dend ob achia, D. allax B ook 1889, was desc ibed om wo colonies collec ed by he H.M.S. Challenge o Ascension Is- land (Sou h A lan ic) (see B ook, 1889: 159). Thomson (1910) epo ed a new inding o Dend ob achia allax o Cape Ve de Islands, and ha speci ic assignmen was subsequen ly main ained by o he au ho s (Op esko and Baye , 1991; Zib owius and Ta iani, 2005). The wo k o Op esko and Baye (1991) ep esen ed a modi ica ion in he unce ain s a us o he genus Den- d ob achia and amily Dend ob achiidae, wi h i s de- ini i e placemen among he oc oco als. Fu he mo e, wi h he desc ip ions o wo addi ional species, hese au ho s es ablished he basic cha ac e s in he ax- onomy o a g oup o species ha lack one o he main oc oco al ea u es ( he calca eous scle i es) bu ha e an a bo escen spiny p o einaceous axis like he membe s o he hexaco allian o de An ipa ha ia, in which he ype species o his genus was ini ially aligned. A e-examina ion o he specimen s udied by Thomson, deposi ed in he Musée Océanog aphique de Monaco, e eals impo an di e ences om he ype ma e ial o D. allax ha allows us o p opose a new name o he Cape Ve de ma e ial. Recen ly Zib owius and Ta iani (2005) epo ed he p esence o he genus Dend ob achia (as D. a llax) om some locali ies in he wes e n Medi e anean Sea (Albo an Sea and he S ai o Sicily), conside ably enla ging he geog aphical dis ibu ion o he ype spe- cies o his genus. Du ing some sampling c uises ca ied ou in he Gul o Cadiz, sponso ed by he TTR p og amme (T aining Th ough Resea ch P og amme), a se o colonies a ibu able o he genus Dend ob achia we e collec ed. The mo phologic s udy o hese colonies showed ha hey a e compa able wi h he ma e ial ci ed as D. allax by Zib owius and Ta iani (2005) on he o he side o he S ai o Gib al a , bu do no co espond o he cha ac e s o he ype ma e ial o D. allax e ised by Op esko and Baye (1991) no o he specimen examined by Thomson (1910) om o Cape Ve de, conside ed he e an unnamed species. This Den- d ob achia ma e ial om he h esholds o he S ai o Gib al a is conside ed he e as an undesc ibed species. The goal o he p esen con ibu ion is o desc ibe wo new species, based on ma e ial p e iously consid- e ed unde he name o he ype species o he genus, Dend ob achia allax. MATERIALS AND METHODS The specimen s udied he e om o Cape Ve de was collec ed by he P ince o Monaco and is pa o he collec ion held by he Musée Oceanog aphique de Monaco (see Thomson, 1910). The specimens om he Gul o Cadiz we e ob ained in a se ies o TTR c uises ca ied ou on boa d he RV P o . Logache . In hese la e c uises, a TV-assis ed g ab (GR) was used o loca e in e es ing sampling si es in he a ge en i on- men s and a geological d edge (D) was also used on some occasions o eco e ca bona e chimneys. The biological ma e ial ob ained was p ese ed in 70% o 96% e hanol. The colonies om sou h Mal a we e collec ed du ing he MARCOS c uise (ISMAR-CNR, Bologna), on boa d he RV U ania (6-19 Ap il 2007) in he S ai o Sicily. Colony e minology mainly ollows Baye e al. (1983) and Op esko and Baye (1991). The ma e ial s udied is deposi ed in he Musée Océanog aphique de Monaco (MOM), in he Na u al His o y Museum (B i ish Museum) in London (NHM), in he Muséum na ional d’His oi e na u elle (MNHN) in Pa is, in he biological esea ch collec ion o he Depa amen o de Biologia, Uni e sidade de A ei o (DBUA) and in he An hozoan e e ence collec ion o he esea ch g oup “Biodi e sidad y Ecología de In e eb ados Ma inos” o he Uni e si y o Se ille (BEIM). RESULTS Family Dend ob achiidae B ook, 1889 Genus Dend ob achia B ook, 1889 Dend ob achia sa men osa n. sp. (Figs. 1B-H, 2) Dend ob achia allax, Thomson, 1910. Ma e ial examined. Holo ype: MOM (INV-21050), 1 colony in alcohol. In label: «S . 1157, 1901, Chale 219 // ue pa Thomson, ANTIPATHARIA, Dend ob achia allax». Diagnos ic desc ip ion o he holo ype. Colony pla- na , abou 160 mm in leng h, spa sely b anched, wi h a p incipal axis p og essi ely dec easing in diame e along he leng h o he colony, and la e al b anches i egula ly dis ibu ed, a ely opposi e, highes o de b anchle s mos ly 10-25 mm long, 0.6-0.9 mm in di- ame e , on a e age abou 1 cm apa on same side o b anches. Usually six, occasionally se en axial idges on b anchle s, inc easing in numbe on la ge b anches. Spines p esen on idges, one ow pe idge; spines a iable in size and shape bu inc easing in size wi h inc easing hickness o b anches, 0.12-0.15 mm long on b anches abou 1 mm in diame e . Main axis on hi d pa o he colony 1.6 mm in diame e wi h abou 14 idges and spines o 0.12-0.17 mm in leng h. Main axis on second pa o he colony 2.2 mm in diame e , wi h abou 20 idges, and spines o 0.17-0.2 mm in leng h. Basal pa o he main axis 3.75 mm in diame- e , wi h abou 32-35 idges and spines o 0.2-0.25 mm in leng h. Hold as well de eloped, ele a ed, 11 mm in diame e , co e ed by spines. Polyps placed bila e ally, al e na e o in nea ly opposi e pai s, 3-5 polyps pe cm. Geog aphical and ba hyme ic dis ibu ion. Den- d ob achia sa men osa n. sp. is cu en ly only known TWO NEW SPECIES OF DENDROBRACHIA • 425 SCI. MAR., 74(3), Sep embe 2010, 423-434. ISSN 0214-8358 doi: 10.3989/scima ,2010,74n3423 om i s ype locali y, o he island o S . Vincen (Cape Ve de Islands), 219 a homs (abou 400 m) in dep h (see Thomson, 1910 as D. allax). E ymology. The speci ic epi he sa men osa (La in o wiggy) e e s o he decumben aspec o he b anches and b anchle s o his species. Rema ks. The specimen e ised he e was collec ed in 1901 by P ince Albe , and assigned by Thomson (1910) o he only known species o Dend ob achia a ha ime, D. allax. Subsequen au ho s conside ed ha assigna ion easonable, and ci ed he inding in ex s (Op esko and Baye , 1991), bu no o he e-examina- ion o he ma e ial has been ca ied ou un il now. Thomson (1910) indica ed in he i s lines o his wo k he ecep ion o ou specimens – h ee d y and one in spi i – om he P ince o Monaco, bu only one o hese colonies (now in e hanol 70º) exis s in he deposi s o he Musée Océanog aphique de Mo- naco (Michèle B uni, pe s. com.). Two o he colonies examined by Thomson had a hold as , he specimen examined he e is appa en ly one o hem. Al hough we canno know wi h ce ain y he a e o he o he Fig. 1. – Dend ob achia allax: A, ype ma e ial, NHM (1890.4.9.27), he specimen on he igh was ha illus a ed by B ook (1889: pla e 10, Fig. 1) (Pho o: Emma She lock, BMNH, London). Dend ob achia sa men osa n. sp., Holo ype MOM (INV-21049), specimen ini ially iden i ied as D. allax by Thomson (1910): B, comple e colony. Spina ion in D. sa men osa n. sp. on axial idges a di e en le els: C, e minal wig, 0.5 mm in diame e ; D, b anch, 0.65 mm in diame e ; E, b anch, 0.9 mm in diame e ; F, b anch, 1.5 mm in diame e ; G, s em, 2.0 mm in diame e ; H, s em, 2.75 mm in diame e . Figu es C o F co espond o b anches o di e en o de s on he same side o he main axis. Figu es G and H co espond o he main axis a mid-dis al and p oximal le els. Figu es C o H a e a he same scale. 426 • P.J. LÓPEZ-GONZÁLEZ and M.R. CUNHA SCI. MAR., 74(3), Sep embe 2010, 423-434. ISSN 0214-8358 doi: 10.3989/scima ,2010,74n3423 specimens, o i he p esen ma e ial was uly ha p e- se ed in spi i , he commen s made by Thomson – had only a ew ex emely b i le polyps – and he s a e and p esence o polyps in he colony we examined indica e ha his is p obably one o he d ied colonies ha was placed in e hanol la e on. An old pencil co ec ion on he egis a ion ca d o his specimen a he MOM e- placing “d ied” by “in alcohol” (Michèle B uni pe s. comm.) also suppo s his hypo hesis. Acco ding o he se o cha ac e s used by Op esko and Baye (1991) in he di e en ia ion o Dend o- b achia species, D. sa men osa n. sp. di e s om i s congene s in he gene al b anching pa e ns and angle in which b anches (and b anchle s) a ise om he p e- ious b anch o de , as well as in he s em diame e / heigh o co allum a io, he a e age dis ance by which b anchle s a e sepa a ed, and he p esence o spines on he axial idges (see de ails in Table 1). On his las poin , D. sa men osa n. sp. is close o he sou h-wes e n Aus alian species D. paucispina wi h espec o he numbe o ows o axial spines pe idge, and he heigh o he spines acco ding o he di e en diame e s o he axis. Howe e , as p e iously men ioned, he b anch- ing pa e n and angle be ween b anches o con iguous Fig. 2. – Dend ob achia sa men osa n. sp. Holo ype, MOM (INV-21049). SEM pho og aphs. A, la e al iew o e minal wig, s e eo pai ; B, de ail o one o he la ge spines on image A; C, la e al iew o e minal wig showing low ele a ions, s e eo pai ; D, de ail o low ele a ions in C; E, axis, c oss sec ion below apex, s e eo pai ; F, axis, c oss sec ion below apex. TWO NEW SPECIES OF DENDROBRACHIA • 427 SCI. MAR., 74(3), Sep embe 2010, 423-434. ISSN 0214-8358 doi: 10.3989/scima ,2010,74n3423 o de s a e comple ely di e en . Addi ional de ails can be obse ed in Table 1 and selec ed cha ac e s used in he key o species. Dend ob achia bonsai n. sp. (Figs. 3-8) Dend ob achia allax, Zib owius and Ta iani, 2005. Ma e ial examined. Holo ype: NHM (2009.9), 1 colony wi h hold- as , TTR-12 c uise, s n. AT 412-D, Al Id isi, 35º14.25 N 06º36.72 W, 230-235 m, 17 Jul 2002. Pa a ypes NHM (2009.10-11), 2 colo- nies. MOM (INV-21898), 1 colony wi h he same sampling da a as he holo ype. Addi ional ma e ial: NHM (2009.12-16), 5 colonies, TTR-12 c uise, s n. AT 388 GR, Fo mosa Ridge, 36º10.26’N 7º43.81’W, 1079 m, 8 Jul 2002. MON (INV-21899), 5 colonies, TTR-12 c uise, s n. AT 388 GR, Fo mosa Ridge, 36º10.26’N 7º43.81’W, 1079 m, 8 Jul 2002. DBUA (01138.02), 38 colonies, TTR-12 c uise, s n. AT 388 GR, Fo mosa Ridge, 36º10.26’N 7º43.81’W, 1079 m, 8 Jul 2002. BEIM (CRO-0019), 20 colonies, TTR-12 c uise, s n. AT 388 GR, Fo mosa Ridge, 36º10.26’N 7º43.81’W, 1079 m, 8 Jul 2002. DBUA (01138.01), 4 colonies, TTR-12 c uise, s n. AT 412-D, Al Id isi, 35º14.25 N 06º36.72 W, 230-235 m, 17 Jul 2002. BEIM (CRO-0020) 2 colonies, one o hem agmen ed,TTR-14 c uise, s n. AT-565 GR, Pen Duick, 35°18.18’N 6°47.65’W 544 m, 9 Aug 2004. DBUA (01139.01), 2 colonies, TTR-14 c uise, s n. AT550 D, Wes o Gib al a S ai , 35º42.10’N 6º30.19’W, 368-392 m, 8 Aug 2004. MNHN (Oc .2009-0219), 2 colonies, MARCOS c uise, s n 44, sou h Mal a, 35º30.506’N 14º06.23’E, 632-467 m, 12 Ap 2007. MNHN (Oc .2009-0220), 18 colonies, MARCOS c uise, sampling da a no eco ded, bu p obably close o hose o he p e ious lo . Diagnos ic desc ip ion o he holo ype. Colony plana , abou 65 mm in leng h, delica e, b anched in a nea ly dicho omous way, wi hou any b anch as p in- cipal axis along he en i e leng h o he colony, main axis be o e i s dicho omy 11 mm in leng h, highes o de b anchle s mos ly 5-20 mm long, 0.15-0.17 mm in diame e , on a e age abou 1 cm apa on same side o b anches. Usually ou idges o he b anches o highe o de s, mode a ely inc easing in numbe ba- sally. Spines sca ce and poo ly de eloped on idges, when p esen , one ow pe idge; spines a iable in size and shape om jus a poin ed ele a ion on he idge o no mo e han 0.035 mm high. Axis on dis al b anch- le s is 0.17 mm in diame e wi h 4 p ac ically smoo h idges wi h deep g oo es in be ween. Axis o 0.25-0.3 mm in diame e , wi h abou 4 idges, and sca ce spines o maximum 0.05 mm. Basal pa o he axis, be o e i s dicho omy, is 0.65 mm in diame e , wi h abou 7-9 wide and ounded idges, wi hou spines and shal- low g oo es. Hold as de eloped as a small disk, no dis inc ly ele a ed, abou 1.4 mm in diame e (possibly la ge , pa ially damaged on one side), wi hou spines. P ese ed polyps abou 1.4 mm in heigh , placed al e - na ely, well sepa a ed om one ano he , be ween 2.5 and 4 mm, 3-4 polyps pe cm. Ten acles wi h 8-9 pai s o pinnules (p obably mo e, bu no co ec ly obse ed due o he s a e o p ese a ion o he so pa s o he colony). Polyps con ac ile o some deg ee, bu no e ac ile. Dis ally some polyps a e dis inc ly ma u e, de eloping oocy es wi h a maximum diame e o up o 0.8 mm. Va ia ions. In gene al, he pa a ypes and he emain- ing examined ma e ial show simila cha ac e s o hose Table 1. – Mo phome ics o Dend ob achia spp. (enla ged om Op esko and Baye , 1991) Pa ame e D. allax D. paucispina D. mul ispina D. sa men osa n. sp. D. bonsai n. sp. Co allum: S em diam./heigh (%) 1.2-1.5 1.1-1.7 0.7 a 2.5 1-1.2 Hold as diame e (mm) --- --- h --- 11 2.1-2.5 B anchle s: Maximum leng h b (cm) ca. 3 ca. 3 ca. 3 ca. 2.5 ca. 2.2 Diame e (mm) 0.5-0.8 0.4-0.8 0.4-0.5 0.6-0.9 0.15-0.17 A g. dis . apa c (mm) 9.4 9.0-9.5 13 5.7 10 Angle espec main s em >45º >45º >60º 80-120º 40-70º Axial idges: Numbe o b anchle s d (5) 6 (7) 6 (7, 8) 5 6 (7) (3)4 Axial spines: Numbe o ows pe idge 1 0-1 1-2+ 0-1 0-1(2 m ) Max. numbe pe mm pe ow d 3-5 (3) 4 (5) 4 (5, 6) 3-7(8) 6-8 Heigh o spines c (mm): Axis diam. ≤0.5 mm 0.05-0.10 --- o 0.06-0.12 0.00-0.02 j 0.00-0.03 Axis diam. 0.6-0.8 mm 0.10-0.15 0.00-0.07 0.10-0.25 0.01-0.09 j 0.00-0.03(0.05 n) Axis diam. 0.8-1.0 mm 0.15-0.25 0.07-0.12 0.26-0.32 0.12-0.15 l Axis diam. 1.0-2.0 mm ca. 0.3 0.12-0.18 0-25-0.40 0.15-0.18 l Axis diam. >2.0 mm ca. 0.5 0.12-0.25 - 0.17-0.25 l Polyps: Maximum heigh (mm) 2.5 2.2 ca. 2.3 1.75 i 1.4 i Numbe pe cm 3-6 3-6 3+ 3-5 3-4 Pai s o pinnules --- 8-10 --- 6-7 g 12 k a specimen may be pa o a la ge colony; b unb anched b anchle s, a ely longe ; c on he same side o he axis; d a e o excep ional da a be ween pa en heses; e heigh o spines e y a iable, commones size anges shown; including en acles; g As epo ed by Thomson (1910), no clea ly obse able in p esen s a e; h p esen in he ype ma e ial bu no desc ibed in de ail; i p ese ed ma e ial, p obably la ge in be e condi ions o conse a ion. Abou 2 mm a e Figu e 3 in Zib owius and Ta iani (2005); j om sligh ly low ele a ions o sho spines; k obse ed by SEM (Fig. 6A, B), usual inspec ion by op ical mic oscopy only e eals abou 8; l his axis diame e has no been obse ed in his species; m obse ed in young colonies; n small colony (28 mm in leng h), obse ed a he basal s em; o axial diame e s ≤0.5 mm ha e no been obse ed in his species; --- no da a a ailable. 428 • P.J. LÓPEZ-GONZÁLEZ and M.R. CUNHA SCI. MAR., 74(3), Sep embe 2010, 423-434. ISSN 0214-8358 doi: 10.3989/scima ,2010,74n3423 in he holo ype in e e ence o diame e and numbe o idges (and o namen a ion) in b anches and b anchle s. The b anching pa e n seems o be mainly dicho o- mous, bu la e al b anches also appea . Some o he sho e colonies (usually smalle han 30 mm in leng h) show a monopodial b anching pa e n, o he s al eady ha e he i s main dicho omy dis inc . The s em be o e he i s ami ica ion a ies om 4 o 17 mm in leng h. Comple e hold as disk wide han in he holo ype ( he la e was p obably damaged by collec ion), om 2.1 o 2.5 mm in diame e . Up o 10 longi udinal idges a e p esen on he basal s em o he pa a ype, he ad- di ional ma e ial examined shows 6 o 14 in numbe , depending on o al leng h and diame e . Spina ion on he main s em be o e he i s ami ica ion a ies in he di e en colonies obse ed. Al hough he holo ype (65 mm in colony leng h) does no ha e spines, colonies (52 mm in leng h) showed sca ce spines on a single line no mo e han 0.03 mm in leng h, a colony, 28 mm in leng h, showed spines o up o 0.046 mm in wo lines pe axial idge. The numbe o pai s o pinnules pe en acle has been ound in SEM obse a ions o be abou 12 (Fig. 6A, B). Op ical mic oscopy obse a- ions usually e eal a lowe numbe o pai s, also due o he s a e o p ese a ion o hese so pa s. SEM and his ological obse a ions showed ad- di ional in o ma ion on he s uc u e o he axis and ep oduc i e ea u es. T ans e se sec ions obse ed by SEM showed a mul ilaye axial s uc u e (Figs. 5B-D, 7D-F), wi h laye s o a iable hickness (Figs. 8A, B). His ological ans e sal sec ions o he axis a di e en le els showed he hickness o he di e - Fig. 3. – Dend ob achia bonsai n. sp.: A, Holo ype, NHM (2009.9), comple e colony, 65 mm in leng h; B, a se o colonies om s a ion AT- 412D, showing pa o he colonial a iabili y obse ed, hold as indica ed wi h an a ow in one o he colonies, he h ee colonies wi h as e isk a e he pa a ypes NHM (2009.10-11) MOV (INV-21898); C, BEIM (CRO-0020) comple e colony, 28 mm in leng h, hold as indica ed wi h an a ow; D, hold as om one o he pa a ypes in B (middle line on he igh );. Spina ion in he holo ype o D. bonsai on axial idges a di - e en le els: E, 0.17 mm in diame e ; F, 0.30 mm in diame e ; G, 0.37 mm in diame e ; H, 0.42 mm in diame e ; and I, 0.50 mm in diame e . Figu es E o H co espond o b anches o di e en o de s on he same side o he main axis. Figu e I co esponds o he main axis be o e he i s ami ica ion. TWO NEW SPECIES OF DENDROBRACHIA • 429 SCI. MAR., 74(3), Sep embe 2010, 423-434. ISSN 0214-8358 doi: 10.3989/scima ,2010,74n3423 en laye s in mo e de ail, and he ue shape o he axial nucleus ( he mos in e nal pa o he axis wi h- ou mul ilaye s uc u e, he unique axial s uc u e obse able in he mos e minal wigs) is 4 idged ( a ely 3 idged) (see Figs. 8c-e). The numbe o laye s subsequen ly dec eases om he basal s em o he dis almos wigs, whe e only he cen al nucleus is p esen . T ans e sal sec ions o he axis nea he dis al ips o he b anchle s show a 2 laye s uc u e (cen al co e plus addi ional laye ). Taking in o Fig. 4. – Dend ob achia bonsai n. sp. MOM (INV-21899): A) a comple e colony wi h hold as , 23 mm in leng h, showing mos o i s polyps de eloping oocy es; B) de ail o a e minal wig showing h ee polyps wi h oocy es o abou 600 µm. BEIM(CRO-0020): C) his ological sec ion o a polyp om a e minal wig showing de eloping oocy es. Fig. 5. – Dend ob achia bonsai n. sp. Holo ype, NHM (2009.9): SEM pho og aphs: A, la e al iew o e minal wig; B, c oss sec ion below apex, showing c uci o m ou line o he axis, no e ha coenenchyme is s ill p esen in he sec ion, illing he angula spaces be ween adjacen longi udinal axial idges, s e eo pai ; C, axis, c oss sec ion o a e minal wig a a lowe le el han B, no e he ou axial idges wi h a mul ilaye s uc u e, s e eo pai ; D, de ail o C showing he nume ous laye s al eady p esen in he axis a he ou - idges s a e. 430 • P.J. LÓPEZ-GONZÁLEZ and M.R. CUNHA SCI. MAR., 74(3), Sep embe 2010, 423-434. ISSN 0214-8358 doi: 10.3989/scima ,2010,74n3423 accoun he ac ha hese specimens a e ound in empe a e la i udes, his 2-laye s uc u e p obably indica es a 2-yea old b anchle . One o he hicke basal s ems sec ioned (abou 0.67 mm in diame e ) belonging o a colony 42 mm in leng h, showed abou 25 laye s (Fig. 8D,E). SEM and his ological sec ions show how new idges a e added (see Figs. 7E, F; 8D, E). The axial cen al co e has la ened (Figs. 3E; 5A; 6C; 7A) and na ow (in sec ion) idges (see Fig. 5B; 8C). The sequen ial addi ion o laye s inc eases he hickness o a idge, gi ing ini ially a dis ally la - ened idge (Fig. 6G, H) wi h sligh ly ele a ed bo - de s, whe e axial spines can appea . The con inuous addi ion o laye s and he inc emen o idges can be easily ollowed in ans e sal sec ions by SEM and his ological sec ions. Apa om he absence o scle i es and he dis inc s uc u e o he axis in he species o he genus Den- d ob achia, he known colonies (nea ly one hund ed) o he new species p oposed he e do no each mo e ha 70 mm in o al leng h, and colonies o abou 15 mm al eady ha e polyps wi h de eloping gonads o abou Fig. 6. – Dend ob achia bonsai n. sp. Colony illus a ed in Figu e 3C, BEIM(CRO-0020): A, one o he ou polyps p esen in a 28 mm high colony, showing he column and pinna e en acles, s e eo pai ; B, de ail o A showing he c own o eigh pinna e en acles; C o H, la e al iew o axis om e minal b anchle (C) o nea he basal s em (G and H), all hese igu es a he same scale, no e he p esence o wo ows o spines in G and H; I, de ail o H, showing he la ge spines a anged in wo ows pe axial idge; J, de ail o one o he la ge spines in G. TWO NEW SPECIES OF DENDROBRACHIA • 431 SCI. MAR., 74(3), Sep embe 2010, 423-434. ISSN 0214-8358 doi: 10.3989/scima ,2010,74n3423 0.7 mm (Fig. 4). This is one o he smalle go gonian species he au ho s a e awa e o ha eaches a ma u e s a e in colonies o such a sho leng h. Howe e , we should ake in o accoun he ac ha a small size is no necessa ily ela ed o a young s a e o sho li e span, since, as was men ioned abo e, abou 25 laye s can be ound a he basal s em le el in colonies o 42 mm in o al leng h. Geog aphical and ba hyme ic dis ibu ion. Den- d ob achia bonsai n. sp. is cu en ly known om he Gul o Cadiz (p esen accoun ), Albo an Sea and he S ai o Sicily (sou h o Mal a in his pape plus ad- di ional locali ies in Zib owius and Ta iani, 2005 as D. allax) be ween 230 and 1080 m in dep h (Fig. 5). E ymology. The speci ic epi he bonsai e e s o he ancien o ien al a o minia u izing plan s g own in con aine s, in allusion o he small and delica e aspec o he colonies o his species in ela ion o he o he species desc ibed in he genus Dend ob achia. Name in apposi ion. Ecological obse a ions. In he Gul o Cadiz Dend ob achia bonsai n. sp. is p esen ly known om i e locali ies ep esen ing h ee di e en ypes o habi a : ca bona e chimneys (si e wes o he S ai o Gib al a , AT550G and Fo mosa Ridge, AT388G and AT389D); dead scle ac inean co als (Pen Duick Esca pmen , AT406G and AT565G ) and he c a e o a mud olcano (Al Id isi, AT412D). In Al Id isi, Dend ob achia bonsai n. sp. was col- lec ed om he nume ous sands ones eco e ed by he geological d edge, and he e o e he dis ibu ion o he species in he Gul o Cadiz appea s o be limi ed by he a ailabili y o a sui able ha d subs a um o se lemen . The ca bona e chimneys, o med inside he sedimen by mic obial media ion bu p esen ly inac i e a e exposed a he su ace o he sea loo by he e osi e ac ion o he Medi e anean ou low (Magalhães, 2007), and he ideo obse a ions (deep- owed TV) ca ied ou du ing TTR c uises a hese si es show e idence o conside able bo om cu en eloci ies. These ideo obse a ions also showed ha he aunal assemblage in all si es was clea ly domi- Fig. 7. – Dend ob achia bonsai n. sp., BEIM(CRO-0019): A, la e al iew o axis o e minal b anchle , s e eo pai ; B, de ail o axial su ace o a 0.34 mm basal s em; C, de ail o axial su ace o a 0.44 mm basal s em; D, c oss sec ion below apex, showing c uci o m ou line o he axis, no e ha coenenchyme is s ill p esen in he sec ion, illing he angula spaces be ween adjacen longi udinal axial idges; E, c oss sec ion o a 6-7 idged axis, no e ha he inc emen in idges is made by he enla gemen o a p e ious idge, and he mul ilaye ed s uc u e o he axis; F, c oss sec ion o a 12 idged axis.