Heteropathes americana, , Opresko (2003)

Horowitz, Jeremy, Opresko, Dennis M. & Bridge, Tom C. L., 2018, Black corals (Anthozoa: Antipatharia) from the deep (916 m - 2542 m) Coral Sea, north-eastern Australia, Zootaxa 4472 (2), pp. 307-326 : 322-324

Heteropathe s cf. americana, Opresko (2003)

( FIgS. 1 ANd 7 )

Heteropathes americana Opresko (2003): 531 –536

Material examined: MTQ MATeRIAL (PReSeRVed IN eTHYL ALCOHOL): G73229 (STATION dATA IN TAbLe 1).

Diagnosis (AfTeR OPReSkO 2003): CORALLUM MONOPOdIAL ANd PINNULATe; PINNULeS ARRANged IN TWO LATeRAL ROWS ANd ONe OR TWO IRRegULAR ANTeRIOR ROWS. LATeRAL PINNULeS SIMPLe, eLONgATe, ARRANged ALTeRNATeLY ANd INCLINed ANd CURVed dISTALLY ANd eXTeNdINg TO THe TOP Of THe CORALLUM; ANTeRIOR PINNULeS SHORT, SUbPINNULATe, ANd eXTeNdINg OUT NeARLY PeRPeNdICULAR TO THe PLANe CONTAININg THe STeM ANd LATeRAL PINNULeS. ANTeRIOR PINNULeS WITH ONe TO THRee SeCONdARY PINNULeS, THe LOWeRMOST TWO USUALLY ARRANged bILATeRALLY. SeCONdARY PINNULeS MAY be SUbPINNULATe, WITH THe TeRTIARY PINNULeS USUALLY ARISINg fROM UPPeR ANd/OR LOWeR SURfACe Of SeCONdARIeS. SPINeS ON LATeRAL PINNULeS SMALL (AbOUT 0.05 MM OR LeSS), TRIANgULAR, ACUTe, COMPReSSed. SPINeS ON ANTeRIOR PINNULeS LARgeR ON ONe SIde Of AXIS (UP TO 0.13 MM) ANd INCLINed dISTALLY. POLYPS 5 MM TO 6 MM IN TRANSVeRSe dIAMeTeR (fROM dISTAL edge Of dISTAL LATeRAL TeNTACLeS TO THe PROXIMAL edge Of THe PROXIMAL LATeRAL TeNTACLeS).

Description of MTQ specimen: MONOPOdIAL WITH PINNULeS ARRANged IN TWO LATeRAL ROWS ANd ONe IRRegULAR ROW Of ANTeRIOR PINNULeS. TOTAL STeM LeNgTH IS 4 CM; HOWeVeR, THe STeM TIP IS bROkeN. LATeRAL PINNULeS ARe SIMPLe, eLONgATe, ARRANged ALTeRNATeLY, eXCePT fOR THe fIRST SeT Of LATeRAL PINNULeS, WHICH ARe NeARLY OPPOSITe, WITH 3 MM SPACeS beTWeeN PINNULeS ON ONe SIde Of THe STeM, ANd ARe CURVed dISTALLY ( FIgURe 7A ). ANTeRIOR PINNULeS RANge beTWeeN 0.8 CM ANd 1 CM LeNgTH, ARe SPACed 0.1 CM TO 0.2 CM APART ANd HAVe ONe TO TWO ORdeRS Of SUbPINNULeS ( FIgURe 7b ). FOUR TO fIVe ROWS Of SPINeS CAN be SeeN fROM ONe ASPeCT ON LATeRAL PINNULeS ( FIgURe 7C ) ANd TWO ROWS Of SPINeS CAN be SeeN fROM ONe ASPeCT ON ANTeRIOR PINNULeS ( FIgURe 7d ). SPINeS ON LATeRAL PINNULeS ARe SMOOTH, SIMPLe, 0.045 MM IN HeIgHT, ANd ARe TRIANgULAR, ACUTe ANd COMPReSSed ( FIgURe 7C ). SPINeS ON ANTeRIOR PINNULeS ARe LeSS UNIfORMLY SHAPed, RANgINg fROM TRIANgULAR TO eXTReMeLY dISTALLY INCLINed, VARYINg IN HeIgHT fROM 0.04 MM TO 0.08 MM, ANd ARe geNeRALLY LARgeR THAN SPINeS ON LATeRAL PINNULeS, eSPeCIALLY ON THe OUTeR CONVeX SIde ( FIgURe 7e ).

Remarks: FOUR NOMINAL SPeCIeS ARe CURReNTLY ReCOgNIzed IN THe geNUS: H. heterorhodzos (FORSTeR COOPeR, 1909), H. americana OPReSkO, 2003, H. pacifica OPReSkO, 2005, ANd H. opreski de MATOS, 2014. SPeCIeS IN THe geNUS Heteropathes ARe IdeNTIfIed bASed ON THe ReLATIVe SIze Of SPINeS ON ANTeRIOR PINNULeS ANd SUbPINNULeS ANd dIffeReNCeS IN THe SUbPINNULATION Of THe ANTeRIOR PINNULeS. THe CIDARIS SPeCIMeN IS LeAST SIMILAR WITH H. opreski beCAUSe H. opreski HAS SHORTeR PINNULeS COMPARed TO THe STeM, HAS SeCONdARY PINNULeS ON LATeRAL PRIMARY PINNULeS, ANd MUCH HIgHeR ORdeRS Of SUbPINNULATION ON THe ANTeRIOR PRIMARY PINNULeS (“HeAVILY SUbPINNULATed” COMPARed TO ONe TO TWO ORdeRS Of SUbPINNULATION fOR THe CIDARIS SPeCIMeN). THe CIDARIS SPeCIMeN IS ALSO UNLIke H. heterorhodzos beCAUSe H. heterorhodzos HAS fIVe TO SIX SeCONdARY PINNULeS ARISINg fROM ONe POINT ON ANTeRIOR PRIMARY PINNULeS WITH NO eVIdeNCe Of TeRTIARY PINNULeS. THeRefORe, THe CIDARIS SPeCIMeN IS LIkeLY TO be eITHeR H. americana OR H. pacifica beCAUSe bOTH SPeCIeS HAVe ONe TO TWO ORdeRS Of ANTeRIOR SUbPINNULeS, LIke G73229. THeSe TWO SPeCIeS dIffeR bASed ON THe LeNgTH Of THe dISTAL eNd Of THe STeM AbOVe THe PINNULATed SeCTION WHeRe H. americana HAS A PINNULATed SeCTION Of ~1 CM fOLLOWed dISTALLY bY>7 CM WITHOUT PINNULATION WHILe H. pacifica HAS PINNULeS eXTeNdINg TO NeAR THe dISTAL eNd Of THe STeM. ALTHOUgH G73229 HAS LONg eYeLASH-SHAPed LATeRAL PINNULeS, LIke H. americana , THe STeM TIP Of THe MTQ SPeCIMeN IS bROkeN WHICH MAkeS IT dIffICULT TO IdeNTIfY THe SPeCIeS bASed ON THe LeNgTH Of THe UPPeRMOST UNPINNULATed SeCTION Of THe STeM. THeSe TWO SPeCIeS ALSO dIffeR IN THe ReLATIVe SIze Of SPINeS beTWeeN LATeRAL ANd ANTeRIOR PINNULeS WHeRe, LIke THe CIDARIS SPeCIMeN, H. americana COLONIeS HAVe SIgNIfICANTLY LARgeR SPINeS ON OUTeR CONVeX SIdeS Of ANTeRIOR PINNULeS WHILe H. pacifica HAS geNeRALLY eqUAL SPINe HeIgHTS beTWeeN PINNULe TYPeS. ALTHOUgH THIS SPeCIMeN MOST ReSeMbLeS H. americana , THe STeM TIP IS bROkeN, ANd THe COLONY LACkS POLYPS, WHICH ARe feATUReS THAT WOULd ALLOW OUR SPeCIeS IdeNTIfICATION TO be MORe defINITIVe. ALSO, THe CIDARIS SPeCIMeN HAS fOUR TO fIVe ROWS Of SPINeS VISIbLe IN ONe VIeW Of LATeRAL PINNULeS ANd TWO ROWS Of SPINeS VISIbLe IN ONe VIeW Of ANTeRIOR PINNULeS, WHICH IS MORe IN LINe WITH H. pacifica (THe H. pacifica TYPe HAS fOUR TO fIVe ANd THRee ROWS Of SPINeS IN ONe VIeW Of LATeRAL ANd ANTeRIOR PINNULeS, ReSPeCTIVeLY), bUT NOT TOO dIffeReNT THAN H. americana THAT IT COULdN’T ReVeAL PLASTICITY fOR THe CHARACTeRISTIC (THe H. americana TYPe HAS fIVe TO eIgHT ANd TWO TO THRee ROWS Of SPINeS IN ONe VIeW Of LATeRAL ANd ANTeRIOR PINNULeS, ReSPeCTIVeLY).

Distribution: THIS SPeCIeS IS kNOWN TO OCCUR IN THe NORTHWeST ATLANTIC OCeAN ANd CARIbbeAN SeA beTWeeN THe dePTHS Of 895 M TO 2200 M ANd THIS STUdY POTeNTIALLY eXPANdS THe dISTRIbUTION TO THe CORAL SeA, AUSTRALIA ( FIgURe 1C ), A RANge eXPANSION Of>15,000 kM. THIS STUdY ALSO POTeNTIALLY eXPANdS THe geNUS ( Heteropathes ) ANd THe fAMILY ( CLAdOPATHIdAe ) TO THe CORAL SeA, AUSTRALIA, WITH RANge eXPANSIONS Of> 8,000 kM ANd ~2,000 kM, ReSPeCTIVeLY.

CONCLUSION

OUR ReSULTS deMONSTRATe THAT THe dIVeRSITY Of bLACk CORALS IN THe deeP CORAL SeA IS HIgHeR THAN THe SINgLe ReCORd Of Abyssopathes lyra BROOk (1889) ReCORded PReVIOUSLY. ALL fIVe SPeCIeS IdeNTIfIed IN OUR COLLeCTION RePReSeNT NeW ReCORdS fOR THe RegION. THe LARge RANge eXPANSIONS (> 15,000 kM) HIgHLIgHT THe LACk Of SAMPLINg IN THe deeP-SeA, ANd We COULd ReASONAbLY eXPeCT SPeCIeS RANgeS TO CONTINUe TO eXPANd AS MORe deeP-SeA HAbITATS ARe SURVeYed . OUR ReSULTS SHOW THAT THe SPeCIeS RePORTed HeRe HAVe MUCH LARgeR geOgRAPHIC RANgeS THAN ReCORded PReVIOUSLY, ANd PROVIde fURTHeR eVIdeNCe THAT MANY bLACk CORALS ARe COSMOPOLITAN. HOWeVeR, IT IS IMPORTANT TO ReMeMbeR THAT THeSe SPeCIeS WeRe IdeNTIfIed bASed ON TRAdITIONAL MORPHOLOgICAL TAXONOMY, ANd THAT geNeTIC STUdIeS ARe Needed TO VeRIfY WHeTHeR MORPHOLOgICAL SPeCIeS ARe COMPRISed Of MULTIPLe CRYPTIC SPeCIeS COMPLeXeS THAT ARe dIffICULT TO dIffeReNTIATe MORPHOLOgICALLY.

THIS STUdY ALSO deMONSTRATeS THe UTILITY Of MUSeUM COLLeCTIONS fOR dOCUMeNTINg THe OCCURReNCe Of POORLYkNOWN SPeCIeS. THe SPeCIMeNS RePORTed HeRe WeRe HOUSed, ALONg WITH OTHeR MATeRIAL COLLeCTed ON THe CIDARIS eXPedITIONS , IN THe MTQ COLLeCTION fOR ALMOST 30 YeARS. THe CIDARIS eXPedITIONS ReMAIN THe MOST COMPLeTe SAMPLINg Of bIOdIVeRSITY IN THe deeP WeSTeRN CORAL SeA, bUT MUCH Of THe MATeRIAL STILL AWAITS eXAMINATION fROM ReSeARCHeRS WITH SUffICIeNT TAXONOMIC eXPeRTISe. DeSPITe ReCeIVINg LITTLe ATTeNTION fOR 30 YeARS, THeSe SPeCIMeNS HAVe NOW PROVIded NeW INSIgHTS INTO THe dIVeRSITY ANd TAXONOMY Of bLACk CORALS IN THe deeP SeA. THeRefORe , OUR ReSULTS deMONSTRATe THe VALUe Of MUSeUM COLLeCTIONS fOR dOCUMeNTINg bIOdIVeRSITY, PARTICULARLY IN POORLY-kNOWN HAbITATS SUCH AS THe deeP SeA . SUCH kNOWLedge CAN PROVIde IMPORTANT INSIgHTS INTO THe CONSeqUeNCeS Of RAPId eNVIRONMeNTAL CHANge ON SPeCIeS dISTRIbUTIONS, ANd PROVIde VALUAbLe INfORMATION TO INfORM CONSeRVATION ANd MANAgeMeNT.

Figures

FIGURE 1. a, Map of collection sites for the specimens in this study and other locations globally where the same species have been collected; b, view of the Central and Eastern Indo-Pacific region; c, new black coral records from the Coral Sea.

FIGURE 7. Heteropathes cf. americana: a, G73229, entire corallum; b, G61967, section of an anterior pinnule with subpinnules; c, G61967, section of lateral pinnule with spines; d–e, G73229, spines on sections of anterior pinnules.