Isoaulactinia hespervolita Daly, 2004

Barragán, Yamaly, Sánchez, Carlos & Rodríguez, Estefanía, 2019, First inventory of sea anemones (Cnidaria: Actiniaria) from La Paz Bay, southern Gulf of California (Mexico), Zootaxa 4559 (3), pp. 501-549 : 522-526

Isoaulactinia hespervolita Daly, 2004

( FIgS. 2 , 12–14 , TAble 6)

Bunodactis mexicana Brusca, 1973

Non Bunodactis mexicana Carlgren, 1949 (nomen nudum)

Non Bunodactis mexicana Carlgren, 1951

Material eXamined. (See TAble 2).

Description. EXTeRNAl ANATOmY ( FIg. 12 ): Well deVelOped pedAl dISC, TO 34 mm dIAmeTeR IN pReSeRVed SpeCImeNS. COlUmN CYlINdRICAl, TO 24 mm heIghT ANd TO 26 mm dIAmeTeR IN pReSeRVed SpeCImeNS, WITh lONgITUdINAl ROWS Of VeRRUCAe fROm dISTAl mARgIN TO pedAl dISC. SmAll, CIRCUlAR mARgINAl pROjeCTIONS, eACh WITh A pSeUdOACRORhAgUS (WITh bASITRIChS ANd p -mASTIgOphOReS A bUT NOT hOlOTRIChS); WITh A NIpple-lIke pROjeCTION. FOSSe. FUllY eXpANded ORAl dISC ANd TeNTACleS TO 43 mm dIAmeTeR, ORAl dISC TO 29 mm dIAmeTeR IN pReSeRVed SpeCImeNS. Up TO 64 TeNTACleS, heXAmeROUSlY ARRANged IN fIVe CYCleS, TO 16 mm leNgTh IN pReSeRVed SpeCImeNS, SImple, STICkY, SmOOTh, All Of SImIlAR leNgTh; TeNTACleS SOmeTImeS bIfURCATe. MeSeNTeRIAl INSeRTIONS VISIble IN pedAl dISC ANd ORAl dISC. MARgINAl STOmA.

INTeRNAl ANATOmY ANd mICROANATOmY ( FIg. 13 ): MeSeNTeRIeS heXAmeROUSlY ARRANged IN fOUR CYCleS: fIRST ANd SeCONd CYCleS peRfeCT; OTheRS ImpeRfeCT. All meSeNTeRIeS feRTIle eXCepT The dIReCTIVeS ONeS. GONOChORIC, SpeRmATIC CYSTS 0.09–0.13 mm IN dIAmeTeR IN SpeCImeNS COlleCTed IN MAY. SAme NUmbeR Of meSeNTeRIeS dISTAllY ANd pROXImAllY. TWO SIphONOglYphS ATTAChed TO TWO pAIR Of dIReCTIVe meSeNTeRIeS. ReTRACTOR mUSCleS STRONg ANd ReSTRICTed, OCCUpYINg OVeR hAlf-leNgTh Of meSeNTeRIeS. PARIeTObASIlAR mUSCleS STRONg ANd ThICk, WITh VeRY ShORT fRee meSOgleAl lAmellA. BASIlAR mUSCleS Well deVelOped, WITh lONg ANd ThIN meSOgleAl pROCeSSeS. MARgINAl SphINCTeR mUSCle CIRCUmSCRIbed. LONgITUdINAl mUSCleS Of TeNTACleS ANd ORAl dISC eCTOdeRmAl. ZOOXANThellAe pReSeNT.

COlOR ( FIg. 12 ): IN lIVINg SpeCImeNS pedAl dISC, COlUmN ANd VeRRUCAe OpAqUe bROWN. ORAl dISC dARk bROWN OR dARk ORANge. TeNTACleS beIge OR bROWN, bASe Of TeNTACleS WhITe; IN SOme SpeCImeNS’ TeNTACleS WITh WhITe CROSSbANdS IN ORAl SIde.

CNIdOm ( FIg. 14 ): BASITRIChS, b -mASTIgOphOReS, hOlOTRIChS, p -mASTIgOphOReS A ANd B2A, p -mASTIgOphOReS A WITh lOOped bASAl TUbUle, ANd SpIROCYSTS. See TAble 6 fOR SIZe ANd dISTRIbUTION.

Geographic and bathymetric distribution. Isoaulactinia hespervolita IS fOUNd ONlY IN The INTeRTIdAl IN The MeXICAN PACIfIC IN PUNTA AbReOjOS, VIZCAINO BAY ANd PUeRTO PeñASCO ( DAlY 2004). ThIS IS The fIRST TIme RepORTed IN TeCOlOTe, LA PAZ BAY, IN The INTeRTIdAl (beTWeeN 0–1 meTeRS).

Remarks. The TWO SpeCIeS Of Isoaulactinia ARe fOUNd ON The COAST Of MeXICO; Isoaulactinia hespervolita IS dISTRIbUTed IN The MeXICAN PACIfIC WheReAS I. stelloides ( MCMURRICh, 1889) IS dISTRIbUTed IN The WeSTeRN ATlANTIC fROm BeRmUdA TO BARbAdOS, AlONg The CARIbbeAN SeA ANd ON The MeXICAN ATlANTIC COAST ( DAlY 2004; GONZáleZ- MUñOZ et al. 2013). Isoaulactinia hespervolita dIffeRS fROm I. stelloides IN The CNIdAe [e.g. IT hAS hOlOTRIChS IN The COlUmN ANd p -mASTIgOphOReS B2A IN The fIlAmeNTS (AbSeNT IN I. stelloides ), ANd IT lACkS p -mASTIgOphOReS A WITh A lOOped bASAl TUbUle IN The TeNTACleS, mARgINAl pROjeCTIONS (NAmed pSeUdOACRORhAgI IN ThIS STUdY), ACTINOphARYNX ANd fIlAmeNTS (pReSeNT IN I. stelloides )], lACkS lONgITUdINAl mARkS IN The ORAl dISC ANd TeNTACleS (pReSeNT IN I. stelloides ) ANd IS gONOChORIC (WheReAS I. stelloides IS heRmAphROdITIC) ( DAlY 2004; GONZáleZ-MUñOZ et al. 2013). HOWeVeR, IN The pReSeNT STUdY We fOUNd SpeCImeNS WITh mARked TeNTACleS (CROSS bANdS) ( FIg. 12D ). IN AddITION, We fOUNd IN SOme SpeCImeNS SmAll NIpple-lIke STRUCTUReS IN The pSeUdOACRORhAgI ( FIg. 12B, C ); The SIZe RANgeS Of The CNIdAe IN TheSe NIpple-lIke STRUCTUReS ARe SImIlAR TO ThOSe IN The ReST Of The pSeUdOACRORhAgI. ThIS IS The fIRST TIme ThIS feATURe IS meNTIONed fOR The geNUS. We AlSO fOUNd SOme SpeCImeNS WITh A feW bIfURCATe TeNTACleS NOT RepORTed befORe ( FIg. 11F ). DAlY (2004) deSCRIbed I. hespervolita hAVINg fOUR OR fIVe CYCleS Of meSeNTeRIeS (fIRST TO ThIRd CYCleS peRfeCT ANd feRTIle bUT STeRIle dIReCTIVeS); hOWeVeR, We ONlY fOUNd SpeCImeNS WITh fOUR CYCleS WITh The TWO fIRST CYCleS peRfeCT ANd All meSeNTeRIeS feRTIle bUT The dIReCTIVeS. DIffeReNCeS IN CNIdAe TeRmINOlOgIeS ASIde, We dO NOT CONCUR WITh DAlY (2004) IN ThAT The p -mASTIgOphOReS B2A (NAmed AS mICRObASIC p -mASTIgOphORe bY heR) IN The

TABLE 6. Size ranges and distribution of cnidae of Isoaulactinia hespervolita Daly, 2004 . N, Total number of capsules measured; M, Ratio of number o specimens in which each cnida was found to number of specimens examined. Sizes in micrometers. Letters in parenthesis correspond with images in Fig. 14 . ((2), Categories named as macrobasic p -mastigophore and microbasic p -mastigophore, respectively by Daly (2004).

fIlAmeNT mIghT be ImmATURe CApSUleS Of p -mASTIgOphOReS A WITh lOOped bASAl TUbUle (NAmed AS mACRObASIC p - mASTIgOphORe bY DAlY). We AgRee WITh GUSmãO et al. (2018) IN TheIR INTeRpReTATION ThAT NemATOCYSTS WITh lOOped OR UNdUlATINg ShAfTS ARe ImmATURe STAgeS WhOSe CApSUleS beCOme STRAIghTeR ANd WhOSe ShAfT beCOmeS ShORTeR AS The helICeS TIghTeN, eSpeCIAllY IN The pROXImAl RegION, WITh A VISIble CeNTRAl ROd-ShAped STRUCTURe ON The pROXImAl ShAfT ANd lATeR WIThOUT IT (See ÖSTmAN et al. 2010A, 2010b ANd dISCUSSION IN GUSmãO et al. 2018). SImIlARlY, We hYpOTheSIZe ThAT The p -mASTIgOphOReS A WITh lOOped bASAl TUbUle IN The COlUmN Of I. hespervolita CORReSpONd TO The ImmATURe STAge Of The SlIghTlY SmAlleR CATegORY Of p -mASTIgOphOReS A AlSO fOUNd IN The COlUmN (TAble 6, FIg. 14J ANd K , ReSpeCTIVelY) beCAUSe We WeRe Able TO fINd INTeRmedIATe STAgeS IN The SpeCImeNS eXAmINed. NeVeRTheleSS, beCAUSe A ThOROUgh STUdY ON TheSe ISSUeS hAS ONlY beeN dONe WIThIN meTRIdIOIdeANS ANd p -mASTIgOphOReS B (ÖSTmAN et al. 2010b), We pRefeR TO kepT The AbOVe CATegORIeS Of NemATOCYSTS SepARATe IN ThIS CONTRIbUTION UNTIl bOTh SpeCIeS Of The geNUS ARe SpeCIfICAllY ReVISed ON ThIS ISSUe. We CONSIdeR The pReSeNCe Of p -mASTIgOphOReS B2A IN The fIlAmeNTS Of The geNUS ANd The fAmIlY NOTAble beCAUSe ThIS TYpe Of NemATOCYST IS NOT COmmON WIThIN ACTINIOIdeANS ( SChmIdT 1974). DeSpITe SlIghT dIffeReNCeS IN The INTeRNAl ANATOmY ANd SIZeS RANgeS Of The CNIdAe (See TAble 6) OUR mATeRIAl fITS Well WITh The deSCRIpTION Of I. hespervolita bY DAlY (2004).

Figures

FIGURE 2. Living specimens of A) Anthopleura dowii. B) Bunodosoma californicum. C) Bunodosoma grande. D) Isoaulactinia hespervolita. E) Phymactis papillosa. F) Phialoba steinbecki. G) Alicia beebei. H) Calliactis polypus.

FIGURE 11. Cnidae of Bunodosoma grande (Verrill, 1869). A, B, E, F, G, H, J, K) Basitrichs. D) Holotrichs. L) b- mastigophore. I, M) p-mastigophore A. N) p-mastigophore B1. C) Spirocyst.

FIGURE 12. External anatomy of Isoaulactinia hespervolita Daly, 2004. A) Lateral view of preserved specimen. B–C) Detail of pseudoacrorhagi with and without nipple-like structure, respectively. D–E) Oral view of living specimen showing marked and unmarked tentacles. F) Detail of tentacles showing a bifurcate tip. Bifurcation (B), Margin (Ma), Nipple-like structure (N), Oral disc (Od), Pseudoacrorhagi (P), Verrucae (Ve). Scale bars: 5 mm.

FIGURE 13. Internal anatomy of Isoaulactinia hespervolita Daly, 2004. A) Longitudinal section of the distal column. B) Cross section of the column at the level of the actinopharynx showing the cycles of mesenteries (cycles marked by numbers). C) Cross section through a tentacle showing ectodermal longitudinal musculature. D) Detail of a longitudinal section of the column showing pseudoacrorhagi. E) Detail of a cross section of the column at the level of the actinopharynx showing the retractor and parietobasilar muscles. F) Cross section of column showing gametogenic tissue. G) Longitudinal section of proximal end showing basilar muscles. Basilar muscles (Ba), Ectoderm (Ec), Endoderm (En), Fosse (Fo), Mesoglea (Me), Parietobasilar muscles (Pa), Pseudoacrorhagi (P), Retractor muscles (Re), Spermatic cysts (Sc), Sphincter (Sp), Verrucae (Ve), Tentacle (Te). Scale bars: A, C–G, 0.1 mm; B, 0.5 mm.

FIGURE 14. Cnidae of Isoaulactinia hespervolita Daly, 2004. A, B, D, F, G, H, L, M, O, P) Basitrichs. I) Holotrich. J) p- mastigophore A with looped basal tubule. Q) b-mastigophore. E, K, N, R) p-mastigophores A. S) p-mastigophore B2a. C) Spirocyst.