Journal of Natural History, 2002, 36, 265–278

New recordsof cave-dwelling mysids from the Bahamas and Mexico withdescription of Palaumysisbahamensis n.sp. (Crustacea: Mysidacea)

GIUSEPPE L.PESCE²and THOMAS M.ILIFFE³ ² Dipartimentodi Scienze Ambientali, University ofL ’Aquila,Via Vetoio, 67100L ’Aquila,Italy ³ Department ofMarine Biology, Texas A&M University atGalveston, Galveston,TX 77553-1675,USA

(Accepted22 August 2000 )

Newlocalities in the Bahamas and Mexico are reported for six species of stygobitic andstygophilic mysids from the genera Spelaeomysis , Stygiomysis , Antromysis and Heteromysis .Inaddition,a newspecies, Palaumysisbahamensis ,isdescribed froma marinecave in the Bahamas. This genus had previously contained only a singlespecies from anchialine caves in Palau, Indo-W estPaci® c. The biogeography andevolutionary origins of stygobitic mysids are discussed. An up-to-datekey to thespecies of the genus Spelaeomysis ispresented.

Keywords: Mysidacea, Spelaeomysis , Stygiomysis , Antromysis, Heteromysis , Palaumysis,Bahamas,Mexico, cave, taxonomy, biogeography.

Introduction Mysids arecommon inhabitants of both fresh and salt water(anchialine) caves and groundwaters in widelydiverse locations (Bowman,1984; Pesce et al., 1994). At least 38species in 19genera of subterranean mysids havebeen reported. In addition to clusters of stygobitic mysid species in Mexico and the Caribbeanand in the Mediterranean, two species ( Spelaeomysislongipes and Spelaeomysiscochiensis ) areknown from India and athird ( Spelaeomysisservatus )from Zanzibar,Kenya and Aldabra. As is the casewith anumber of stygobitic taxaincluding remipedes, speleophriid, misophrioid copepods, epacteriscid calanoidcopepods, hadziid and pardaliscid amphipods, thaumatocyprid ostracods and thermosbaenaceans (Boxshall and Jaume, 1999),these distributions suggest aTethyanorigin involvingstranding, whereby the cavesand groundwaters inhabited bytheir marine ancestors were uplifted during regressions of the Tethys and the Mediterranean. Most freshwater subterranean mysids occur in localities not far from the coast, indicating arelatively recent origin from marine ancestors. Although manystygobitic species areendemic to speci® ccaveand /or groundwater systems on asingleisland or landmass, some

Journalof NaturalHistory ISSN0022-2933 print /ISSN1464-5262 online Ñ 2002Taylor & FrancisLtd http://www.tandf.co.uk /journals DOI:10.1080 /00222930010005033 266 G.L.Pesce and T.M.Ili Œe such as Stygiomysisholthuisi (from cavewaters in the Bahamas,Anguilla, St. Martin and Puerto Rico) and Spelaeomysisservatus (from cavewaters in Kenya,Zanzibar and Aldabra) haveremarkably wide distributions. An up-to-date keyto the species of the genus Spelaeomysis is presented.

Taxonomicaccount Order MYSIDACEA SuborderMYSIDA FamilyLEPIDOMYSIDAE Clarke,1961 Spelaeomysisquinterensis (Villalobos,1951 ) (® gures 1±4 ) Materialexamined .Tamaulipas,Mexico: cavespring on the Rio Guayalejonear Juamave;15 March 1998;one mature female (length 7.5mm) collected with vial from watercolumn in 10mdepth byT. M.Ili Œe. Taxonomicnotes .The singlespecimen weexamined from acavespring on the Rio Guayalejois identical to S. quinterensis described and illustrated byVillalobos (1951)from the type-locality (Quintero cave,Tamaulipas, Mexico), aswell as by Bowman( 1973,1982 )and Reddell (1981),also from Mexico, di Œering only bythe following minor characteristics: (1)Antennal scalemore rounded and slightlywider ascompared to Villalobos’ description and ®gures; antennal ¯agellumwith more and longer segments (® gure 2). (2)Sixteen to 18long spines on the mediallobe of uropod (® gure 4)(vs 20or more, and shorter spines both in Villalobos’and Bowman’s®gures). (3)Telson armed with 33spines (® gure 1)(vs 25and 27spines in Villalobos’ and Bowman’s®gures, respectively); moreover in the specimen from Guayalejospring, the medialapical spine is ¯anked bytwo slender plumose setae (vs the same spines ®gured asnaked in the originaland following descriptions and ®gures). However,in this lastregard, we suppose that the re-examination of typicalmaterial could revealthe presence of the same plumose setae also in S. quinterensis ,since these setae havebeen reported and ®gured in other species of the genus ( S. bottazzi, S. longipes) and probably they could be present, but overlooked, alsoin the remaining ones. (4)Pleopod 2(® gure 3)slightlyshorter and less setulose ascompared to Villalobos’® gures. The peculiar telson armature could justify recognition of the Guayalejospring specimen asa distinct species or subspecies, but until enough materialfrom this locality,as well as from the type-locality,becomes availableto assess adequately the variabilityof S.quinterensis ,weconsider the Guayalejospring and the Villalobos’ materialto be conspeci® c. Habitat.This spring is located on the south bank of the Rio Guayalejoas it passes through alargecanyon crossing the Sierra Madre Oriental. The spring pool is located about 50minland from the riverbank and consists of ashallowbasin about 5min diameter, beneath arock ledge.Underwater, acavetrends awayfrom the riverfor about 100mbefore coming back to the surface in asmallair-® lled chamber with possible dry cavepassages leading o Œ.Maximum depth in the under- watercave was 15m. The stygobitic cirolanid Speocirolanadisparicornis Botosaneanu Cave-dwellingmysids from the Bahamasand Mexico 267

Figs 1± 4. Spelaeomysisquinterensis .(1)Telson;( 2)antennalscale; ( 3)pleopod2; (4)uropod,medial lobe. and IliŒe,1999 and the amphipod Seborgia near hershleri (det. J.R.Holsinger, 13April 1999)werealso collected from the cave. Remarks. The genus Spelaeomysis presently includes nine named species, seven from various groundwater habitats (anchialine caves,springs and wells)in south Italy,Zanzibar, Mexico and Cuba,one from prawn culture ®elds in India, and another one from crab burrows in Colombia. Recently, GarcõÂ a-Garza et al. (1996) presented akeyto the known species in the genus, including only seven species and omitting S. bottazzii Caroli,1924 and S. cochinensis Panampunnayil and Viswakumar,1991. Moreover, in the same paper, the authors misspelled the name of S. servatus with S. serratus. 268 G.L.Pesce and T.M.Ili Œe

Three species arepresently known from subterranean watersin Mexico: Spelaeomysisquinterensis (Villalobos,1951 )[cavewaters, Tamaulipas] Spelaeomysisolivae Bowman,1973 [cave waters, Oaxaca] Spelaeomysisvillalobosi Garcõ a-Garza,Rodriguez-Almaraz and Bowman,1996 [phreatic and cavewaters, Nuevo Leo  n] The remaining species come from the following localities: Spelaeomysisbottazzii Caroli,1924 [anchialine cave and phreatic waters;south Italy] Spelaeomysisservatus (Fage,1924 )[cavewaters; Kenya, Zanzibar, Aldabra] Spelaeomysislongipes (Pillaiand Mariamma,1963 )[phreatic waters,India] Spelaeomysisnuniezi Bacescuand Orghidan, 1971[cave waters, Cuba] Spelaeomysiscardisomae Bowman,1973 [cave waters, crab burrows; Columbia, San Andres] Spelaeomysiscochinensis Panampunnayil and Viswakumar,1991 [ prawn culture ®eld; India]

Keyto the species of the genus Spelaeomysis 1Eyestalkswith few disto-lateral ommatidia ...... 2 ±Eyestalkswithout ommatidia ...... 4 2Telsonmore than twice longer than wide ...... S.cochinensis ±Telsonless than 1.5 longer than wide ...... 3 3Apicalspine of telson about twice length of two ¯ ankingspines . .. S. servatus ±Apicalspine of telsonmore than six times length of two¯ ankingspines . S.cardisomae 4Eyestalksmedially fused forming a singleplate ...... S. longipes ±Eyestalksseparate ...... 5 5Eyestalksproduced anterolaterally into subtriangular lobes ...... 6 ±Eyestalkssubquadrangular, not produced anterolaterally ...... 7 6Pleopod4 withfour-segmented exopod; telson slightly longer than wide; lateral margin slightlyconcave near midlength ...... S.quinterensis ±Pleopod4 withtwo-segmented exopod; telson about as long as wide, lateral margin convex...... S.villalobosi 7Telson,margin of distal half armed with spines ...... 8 ±Telson,margin completely armed with spines ...... S.bottazzii 8 Telson L/W1.5,with about 20 marginal spines ...... S. nuniezi ± Telson L/W1.1±1.2, with about 40 marginal spines ...... S. olivae

FamilySTYGIOMYSIDAE Caroli,1937 Stygiomysiscokei Kallmeyerand Carpenter, 1996 Materialexamined .Yucatan, Mexico: Pabakal,Eknakan; 25June 1998; one female (8.5mm) and one male( 7.7mm), collected with vialsfrom the water column in 20±33 mdepths. Cenote San Eduardo, Tecoh; 26June 1998;two females (7.9,8.1 mm) and one male( 7.7mm) collected with vialsfrom the watercolumn in 15±27 mdepths. Cenote Kankirixche, Mucuyche  ;1July1998; one female (9.1mm) and one juvenile collected with vialsfrom the watercolumn in 30±50 mdepths. Cenote Kankirixche, Mucuyche  ;19November 1998;one female (9.0mm) collected with vialsfrom the watercolumn in 30±50 mdepths. Cenote Pabakal,Eknakan; 26June 1999;two females (8.3,8.5 mm) collected with vialsfrom the watercolumn in 20±26 mdepths. Cenote Dzonot-ila, Abala Á ;30October 1999,two juv.collected with vialsfrom watercolumn in 30-40m depths. Cenote Pabakal,Eknakan; Cave-dwellingmysids from the Bahamasand Mexico 269

31October 1999;three females (7.9±8.6 mm) and one male( 7.9mm), collected with vialsfrom watercolumn in 20±33 mdepths. Quintana Roo, Mexico: Actun Ko, Akumal; 28June 1999;one female (8.8mm) and one juvenile collected with vials from the watercolumn in 8±13 mdepths. Remarks.Caroli( 1937)created the familyStygiomysidae and the genus Stygiomysis to accommodate materialfrom anchialinecave waters of the Salentine Peninsula (south Italy).The genus Stygiomysis atpresent includes sixdescribed species: Stygiomysishydruntina Caroli,1937 [anchialine and phreatic waters;south Italy] Stygiomysisholthuisi (Gordon, 1958)[cavewaters; Bahamas, Anguilla, St. Martin, Puerto Rico] Stygiomysismajor Bowman,1976 [cave waters; Jamaica] Stygiomysisclarkei Bowman, IliŒeand Yager,1984 [cave waters; Bahamas] Stygiomysisaemete Wagner,1992 [ phreatic waters;Dominican Republic] Stygiomysiscokei Kallmeyerand Carpenter, 1996[cave waters; Y ucatan, Mexico]. Three other undescribed species areknown from the Salentine Peninsula (south Italy)( Pesce, 1975),Quintana Roo, Mexico and Florida,USA (Bowman,in litt.). The remarkable distribution of Stygiomysis undoubtedly points to aTethyan origin, allthe species of the genus being actuallyknown from the Caribbeanand surrounding areas,and south Italy. Stygiomysiscokei is alargespecies, wellcharacterized bythe unusually long telson and verynarrow uropodal protopods. This species waspreviously known only from cavesnear Tulum, Quintana Roo, Mexico. Our collections, therefore, considerably extend the rangeof S. cokei to include four in the state of Yucatan, located approximately200 km west of Tulum on the opposite side of the Yucatan Peninsula. Only minor morphological di Œerences werefound in the present materialas compared to the originaldescription and illustrations of the species (body length, number of setae on mediodistal marginof the lamellaof pleopods 3±5, armature of the uropodal protopod).However,so far little is known about the variabilityof the species of this genus, and the entire familyappears to be remarkablyuniform in manyfeatures (Kallmeyerand Carpenter, 1996). Habitat.Cenote Pabakal(` Mud Stains’)is located about 45km south-east of Merida, near the villageof Eknakan, Yucatan. From the 30-mwide, cave-like entrance to this cenote, abreakdown slope descends to a30mwideby 20 mlong lakecontaining large,stalagmitic columns. The eastern passagesplits and reaches a maximum depth of 23mat140 mpenetration. The western passagedescends to 30mdepth at190 mpenetration. Also collected from this cavewere the cirolanid isopod Yucatalanarobustispina Botosaneanu and Ili Œe,1999, copepods, amphipods and thermosbaenaceans. Cenote San Eduardo is located near the villageof Tecoh, 41km south-east of Merida. This cenote is entered through adry caveand contains two di Œerent and unconnected underwater caves.The largestof these begins from the main pool on the north side of the cave.From this 15mwideby 5 mlong pool, abreakdown slope ends atadepth of 24mand penetration of 57m. On the right side of the pool, asmalltunnel continues past severalsharp turns to a30mdiameter, circular room, containing alargeair bell atthe top. Asecond pool lies to the south of the entrance. The underwater passageon this side of the cenote is shallower and less extensive. Cenote Kankirixche (`YellowFruit Tree’)is located 49km south of Merida, near 270 G.L.Pesce and T.M.Ili Œe the town of Mucuyche  ,Yucatan. Asteep, 15mentrance slope leads to alarge underground lake.W ater depths in the entrance arearange from 5to nearly50 m, whilethe room is almost circular with adiameter of approximately90 m. In the south-west corner of the cavern,a lowbut widetunnel at50± 53 mwaterdepths passes through abedding plane that opens onto achamber, about 90mlong and 45mwidewith a¯oor to ceilingheight of approximately18 m. Twopassages lead out of this room, one of which has been explored to amaximum penetration of 313mand depth of 53m. Ahalocline is present at50 mdepth. Cenote Dzonot-ila is located 52km south of Merida, near the town of Abala  , Yucatan. The cenote entrance consists of arectangular,12 mdeep wellshaft, provid- ingaccess to anunderground lake.The largestsection of the caveis a40mwideby 30mhigh passagewith aridge of largebreakdown blocks running down the centre and deepest depths alongthe walls.At the far end of this passage,a smallrestric- tion leads to a30mwideby 2 mhigh room containing numerous stalactites and stalagmites.Maximum waterdepth in the caveis 39m. Actun Ko is alargeunderwater cavesystem located between Playadel Carmen and Tulum, alongthe Caribbeancoast of the Yucatan Peninsula. The entrance consists of acollapsed sinkhole with apool running in asemicircle alongthe margins. This cavehas severalentrances and severalkilometres of explored submerged pas- sages.The in this caveis atabout 12±14 mdepth.

Stygiomysisclarkei Bowman, IliŒeand Yager,1984 Materialexamined .Grand BahamaIsland, Bahamas:Lucayan Caverns, Freeport; 6August 1998,one aberrant (female?) specimen collected with vialfrom the watercolumn in 5±10 mdepths. LucayanCaverns, Freeport; 18August 1998, one immature specimen (female?) collected with vialfrom the watercolumn in 5±10mdepths. LucayanCaverns, Freeport; 20August 1998;one female (5.5mm) collected with vialsfrom the watercolumn in 5±10mdepths. LucayanCaverns, Freeport; 22August 1998;two females (5.9,6.1 mm) collected with vialsfrom the watercolumn in 5±10 mdepths. Remarks.The three adult specimens from LucayanCaverns, Grand Bahama® t the originaldescription of the species, except for the following minor di Œerences, which, in our opinion, could better characterize the Lucayanpopulation rather than justify the proposition of anewspecies or subspecies. (1)Distal armature of telson: 3 1 41 31 41 3, or 31 31 31 31 3 (vs 31 31 31 31 3in the originaldescription). (2)Protopodal process of uropods with one lateralapical seta and ®veapical spines, followed bytwo short spines, one longer spine and eight short setules (vs one lateralapical seta, ®veapical spines followed byfour short spines, one long spine and sixto eight spinules, in the originaldescription). (3)Antenna 1,outer ¯agellum14- or 15-segmented (vs 17±19 in the original description), inner ¯agellumnine-segmented (vs ten-segmented in the original description). Stygiomysisclarkei is presently known only from anchialinecaves in Middle Caicos,Providenciales and Grand Bahamaislands (present data). Habitat. LucayanCaverns is located about 20km east of Freeport on Grand BahamaIsland. It is the longest explored cavein the Bahamaswith more than Cave-dwellingmysids from the Bahamasand Mexico 271

10km of surveyed underwater passages.The surface watersin the caveare fresh, with ahalocline at16 mdepth and full strength seawater beneath. Most passages wereformed atthe same depth asthe halocline bymixing corrosion between fresh and saltwaters. An unusual feature of this caveis the presence of largeamounts of ¯occulent organicsediments, probably of bacterialorigin, that occur below the halocline.

Stygiomysisholthuisi (Gordon, 1958) (® gures 5,6 ) Materialexamined .Quintana Roo, Mexico: Cenote MayaBlue, Tulum; 13March 1994,one immature specimen (female?) collected with vialfrom the watercolumn in 15±20 mdepths. CasaCenote, Tulum; 14January 1996; one female (7.1mm) collected with plankton net from 6±8 mdepths (halocline at7m). Yucatan, Mexico: Cenote Mucuyche  , Mucuyche ;4July1999; eight females (5.5±6.7 mm), three males (4.5±5.9mm) and three juveniles collected with plankton net from watercolumn in 20±37 mdepths. Remarks.Described byGordon (1958)to accommodate materialfrom ground- watersof Devil’sHole (St. Martin, Lesser Antilles), Stygiomysisholthusi has been successively collected from severallocalities in the Caribbean,namely Puerto Rico (Bowman,1976 ),Anguilla( Botosaneanu, 1980)and Grand BahamaIsland (Bowman et al.,1984).The present discovery in Yucatan (Mexico) greatlyextends the known distribution rangeof the species. Twoof the Yucatan collection sites are located alongthe Caribbeancoast, whileanother is from near the opposite side of the Peninsula in the state of Yucatan.

Figs 5, 6. Stygiomysisholthuisi. (5)Telson;( 6)uropodprotopod, backward prolongation. 272 G.L.Pesce and T.M.Ili Œe

The materialfrom Yucatan shows good agreement with Gordon’sdescription and illustrations, aswellas with the other descriptions from Puerto Rico, Anguilla, and Grand Bahama,with respects to the main characters that distinguish S.holthuisi from the other congeners. In the following description only the main di Œerences ascompared to the original and the subsequent descriptions arereported. Telson slightlylonger than wide (® gure 5)(vs nearlyas wide as long in Gordon’sdescription; slightlylonger than widein specimens from Anguilla,Grand Bahamaand Puerto Rico); two to four short spines ®llthe gapsbetween lateraland median apicalspine groups (vs four to ®vespines in Gordon’sdescription; three in specimens from Anguilla,Grand Bahama and Puerto Rico). Antennal ¯agellum13- or 14-segmented (vs 16±18 in Gordon’sdescription; no information is availablefor materialfrom other localities); antennular ¯agellasub- equal in length, both inner and outer ¯agella17- or 18-segmented (vs inner ¯agellum 28-segmented, outer ¯agellum16 /18-segmented). Malesecond pleopod less setulose than in the originaland following descriptions and ® gures. Backwardprolongation of the uropod protopod (® gure 6)with ®vestrong apical and subapical spines and two to three thin setules on the outer margin;inner margin armed with two to three spinules and four strong spines (vs the same marginarmed with row of spinules interrupted byone or two stouter spines in Gordon’sdescription and ®gures; more spines on the same marginand lackingthe outer subapical setula in specimens from Grand Bahamas). The propod of uropod armature and the construction and spinulation of the telson could justify recognition of the specimens from Yucatan asa distinct species or subspecies. However,until enough materialis availableto determine the variability of S.holthuisi ,weconsider the Yucatan, Anguilla,Grand Bahama,Puerto Rico and St. Martin specimens to be conspeci® c.Planned DNA work on these populations could better determine their e Œectivereproductive and genetic separation. Habitat.Cenote MayanBlue is located about 5km inland from the Caribbean coast, about 3km south of Tulum Pueblo, Yucatan. Primaryorientation of this 15.5km long caveis perpendicular to the coast suggestingthat it serves asa major freshwater drainageconduit to the sea.Cave passages are predominantly developed atthe halocline in 15mwaterdepths where mixingcorrosion between fresh and salt wateroccurs. Water abovethe halocline averagesless than 2g /lsalinity,while below the abrupt halocline at18 mdepth, salinityis 35g /l. Shrimp [Typhlatya spp. and Creaseriamorleyi (Creaser, 1936)],remipedes ( Speleonectestulumensis Yager,1987 ), ostracods (Danielopolinamexicana Kornicker and Ili Œe, 1989 and Spelaeoeciamayan Kornicker and Ili Œe,1989 ),thermosbaenaceans ( Tulumellaunidens Bowman and IliŒe,1988 ),mysids ( Antromysiscenotensis Creaser,1936 ),amphipods ( Tuluweckelia cernua Holsinger, 1990),isopods [ Bahalanamayana Bowman,1987 and Creaseriella anops (Creaser, 1936)]and ®sh [ Ogilbiapearsei (Hubbs, 1938)]inhabit the cave (IliŒe, 1993). CasaCenote is located about 10km north of Tulum Pueblo, Yucatan. It connects directly to the CaribbeanSea and is the resurgence for Systema Nohoch Nah Chich, one of the longest underwater cavesin the world. in this caveare at about 8±10mdepth. Cenote Mucuyche  is located within the ruins of ahacienda in the villageof Mucuyche ,Yucatan. The crescent-shaped sinkhole entrance is approximately30 m Cave-dwellingmysids from the Bahamasand Mexico 273 long by15 macross. Abreakdown slope with a¯ight of steps descends to a30m long by10 mwide,gravel and rock ¯oored pool. Against the far bedrock wall,a narrow hole at5 mdepth opens into a50mlong, 10mwidebreakdown chamber that anglesdiagonally down to 30mdepth. At this point, averticalbreakdown shaft ascends to 15mdepth before choking o Œ.Also collected from the cavewere cope- pods, mysids ( Antromysiscenotensis ),thermosbaenaceans, amphipods and isopods [Creaseriellaanops (Creaser, 1936)].

FamilyMYSIDAE Dana, 1850 Palaumysisbahamensis n. sp. (® gures 7±13 )

Materialexamined .South Andros Island, Bahamas:Atlantis BlueHole, 2October 1999;one female (holotype), three females and one male( paratypes) collected with 93 mmmesh plankton net from the watercolumn in 60±70 mdepths. Materialdissected and preserved on cover slips in the `Crustaceans collection’ atthe Dipartimento di Scienze Ambientali, University of L’Aquila, Italy( My-Pa /01± My- Pa/05). Description. Bodysize 1.9±2.5mm. Alcohol decolourized the specimens which appear white transparent. Livespecimens werenoted asbeing bright red. Cephalothorax largerthan abdomen. Integument translucent. Anterior part of cara- paceforming alargetriangular area. Antennule (® gure 13):peduncle short and thick; aprominence (rudiment of male lobe) bears four to ®veaesthetascs (male) and averyreduced, apomorphic, two- segmented ¯agellum.The main ¯agellumvery long, exceedingthe length of the body. Antenna (® gure 9)with ashort peduncle and arudimentary scale. Eyeslarge, suboval. Labrum slightlyprotruding anteriorly. Mouthparts not wellvisible since specimens partiallydamaged, but seemingly without distinguishing characteristics. Peraeopods allalike, both in malesand females; dactylus asin ®gure 7.Very rudimentary oostegites. Pleopods (® gures 10,12 )tiny, allalike except the fourth malepleopod which is armed with averylong distal seta (® gure 10).`Pentagonal zones’ on the ventralside of eachpleonite, reported in P. simonae Bacescuand Ili Œe,1986, apparently absent. Telson (® gures 8,11 )slender, subtriangular, about twiceshorter than the last pleonite (® gure 11),and bearingtwo apicalspines, smalland not articulated. Uropods (® gure 11):exopod slightlyshorter than endopod. Endopod provided with alargestatolith and completely devoid of spines on the inner margin;other setation asin ®gure 11,distal setae not ®gured. Remaining characteristics asin P. simonae. Remarks. Palaumysisbahamensis n. sp. is similarin most respects to P. simonae, described byBacescu and Ili Œe(1986)from cavewaters of Palau( Micronesia), but diŒers in some important characteristics such as:telson distinctly longer than wide, only half aslong the lastpleonite (vs one third aslong ),and bearingtwo un-articulated spines distally(vs these spines are® gured asarticulated );antennular ¯agellumapomorphic, two-segmented (vs four-segmented);slightlyshorter male pleopod IV. The highlyanomalous distribution of this genus, with species occurring in cave 274 G.L.Pesce and T.M.Ili Œe

Figs 7± 13. Palaumysisbahamensis: (7±9, 11± 13 )holotype,( 10)maleparatype. ( 7) Peraeopod2 dactylus;( 8)telson;( 9)antenna,peduncle; ( 10)malepleopods 3 and4; (11)abdomen( lastpleonite), telson and uropods; ( 12)pleopod2; ( 13)antennula, ¯agellumand eye. watersof Palau( 134 ß E)in the western Paci®c and Andros (78 ß W)in the western Atlantic, is remarkable, but not necessarilyunique. The anchialinecave-limited, misophrioid copepod genus Expansophria includes species from Palauand the GalapagosIslands, on opposite sides of the Paci®c, from the CanaryIslands in the Eastern Atlantic and from Sardinia in the Mediterranean (Boxshalland Ili Œe, 1987, 1990;Jaume and Boxshall,1996b ).Likewise,another anchialinemisophrioid, Speleophriopsis ,includes species from the CanaryIslands, BalearicIslands, Bermuda and Palau( Boxshalland Ili Œe,1990; Jaume and Boxshall,1996a, 1996b ).Such Cave-dwellingmysids from the Bahamasand Mexico 275 distribution patterns suggest that these fauna arerelicts of the once widespread, warmwater fauna of the Tethys Seathat colonized anchialinehabitats from shallow water/hyperbenthic environments prior to the closure of the Tethys Sea( Boxshall and Jaume, 1999). Habitat. Atlantis BlueHole is anocean , or submarine cave,located near GrassyCay, South Andros Island. The caveentrance consists of a15mlong by5 mwidevertical ® ssure, surrounded byliving coral heads in 3±4 mwaterdepth. This shaft descends to about 40mdepth, where averticallyorientated ®ssure extends for more than 350m, reachingdepths in excess of 85m. Such fracture cavesparallel the submerged escarpment that marks the edgeof the shallowwater platform. They arebelieved to haveformed byslumping of the exposed bank marginduring glacial periods of lowered sealevel in the Pleistocene. Such caveshave strong, tidally reversing currents that allowdivers to enter only atslack when the currents are in the process of changingdirection. Athermocline is typicallyencountered atabout 60mdepths with colder waterbelow. This colder waterdoes not ¯owout of the caveentrance, suggestingthat watercirculation occurs primarilyat shallower depths within the cavesystem. Other fauna collected from the caveincluded copepods, cumaceans and amphipods.

Palaumysis Bacescuand Ili Œe, 1986 Reviseddiagnosis .Length 1.6±2.5 mm. Antennal scalerudimentary. Apomorphic inner antennal ¯agellum(two, four segments). Strong peraeopods with carpopro- podus not divided. Twopairs of oostegites, rudimentary. Telson subtriangular, armed with two distal, articulated or not articulated spines. Typespecies : P. simonae Bacescuand Ili Œe,1986 from cavewaters of Palau (Micronesia).

Antromysis( Antromysis)cenotensis Creaser,1936 (® gures 14±21 ) Materialexamined .Yucatan, Mexico: Cenote Ucil,Cenotillo; 15December 1991, two females (3.5,3.8 mm) collected with 93 mmplankton net from watercolumn in 0±10mdepths. Cenote Mucuyche  , Mucuyche ,Yucatan, Mexico; 4July1999; eight females (3.4±4.1mm), three males( 3.1±3.3mm) and two juveniles collected with plankton net from watercolumn in 20±37 mdepths. Remarks.The species is widespread in groundwaters of the northern Yucatan Peninsula. Bowman( 1977)did not ®nd `obvious di Œerences among specimens from the various localities’.On the contrary, in our specimens wepointed out relevant variation,also in the same sample, regardingthe shape and the armature of the telson, which is slightlylonger than wide[ vsnearlyas long aswide,both in Creaser’s (1936)and Bowman’s(1977)description and ®gures] and bears four to six( 2 1 2; 21 3; 31 11 2)apicalspines, in some specimens the medialfused with the telson [vsalways four apicalarticulated spines (2 1 2)in the originaland subsequent descriptions and illustrations] (® gures 14,17, 18, 20, 21 ).Another minor di Œerence is the presence on our specimens of two (vs one) setae on the basalinner marginof the malepleopod 4(® gure 19),and the eyestalks (® gure 16)closer to eachother than in previous descriptions. In our opinion, the abovedi Œerences, however,could ®tthe widevariability of this species, which is widespread in groundwaters of the Yucatan karst system. 276 G.L.Pesce and T.M.Ili Œe

Figs 14± 21. Antromysiscenotensis. (14,17, 18 )Telson(female); ( 20,21 )telson(male); ( 15) antenna2 scale(female); ( 16)anteriorend, dorsal (female); ( 19)malepleopod 4.

In Cenote Mucuyche  , Mucuyche ,Yucatan, Mexico, Antromysis(Antromysis) cenotensis livesin association with Stygiomysisholthuisi.

Heteromysis (Heteromysis) cf. odontops Walker,1898 sensu Tattersall,1951 Syn. Heteromysis spinosus Holmes, 1900 Materialexamined .ExumaIslands, Bahamas:Angel® sh BlueHole, Stocking Island; 18July 1998; three females (3.1±3.3 mm) collected with suction bottle approximately360 minside the caveat a depth of 29m. South Andros Island, Cave-dwellingmysids from the Bahamasand Mexico 277

Bahamas:South Bight #2Blue Hole, 4October 1999;three females (3.0±3.5mm), two males( 3.0,3.2 mm) and three juveniles collected with plankton net and suction bottle from surface of siltysediments in 40mdepths. Exley’sBoilingHole; 5October 1999;three females (3.6±3.8 mm) collected with plankton net and suction bottle from watercolumn and surface of siltysediment in 60±70 mdepths. Remarks.This stygophilic species wasdescribed byW alker (1898)based on materialfrom Puget Sound. Successively, Holmes (1900)described averysimilar species, Heteromysis spinosus ,from California;W. M.Tattersall( 1951)describing materialfrom West Coast of Panamasynonymized the latter with H. odontops, pointing out aswell some negligibledi Œerences between the two taxa.Later, O.S.Tattersall( 1967)transferred H. odontops described byW. M.Tattersallfrom Panamato anewspecies, H.panamensis . Our materialfrom Bahamasis veryclose to the species odontops Walker, 1898 and Tattersall( 1951),di Œering only byminor characteristics, which could well® t the widevariability of this species. The lackof su  cient number of specimens, especiallymales, causes us to ascribe provisionally our materialto H.odontops.

Acknowledgements Caveresearch in the Bahamaswas supported bygrants from the Caribbean Marine Research Center (NOAA)and the National Science Foundation, Biotic Surveys and Inventories Program ( #9870219).Bahamiancave studies werecarried out aspart of BahamianBlue Holes Research Project and in conjunction with the Rob Palmer Blue Holes Foundation. Weespeciallythank Dan Malone, BrianKakuk and Stephanie Schwabe for assistance with these investigations. Mexicancave studies werecarried out in collaboration with the Universidad Auto  noma de Yucata  n, Yucatan Secretarõ a de Ecologõ aand the Asociacio  nYucatecade Espeleobuceo. We thank Ro gerMedina, Fernando Rosado, Agustõ n Garcõ a,Roberto Hashimoto, Carlos Va rguez, Brett Dodson, Mike Madden and Steve Gerrard for assistance with our Mexicancave studies. This paper is acontribution of the International BiodiversityObservation Year( 2001±2002 ).

References Bacescu, M. and Iliffe, T.M., 1986,Contribution to the knowledge of Mysidacea from westernPaci® c: Aberomysismuranoi n.gen., n. sp. and Palaumysissimonae n. gen. n. sp.from marine caves on Palau, Micronesia, Travauxdu Muse Âumd’ Histoirenaturelle GrigoreAntipa , 28, 25± 35. Botosaneanu, L., 1980, Stygiomysisholthuisi foundon Anguilla (Crustacea: Mysidacea), Studieson the Fauna of Curacao and Other Caribbean Islands , 61, 128± 132. Bowman,T.E., 1973,Two newAmerican species of Spelaeomysis (Crustacea:Mysidacea) froma Mexicancave and land crab burrows, Associationfor Mexican Cave Studies Bulletin, 5, 13± 20. Bowman,T.E., 1976, Stygiomysismajor ,anewtroglobitic mysid from Jamaica, and extension ofthe range of S.holthuisi toPuerto Rico (Crustacea: Mysidacea: Stygiomysidae), InternationalJournal of Speleology , 8, 365± 373. Bowman,T.E., 1977,A reviewof the genus Antromysis (Crustacea:Mysidacea), including newspecies from Jamaica and Oaxaca, Mexico, and a redescriptionand new records for A.cenotensis ,inJ. Reddell(ed.) Studieson theCaves and Cave Fauna of theY ucatan Peninsula, Associationfor Mexican Cave Studies Bulletin , 6, 27± 38. Bowman, T.E., 1982,Mysidacea, in S. H.Hurlbertand A. Villalobos-Figueroa(eds) Aquatic Biotaof MeÂxico , CentralAmerica and the W estIndies (SanDiego, CA: SanDiego State UniversityF oundation),pp. 201± 202. 278 Cave-dwellingmysids from the Bahamasand Mexico

Bowman,T.E., 1984,Mysidacea, in L. Botosaneanu(ed.) StygofaunaMundi (Leiden,The Netherlands:E. J.Brill),pp.405± 409. Bowman, T. E., Iliffe, T. M. and Yager, J.,1984,New records of the troglobitic mysid genus Stygiomysis : S. clarkei,newspecies, from the Caicos Islands, and S.holthuisi (Gordon)from Grand Bahama Island (Crustacea: Mysidacea), Proceedingsof the BiologicalSociety of W ashington , 97, 637± 644. Boxshall, G. A. and Iliffe,T.M., 1987,Three new genera and ® venew species of misophrioid copepods(Crustacea) from anchialine caves on Indo-W estPaci® c andNorth Atlantic Islands, ZoologicalJournal of theLinnean Society , 91, 223± 252. Boxshall, G. A. and Iliffe,T.M., 1990,Three new species of misophrioid copepods from oceanicislands, Journalof NaturalHistory , 24, 595± 613. Boxshall, G. A. and Jaume,D.,1999,On theorigin of misophrioidcopepods from anchialine caves, Crustaceana , 72, 957± 963. Caroli, E., 1937, Stygiomysishydruntina n.gen., n. sp., Misidaceo cavernicolo di Terra d’Otranto,rappresentante di una nuova famiglia. Nota preliminare, Bollettinodi Zoologia,Padova , 8, 219± 227. Creaser, E.P.,1936,Crustaceans from Y ucatan, CarnegieInstitute of W ashington Publications , 457, 111± 132. GarciÁ a-Garza, M. E., Rodriguez-Almaraz, G. and Bowman, T. E., 1996, Spelaeomysis villalobosi ,anewspecies of mysidacean from northeastern Mexico (Crustacea: Mysidacea), Proceedingsof theBiological Society of W ashington , 109, 97± 102. Gordon, I.,1958,A newsubterranean crustacean from the West Indies, Nature, 181, 1552± 1553. Gordon, I.,1960,On a Stygiomysis fromthe West Indies, with a noteon Spelaeogriphus (Crustacea,Peracarida), Bulletinof the British Museum (Natural History ),Zoology , 6, 285± 324. Holmes,S.J.,1900,Synopsis of California stalk-eyed Crustacea, CaliforniaAcademy of Sciences, 7, 1± 262. Iliffe,T.M., 1993,Fauna Troglobia Acua Âticade la Peni  nsulade Y ucataÂn,in S. I.Salazar- Vallejoand N. EmiliaGonza Âles(eds) BiodiversidadMarina y Costerade Me Âxico (MeÂxico,DF: CommisionNacional para la Biodiversidad y CIQRO), pp.673± 686. Jaume, D. and Boxshall,G.A., 1996a,A newgenus and two new species of cave-dwelling misophrioidcopepods from the Balearic Islands ( Mediterranean), Journalof Natural History, 30, 989± 1006. Jaume, D. and Boxshall,G.A., 1996b,The persistence of an ancient marine fauna in Mediterraneanwaters: new evidence from misophrioid copepods living in anchihaline caves, Journalof NaturalHistory , 30,1583±1595. Kallmeyer, D. E. and Carpenter,J.H.,1996, Stygiomysiscokei ,newspecies, a troglobitic mysidfrom Quintana Roo, Mexico ( Mysidacea:Stygiomysidae), Journalof Crustacean Biology, 16, 418± 427. Pesce,G.L., 1975,On a Stygiomysis (Crustacea,Mysidacea) from the Southern Italy, BollettinoMuseo Civico di StoriaNaturale, V erona , 2, 439± 443. Pesce, G. L., Juberthie-Jupeau, L. and Passelaigue, F., 1994,Mysidacea, in V. Decuand C.Juberthie(eds) EncyclopaediaBiospeologica (Moulis,Bucarest: Societe Áde BiospeÂologie),pp. 113± 119. Reddell,J.R., 1981,A reviewof cavernicole fauna of Mexico, Guatemala and Belize, Bulletinof theTexas Memorial Museum , 27, 1± 327. Tattersall, O.S.,1967,A surveyof the genus Heteromysis (Crustacea,Mysidacea) with descriptionof ® venew species from tropical coastal waters of the Paci® c andIndian Oceans,with a keyfor the identi® cation of theknown species of thegenus, Transactions oftheZoological Society of London , 31, 157± 193. Tattersall,W.M., 1951,A reviewof theMysidacea of theUnited States National Museum, BullettinU.S. NationalMuseum , 201, 1± 292. Villalobos,A., 1951,Un nuevoMisidaceo de lasgrutas de Quinteroen elestadode Tamaulipas, Analesdel Instituto de Biologia,Universidad Nacional Autonoma de Mexico , 22, 191± 218. Walker,A.O., 1898,Crustacea collected by W.A.Herdman,F.R.S. inPuget Sound, Paci® c coastof North America, September 1897, TransactionsLiverpool Biological Society , 12, 268± 287.