Contributions to Zoology, 66 (2) 65-102 (1996) SPB Academic Publishing bv, Amsterdam

New hypogean cyclopoid copepods (Crustacea) from the Yucatán Peninsula,

Mexico

Frank Fiers Janet W. Reid Thomas M. Iliffe & Eduardo Suárez-Morales

1 Invertebrate Section, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Bel-

2 gium', Department of Invertebrate Zoology, MRC-163, National Museum ofNatural History, Smithsonian

3 Institution, Washington DC 20560, U.S.A.; Department of Marine Biology, Texas A&M University,

4 Galveston, Texas 77553-1675, U.S.A.; ECOSUR, El Colegio de la Frontera Sur - Unidad Chetumal, Apdo

Postal 424, Chetumal, Q. Roo 77000, Mexico

Keywords: Diacyclops, Mesocyclops, Copepoda, Cyclopoida, biogeography, evolution, hypogean, karst,

species-flock, taxonomy, Mexico

Abstract del género Diacyclops ocurrenraramente en las regiones tropi-

cales los dos descritos el tercer y Diacyclops aquí son segundo y

del en México. La Four unknown of representantes género registrados especie previously hypogean species cyclopoid cope- ha encontrado de béntica D. se en un grande cuerpo agua pods were collected in cenotes and wells of the Yucatán Penin- puuc

subterránea (cenote). chakan se ha encontrado sólo Mexico. chakan and D. differ Diacyclops sula, Diacyclops sp. n. puuc sp. n. estes de subterrá- from their in excepcionalmente en cuerpos grandes aguas congeners combining 3-segmented swimming

es frecuente abundante en and neas, pero y pozos. legs, 11-segmented antennules, legs 1-4 endopodite seg-

Las dos de M. chaci n. M. especies Mesocyclops, sp. y yutsil ment 2 all with 2 setae. Species of Diacyclops rarely occur in la béntica M. reidae sp. n. son muy semejantes a especie tropical regions, and the Diacyclops described here are only the Petkovski, están modificadas la vida hipógea con la second and third species recorded from Mexico. The benthic pero para

de ornamentaciones en el cuerpo y el D. found in the reservoir of pérdida parcial adelgaza- puuc was large underground a miento de las natatorias bucales. chakan encountered in such patas y partes Mesocyclops cenote. Diacyclops was large open chaci vive in creviculares las de sp. n. lugares como paredes subterranean water basins, but more frequently and abundantly

cavernas n. se carac- in wells. pozos y pequeñas. Mesocyclops yutsil sp.

teriza el más de las es The M. chaci and M. por pronunciado adelgazamiento patas, two Mesocyclops species, sp. n. yutsil vive de subterráneas. planctónica y en cuerpos grandes aguas sp. n., most closely resemble their epigean benthic congener M. Los apéndices extremadamente adelgazados distinguen las dos reidae Petkovski, but are modified by loss of some body orna-

especies de los demás Mesocyclops son similares a los de la ment and attenuation of swimming legs and mouthparts. y delamarei Lescher-Moutoué. Las chaci crevicular and especie hipógea Kieferiella Mesocyclops sp. n. occupies spaces (wells de consideradas small The second M. with tres especies Mesocyclops son como un parti- caverns). species, yutsil sp. n., more cular ha radiado dentro de conjunto que como especialistas un pronounced attenuation of legs, has a planktonic life in large ambiente altamente dinámico. subterranean volumes. The attenuated geomorfológico water extremely appen- dages ofboth species distinguish them from all other Mesocy- clops, and resemble those of the hypogean Kieferiella delama- rei Lescher-Moutoué. These three species are considered as a Introduction species-flock which have radiated as specialists within a highly dynamic geomorphological environment. Collections of crustaceans from cenotes, wells and

caves in the States of Yucatán and Quintana Roo,

Resumen Mexico, contained four previously unknown cy-

clopine copepods, two Diacyclops and two Meso-

Se recolectaron, en cenotes de la Peninsula Yucatán, y pozos cyclops. These are described and their possible México, cuatro especies de copépodos ciclopoides hipógeos systematic affinities discussed by F. Fiers and J.W. desconocidos. chakan D. previamente Diacyclops sp. n. y puuc Reid. We describe the geological and ecological difieren de al combinar natatorias sp. n. sus congéneres patas conditions that have contributed to the tri anténulas de 11 2 el might segmentadas, segmentos y setas en se- evolution of these gundo segmento del endopodito de las patas 1-4. Las especies hypogean species.

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Methods Type-specifications. - Holotype, dissected 9, mounted on 3

slides, labeled COP 3863a,b, c; allotype CT, dissected, mounted

on 3 slides, COP 3864a, b, c; dissected paratypes: 1 Ç COP Some specimens, collected by T.M. Iliffe and colleagues, were , 3865a, b, c; 1 9, COP 3866a; 1 cr, COP 3867a,b, c; ethanol- taken with a plankton net from the surface to as deep as 30 m in 69 COP and preserved paratypes: 9 9,1 CT, 3868, sample several cenotes. Although the water in most cenotes was"fresh" filtrate (still containing specimens), COP 3920; 24 9 9, (0-2%o) at those depths, most samples contained copepods of many 1 5 USNM 274313. CT, copepodids, both continental freshwater and marine affinities. The latter of Type-locality: man-made well (pozo), located onproperty were sent to appropriate specialists for determination and

"Rancho Antonio Kanah" along Kinchil - Celestún road description. (Yucatán), approximately 23 km from Kinchil, and 1 km from Crustaceans collected by F. Fiers and colleagues came from road. Coordinates (estimated): 20°53'30"N, 90°07'09"W. Well of habitats, man-made wells, a wide variety including open fine has diameter of 1 m, depth 4 m. Bottom sediments are cenotes and nearly closed aguadas (karstic caverns with a small brilliant white sand. At time of sampling, well contained 1 m of to large water pool). All samples were taken with a plankton net water, and was covered with iron lid. Sample MEX 93-88, leg. that was repeatedly lowered in the water column and rapidly - J. Vargas, M. Herrera, and F. Fiers, 8 November 1993. Addi- withdrawn to create a current sweeping the walls of the water tional fauna: 1 9 V Macrocyclops reservoirs. copepod copepodid stage

albidus s. str., COP 3869a, b, and crustacean the F. and his assistants collected (Jurine, 1820) c; In same way, Dr. Moravec fauna cenotensis (Creaser, chaci in closed man-made well Antromysis 1936), Typhlatya pear- Mesocyclops sp. n. a near sei Creaser, 1936;ostracodes; 1 stygobiotic amphipod. Cheuman, Yucatán, and used this species succesfully as the

experimental intermediate host of two nematode species

Additional material. - parasitic in fish (F. Moravec, in litt, to F. Fiers). (1) Chen-Ha Cenote, Chochóla (Yucatán), west side of main Specimens were fixed in formalin and transferred to 70-75% highway midway between Chochóla and Maxcanu. Coordi- ethanol for long-term storage. For taxonomie examination, they nates: 20°34'10"N, 89°52'30"W. Commercially operated fresh- were transferred in stages to glycerine and examined either in of 95 water swimming cenote consisting open pool m long by glycerine (J.W. Reid and F. Fiers) or in lactic acid (J.W. Reid). 64 m wide, with large underwater cavern entrance extending Permanent mounts were made in polyvinyl lactophenol (PVL)

25 m maximum in 24 in little chlorazol black added in horizontally; depth open pool m, cavern with a E (J.W. Reid) or glycerine mesh 30 m; bottom primarily mud. Sample taken with 93 |im with sealed coverglasses (F. Fiers). J.W. Reid made most plankton net at 18-28 m depths in cavern. Sample 93-043, leg. drawings at magnifications of600x and confirmed the details at T.M. Iliffe, 6 July 1993: 1 9, dissected on slide in PVL, USNM lOOOx using an oil immersion lens on a Wild M30 microscope

259839. - Additional copepod fauna: Mastigodiaptomus albu- fitted with a drawing tube. F. Fiers made his drawings at 1250 x 1 9 4 copepodids, USNM querquensis (Herrick, 1895), , using an oil immersion lens on a Leitz Dialux 20, equipped with

278028; albidus s. Str., 1 CT, USNM 278030; tube. Undissected in 70% Macrocyclops a drawing specimens were preserved 1 USNM 278029; Thermocyclops ethanol. Microcyclops sp., copepodid,

and USNM and inversus Kiefer, 1936, 119 9 CTCT, 278031; The specimens were deposited in the collections ofthe De- crustacean fauna: amphipods, thermosbaenaceans. partment of Invertebrate Zoology, United States National Mu- (2) Mucuyché Cenote, located within the ruins ofa hacienda in seum of Natural History, Smithsonian Institution (USNM) and the village of Mucuyché (Yucatán). Coordinates: 20°37'23"N, in the Invertebrate Collection of the Royal Belgian Institute of 89°36'18"W. From the crescentic sinkhole entrance, a flight of Natural Sciences, Brussels (COP). to steps leads down a breakdown slope a 30 m long by 10 m

wide, gravel and rock floored freshwater pool. On the far side of

the about 8 hole pool at m water depth, a narrow opens onto a Descriptive part 50 m long, 10 m wide breakdown chamber that angles diago-

vertical breakdown nally down to 30 m depth. At this point, a Burmeister, 1834 Family Cyclopidae shaft ascends to 15 m depth before choking off. Sample taken

chamber. Subfamily Cyclopinae Dana, 1853, emend. Kiefer, with plankton net at 20-30 m depth in breakdown

1927 Sample 93-045, leg. T.M. Iliffe, 9 July 1993: 1 cr, USNM

259840, 1 copepodid, USNM 259842. - Other crustacean Genus Diacyclops Kiefer, 1927 fauna: mysids (Antromysis cenotensis), thermosbaenaceans,

and amphipods, isopods [Creaseriella anops (Creaser, 1936)]. Diacyclops chakan Fiers & Reid, sp. n. (3) Yuncu Cenote, located 1.5 km west ofYuncu (Yucatán), on

(Figs. 1-7) east side of abandoned railroad right-of-way running north to

south. Coordinates: 20°34'51"N, 89°36'46"W. Vertical pit en-

- Suárez-Morales 1996: 7 diameter and 10 Synonymy. Diacyclops sp. A, et al., trance, m m deep; a freshwater, U-shaped

27-30. - leuckarti of extends 3/4 ofthe around the northern side ofthe 40 124, figs. ?Mesocyclops Claus, 1857, pool way m

Wilson, 1936: 82, 85-88 (partim); Pearse & Wilson, 1938: 153 long by 37 m wide entrance chamber. The pool on the east side

of the about but the side (partim). chamber averages 1 m deep, on west

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Coordinates well, 1 diameter,35 m with 1.5 m ofwater. the pool extends down to over 30 m deep where it pinches out m deep, J. between breakdown and the bedrock wall. Sample taken with 20°48.216' N, 88°11.895' W. Sample Mex 94-019, leg.

and M. Herrera, 18 1994: 30 9 9,2 acr, and plankton net at 15-30 m depths. Sample 93-046, leg. T.M. Iliffe, Vargas April

COP c. - 259841. - Additional 4 COP 1 dissected, 3882a, b, 10 July 1993: 1 9, USNM copepod copepodids, 3883; 9,

crustacean fauna: fauna: subspecies of Tropocyclops prasinus (Fischer, 1860) Additional copepod fauna: calanoids; and

cf. s. 1., 5 9 9,2 CT CT, USNM 278027; Mesocyclops yutsil sp. n., Antromysis cenotensis, Typhlatya pearsei.

Cenote, Yuncu 0-5 m, sample see below. Other crustacean fauna: mysids (Antromysis ceno- (10) Yuncu (Yucatán), depth

T.M. Iliffe: tensis), ostracodes, thermosbaenaceans, amphipods, and iso- 94-023, 13 August 1994, leg. 7ÇÇ,lcr,4 cope-

- fauna: Mastigo- pods. podids, USNM 271850. Additional copepod 271855; Presumida 1.5 km from La nesus (Bowman, 1986), 1 9, USNM (4) Pozo (well) near (Quintana Roo), diaptomus 271853; Presumida (7.5 km southeast ofMorelos) on road to Chetumal; Macrocyclops albidus s. str., 1 o', USNM Mesocyclops

USNM chiltoni 1 USNM m man-made well 1.5 m of n., 271864; cr 80 cm diameter, 6 deep containing yutsil sp. Paracyclops , ,

side from the main road. of s. 1., 200+, water; about 2 km at the right 271862; subspecies Tropocyclops prasinus

Estimated coordinates 19°46.250'N, 88°45.704'W. Sample Mex USNM 271865; marine cyclopoids. Roo), 94-008, leg. J. Vargas, V. Ceja, and F. Fiers, 12 April 1994: (11) Ponderosa Cenote, Puerto Aventuras (Quintana part south of - km cave located 4 km Puerto 1 dissected 9, COP 3870a, b, c; 13 9 9, 3 CT CT, COP 3871. of 11.5 long system

from main coastal Additional copepod fauna: Mesocyclops reidae Petkovski, Aventuras and 1 km inland (west) highway.

Coordinates: 87°14'W. extends back 1986: 1 9, dissected, COP 3872a, b, c, 16 9 9, 2 copepodids, 20°31'N, Large cavern

from this underwater COP 3873; and crustacean fauna: Antromysis cenotensis, stygo- 90 m to the Corral Cenote; an passage air-filled chamber called the biotic amphipods. extends over 600 m to a partly

Halocline at 11.5 taken with net (5) Aguada (Quintana Roo): cavern located 3 km left of More- Chapel. m. Sample plankton

halocline in to at los-Chetumal road, small water reservoir, 4 m long, 2 m in dia- from water column at or below passage Chapel

1.10 end of domestic 10-16 95-020, T.M. Iliffe, 25 1995: meter, deepening to m at extreme cavern; m depths. Sample leg. July material; 0%o. 1 9,2 1 condition, dead when use; bottom covered with fine organic salinity copepodids, nauplius (poor fauna: Estimated coordinates 19°51'00"N, 88°35'H"W. Sample Mex caught), USNM 264231. - Additional copepod harpac-

94-009, leg. J. Vargas, V. Ceja, and F. Fiers, 12 April 1994: 9 ticoids.

- fauna: 9 9,3 copepodids, COP 3874. Additional copepod

reidae: 2 COP 3874; Paracyclops chiltoni Mesocyclops 9 9, Description of female. — Length of holotype 676 (Thomson, 1882), COP 4090; and crustacean fauna: Antromysis of 5 from 551 to 727 |im; lengths paratypes ranging Tulumella cenotensis, Creaseria morleyi (Creaser, 1836), sp. = 570 mean 679 |im (Chen Ha specimen |am, (6) Pozo (well) 1 at San Domingo (Quintana Roo), on left side Yuncu 560 telescoped). ofMorelos-Chetumal road; first village east of Lago Esmeralda, specimen |im: specimens

man-made well on side of slender in dorsal with on dirt road to La Esperanza; right Habitus (Fig. la) view, post-

road domestic 14 1 through village, uncovered, use, m deep, m erolateral margins of pedigerous somites 3, 4 and diameter, containing 1 m of water. Estimated coordinates 5 produced posteriorly (less produced in Yuncu 19°46.436'N,88°42.721'W. Sample Mex 94-011, leg. J. Vargas, specimens), without surface ornament except for V. Ceja, and F. Fiers, 12 April 1994: 1 9,5 copepodids, COP dorsal sensilla (latter not illustrated); genital dou- 3876. - Additional copepod fauna: Mesocyclops reidae: 1 dis- ble widest in anterior half ta- sected 9, COP 3871a, b, c, 1 9, COP 3870; calanoids; and somite (152 jim),

crustacean fauna: Antromysis cenotensis, Typhlatya cf. pearsei. pering posteriorly (Fig. 2a, b); about as long as

Pozo 2 at San Domingo (Quintana Roo), same village as in (7) wide (ratio length/width 1 : 0.94); ratio urosome/ ± than nr. (6) but on left side of dirt road, situated 4 m higher body length: 1 : 2.89. Hyaline fringes of uroso- previous locality; man-made well, 16 m deep, 1.20 m diameter, mites weakly crenulate dorsally and ventrally; anal containing about 2 m of water, uncovered, domestic use. Esti-

C with small mated coordinates 19 47.501'N, 88°42.721'W. Sample Mex somite ornamented spinules along pos-

94-012, leg. J. Vargas, V. Ceja, and F. Fiers, 12 April 1994: terior margin; surface naked except for paired

12 , 64 COP 3877. - Additional copepod 9 9 copepodids, dorsal sensilla; anal operculum wide, weakly cres- fauna: Eucyclops cf. conrowae Reid, 1992, COP 3862; and centic; anal sinus smooth. crustacean fauna: ostracodes, stygobiotic amphipods. Caudal 2.5 ramus (Fig. 2c, d) (in holotype, rang- (8) Pozo "Ticuch", 500 m left, 1 km out of Ticuch Village times to 88°08.189'W. from 2.29 to 2.64 in longer (Yucatán) on road Valladolid, 20°41.786'N, ing paratypes)

m indented in Man-made well, 1 m diameter, 36.5 m deep, containing 1.5 than wide with large triangular area an-

water. 94-015, J. and M. Herrera, 18 Sample Mex leg. Vargas terior half of medial margin; surface smooth except dis- April 1994: 100+ 9 9, cr ce, and copepodids, COP 3881; 1 for few small spinules on anterior third of outer

sected 9. COP 3880a, b, c. - Additional crustacean fauna: and of lateral and later- margin, near implantation none.

almost terminal setae; apical ventral margin some- (9) Pozo "Temozon" in Temozon Village (Yucatán), man-made

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Fig. 1. chakan n., COP 3863; b, ￿, COP 3864: a, habitus, dorsal indicates maximum Diacyclops sp. a, c—d, holotype ￿, allotype (arrow

length ofantennule); b, habitus, dorsal; c, mandible; d, labrum.

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2. chakan n., COP 3865: a, abdomen, dorsal; b, ventral; c, caudal ramus, caudal Fig. Diacyclops sp. paratype ￿, abdomen, ventral; d, ramus, dorsal.

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3. Fig. chakan sp. n., a, COP 3863; b—e, 3866; f, COP 3865; h, ￿, Diacyclops g, holotype ￿, paratype ￿, COP paratype ￿, allotype

COP 3864: a, anomalous antennule; b, antennule; c, antennule; d, antennular segment V; e, antennular segment X; f, basipodite of

antenna, caudal view; g, antenna, frontal view; h, appendages ofsecond endopodal segment of antenna.

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Caudal surface of with what produced, with pore orifice at tip (arrow: Fig. ment. basipodite (Fig. 3f)

Chen Ha 25 of slender 2c); lateral seta (30 spec. um, proximal group long spinules along

= short 26 28.5 at outer and and 2 rows of Yuncu spec. (am, mean urn) arising abexopodal margins, surface minute 4 base of posterior third of outer margin, rather ro- spinules on (3 ones, longer ones;

of 2 ones in Chen Ha distal half bust in appearance, plumose along anterior side only long specimen);

1.2 times with of 4 slender 5 in Chen stem; lateralmost terminal seta plumose, irregular row spinules,

Chen Ha Ha Frontal side of 3g) as long as ramus; dorsal seta (91 |im; specimens. basipodite (Fig.

with hair-like 95 with minute basal furnished row of along spec. 90, Yuncu spec. |xm) spinules

of and crescentic row articulation, inserted at 8/10 length ramus, proximal abexopodal margin,

of slender of slightly medially to dorsal midline, distal half 7 spinules near midlength exopodal

plumose; lengths of lateralmost to medialmost ter- margin (4 spinules in Chen Ha specimen). with 12 blunt central teeth minal setae: 56, 209, 333, and 95 |im (Chen Ha Labrum (Fig. ld)

bro- between rounded lateral and 2 spec.: 38, 157, 276, 73, Yuncu spec.: 58, 200, produced corners,

in of hairs ken, 98). Median terminal setae slightly swollen rows long on frontal surface. Cutting edge

proximal fourth, and plumose; medialmost seta concave.

Mandible 1.85 times longer than ramus. (Fig. lc) with complex biting edge

1 Innermost Seminal receptacle (Fig. 2b) with anterior part formed by sharp teeth and seta. dorsal

with little produced and nearly absent; posterior part surface row of spinules parallel to biting edge. broad, rounded, reaching posterior third of genital Mandibular palp small but distinct, bearing normal

and canal 2 setae (278 um) double somite; lateral arms narrow pore armament: long, finely plumed

straight. and 1 short smooth seta (39 um).

with 11 Antennule (Fig. 3a-e) normally 11-segmented Arthrite of maxillule (Fig. 4d) append- and and innermost ones (paratypes, Chen Ha and Yuncu material) ages: strong, hookshaped, curved furnished reaching middleof second thoracic somite (Fig. la: jointed with a long one, partially

with setules side Next out- arrow); surface of segments smooth, except for long along one of stem.

comb I. and constricted in short of spinules on segment Segments ermost seta large rigid, distinctly

(Roman numerals) with number of setae (Arabic middle and plumose in distal half. Maxillular palp

numerals), spines and aesthetascs in parentheses: with normal armament of 3 endopodal, 1 exopodal

I (8), II (4), III (8), IV (3), V (1+spine), VI (2), VII and 3 medial setae. Yuncu specimens with arthrital

(3), VIII (2+aesth.), IX (2), X (3), XI (7+aesth.). appendages all ornamented with setules.

with basis and striated Maxilla with normal and Spine on segment V thick (Fig. 4a) morphology

teeth middle tip (Fig. 3d). Aesthetasc on segment VIII reaching setation, claw armed with very fine on half of border and short of teeth in midlength of segment. Slender naked seta on seg- concave group

aesthetasc middle of convex border. ornamented ment X may represent (Fig. 3e). Seg- Endopodite

with 3 third but mentation variable: Chen Ha specimen with par- rigid setae, plumose on proximal

with on middle and distal third, 1 slender tially divided segment III; holotype specimen pinnate and 1 short naked segment III entirely divided, forming 12-seg- plumed seta seta. with normal mented antennule; paratypes (COP 3866) with Maxilliped (Fig. 4e) appearance,

in and VIII. armed with ornamented with remnants ofarticulations segments VII long setae broadly for 2 No hyaline membrane on distalmost segments (left spaced rigid plumes, except smooth apical of antennule of holotype female, COP 3863, broken setae and spinulose distal half one seta on penul- Surface of in two parts). timate and one on terminal segments.

but with 2 combs in Antenna (Fig. 3f-h) of 4 segments, bearing 2 segment 1 smooth, of spinules

Ha 2 with 3 crescentic abexopodal setae and 1 long finely feathered exo- Chen specimen; of segment

second with combs and 1 frontal of 3 podal seta on basipodite; segment 1, posterior comb; segment

with 9 and with and of 4 third (second endopodal) segment ter- series of frontal spinules, segment smooth. minal segment with 7 slender setae. Chen Ha spec-

with and 8 second 1-4 with imen 7 setae on endopodal seg- Legs (Figs. 5a-d, 6a-e) 3-segmented

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Fig. 4. chakan n., c—e, COP 3863; b, COP 3865: a, maxilla;b, 5; c, 5 medial Diacyclops sp. a, holotype ￿, paratype ￿, leg leg spine; d, maxillule; e, maxilliped.

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COP 3864: 1 5. chakan sp. n., a—d, COP 3863; e, allotype ￿, a, leg 2, anterior;b, leg endopodite, posterior; Fig. Diacyclops holotype ￿, of male, c, leg 1 protopodite and exopodite, posterior; d, leg 3 coupler, anterior; e, third endopodal segment of leg 2 posterior.

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rami. Praecoxa with short row of setules near outer Egg sacs containing 2 relatively large eggs (ob-

border. Coxopodite of leg 1 ornamented with long served in only 2 paratype specimens).

slender setules along outer border and on posterior

surface (Fig. 5c); anterior surface with 2 small Description of male. - Length: 544 (im (500 jim in

with combs of spinules near outer margin (Fig. 6c). Mucuyché specimen), same appearance as

Coxopodite of legs 2-4 each with smooth anterior female (Fig. lb). Greatest width of sixth thoracic

1. surface, except for 2 rows of minute spinules along somite 126 length/width ratio: 0.66 : distal border. Posterior surface of leg 4 coxopodite Caudal rami (Fig. 7a) slightly shorter than in fe-

of male. ratio: 2:1. General (Fig. 6d) with 2 combs spinules near outer bor- Length/width appear-

der, and transverse row of long spinules along ance of caudal setae as in female.

of all smooth. Antennule with 16 distal border. Couplers legs Leg 1 (Fig. 7b) geniculate, seg-

basis with medial spine reaching slightly beyond ments; terminal segment extended in blunt trans-

second median and endopodite segment; margin parent process.

with medial corner rounded. Basis of legs 2-4 Leg 2 endopodite terminal segment (Fig. 5e)

articulation with with terminal 1.3 times spinule row near endopodite; me- outer spine as long as seg-

dian and medial distal edges produced. Terminal ment. Inner setae on middle and terminal segments

segments of legs 1-4 exopodites with 2, 3, 3, 3 of leg 3 endopodite (Fig. 6f) distinctly different

spines and 4, 4, 4, 4 setae, respectively. Exopodal from female: distal seta on middle and proximal

spines of legs 1 and 4 slender, of legs 2 and 3 rela- seta on terminal segment distinctly more robust,

tively stout; exopodal spines of leg 1 slightly ex- ornamented with long spinules along most of me-

tended in slender hairlike tips. Ornamentation of dial side of stem and short spinules on distal third

2-4 and distal of side of median inner exopodal spines of legs outer spine outer stem; seta on terminal

on terminal endopodal segment of legs 1-3 located segment with long spiniform setules along medial

in median part of stem (length of ornamentation side of stem, plumose along lateral face. Leg 4 endo-

variable), distal part of spines smooth and blunt. podite segment 3, 2.5 times as long as wide in allo-

Leg 4 terminal endopodal segment 2 times as long type, ranging from 2.4 (paratype) to 2.7 (Mucuyché

as wide in holotype (1.7-1.9 in Yuncu specimens); specimen). Proportional lengths of terminal spines

with 2 distal spines: medial spine as long as seg- on endopodite segment 3 as in female.

ment, outer spine 1.2 times as long as segment; Leg 5 (Fig. 7a) as in femalebut with seta/spine ratio

medial with of and spine slightly "sprung" medially, slen- only 2.1 : 1, spine/exopodite ratio: 1.28 : 1.

der tip. Surface of leg 6 with transverse row of spinules.

for with broad Outer furnished with Leg 5 (Fig. 4b, c) typical genus, margin 1 plumose seta, 1

and basal segment and subterminally implanted medial smooth spine, 1 armed spine.

spine on exopodite. Exopodite about 1.5 times as

long as wide, furnished with some minute spines Etymology. - The species is named chakan, which

near insertion of medial spine. Medial spine irregu- in Mayan refers to feathers, because of the long

larly armed along inner and outer margin. Spine/ setae of the caudal ramus and the swimming legs;

seta ratio: 3.8; spine/exopodite ratio: 1.66. Holotype proposed in apposition. and with medial some paratype specimens straight

spine, Chen Ha and other paratypes with more Discussion and comparisons. - Diacyclops chakan

curved 4c). is discussed with D. n. spine (Fig. together puuc sp. 6 with 1 medial and Leg (Fig. 2a) seta (30 urn long)

2 blunt outer elements, outermost slightly longer

than median one.

chakan Fig. 6. Diacyclops sp. n., a—b, e, holotype COP 3863; cd, COP 3864; f, allotype ￿, COP 3864: 3, ￿, paratype ￿, a, leg anterior; b, leg 4, anterior; c, leg 1 coxopodite, anterior; d, leg 4 coxopodite, posterior; e, terminal spines ofleg 4 endopodite; f, second

and third segment ofleg 3 endopodite ofmale, anterior.

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7. chakan Fig. Diacyclops sp. n., allotype ￿, COP 3864: a, fifth thoracic somite and urosomites, ventral; b, contour of antennule.

COP Hubicu Cenote Diacyclops puuc Fiers, sp. n slides, 3919a, b, c. Type-locality: (Yuca-

km from (Figs. 8-10) tán), 6 Temozon Village beside dirt road leading to unnamed ranch. Coordinates 20°49.132' N, 88° 10.348' W.

cenote - Closed in form of with 1.5 diameter Synonymy. Diacyclops sp. B, Suárez-Morales et al., 1996: cone, m open roof,

- 40 diameter lake 25 below from 125, fig. 31. ?Mesocyclops leuckarti Claus, 1857, of Wilson, m m ground surface; sample

close to 1936: 82, 85-88 (partim); Pearse & Wilson, 1938: 153 (partim). walls, 0-15 m deep; sample Mex 94-16, 18 April 1994, leg. Joaquin Vargas and Miguel Herrera. Additional copepod

Type-specifications. - dissected on Single 9 (holotype) three fauna: calanoids, Macrocyclops albidus s. str., COP 3922; sub-

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8. n., COP 39 19a—c: a, anal somite and left caudal ramus, dorsal; b, abdomen, ventral; c, 5; Fig. Diacyclops puuc sp. holotype ￿, leg d, genital field; e, leg 6.

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of 9. COP 3919a—c: a, antenna, caudal;b, 1 frontal; c, third endopodalsegment leg Fig. Diacyclops puuc sp. n.,holotype ￿, leg coupler,

third of 2 frontal ornamentation 2, frontal; d, endopodal segment leg 3, frontal; e, leg coupler, (setal not drawn).

species of Tropocyclops prasinus s. 1., COP 3904; other crusta- Antennule 11-segmented, without indications of

cean fauna: ostracodes. vestigial articulations. Segments (Roman numer-

with number of setae of female. - Remark: because the als) (Arabic numerals), Description pres-

ent resembles chakan in and aesthetascs in I II (4), species D. many aspects, spines parentheses: (8), III (8), IV (3), V VI (2), VII VIII only the differences between both species are de- (1+spine), (3),

scribed below. (2+aesth.), IX (2), X (3), XI (7+aesth.). Aesthetasc

VIII articulation 812 with rounded on Body length um, pleurotergite, segment reaching just beyond

not posteriorly produced, of pedigerous somite 5. with segment IX.

Seminal receptacle (Fig. 8b, d) almost as in D. cha- Basipodite of antenna (Fig. 9a) with, on caudal

but 2 kan, posterior part more linguiform and less surface: horseshoe-shaped rows of spinules with with produced posteriorly. (proximalmost row 9 minute, medial row

Caudal rami 2.55 wide. 6 in (Fig. 8a) times as long as long spinules) proximal half, and an irregular

Lateral terminal seta (68 um) slightly longer than longitudinal row of 11 long spinules in distal half;

medial terminal 1 ramus, and seta (119 um) fully on frontal surface: short row of setules near prox-

twice and 1 as long as ramus. imal abexopodal margin median longitudinal

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of abexo- of 3 and 4 each with one medial row long spinules near exopodal margin; legs 1, only seta, with medial podal margin with slender spinules on proximal and the leg 4 endopodite segment 3 a

In the half, and exopodal margin with 4 long proximal terminal seta and a lateral terminal spine.

the setules. Tibetan D. tenuispinalis (Shen & Sung, 1963),

Couplers of legs 1-4 smooth (Fig. 9b: leg 1; 9e: setation of the swimming legs is incompletely de-

This has caudal ramus leg 2) and proportional lengths of segments and scribed. species a long

6.5 than differs in setae as in D. chakan. Terminal endopodal seg- (about times longer wide) and

other from D. chakan and D. All three ments of leg 2 (Fig. 9c) and leg 3 (Fig. 9d) as illus- ways puuc.

trated. Leg 5 (Fig. 8c) closely resembling leg 5 of species of the antipodean D. michaelseni - group

D. chakan, but terminal seta distinctly (2.5 times) also have 3-segmented swimming legs and 11-seg-

michaelseni longer thaninner subterminal spine. Leg 6 (Fig. 8e) mented antennules. Two of these, D.

with 2 blunt elements and 1 short plumose seta. (Mrázek, 1901) and D. cryonastes Morton, 1985,

in the Leg 1 coxopodite (Fig. 10a) with entire anterior differ from D. chakan and D. puuc having

1 2 1 seta surface smooth, except for 2 rows of minute spi- leg endopodite segment with only (legs

2 each has 2 nules along distal margin; medial spine of basis 2-4 endopodite segment setae); also,

in least D. and D. michaelseni the reaching only to midlength of endopodite segment at cryonastes leg

with 4 and the basal of 5 of the 2; outer spines on exopodite slender, long coupler segment leg of These hairlike attenuations, and setae also with attenu- female are ornamented with rows spines.

Morton for ated naked tips (arrowed in illustration). Leg 4 attributes were described by (1985)

with short D. which is known from Tasmania and coxopodite (Fig. 10b) transverse row of cryonastes,

southeastern spinules on posterior face; exopodite spines slen- extreme Australia. Their presence was

D. der, with smooth, slightly attenuatedtips; terminal confirmed by inspection of specimens of mi-

chaelseni endopodite segment 1.6 times as long as wide, with from Tierra del Fuego (USNM 264526),

from proportional lengths of terminal spines as in D. of which D. skottsbergi (Lindberg, 1949)

chakan. South Patagonia is a synonym (Menu-Marque,

1991). As incompletely described by Borutzky &

mem- - is named after the D. the Antarctic Etymology. The species mag- Vinogradov (1957), mirnyi, ber of the michaelseni- differs from D. cha- nificent Mayan post-classical architectural style group,

caudal ramus Puuc, characteristic for the region containing the kan and D. puuc in having a longer

type-locality of the species. (4.5-5 times longer than wide) and slightly in the

shape of the seminal receptacle.

- of the antennule is variable in Discussion and comparisons. Diacyclops puuc Segmentation of and the articulation of shares many characteristics with D. chakan and the some species Diacyclops,

of and III D. chakan differences seem to be a matter dimensions segment in the holotype of (forming

and the of proportional lengths of appendages. Diacyclops a 12-segmented antennule) remnants ar-

than its ticulations in VII and VIII that puuc is much larger congener (812 um vs. segments suggest

could have with 613 um) and has a rather short medial spine on leg some populations an antennule 12,

The other in the for is the denser 14 or 15 1. Diagnostic D. puuc spinule pat- segments. only species

Whereas the Americas with antennule and tern on the antennal basipodite. spi- a 12-segmented

is D. crassicaudis nule ornamentation on the caudal side of the basi- swimming legs all 3-segmented

is is in D. it s. which a much more podite in D. chakan very reduced, puuc (Sars, 1863) 1., grosser,

consists of three well-defined rows. heavily sculptured benthic species lacking a me-

the 1 and with In the few have dial on a more large genus Diacyclops, species spine leg basipodite all rami of the swimming legs 3-segmented, to- slender caudal ramus than D. chakan and D. puuc.

American antennule 14 gether with an 11-segmented antennule in the fe- No Diacyclops has an with

male. The only described species in North America or 15 segments.

with these attributes, D. jeanneli putei (Yeatman, The modified ornamentation of the setae of the

1943) has the middle segments of the endopodites leg 3 endopodite and the different length of the

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10. n., COP 3919a—c: a, 1, frontal; b, 4, frontal. Fig. Diacyclops puuc sp. holotype ￿, leg leg

terminal leg 2 endopodal spine in the male of D. species of Halicyclops (cf. e.g. Da Rocha, 1991),

in other chakan (also expected to occur in D. puuc) seem to but have been rarely reported cyclopoid be unique features. Sexual dimorphisms in post- genera. In Diacyclops, so far only D. dimorphus

D. maxillipedal legs are known to occur generally in Reid & Strayer, 1994, and to some extent virgi-

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1993a sexual in four resemble each other in three- nianus Reid, possess dimorphism species having the swimming legs, but in the segmentation of the segmented rami and identical spination and seta- leg 4 exopodite. Re-examination of males of D. tion ofthe swimming legs, the leg 1 basipodite with

membrane the bisetosus (Rehberg, 1880), D. bicuspidatus (Claus, a spine, a present on terminal two

1. andD. antennule has narrow ser- 1857) s. languidus (G.O. Sars, 1863) from segments (D. hispidus a

indications of dimor- XVI XVII Belgian localities revealed no rate membrane on segments and rather

the phic ornamentation on the post-maxillipedal legs. than only on XVII as reported by Reid, 1988),

because of of the and However, descriptions cyclopoids are exopodite seta antenna present, no re- generally based on female morphology, other ex- ductions in the mouthparts. However, D. hispidus

with amples of modified setae in male natatorial legs and D. bernardi are relatively robust, the

in of or the relation- may have been overlooked. As will be seen the antennule 16 17 segments, length description of M. chaci, in males the distalmost ships of the terminal caudal setae different and the

be different in caudal setae much more elabo- endopodal setae may quite length relatively shorter,

the 1-4 from the corresponding structures of the female. rate ornamentation on antenna and legs

Dahms & Fernando (1993) discovered sexual di- basipodites, stouter swimming legs with robust morphisms in the shape and length of several spines and relatively short setae, and the distal

1-4 spines and setae on the post-maxillipedal legs of margins of the legs couplers more developed,

Mesocyclops leuckarti, although not at the same the leg 4 coupler ofD. bernardiwith two dentiform much Dia- locations as in D. chakan and M. chaci. processes, and the leg 5 spine longer.

ofthe known has the medial surface of the cau- Few species genus Diacyclops are cyclops hispidus from tropical regions, and records from the neo- dal ramus ornamented with tiny spines. Diacyclops tropics are scarce. Only D. bernardi (Petkovski, bernardi has a tendency toward reduction of the

1986) has been previously recorded from Mexico, number ofsegments ofthe antennule, having 17 or from a pond near Mérida, State of Yucatán (Reid, more usually 16 (Reid, 1993b).

The feature in D. chakan and D. that is 1993b). The same species is also known from Isla only puuc

animals is San Andrés, Colombia, and from Louisiana, south- more usual in benthic than in planktonic

the & ern U.S.A. (Petkovski, 1986; Reid, 1993b). Diacy- 11-segmented antennule (Reid Strayer, clops hispidus Reid, 1988 was collected near the 1994). The reduced antennule supports an hypo-

of that both derived Pacific coast Colombia, and a similar, as yet un- thesis Diacyclops are from some described species from northeastern Brazil (Reid, benthic ancestor resembling D. bernardi and D.

Dussart & two indicate that D. unpublished data). Defaye (1985) gave hispidus. However, arguments

record of the from chakan and share ancestor a European D. bisetosus Cuba, D. puuc may a common

with the of which was repeated by Reid (1990), but this record a planktonic species. First, presence

atavistic remains of articulations in is in error (B. Dussart, in litt, to J.W. Reid). Marten segments III,

and in several of chakan et al. (1994) reported a single unidentifiable cope- VII VIII specimens D. podid of Diacyclops sp. from Honduras. Diacy- lead us to suppose that the 11-segmented antennule

and 16- clops bernardi, D. hispidus, D. bisetosus all was derived directly from a or 17-segmented have the antennule of the female of 16 or 17 seg- antennule. The second indication may be the rela-

two antennule of both which ments, among other differences from the new tively long species, species. reaches the middle of the second thoracic somite.

We infer from the collection information that In most interstitial species (Reid & Strayer, 1994)

crevicular and in such D. lan- both D. chakan and D. puuc are benthic European hypogean species as species. Because of our present poor understanding guidus s. 1. and D. languidoides (Lilljeborg, 1901)

it is rather 1. antennule of the systematics ofDiacyclops, chancy s. (F. Fiers, personal observations), the to speculate about their possible closest relatives. does not reach beyond the posterior margin of the

benthic The two neotropical species D. hispidus céphalothorax, being usually only as long as 2/3 of andD. bernardi may share a common ancestor with the céphalothorax length. the two Diacyclops species described here. These Wilson (1936 and in Pearse & Wilson, 1938) re-

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USNM and 30+ USNM 271864. - Site ported Mesocyclops leuckarti from (respectively) 271861, copepodids,

description and additional copepod fauna: see under D. chakan. 27 and 10 cenotes and other localities near Mérida (2) Mayan Blue Cenote, anchialine cave located 3 km south of má in Yucatán. The new Diacyclops Mesocyclops the village of Tulum Pueblo (Quintana Roo). Coordinates as well as M. reidae and (more sporadi- species, 20°11'38"N, 87°29'50"W. Mayan Blue is part of the 18.5 km cally) M. longisetus var. curvatus Dussart, 1987 long cave system Systema Naranjal. Primary orientation of the

to that it be distributed in the cave is perpendicular the coast, suggesting serves as a appear to widely cenotes near major drainageconduit to the sea. Cave passages are predomi- Mérida. It is likely that Wilson misidentified some nantly developed at the halocline in 17 m water depth, where or all of them as M. leuckarti, which was at that mixing corrosion between fresh and salt water occurs. Salinity time defined and to be cosmo- less while poorly presumed of water above the halocline averages than 2%o, politan. below the abrupt halocline, salinity is 35%o. Sample taken with

plankton net from water column in 10-20 m depths of cave

interior. Sample 94-025B, leg. T.M. lliffe, 16 August 1994:

3 copepodids, USNM 271860. - Additional copepods: diapto- Genus Mesocyclops G.O. Sars, 1914 mids, 1 misophrioid.

(3) Najarone Cenote, Tulum (Quintana Roo), anchialine cave

located 3 km south of Tulum Pueblo. Coordinates 20°12'01"N, Mesocyclops yutsil Reid, sp. n

87°30'01"W. This cave is situated upstream (farther inland) (Figs. 11-15) from Mayan Blue and is also part of the Systema Naranjal.

from the Chac's Room is a large dome room 450 m into the cave

- Suárez-Morales Synonymy. Mesocyclops sp. A, et al., 1996: entrance pool. Sample taken with plankton net from water co-

131-132, figs. 37-39. - ? Mesocyclops leuckarti Claus, 1857 of: lumn in 16-18 m depths ofcave interior and 6-10 m depths of Wilson, 1936: 82, 85-88 (partim); Pearse & Wilson, 1938: 153 Chac's Room. Sample 94-027, leg. T.M. Iliffe, 20 August 1994: (partim). Mesocyclops cf. yutsil, 1 9 copepodid stage V (poor condi-

tion), USNM 271859. - Additional copepods: marine cyclo-

Type-specifications. - 9, USNM 259843; allotype Holotype poids, harpacticoids.

USNM 259844, each dissected on 1 slide in PVL, from Cf, (4) 27 Steps Cenote, Akumal (Quintana Roo), coordinates

Yuncu Yuncu 15-30 m, 93- Cenote, (Yucatán), depth sample 20°24'21"N, 87°19'39"W, a cave about 1.5 km west of main

T.M. 10 1993. 1 dissected 046, Iliffe, Paratypes: 9 on at ofa 30 m 20 m wide leg. July > highway Akumal, consisting long by by slide, USNM 259845, and 3 9 9,1 a and 20 copepodids, of the 8 m deep sinkhole with a pool along the undercut edges

USNM 259846, 93-046. - Site and addi- and three off under The far sample description pool passages leading water. pas- tional fauna: under D. chakan. extends 12 diameter air-filled dome copepod see sage to a m room con-

Noc Ac Cenote, a freshwater cave located 1 km south ofthe taken from surface water in air taining many tree roots. Sample

of village Noc Ac (Yucatán), 4 9 9,1 o\ 4 copepodids. dome at 0-5 m depth. Sample 95-021, leg. T.M. Iliffe, 27 July

Coordinates 21°04'45"N, 89°43'15"W. A circular, 4 m diameter 1995: 1000+ (mainly copepodids), USNM 264232. - Additional sinkhole entrance drops 3 m vertically into a clear pool, 3 m or copepods: Mastigodiaptomus texensis (M.S. Wilson, 1953), more deep. The rock surrounding the entrance sinkhole is 100+ (mainly copepodids, nauplii), USNM 264233.

to form at water Gruta Tzab-Nah (or Tecoh 2 km undercut a room 22 m long by 14 m wide level. (5) Dzab-Nah), (Yucatán),

south of the of Tecoh the road to Detrital organic matter and large breakdown boulders cover village on Telchaquillo; of Coordinates 20°44'50"N, most of the bottom. At opposite ends of the pool, segments of entrance is 100 m east road.

89°28'40"W. A in the leads to the cave continue down over breakdown to 35 and 21 m depths, walking passage cave a bridge but found. fish across a 7 m chasm with a lake at the bottom, then no passage development was Numerous are deep past

several fissure a 30 m diameter lake. Under present in all sections of the entrance pool. Sample taken with deep pools to water,

the bottom of the lake down to 20 wide plankton net at 10-15m depths. Sample 93-044,leg. T.M. Iliffe, sandy slopes a m

submergedcave entrance at 15 m depth. This underwater 7 July 1993, USNM 259847. - Additional copepod fauna: sub- pas-

of solutional origin continues for 130 m to 33 m depth species of Tropocyclops prasinus s. 1., 1 9, USNM 278026; sage

where it ends. While the water in this section of the marine cyclopoids, harpacticoids, misophrioids; other crusta- abruptly

cave is exceptionally clear, other pools in the cave are murky cean fauna: isopods (Creaseriella anops) and shrimp (Typhla- with a thick scum at the surface, apparently from liquid organic tya sp.), collected from the deeper waters in darkness.

wastes from a processing plant. 2 nearbyhenequen (sisal) Sample Mucuyché Cenote, Mucuyché (Yucatán), 9 9,2 copepo- collected with plankton net from water column of last lake at dids, depth 20-30 m, sample 93-045, leg. T.M. Iliffe, 9 July T.M. Iliffe, 27 June 1991: 0-6 m depths. Sample 91-021 A, leg. 1993, USNM 259848. Site description and additional copepod

- fauna: 4 Ç 9 and 1 cr, USNM 274244. Additional copepod fauna: see under D. chakan.

Mesocyclops chaci, see below; and crustacean fauna: ostra-

codes, Creaseriella thermosbaenaceans. anops, Additional material. -

(1) Yuncu Cenote (Yucatán), depth 0-5 m, sample 94-023, leg.

1 - of T.M. Iliffe, 13 1994: 72 9 9,1 o 38 Description of female. Lengths (|xm) holotype, August , copepodids,

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11. n., a, Noc Ac Cenote, USNM 259847; b—f, Yuncu Cenote, USNM 259843: Fig. Mesocyclops yutsil sp. paratype ￿, holotype ￿,

somite 5 and double and anal somite and a, habitus, dorsal; b, pedigerous genital somite, ventral; c, copulatory pore pore canal; d,

caudal anal somite caudal ramus, dorsal; e, and ramus, ventral; f, leg 5.

590, of 4 paratypes from Yuncu, 536, 568, 590, eral margins of pedigerous somite 4 rounded. Pedi-

of 3 females from Noc of somite 5 without surface 612; Ac, 588, 592, 612; gerous ornament except 1 female from Mucuyché, 608. (Some individuals pair of dorsal sensilla. Genital double somite (Fig.

each from cenote partly decomposed, not measured). lib) slightly longer than wide, anterior 2/3 ex-

Habitus (Fig. 1 la) in dorsal view slender, posterolat- panded; without visible surface ornament except

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12. n., a—d, f, Yuncu Cenote, USNM 259843; e, Yuncu Cenote, USNM 259845: Fig. Mesocyclops yutsil sp. holotype ￿, paratype ￿,

antennule; b, antenna antenna mandible. a, antenna; c, basipodite, caudal; d, basipodite, frontal; e, labrum, frontal; f,

pair of sensilla near posteroventral border. Seminal late. Anal somite (Fig. lid, e) naked except for

dorsal of dorsal and receptacle (Fig. lib) with rounded anterior and pair of sensilla, pair pores, row

of small posterior expansions; lateral arms broad; copula- spines on posteroventral margin above tory pore slightly sclerotized, pore canal (Fig. 1 lc) each caudal ramus; anal operculum wide, slightly

curved from unsclerotized. Caudal ramus short, broad, dorsally pore. Hyaline crescentic, (Fig. 11a, borders of urosomites (Fig. 11a, b) weakly crenu- d, e) 3.0 times longer than wide; medial surface

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13. n., Yuncu Cenote, USNM 259843: a, maxillule; b, maxilla; c, Fig. Mesocyclops yutsil sp. holotype ￿, maxilliped.

ornamented with few at 14. Narrow membrane naked; only tiny spines ment serrate hyaline on seg- base of lateralmost terminal caudal seta. Lateral ments 16 and 17, on segment 17 extending from seta inserted at posterior third of ramus. All caudal midlength seta to distal end of segment.

with fine of dorsal setae plumage, plumage seta Antenna (Fig. 12b-d) of 4 segments. Basipodite of sparse. Lengths caudal setae of holotype (um): with 3 setae, exopodite-seta long. Endopodite seg- lateral dorsal 2 with 8 anterior in 40, 92, lateralmost to medialmost ter- ment setae on margin most minal 35, 145, 292, 51. Dorsal caudal seta of specimens, holotype and 1 female from Noc Ac

Noc Ac with 1 paratypes from (Fig. 11a) inserted slightly additional proximal seta on antenna; another more anteriorly on caudal ramus than in female fromNoc Ac with 9 setae on both antennae.

Yuncu Small surface of in populations from and Mucuyché, and rela- spines on basipodite arranged

but still than lateralmost tively shorter, longer ter- basic pattern for Mesocyclops (cf. Van de Velde, minal caudal seta. 1984a, 1984b), except 3 longitudinal rows along

Antennule (Fig. 12a) of 17 segments, reaching posterior surface each composed of relatively few

distal of just past margin pedigerous somite 2 or to spines; additionally, 2 distal groups of 2-3 tiny mid-pedigerous somite 3. Segments (Roman nu- spines.

with number of merals) setae (Arabic numerals), Labrum (Fig. 12e) with 18 or 19 tiny teeth be- spines and aesthetascs in parentheses: I (8), II (4), tween little developed rounded lateral corners, and

III IV V VI 2 of hairs frontal surface. (2), (6), (3), (1+spine), VII (2), VIII groups long on

(1), IX (1), X (0), XI (1), XII (1+aesth.), XIII (0), Mandible(Fig. 12f), palp with normal 2 long and

IX XV XVI XVII 1 (1), (2), (2), (7+aesth.). Aesthe- short setae; surface otherwise unornamented ex-

on 12 distal end of of hairlike distal tasc segment reaching past seg- cept row spinules near teeth.

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USNM 259847: Fig. 14. yutsil sp. n., a—c, Yuncu Cenote, USNM 259843; d—f, paratype Noc Ac Cenote, Mesocyclops holotype ￿, ￿,

1 and 2 3 and of 1 and a, leg coupler, frontal; b, leg coupler, caudal; c, leg coupler, caudal; d, proximal part leg coupler, frontal; e, leg

2 coupler, frontal; f, leg 3 coupler, frontal.

Maxillule (Fig. 13a), palp lacking spines on sur- distalmost seta of precoxa long, plumed.

of Maxilla face; armament coxa, precoxa and palp normal (Fig. 13b) slender with attenuate ap- for thinner without of genus except appendages longer and pendages; coxa spines on surface; claw

in mid- than usual Mesocyclops (cf. M. leuckarti, as re- basis with row of slender "teeth" along about described by Dahms & Fernando, 1993), and next dle third of length.

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15. n., a, Yuncu Cenote, USNM 259843; b, Ac Cenote, USNM 259847; Fig. Mesocyclops yutsil sp. holotype ￿, paratype ￿, Noc c, d, allotype ￿, Yuncu Cenote, USNM 259844; e, paratype ￿, Yuncu Cenote, USNM 259847: a, leg 4 and coupler, caudal;b, leg 4

and anterior with and of coupler, frontal; c, posterior prosome urosome legs 5 6, right lateral; d, antennule; e, semi-diagrammatic view part of antennule segment I showing normal complement of aesthetascs.

Maxilliped (Fig. 13c) slender, basis rather short; Swimming legs 1-4 (Figs. 14a-f, 15a, b) all with setae long, attenuate; rows of small spines on coxa 3-segmented, slender rami; terminal segments of and with 3 with 3 and basis, basis transverse rows of spines exopodites 2, 3, 3, spines 4,4,4,4 setae,

surface. No visible. along outer respectively. pores Exopodite spines

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flexible slender, spines of leg 1 with whiplike tips; 592; of paratype from Yuncu, 532; of paratype

these tips longest in specimens from Mucuyché from Noc Ac, 588 (extended in lactic acid).

Yuncu. Terminal of of and spines endopodites legs Habitus and appendages as female except for

1-3 slender, nearly as long as terminal 2 segments normal sexual dimorphism in antennule, urosome

Most than and and combined. setae as long as or longer leg 6, as follows.

with rami, thin whiplike tips; tips of setae of leg 1 Antennule (Fig. 15d, e) geniculate, of 16 seg-

bare, completely plumed in legs 2-4. Couplers of ments. Segments 1, 4, 9, and 13 of both antennules

all legs without surface ornament; in specimens each with 1 aesthetasc in both males from Yuncu.

from Yuncu, distal margins of couplers of legs 1-3 Paratype from Noc Ac with normal complement of

each with 2 rounded aesthetascs slightly expansions, expan- on both antennules, specifically with 3

sions of 3 4 with aesthetascs leg most pronounced; leg coupler on segment 1 (Fig. 15e).

2 directed small medially dentiform expansions. In Antenna endopodite segment 2 with 7 setae on

specimens from Mucuyché and Noc Ac, paired ex- anterior margin in both males from Yuncu; with 8

of 3 pansions more developed, expansions leg as setae in male from Noc Ac.

well as of leg 4 acute. Leg 1 with plumed spine on Leg 6 (Fig. 15c) consisting of small bare plate

medial expansion of basipodite; in Mucuyché and bearing long dorsal seta and 2 shorter spiniform

Yuncu specimens, this spine extremely slender, setae, these subequal in length.

end reaching past distal of endopodite segment 2;

- is in Noc Ac specimens, this spine slightly stouter, Etymology. The species named yutsil, meaning

to distal end of beautiful in for the at- reaching nearly endopodite seg- or graceful Mayan, striking

of in ment 2. Legs 2 and 3 similar except leg 2 slightly tenuate aspect its appendages; proposed appo-

larger and segments of rami stouter; in holotype, sition.

spine on leg 2 exopodite 1 directed posteriorly like

3. Discussion and comparisons. - Mesocyclops yutsil corresponding spine on leg In paratype speci- is discussed together with the following mens from all cenotes, spines on first segment of species,

1 2 extended M. chaci. exopodites of legs and laterally; some

slightly rotated; this extension and rotation more

noticeable in leg 2. Leg 4 coxopodite with several chac Mesocyclops iFiers, sp. n of rows spines on posterior surface; medial expan- (Figs. 16-21) sion of basipodite bare. Leg 4 endopodite terminal

segment 4 times wider than long; terminal spines - Suárez-Morales 1996: Synonymy. Mesocyclops sp. B, et al., slender, longer than segment, each finely spinulate 133-134, figs. 40-42. - ?Mesocyclops leuckarti Claus, 1857, of both along most margins; lateral terminal spine of: Wilson, 1936: 82, 85-88 (partim); Pearse & Wilson, 1938: about 1.2 times longer than medial terminal spine. 153 (partim).

Setae of this segment reaching past ends of termi- - Type-specifications. Holotype 9, dissected on three slides in nal spines in Mucuyché and Yuncu specimens, not glycerine, COP 3813a, b, c. Allotype cr, dissected on three to of Noc Ac quite ends terminal spines in speci- slides in glycerine, COP 3816a, b, c. Paratypes: 3 9 9, dis-

mens. sected, mounted in glycerine (COP 3812a, b; COP 3814a, b, c

and COP Leg 5 (Fig. lib, f), basal segment broad, distinct 3815a, b, c); 32 9 9,2 cr cr, 13 copepodids, COP 3811 and COP 3817. from lateral somite, bearing long seta; distal seg- Type locality: permanently covered well with diameter of ment with long plumed terminal seta and shorter, 1.5 m and depth 8 m, containing 0.5 m water, at Cheuman finely serrate slender spiniform seta which is in- (Yucatán), on the road from Caudel to Sierra Papacal, about 12

serted at distal third of medial margin of segment. km N.W. from Mérida. Coordinates 21 °03.859'N, 89°42.288'W.

Leg 6 (Fig. 11a) consisting of small bare ovoid Leg. F. Moravec, CINVESTAV-IPN (Mérida). Topographic

Tizimin subterráneas with map: F 16-7, Aguas (27-8-83) indicates a plate 2 small spines and 1 long dorsal seta. chlorinity of 213.0 mg/1. Egg sacs not present on any specimen examined.

Additional material. -

of male. - Description Lengths (jim) of allotype, Gruta Tzab-Nah, Tecoh (Yucatán), sample 91-021A, leg. T.M.

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16. chac n., a, COP 3814;b, e, COP 3812; c—d, f, COP 3813: a, habitus, Fig. Mesocyclops isp. paratype ￿, paratype ￿, holotype ￿, d, f, field. dorsal; b, abdomen, dorsal; c, abdomen, ventral; leg 5; e, leg 6; genital

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17. chac COP of Fig. Mesocyclops i sp. n., a, e, f, paratype ￿, COP 3814; b—d, g, h, allotype ￿, 3815: a, antennule; b, contour

anterior side of of of antennule of and XVII antennule; c, segments VIII to XIII antennule male; d, segment Iof male; e, segments XVI

of antennule of third of 3 of third of 4 male. female;f, antenna, frontal side; g, exopodal segment leg male; h, exopodal segment leg of

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USNM 274244. - Site Iliffe, 27 June 1991: 4 9 9,1 er, denticles and situated only in distal halfof segment description and additional copepod fauna: see under M. yutsil. (Fig. 17e).

Antenna (Fig. 17f) 4-segmented; basipodite with

Description of female. - Length of holotype 730 1 long exopodal seta and 2 medial setae. Frontal

to 730 in surface of with 1 cluster of 17 Um, ranging from 710 |am paratypes. basipodite (Fig. 18h)

with lat- in and Habitus (Fig. 16a) slender in dorsal view narrow spinules middle 3 minute spinules on eral edges of pedigers 3 and 4 slightly posteriorly proximal third of outer margin. Inner proximal

1 of Caudal produced. Pediger 5 without surface ornament, ex- third with oblique row tiny spinules.

for usual 2 sensilla. with 2 short distal cept dorsal Eye present, unpig- side of basipodite (Fig. 18g)

± drawn and 5 and 2 mented(specimens fixed in 4 % formalin, spinule groups (6 spinules) proximal

to outer only few days later). Genital double somite (Fig. spinule groups (3 and 7), parallel margin.

16b, c) wider than long (LAV ratio: 0.77 : 1). Poste- Inner margin with 3 minute spinules on proximal

abdomi- third. Second with 1 and third rior margins of genital double somite and segment seta seg- nal somites each with weakly incised hyaline fringe. ment with 9 (8 attenuated) setae. Segment 4 with 7

4 of these Seminal receptacle (Fig. 16f) with rounded ante- distal setae, attenuated distally.

of rior and posterior expansions; lateral arms broad, Mandible (Fig. 18a) with normal complement nearly perpendicular to longitudinal body axis; 2 long and 1 short setae. Gnathobasis surface smooth

bit- sclerotized with for 1 short row of narrow near copulatory pore straight, broad, except spinules

lateral canal posteriorly directed pore canal; arms ing edge. distinctly thicker in medial third. Anal somite Maxillule (Fig. 18b) without ornament on sur-

Armament of and smooth except for pair of dorsal sensilla, pair of face of palp. praecoxa, coxa palp of ventral and row of minute normal for setae attenuated. pores, spines along post- genus, except palp eroventral margins. Anal operculum wide, weakly Maxilla (Fig. 18f) somewhat broader than in M. crescentic, unsclerotized. yutsil. Proximal endite with 2 long (50 (im) plu-

times endite set with Caudal ramus (Fig. 16b, c) 3.10 longer mose setae. Median densely spi- dis- than wide, without ornament (length 67 fini). Lat- nules along stem (distal part broken in the 3

armed with narrow teeth eral seta inserted at posterior third of ramus. All sected females). Claw

from median third caudal setae finely plumed except for smooth dor- to distal tip. Two-segmented

with 2 slender setae and 3 sal seta in holotype. Lengths of holotype caudal endopodite (Fig. 18e, f) smooth. setae (um): lateral 30, dorsal 55, lateralmost to long attenuated setae, all setae medialmost terminal 40, 219, 323, 57. Holotype Maxilliped (Fig. 18c, d) with 3 curved rows of with aberrant median terminal seta on right caudal slender spinules on caudal side of second segment.

median Frontal ramus (shorter than outer one). Inner ter- surface of first and second segments orna-

of Setae attenu- minal seta slightly bulbousjust distally frombreak- mented with groups narrow spines. of ing plane. ated, with whiplike tips except for median seta

1 4. Antennule (Fig. 17a) of 17 segments, reaching segment and distalmost seta of segment posterior edge of second pedigerous somite (Fig. Legs 1-4 (Figs. 19a-d, 20a-i) with 3-segmented

of 1 and 2 robust than slen- 16a). Segments (Roman numerals) with number of rami; aspect legs more

Terminal of setae (Arabic numerals), spines and aesthetascs in der legs 3 and 4. segments exopodites

V 3 and 4 parentheses: I (8), II (4), III (2), IV (6), with 2, 3, 3, spines 4, 4, 4, setae, respec-

of and 3 (1+spine), VI (2+spine), VII (2), VIII (1), IX (1), X tively. Spines on exopodites leg 2 leg more

of (0), XI (1), XII (1+aesth.), XIII (1), XIV (1), XV robust than in M. yutsil, and spines leg 1 exo-

with at most half as (2), XVI (3), XVII (7+aesth.). Aesthetasc on seg- podite flagellum-like tip, long

of 1 ment XII reaching far beyond segment XIV. Seg- as in M. yutsil. Medial basipodite spine leg

with ment I with transverse row of slender spinules. flagellum-like tip, not reaching distal margin

rami Hyaline membrane on segment XVI finely dentic- of second endopodal segment. Setae on leg 1

naked slender ulate and only half as long as segment. Hyaline attenuated; tips, however, not as as Distal third membrane of segment XVII with slightly larger in M. yutsil. spines on endopodal seg-

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chac Fig. 18. Mesocyclops isp. COP 3814; d, COP 3812; e—h, COP 3813: n., a—c, paratype ￿, paratype ￿, holotype ￿, a, gnathobasis

of maxillar mandible;b, maxillule; c, maxilliped, caudal; d, maxilliped, frontal; e, endopodite;f, maxilla; g, antenna basipodite, caudal;

h, antenna basipodite, frontal.

19. Fig. chac n., COP 3814: a, 1; b, 2; c, 3; d, 4 ornamentation in bd not drawn, all Mesocyclops isp. paratype ￿, leg leg leg leg (setal

illustratedin frontal view).

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20. chaci COP 3812: 1 b, 1 c, 2 d, 3 Fig. Mesocyclops sp. n., paratype ￿, a, leg coxopodite; leg coupler; leg coxopodite; leg coxopodite;

illustrated caudal e, leg 2 coupler; f, leg 3 coxopodite; g, leg 3 coupler; h, leg 4 coxopodite; i, leg 4 coupler (all in view).

of 2 and of short 4 ments leg leg 3 as long as supporting seg- proximal row spinules. Leg coxopodite

ments. Distal spines of leg 4 terminal endopodal (frontal) with some minute spinules perpendicular

lateral in COP and 2 segment about 2/3 segment length, subequal in to margin (not visible 3812)

length, inner one with distinct twist in proximal rows along distal margin. Caudal (Fig. 20h) sur-

4 in third. Terminal endopodal segment of leg 4, 3 face of leg coxopodite as preceding legs ex-

times as long as wide, with inner setae reaching not cept for additional row of slender spinules near

quite to ends of distal spines. Frontal surface of leg outer margin. Couplers of leg 1 (Fig. 20b) and leg 2

1 coxopodite with 5 long slender spinules along (Fig. 20e) with rounded expansions, expansions of

3 and 4 outer margin and 2 short rows of minute spinules leg (Fig. 20g) leg (Fig. 20i) acute.

with rather slender basal along distal margin. Caudal surface (Fig. 20a) with Leg 5 (Fig. 16d) seg-

4 distinct from slender spinules near outer margin and short row ment, somite, bearing long lateral

of minute spinules in middle of distal margin. seta. Distal segment twice as long as wide, bearing

Coxopodites of leg 2 and leg 3, frontally, with 1 plumed terminal seta (50 |im) and long serrate

row of slender spinules along outer margin and spiniform seta (nearly 70 (im), implanted at distal

with 2 rows along distal margin. Caudal surfaces of 3/4 of medial margin of segment.

leg 2 and leg 3 coxopodites (Fig. 20c, d, f) orna- Leg 6 (Fig. 16e) present as small plate with 2

mented with oblique row of long and slender spi- short equal spines and 1 long plumed seta.

nules near outer margin and with median distal and Egg sacs containing 6 to 8 eggs.

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21. chaci COP 3815: Fig. Mesocyclops sp. n., allotype ￿, a, habitus, dorsal; b, abdomen, dorsal; c, abdomen, lateral; d, abdomen, ventral.

Description of male. - Lengths of allotype, 660 3 aesthetascs; segments IV, VIII and XII each with 1

Um, of paratypes: 655 and 660 aesthetasc.

in for Habitus (Fig. 21a) as female, except normal Legs as in female, except for proportional lengths sexual in and 6. medial of dimorphism antennule, urosome leg of spines of third exopodal segments leg

Antennule (Fig. 17b-d) geniculate, 15-segmented; 3 and leg 4, specifically (L spine/ L segment) 1.33 first segment (Fig. 17d) with normal complement of in leg 3 (Fig. 17g) and 1.20 in leg 4 (Fig. 17h).

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for several African Plumage of all setae and attenuation of leg 1 spines de Velde (1984b) species. and setae as in female. However, this spine orientation is undependable

fixed Leg 6 (Fig. 21c, d) consisting of unornamented for genus diagnosis, as every specimen may and the lateral of plate bearing 1 long dorsal seta, 1 shorter median not show it, more proximal spines 1-3 sometimes extend in of seta and 1 spiniform ventral seta. legs laterally species bernardi other genera, e.g. Diacyclops (cf. Reid,

Etymology. - The species is named after the Mayan 1993b) and D. hispidus (cf. Reid, 1988).

in the deity Chac, the ubiquitous patron of lightning and Mesocyclops chaci resembles M. yutsil at- rain. tenuated setae on the mouthparts and leg 1, the

slender shape of legs 3 and 4, and the short termi-

Discussion and comparisons. - Present diagnoses nal segment of the antennule. These features easily

the and Ther- both from other Be- of genera Mesocyclops, Diacyclops, distinguish species congeners.

sides details of the on the mocyclops differ very little, sometimes rendering spinule patterns coxopo-

the assignment of species problematic (Reid, 1993b). dites of the legs and basipodite of the antenna,

M. chaci M. Many species of Thermocyclops and a few of Dia- is easily distinguishable from yutsil by

and with the robust of cyclops are planktonic slender, attenuate the larger body shape, aspect leg 1, appendages similar to those of M. yutsil. However, and the distinctly longer medial serrate seta of leg

here the in M. is half the M. yutsil and M. chaci are assigned to ge- 5, which yutsil only as long as

the nus Mesocyclops because of the placement of distal seta. other of spiniform seta of leg 5, medially rather than sub- Four neotropical species Mesocyclops

in with and M. terminally on the distal (exopodite) segment, as share several key characters M. yutsil 1 Diacyclops and Thermocyclops. Also, no species of chaci, as listed by Dussart (1987): leg basipodite

Thermocyclops has triangular dentiform projec- with a spine, leg 4 coupler with two dentiform tions 4 with horizon- on the leg coupler, although several have processes, seminal receptacle nearly

of and caudal short rounded ones (Herbst, 1986). The spine patterns tal lateral arms, ramus relatively than M. rei- the antennule basipodite are similar in these three (about 3 times longer wide). These are

of the dae, M. intermedius M. Kiefer, genera, but the pattern two new species most Pesce, 1985, ellipticus resembles that of Mesocyclops (cf. Fiers & Van de 1936, and M. paranaensis Dussart & Frutos, 1986.

Velde, 1984; Van de Velde, 1984a, b). Mesocyclops ellipticus, which has been confused

of and be restricted to northern The proportions of antennule segment XVII with M. reidae may the female have been used to discriminate between South America (Petkovski, 1986), M. intermedius,

in and M. Mesocyclops and Thermocyclops. In previously known from groundwater Bonaire, para-

is about from Para- known Mesocyclops species, this segment naensis, a planktonic species Brazil,

differ from both 3-5 times longer thanbroad, and in Thermocyclops guay and northern Argentina, it is about 2 times longer than broad (Reid, 1985; Mesocyclops species described here in having the

lateral the rami based on personal communication to J.W. Reid pediger 5 with spines, caudal from J.F. Saunders III, 1984, and J.W. Reid, per- haired along the medial surface, and the medial-

than 2.5 times sonal observations). In M. yutsil and M. chaci, the most terminal caudal seta more only known exceptions to this rule, segment XVII longer than the lateralmost terminal caudal seta is short, only about 2.3 times longer than broad. (Dussart & Frutos, 1986; Kiefer, 1936; Pesce,

Dahms & Fernando (1993) and Kiefer (1981) 1985). noted the lateral extension and rotation of the lat- A close ancestral relationship between M. yutsil eral in and chaci M. spine of leg 2 exopodite segment 1 some M. and reidae, a small, stout, mainly

of that is in the Antilles species Mesocyclops. This is apparently a gen- epibenthic species common eral feature of the is and Central America into southern is eas- genus (Kiefer, 1981). It pres- Mexico,

has the 5 ent in M. yutsil, M. longisetus var. curvatus, M. ily inferred. Mesocyclops reidae pediger reidae, and M. ruttneri Kiefer, 1981 (J.W. Reid, with stiff lateral spines, and the robust swimming

and is otherwise personal observations), was illustrated by Van legs that are normal in the genus. It

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remarkably similar to M. yutsil in the short medial- in the male antennule, at least in the Yuncu popula-

caudal with- most terminal caudal seta, the ramus tion.

the XVII is out hairs on the medial surface, the structure of the In M. reidae, antennule segment usu- seminal receptacle including details of the copula- ally about 3 times longer than broad (cf. Petkovski,

F. Fiers and tory pore and pore canal, the narrow, finely serrate 1986; Reid, 1993b; Yeatman, 1977; antennular hyaline membrane with the membrane J.W. Reid, personal observations). Smith & Fer-

the showed on segment 17 not extending proximally past nando (1978, 1980) a slightly shorter seg-

midlength seta, the simple antenna basipodite spine ment for “Mesocyclops ellipticus”, from Cuba;

of the that have been M. reidae pattern, the three transverse rows spines on however, population may

local basis of the maxilliped, and the paired processes of (Petkovski, 1986; Reid, 1990). Although

1-4 which this wells in the legs couplers, are always well devel- populations of species (from Quintana

94-012: oped in M. reidae and are more or less developed Roo: Mex 94-008, Mex 94-009, Mex see

in different populations of M. yutsil and M. chaci additional material of D. chakan) show a tendency

differ- reduce the number of V (Petkovski, 1986; Reid, 1993b). Consistent to segments as segments

ences betweenM. reidae,M. yutsil andM. chaci are and VI are partially fused, segment XVII still has

in the usual 1 the spines on pediger 5 which are always present length/width ratio of 3 : (F. Fiers, per-

M. reidae and apparently never in M. yutsil and sonal observations).

M. the short caudal ofM. takes intermediate chaci, dorsal seta reidae, Mesocyclops chaci clearly an

in the clade Within which is never longer than the lateralmost terminal position M. reidae-chaci-yutsil.

caudal seta, and the fewer (about 11) and larger this species clade we see a tendency towards re-

of of reidae duction of size and towards slender teeth the labrum M. versus the many body a more

tiny teeth of M. yutsil and M. chaci. Additional dif- aspect of the legs. Generally, Mesocyclops species

the short have robust with medial third ferences are stout leg 1 basipodite spine legs spines on the

ofM. reidae, which never reaches past midlength endopodal segments of the legs as long as the seg-

of endopodite segment 2, and the overall gracile ment (in leg 1) but distinctly shorter in legs 2 to 4.

form of of chaci of the intermedius still shows legs 3-4 M. and legs I—4 M Even small M. a normal yutsil, especially the whiplike extensions of some proportional spine length of 0.83 in leg 4. Mesocy-

and the There M. chaci and dis- setae spines on swimming legs. are clops reidae, M. yutsil, however,

slight differences in the antennal basipodite spine play a quite different picture, with a clear tendency

in which the ofthe the medial terminal patterns, spine rows and lengths to prolong endopodal spines,

spines become gradually shorter, including an ad- reduce body size, accentuate the attenuation of the

of distal the ditional distal and proximal group a few tiny parts of setae and spines of leg 1, and

M. which in In spines on the caudal side in yutsil com- shorten the terminal antennular segment (XVII).

parison with its two congeners shows the shortest Table I, the proportional lengths of the medial ter-

and It is clear from the that of spines rows. foregoing minal spines and body size the three species are

most ofthe morphological differences among these compared with those of M. leuckarti. The local

species are a matter of proportion, and a tendency Yucatecan populations of M. reidae have medial

toward reduction in body ornament and swimming terminal spines equal or slightly longer than the

leg coupler development in M. chaci and M. yutsil. segment (F. Fiers, personal observations). Mea-

far As as known, males of M. reidae have the surements of the medial terminal spines on leg 4 of

full normal complement of aesthetascs on the M. reidae illustrated by other authors (in most antennule (confirmed on two males from Chichen cases legs 1-3 were only partially ornot at all illus-

Itza, Yucatán, leg. G. Rodríguez-Almaraz, USNM trated) revealed that the foreign populations of this

264523, and on four males from El Progreso, Hon- species have significantly shorter spines in this leg,

G. G. from duras, leg. Marten, USNM 268020). The ranging 0.85 in Pesce (1985, as M. ellipticus)

same complement ofaesthetascs is displayed in the to 0.93 in Reid (1993b). Comparable proportional

M. the found in three males of chaci, but M. yutsil shows a ten- lengths of leg 4 spine are the descrip-

dency toward reduction of the aesthetasc number tions of M. paranaensis (Dussart & Frutos, 1986:

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Table I. Comparison of medial terminal endopodal spine length and body size of female in some species of Mesocyclops.

Length medial terminal endopodal spine / length segment 3

Body Leg 1 Leg 2 Leg 3 Leg4

length (um)

M. leuckarti1 1000-1153 1.00 0.71 0.86 0.92

2 M. reidae 800-1200 1.00 1.10 1.10 0.85-1.052

M. chaci 710-730 1.18 1.06 1.08 1.00

M. yutsil 536-612 1.52 1.41 1.32 1.29

2 'After Van de Velde (1984b). After Petkovski (1986), Reid (1993b), and F. Fiers, personal observations.

0.83; Lowndes, 1934:0.91), M. intermedius (Pesce, General discussion

1985: 0.86) and M. ellipticus (Kiefer, 1936: 0.94;

Dussart, 1984: 1.00), three species which share As discussed in the former paragraphs, morpho-

several key characteristics with the species clade logical similarities suggest close ancestral relation-

described here (see discussion above). ships betweenDiacyclops chakan and its local ben-

reidae lives Mesocyclops mainly in epigean thic congener D. puuc, and between Mesocyclops

habitats such as small waters and artifi- and M. chaci and the local benthic ephemeral yutsil congener

cial containers (Marten et al., 1994), ricefields M. reidae. The differences consist of some attenu-

& ation in in M. (Reid, 1993b), a lagoon (Smith Fernando, 1978, appendages (carried to an extreme

1980), and small ponds (E. Suárez-Morales, J.W. yutsil) and tendencies toward reduction in body

Reid & G. Rodríguez-Almaraz, unpublished data), and appendage ornamentation. We infer from col-

and also in habitats: the interstitial of hypogean a lection information that D. chakan, D. puuc, and

sandy riverbank (Pesce, 1985), springs (Petkovski, M. chaci are benthic crevicular living species and

1986), a cave (Yeatman, 1977, as M. ellipticus), that Mesocyclops yutsil inhabits large open spaces and dug wells (Pesce, 1985; present contribution). of the karst, at depths close to the surface.

With respect to their gracefully attenuate appen-

The collection information implies that M. chaci dages, M. yutsil and M. chaci (although M. yutsil

benthic M. is a crevicular species, while yutsil lives more than M. chaci)i strikingly resemble another sub-

in of the at close to terranean delamarei large open spaces karst, depths species, Kieferiella (Lescher-

the surface. As such it seems that M. yutsil shared a Moutoué, 1971; 1976), which is known from the

crevicular with M. saturated in France. living ancestor chaci, but zone of a karst system The ac- evolved for a planktonic existence in the Yucatán tual microhabitatof K. delamareiis not known. A

cenotes. It is as if the near ancestor of M. reidae, few specimens were taken from a spring and a

with a propensity to invade hypogean habitats, groundwater seep (Lescher-Moutoué, 1971), and evolved for an existence in from 60 well exclusively hypogean a many were pumped a m (Lescher- karstic environment. When the smaller karstic Moutoué, 1976). Several typically epigean benthic

cavities interstitial became and of the (crevices, etc.) larger planktonic cyclopoids genera Diacy-

through solution of the limestone, an entire new clops, Eucyclops, Megacyclops, Paracyclops, and environment became available for occurred in the latter hypogean spe- Tropocyclops sample

cies. It has been suggested several times that an- (Lescher-Moutoué, 1976). In contrast to the typical

cestral copepods were epibenthic, giving rise to facies of most interstitial cyclopines, which have

forms discussion planktonic (cf. by Huys & stocky wedge-shaped bodies and short reduced ap-

Boxshall, 1991). The hypothesized relationship be- pendages (Reid & Strayer, 1994), K. delamarei and

tween M. reidae, M. chaci, and M. yutsil serves as both Yucatecan Mesocyclops are slender, with at- another demonstration of this supposed sequence tenuated appendages such as are more usually

on the intrageneric level. found in planktonic species, although in these three

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of several of the species the degree of attenuation is extreme. Sig- cenote food webs. The presence

usual local in nificant diagnostic features of the genus Kieferiella epigean planktonic copepods some

member of the of the the of Lescher-Moutoué, 1976, a Mesocy- samples implies availability phyto-

the and/or detritus. The form of the clops-Thermocyclops-Diacyclops group, include plankton attenuate

K. and M. unusual elongation of the swimming leg rami, mouthparts of both delamarei yutsil sug-

of the that feed on or- setae and spines, the long setiform tips leg 1 gests they may chiefly particulate

in the exopodite spines, and the lack of aesthetascs in the ganic matter and possibly phytoplankton swim- antennuleof the male. Mesocyclops chaci and M. case of the latter species. The long slender yutsil share the former features, while M. yutsil ad- ming legs with their delicate setae may serve to

reduction in in the water with ditionally shows a tendency toward of maintain the animals position situation the number of aesthetascs in the antennule of the minimal expenditure of energy, in a

Because of be rela- male, at least in one population. both where rapid avoidance predators may

aesthe- Most cenote fishes feed Yucatecan Mesocyclops species do possess tively unimportant. upon

male antennule and the 5 benthic fauna and seem to tascs on the leg spiniform including copepods

avoid the of the cenotes seta inserted medially on the distal segment (rather central (illuminated) parts

& Plank- than subterminally as in K. delamarei, Thermocy- (Navarro-Mendoza Valdés-Casillas, 1990).

behaviorof be an clops, and Diacyclops) it does not seem appropriate tonic some cenote copepods may

to them to the to avoid assign genus Kieferiella. Another, adaptive strategy predators. of the 1 have possibly genus-level distinction is that in K. dela- The attenuate tips leg spines may other than swim- marei the next lateralmost terminal caudal seta is some function, possibly tactile,

shorter than the medialmost Short hairlike occur on reduced, equal or ter- ming. tips swimming leg

of both minal caudal seta. The leg 4 coupler of K. dela- lateral spines of some cyclopines plank-

tonic and rutt- marei has two rounded marginal expansions but is epibenthic habit, e.g. Mesocyclops

dussarti de otherwise unornamented (Lescher-Moutoué, 1971; neri (cf. Reid, 1993b), M. Van Velde,

M. Van de 1976). The terminal segments of the antennule of 1984b, and kieferi Velde, 1984b; and are

membrane well in the local of M. K. delamareilack a hyaline (J.W. Reid, demonstrated populations

personal observation). Because of its overall simi- reidae (F. Fiers, personal observations).

It for of to occur larity to the specialized M. yutsil, we speculate is unusual species Mesocyclops

whether the principal habitat ofK. delamareimight in hypogean and cave habitats. The only other con-

in the karst known exclusively from a cave environment be in large open spaces groundwater. gener from The similarities between K. delamarei, M. chaci is M. cuttacuttae Dumont & Maas, 1985

for northern Australia. and M. yutsil imply some function appendage Mesocyclops pilosus Kiefer,

small attenuation in the hypogean environment. Most 1930 was found in a cave and ponds on

and Aldabra species of Mesocyclops are omnivorous, tending Madagascar (Kiefer, 1930; 1981).

i.e. toward carnivory, with sturdy biting mouthparts. Each closely resembles local epigean species,

is usual for the There is considerable variation in types of cenotes within parameters genus (Dumont

& reidae lives in both depending on light input, benthic algae, phyto- Maas, 1985). Mesocyclops

and environments. The plankton, current patterns, and human impact. epigean hypogean com- North and Cen- Some cenote pools (e.g. Mayan Blue) are season- mon, normally epigean planktonic

with of water in tral American M. edax A. Forbes, 1891) has ally stratified a layer murky the (S.

been found in Mammoth 1-2 m clear waters. Cave, U.S.A. (Chappuis, upper overlying very Cope-

be in this and in interstitial sand of a partly dry pods appear to most numerous murky 1929)

streambed comm. to J.W.Reid, layer. In the caves, most troglobiotic species (my- (D.L. Strayer, pers.

sids, atyid shrimp, thermosbaenaceans, etc.) are 1994). Of course several Mesocyclops species

habitats such exclusively found swimming in the water column, commonly occur in semi-hypogean

where conditions suggesting that this is the location of their food as shallow dug wells, pondlike

well obtain source. Perhaps bacteria or protozoans as as apparently (cf. Kiefer, 1981; Pesce, 1985;

Van de it is that particulate organic matter may be involved in the Velde, 1984b). Although likely

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additional collections of Mesocyclops will be made line extended from Campeche to Maxcanu in the

modified the Sierrita de Ticul Peto in the from open waters in caves, strikingly spe- west; along to

M. be in the from Peto Chichen Itza and cies such as yutsil are to expected only northwest; to beyond unusual large subterranean pools developed in Valladolid in the northeast; and roughly 100 km

inland with the karst topography. parallel present Caribbean coast-

The three Mesocyclops species: M. reidae, M. line from east of Valladolid to Chetumal in the

in the central south- chaci and M. yutsil are considered here as a species south. Thus, contrast to and flock which have radiated as specialists within a eastern cenotes (those in the region above 30 m, highly dynamic geomorphological environment. including inland from Chetumal) where karstifica-

Lacustrine species flocks are defined as mono- tion continued, the karst processes were altered in

of three and sub- the northern and eastern karstic The fresh- phyletic groups or more species plain. species which are endemic to a particular lake, and water hypogean fauna within this area disappeared

known in Baikal and marine elements ther- are only for cyclopoids Lake was replaced by (e.g.

(Boxshall & Evstigneeva, 1994). Although the mosbaenaceans). definition refers particularly to lakes, the karstic After the sea retreated, percolating fresh water

and Yucatán plain can be considered as an immense (precipitation up to 1500 mm/yr subterranean subterranean water reservoir recharged annually water flow) refilled the old karst cavities and karst-

6 3 with 9,800 X 10 m of fresh water. It has beenesti- ification processes were reactivated. However, up mated that along only the 1,100 km northern coast- to the present time, saline waters still form the

6 3 X the and environ- line, 9,450 10 m of fresh groundwater is dis- deeper strata of water act as an

into the In this charged annually sea (Back, 1985). In mental barrier to subterranean dispersion.

and still become other words, it seems as if the Yucatán Peninsula is situation, populations could can

from each other drifting on a gigantic water lake extending through- rapidly and efficiently separated out its subterranean karstic topography. by fluctuations of the halocline, resulting in drastic

Large subterranean karstic cavities are only a reduction of genetic exchange. This geological his- transitional geomorphological phenomenon. When tory and suggested scenario explain the fact that karstification proceeds and the limestones erode populations of closely related species (such as M.

encountered in further, the typical cenote (from the Mayan word chaci and M. yutsil) can be geo-

Tz'onot or D'zonot, meaning well) is formed when graphically close localities (Cheuman is about 2

sink- km the roof of the cavern collapses, forming a from Noc Ac). hole. At that moment the entire physical and chem- ical situation of the water body is drastically al- Acknowledgements tered as it becomes exposed to epigean influences.

The entire fauna and flora changes rapidly, espe- We thank Dr. Harry C. Yeatman for helpful comments on early cially under the tropical conditions of these waters. figures of Mesocyclops yutsil. Prof. Silvina Menu-Marque's Specialists such as M. chaci and M. can no yutsil gift of specimens of Diacyclops michaelseni, Prof. Gabino

succeed in this and are longer particular place Rodriguez-Almaraz' and Dr. Gerald G. Marten's gifts of speci-

forms M. Lescher- replaced by primarily epigean such as mens of Mesocyclops reidae, and Dr. Françoise

Moutoué's of of delamarei the longisetus curvatus. gift specimens Kieferiella to United States National Museum of Natural History (Smith- Geological evidence indicates that the northern sonian Institution) permitted confirmation of important com- central plain (mainly of Mio-Pliocene with a age to parative characters. We are indebted Dr. Frank Moravec, nucleus ofEocene and two small lenses of Oli- age, visiting professor in the Parasitology Section ofCINVESTAV-

cf. IPN de Estudios Avanzados del In- gocène age, Lopez-Ramos, 1975; Weidie, 1985) (Centro Investigación y

stituto Politécnico Mérida, for collection and dona- was submerged by Pleistocene seas during the Yar- Nacional),

3 tion of several samples, permitting the discovery of Mesocy- mouth interglacial (170-220 x 10 Y. B.P.). At that clops chaci. The Department of Invertebrate Zoology, United time seas reached the highest level during the Pleis- States National Museum of Natural History provided research the tocene, about 30 m above present (Back, 1985; facilities to J.W. Reid. T.M. Iliffe's collections were supported & Van At that time the shore- Haq Eysinga, 1987). by National Science Foundation grants BSR-8215672 and BSR-

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8417494, the Texas A&M University at Galveston Research Dussart, B.H. & S.M. Frutos, 1986. Sur quelques Copépodes

Enhancement Program, and the Texas Institute of Oceano- d'Argentine. Revue Hydrobiol. trop., 18(4)" 1985": 305- graphy. James Coke, Michael Madden, John Pohlman, Brett 314.

Dodson, Dr. John Markham, Dr. Virginia Urbieta, Dr. Elva Fiers, F. & I. Van de Velde, 1984. Morphology of the an-

Escobar, Dinah Drago, and Juan José Fucat assisted T.M. Iliffe tenna and its importance in the systematics of the Cyclo- with collections. cave diving Logistical assistance was provided pidae. Crustaceana, Suppl. 7(2): 182-199. by the Centro de Investigaciones de Quintana Roo (CIQRO) in Forbes, S.A., 1891. On some Lake Superior Entomostraca.

Chetumal, the Universidad Autónoma de Yucatán (UADY) in Ann. Rep. U.S. Commnr. Fish Fisheries, 1887: 701-718,

Mérida, and the Universidad Nacional Autónoma de México Pis. I-IV.

(UNAM) Marine Laboratory in Puerto Morelos,Quintana Roo. Haq, B.U. & F.W.B. Van Eysinga, 1987. Geological time ta-

F. Fiers was offered the opportunity to make collections in ble (4th ed.). (Elsevier Science Publishers B.V., Amster-

Yucatán by the researchers of the Parasitology Section at dam).

CINVESTAV-IPN during his stays at the Mexican Institute in Herbst, H.-V., 1986. Beschreibung des Thermocyclops the framework of the marine hastatus antillensis mit einem European Community granted n. ssp. Bestimmungsschlüs- pollution project in the Gulf ofCampeche. F. Fiers honors also sel für die Gattung Thermocyclops Kiefer, 1927. Bijdr. the friendship and field assistance of the CINVESTAV-IPN Dierk., 56(1): 165-180. researchers, Joaquin Vargas, Miguel Herrera, Victor Ceja, and Huys, R. & G.A. Boxshall, 1991. Copepod evolution: 1-468 not least Thomas Sholtze, who was badly attacked by (Ray Society, London).

Africanized bees during the November 1993 field trip. We all Kiefer, F., 1930. Zur Kenntnis der freilebenden Copepoden felt his pain. Madagaskars. Zool. Anz., 87(1/2): 42^46.

Kiefer, F., 1936. Brasilianische Ruderfusskrebse (Crustacea

Copepoda) gesammelt von Herrn Dr. Otto Schubart. V. References Mitteilung. Zool. Anz., 116(1/2): 31-35.

Kiefer, F., 1981. Beitrag zur Kenntnis von Morphologie,

Back, W., 1985. Hydrogeology of the Yucatan. In: W.C. Taxonomie und geographischer Verbreitung von Mesocy-

Ward, A.E. Weidie & W. Back (eds.), 1985. Geology and clops leuckarti auctorum. Arch. Hydrobiol., Suppl. 62

hydrogeology of the Yucatan and the Quaternary geology (Monogr. Beitr.), 1: 148-190.

of northeastern Peninsula: Yucatan 99-124 (NOGS Publi- Lescher-Moutoué, F., 1971. Les cyclopides de la zone noyée

cations, University ofNew Orleans). d'un karst. II. Mesocyclops (Thermocyclops) delamarei

E.V. & M.E. 1957. Occurrence of Annls. 26: 473—479. Borutzky, Vinogradov, sp. n. Spéléol.,

the Ant- 1976. Les de la Cyclopidae (Acanthocyclops mirnyi, sp. n.) on Lescher-Moutoué, F., cyclopides zone noyée

arctic continent. Zool. Zh., 36(2): 199-203 (In Russian; d'un karst, III. Création du genre Kieferiella à la suite de

abstract in English). nouvelles observations sur l'espèce delamarei (Crustacé,

Boxshall, G.A. & T.D. Evstigneeva, 1994. The evolution of Copépode). Annls. Spéléol., 31: 91-98.

flocks of species copepods in Lake Baikal: a preliminary Lindberg, K., 1949. Contributions à l'étude des Cyclopides

analysis. In: Speciation in ancient lakes. Arch. Hydrobiol. (Crustacés Copépodes). K. Fysiogr. Sällsk. Lund Förh.,

Beih. Ergebn. Limnol., 44: 235-246. 19: 98-121.

1929. cavernicoles de 1975. of the Yucatan Chappuis, P.A., Copépodes l'Amérique Lopez-Ramos, E., Geological summary

du Nord (Note préliminaire). Bull. Soc. Sti. Cluj, 4(2): Peninsula. In: A.E.M. Nairn & F.G. Stehli (eds), The

51-57. ocean basins and margins, 3. The Gulf of Mexico and the

Claus, C., 1857. Das Genus Cyclops und seine einheimischen Caribbean: 257-282 (Plenum Press, New York, London).

Arten: 1-40, Taf. I—III (Inaugural-Dissertation, Marburg). Lowndes, A.G., 1934. Results of an expedition to Brazil and

Dahms, H.-U. & C.H. Fernando, 1993. Redescription of Paraguay in 1926-27. Copepoda. J. Linn. Soc. Lond.,

Mesocyclops leuckarti (Copepoda, Cyclopoida), including (Zool.) 39: 83-131.

of its Int. Revue G. G. M. E. Fernandez & J.W. a study naupliar development. ges. Marten, G., Borjas, Cush,

Hydrobiol., 78(4): 589-609. Reid, 1994. Control of larval Aedes aegypti (Diptera:

Dumont, H.J. & S. 1985. in breed- Maas, Mesocyclops cuttacuttae sp. Culicidae) by cyclopoid copepods peridomestic

n. from a cave in northern Australia (Crustacea: Cope- ing containers. J. med. Entomol., 31(1): 36-44.

poda, Cyclopoida). Beagle, 1(13): 115-122. Menu-Marque, S., 1991. Los copépodos del genero Acantho-

Dussart, B.H., 1984. Some Crustacea Copepoda from Ven- cyclops de Tierra del Fuego. Biol. Acuática, 15: 142-143.

ezuela. Hydrobiologia, 113: 25-67. Morton, D. W., 1985. Revision of the Australian Cyclopidae

Dussart, B.H., 1987. Sur quelques Mesocyclops (Crustacea, (Copepoda: Cyclopoida), I. Acanthocyclops Kiefer, Dia-

du Sud. 149— Kiefer Copepoda) d'Amérique Amazoniana, 10(2): cyclops and Australocyclops, gen. nov. Austr. J.

161. mar. freshw. Res., 36: 615-634.

Dussart, B.H. & D. Defaye, 1985. Répertoire mondial des Mrázek, A., 1901. Siisswassercopepoden. Ergebnisse der

Copépodes Cyclopoïdes: 1-236 (Éditions du C.N.R.S., Hamburger Magalhänischen Sammelreise, 2: 1-29 (Natur-

Bordeaux). historisches Museum, Hamburg).

Downloaded from Brill.com10/08/2021 06:20:44AM via free access 102 F. Fiers et al. - New copepods from Mexico

Navarro-Mendoza, M. & C. Valdés-Casillas, 1990. Peces Rocha, C.E.F. da, 1991. A new species of Halicyclops

California, and a revision of cavernícolas de la Península de Yucatán en peligro de (Copepoda, Cyclopidae) from

material in the collections of the US extinción, con nuevos registros para Quintana Roo. In: some Halicyclops

226: 29-37. J.L. Camarillo & F. Rivera (compilers), Áreas naturales Museum ofNatural History. Hydrobiologia,

México en extinción: 218-240 Sars, G.O., 1863. af de indenlandske Ferskvandsco- protegidas en y especies Oversigt Videnskabs-Selsk. Christiana, 1862: 212- (E.N.E.P. Iztacala, U.N.A.M., Mexico). pepoder. Forh.

Pearse, A.S. & C.B. Wilson, 1938. Copepoda from Yucatan 262.

Shen, & T.-h. 1963. Notes on collected caves. Pubis. Carnegie Insta., 491: 153-154. C.-j. Sung, Copepoda

China. Pesce, G. L., 1985. Cyclopids (Crustacea, Copepoda) from from Shigatze and Gyangtse regions in Tibet, Acta

West Indian groundwater habitats. Bijdr. Dierk., 55(2): zool. sin., 15(1): 79-97 (in Chinese; abstract in English).

295-323. Smith, K. & C.H. Fernando, 1978. The freshwater calanoid

Petkovski, T.K., 1986. Zur Taxonomie des Genus Mesocy- and cyclopoid copepod Crustacea of Cuba. Can. J. Zool.,

clops G. O. Sars 1914 (Crustacea, Copepoda Cyclopoida) 56(9): 2015-2023.

& C.H. 1980. Guía los in der Neotropis. Acta Mus. maced. Sei. nat., 18(3/149): Smith, K.E. Fernando, para Copé-

de Cuba: 1-28 47-79. podos (Calanoida y Cyclopoida) (Acade-

mia de Ciencias de Cuba, Havana). Reid, J.W., 1985. Chave de identificaçâo e lista de referen-

1996. cias as continentais sulameri- Suárez-Morales, E., J.W. Reid, T.M. Iliffe & F. Fiers, bibliográficas para espécies

de los continentales de canas de vida livre da ordern Cyclopoida (Crustacea, Catálogo Copépodos (Crustacea)

Copepoda). Bolm. Zool., Univ. Sào Paulo, 9: 17-143. la Península de Yucatán, México: 1-296 (ECOSUR/

Reid, J.W., 1988. Cyclopoid and harpacticoid copepods CONABIO, Mexico).

(Crustacea) from Mexico, Guatemala, and Colombia. Velde, I. Van de, 1984a. Introduction of new diagnostic char-

Trans. Am. microsc. Soc., 107: 190-202. acters in Mesocyclops, with African species as an exam-

Reid, J.W., 1990. Continental and coastal free-living Cope- ple. Crustaceana, Suppl. 7, Stud. Copepoda, 2: 404-419.

poda (Crustacea) of Mexico, Central America and the Velde, I. Van de, 1984b. Revision of the African species of

L. & J.G. Robinson the Sars 1914 Caribbean Region. In: D. Navarro genus Mesocyclops (Copepoda: Cyclopi-

109: 3-66. (eds.), Diversidad biológica en la Reserva de la Biosfera dae). Hydrobiologia,

of the Platform. In: de Sian Ka'an, Quintana Roo, México: 175-213 (Centro Weidie, A.E., 1985. Geology Yucatan

de Investigaciones de Quintana Roo (CIQRO) & Program W.C. Ward, A.E. Weidie & W. Back (eds.), Geology and

of Studies in Tropical Conservation, University of hydrogeology of the Yucatan and the Quaternary geology

Florida; Chetumal,Quintana Roo). of northeastern Yucatan Peninsula: 1-19 (NOGS Publica-

Reid, J.W., 1993a. Diacyclops virginianus, a new species of tions, University ofNew Orleans).

Cyclopoida (Crustacea: Copepoda) from Goose Creek, Wilson, C.B., 1936. Copepods from the cenotes and caves of

cladocerans. Pubis. Virginia. Maryland Naturalist, 37: 36^45. the Yucatan Peninsula, with notes on

Reid, J.W., 1993b. New records and redescriptions of Ameri- Carnegie Instn., 457: 77-88.

and of bernardi Yeatman, H.C., 1943. Rare cyclopoid copepods from wells in can species of Mesocyclops Diacyclops

(Petkovski, 1986) (Copepoda: Cyclopoida). Bijdr. Dierk., North Carolina. J. Elisha Mitchell scient. Soc., 59: 27-36.

63(3): 173-191. Yeatman, H.C., 1977. Mesocyclops ellipticus Kiefer from a

J.W. & D.L. 1994. Mexican In: J.R. Reddell (ed.), Studies on the Reid, Strayer, Diacyclops dimorphus sp. cave. caves

n. (Crustacea: Copepoda: Cyclopoida) from Florida, and cave fauna of the Yucatan Peninsula. Bull. Assoc.

Cave Stud., 6: 5-7. U.S.A., with comments on morphological characters of in- Mex.

terstitial cyclopine cyclopoids. J. North Am. benthol.

Soc., 13: 250-265. First draft received: 4 December 1995

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