Bijdragen tot de Dierkunde, 54 (1): 51-65 — 1984

Amsterdam Expeditions to the West Indian Islands, Report 39.

Arubolana parvioculata n. sp. (, )

from the interstitial of an intermittent river in Jamaica,

with notes on A. imula Botosaneanu & Stock and A. Aruboides

(Bowman & Iliffe)

by

Jos Notenboom

Institute of Taxonomie Zoology ( Zoölogisch Museum), University of Amsterdam,

P.O.Box 20125, 1000 HC Amsterdam, The Netherlands

6 de Summary (Discovery Bay). Jusqu’à présent, genres

stygobiontes, avec 9 espèces, sont connus de 7 îles des

Arubolana parvioculata, a new stygobiont of cirolanid Indes Occidentales. La nouvelle espèce est de petite taille is described from habitat isopod , an interstitial et allongée, caractères typiques des habitants des intersti- near the mouth of an intermittent river, the Rio Secco, ces. C’est une espèce euryhaline. Discovery Jamaica. This is the first subterranean Bay, Une donnée Arubo- description supplémentaire est pour cirolanid from 6 of Jamaica. Alltogether, genera stygo- lana imula Botosaneanu & Stock, 1979 (espèce-type du biont from 7 islands cirolanids, with 9 species, are known genre); celle-ci est réalisée sur des exemplaires supplémen- in the West Indies. The new species has a small and taires capturés dans la terra typica. Bermudalana aruboides which is ofinhabitants ofinterstitia. elongate body, typical Bowman de & Iliffe, 1983, de grottes Bermuda, est consi- It is also euryhaline. dérée comme appartenant à Arubolana. On souligne les dif- An additional description is given of Arubolana imula férences morphologiques et écologiques entre les trois Botosaneanu of the & Stock, 1979, type-species , espèces d’Arubolana; certaines de ces différences sont habi- based from the Ber- on new specimens type-locality. considérées tuellement comme permettant une distinction

mudalana aruboides Bowman & from Iliffe, 1983, caves on niveau Il donc les trois au générique. est possible que espè- the oceanic island is referred the Bermuda, to genus ces devront être considérées comme appartenant à des Arubolana. The morphological and differences ecological de sous-genres distincts, mais, compte tenu l’imparfaite

between the three Arubolana are out. Some species pointed connaissance le décision que nous avons sur groupe, cette

of these differences are considered characteristic of usually n’a été pas prise.

distinction on therefore the three generic level; species On les Arubolana dérivées d’un peut supposer que sont possibly have to be recognized as members of different ancêtre marin du type Metacirolana, mais il est difficile but of limited this subgenera, on account our knowledge d’établir scénario des événements. On un considère A. decision has not been made. imula élément de tandis A. comme regression, que aruboides It is presumed that the Arubolana species originated from et A. parvioculata peuvent être aussi bien des éléments de a Metacirolana type of marine ancestor. A general evolu- regression et/ou de dispersion. tionary scenario for Arubolana is difficult to construct. A.

imula but is considered a regression element, A. aruboides

and A. parvioculata can be either regression and/or dispersal

elements. INTRODUCTION

Résumé In the series of publications dealing with the

stygobiont fauna collected during the Amster- Une espèce nouvelle d’Isopodes Cirolanides, Arubolana par- dam Expeditions to the West Indian Islands, vioculata, est décrite. Ce premier Cirolanide hypogé de la this is the third article cirolanid Jamaïque a été découvert dans un habitat interstitiel, près concerning

de l’embouchure rivière d’une intermittente, le Rio Secco isopods. The previous publications in this series

Stock were by Botosaneanu & (1979) and

* Notenboom In the (1981). present paper a new Report 38 is published in the same issue of this journal. species from Jamaica is described from the 52 J. NOTENBOOM - ARUBOLANA

table in of the water river sediments near the coast. The peduncle first antenna in

Furthermore, Arubolana imula Botosaneanu & cirolanids is composed of three articles of which

Stock, 1979, the original description of which article one and two can be partly or totally

based male has been fused. In the distal of the third article dif- was on one juvenile only, part a

studied based ferentiated be again, now on more specimens zone can recognized, separated

from the type-locality, collected during the 1980 from the third article (figs. 5-6, 33-34). This

Bermudalana aruboides Bowman expedition. & II- zone has often been illustrated by isopodologists

the iffe, 1983, is transferred to genusArubolana. (Bowman, 1966; Monod, 1930; Racovitza,

The affinities, position within the family, and 1912; Rioja, 1956) but has rarely been

of the Arubolana there three the zoogeography species are described. Theoretically are

is of the discussed. possibilities: this zone part peduncle, or

Until five the years ago, only hypogean a flagellum article, or an articulation zone. In

from cirolanids known the West Indies were the both Arubolana imula and A. parvioculata, setae

Cuban trichostoma this which species Haptolana Bowman, are implanted on apical zone, sug-

and cubensis it is articulation between 1966, Troglocirolana** (Hay, 1903). gests that not just an

the few different and observation During past years, however, flagellum peduncle. Although biologists have contributed to this fauna, from is very difficult either with light microscopy or

several islands: Botosaneanu & Stock, 1979 with scanning electron microscopy, it is my im-

(Arubolana imula from Aruba), Carpenter, 1981 pression that the limit between peduncular arti-

from San Salvador cle 3 and this is either (Bahalana geracei Island), zone only partially or not

1981 Bahalana from all and that the itself is rather Notenboom, ( cardiopus at chitinized, zone

and Haitilana** radicicola and H. membranous. This that it Mayaguana, suggests belongs to acanthura from Haiti), and finally Bowman & the peduncle. Botosaneanu& Stock (1982) men-

1982 ** from Grand tioned similar situation in the Franz, (Anopsilana crenata a genus Cyathura

The result is that the 6 Cayman). at moment (Anthuridea), and they reached the same con-

with 9 known from 7 islands clusion: this differen- genera species are they considered zone as a

tiated of last with (see map 1). part the peduncular article,

Most of these cirolanids inhabitants of sensorial function. Bruce are possibly a prevailing

the of this cave waters; however, two species (in press) considers zone as being a

Haitilana known from karstic and terminal in are a spring a "fourth small fused article", and

and discussed it that it well, respectively, a new species my opinion seems probable originated in this discovered in another of from fourth article. paper was type a peduncular

Another in the literature groundwater habitat, the interstitial of a tem- problem on

the porary river. cirolanid isopods is the confusion in ter-

used authors for the minology by some man-

dibular 35 and In parts (figs. 9-10, 37). my Some remarks on the morphology of stygobiont these have be named follows: opinion parts to as cirolanids the strongly sclerotized, dark coloured, triden-

I median is the While studying stygobiont cirolanids, en- ticulated margin masticatory

in the dif- blade is the triar- countered some obscurities use by or pars incisiva; laterally

ticulated with setation the second ferent authors of morphological terms. In this palp, on and section the used for of third between the and the terminology some parts article; palp the cirolanid body will be discussed. masticatory blade, small unarmed lobes are

found, which represent the molar process or

is pars molaris; dorsomedially a denticulated,

mobile the * * triangular, (articulate) process, Bruce (in press) regards Troglocirolana and Haitilana as lacinia between and the with mobilis; lacinia mobilis synonymous Anopsilana Paulian & Delamare Debout-

blade is armed with teville, 1956, considered a paraphyletic genus. masticatory a lobe, strongly BIJDRAGEN TOT DE DIERKUNDE, 54 (1) - 1984 53

spines, the incisor; sometimes the masticatory TAXONOMIC PART

blade has an accessory spine laterally.

Arubolana Botosaneanu & Stock, 1979 Carpenter (1981), on the contrary, named the

incisor, lacinia mobilis, and the lacinia mobilis, Diagnosis. — Depigmented Cirolanidae (ex- Bruce named the molar; (1981) masticatory for brown blind cept masticatory blades), or

blade, incisor, and the incisor, molar process; with small able to roll into a eyes. Body not ball; Bowman & Iliffe (1983) named the masticatory pleon with 5 free segments, lateral margin of blade, incisor, the lacinia mobilis, molar, and segment 5 free or overlapped by segment 4. the incisor, lacinia. Clypeus much wider than high, anterior margin With the there to pereiopods, is a respect of frontal lamina broad. Antenna 1 not longer in whether problem deciding a pereiopod is than the peduncle of antenna 2; peduncle

prehensile or ambulatory. Bruce (pers. comm.) 3-articulated; flagellum 5-articulated, with

the criterion: when the dac- adopted following aesthetascs. Peduncle of antenna 2

is than the of the tylus longer greatest length with few 5-articulated, flagellum relatively ar- propodus, the is considered pereiopod prehen- ticles. Mandible and first maxilla normal; sec- when the is it is sile; dactylus shorter, con- ond maxilla showing loss of articles. Max-

sidered ambulatory. In opinion this is too my illipedal palp 4-articulated (articles 2 and 3

a view. The best criteria are observa- simple endite with or fused); one two pappose setae, tions on living specimens, but these are usually possibly with coupling element. Pereiopods 1

available. to Bruce's not According criterion, and in- 2 prehensile, pereiopod 3 ambulatory or the first and second pereiopods of Arubolana termediate in shape between ambulatory and should be called In the ambulatory. my opinion 4 7 clearly prehensile, pereiopods to am- first and second pereiopods are clearly prehen- bulatory. Rami of pleopods 1 and 2 undivided; in sile this taxon, while the is much propodus exopodites of third to fifth pleopods wider and and than the dactylus, merus carpus 2-segmented. Appendix masculina implanted wider than the and are long. Furthermore, first subterminally on the median margin of en- second pereiopods are relatively short and dopodite, straight in adult males, possibly with and in strongly built, are, preserved specimens, elements. apical spiniform Uropodal pro- pressed against the body, while the other topodite with median margin produced. Telson based A. pereiopods are not (observations on trapezoidal, scarcely armed. imula and A. parvioculata).

last remark concerns the My chaetotaxy. Type-species. — Arubolana imula Botosaneanu

There is no uniformly defined and used system & Stock, 1979. An additional description of it is

for the nomenclature of setae. given in the sequel, after the description of the

However, setae an role in play important new species Arubolana parvioculata. Some

crustacean . Broodbakker & remarks A. aruboides on (Bowman & Iliffe, 1983)

described a model for the Danielopol (1982) are made as well.

ostracods. chaetotaxy of They adopted some

general terms from decapod literature, which Arubolana parvioculata n. sp. are also useful for the description of cirolanid (Figs. 1-27, 47-48) setae: simple setae have a smooth distal shaft;

serrate setae have or toothlike setules; spiky Material examined. — Amsterdam Expeditions to the

flexible setules plumed setae possess (hairy West Indian Islands, 1982. Jamaica: Interstitial water in

the sediments near the mouth of the Rio Secco in the appearance), they can be subdivided into dry riverbed, Bay "N coll. when the setules Discovery (18°27'21 77°24'34"W); plumose setae are arranged Stock: 82/134 J. H. sta. (28 March 1982, about 15 m from in one or two rows the distal along largest part the Museum Amsterdam coll. sea, Zoölogisch no. ZMA and setae when the setules arise pappose Is. 105.247 a & b, 3 a Cf and 1 9 ); sta. 82/136 (28 March

from all sides of the distal 1982, about 35 from part. m the sea, ZMA coll. no. Is. 105.248, 54 J. NOTENBOOM - ARUBOLANA

March 2 Cf O" and 29 9); sta. 82/138 (29 1982, between wider than high, with freely projecting, the coll. Is. 4 preceding stations, ZMA no. 205.249, C O" rounded 3 and apex (figs. 47-48). and 7 9 9 > one of which damaged). The holotype is a 2.8 Mandibles with asymmetrical masticatory the other mm long male from sta. 82/134, specimens are blades, right mandible with 3 large teeth and 1 paratypes. small median tooth, left mandible with 3 flat

Description. — Body (fig. 1) 3.2-3.3 times teeth; lacinia mobilis longer than high with 14

maximum 15 small incisor with about 8 longer than wide. Males range to a or spines; spines

of females 2.9 the with small length 2.8 mm, to mm. (one naked, remaining ones

Pereionite 1 slightly longer than the others, spikes); palp slender, 3-articulated, a distal

4 well 5 7 of about the of 5 to 7 3 pereionites 2 to as as to group setae on segment 2, segment

with same size, last three pereionites longer than the distally 3 to 5 setae, tip with 1 or 2 longer

of three preceding ones (fig. 1); posterior corner setae (figs. 9-10).

coxal plates 2 and 3 rounded, plate 4 rect- Maxilla 1 : gnathal surface of exopodite with

and 5 7 10 angular plates to posteriorly pointed strongly sclerotized setae, one naked, two

with the (fig. 2). Penes prominent on sternite 7 (fig. 12). several spikes, and remaining ones

wide with endite armed with Pleonites 1 to 4 almost as as pereionite 7, 1 or 2 spikes; 3 long,

and pleonite 1 partly covered dorsally by pereionite pappose setae two simple setae (fig. 7).

7 (fig. 1); epimera 1 to 4 posteroventrally Maxilla 2 strongly reduced, consisting of two

5 covered 4 fused armed with 3 setae pointed, epimera partly by epimera segments, apex long

(fig. 2). Telson trapezoidal, narrow at posterior (all pappose) and 2 or 3 simple setae (fig. 8).

margin, which is slightly concave, crenate and Maxillipedal endopodite 4-segmented, seg-

with armed with a few simple setae (fig. 21). ment 1 squarish one seta, segment 2

last with 1 4 3 with Antenna 1 short, reaching halfway to largest + setae, segment squarish

peduncular article of antenna 2 and to the 1 + 3 setae, segment 4 the smallest, armed with

posterior margin of the head; peduncle 7 setae (2 plumose); endite with only 1 or 2 pap-

3-articulated, articles 1 and 2 of about the same pose setae (fig. 11).

article 1 basis and ischium length, article 1 distally with 3 or 4 setae, Pereiopod prehensile,

with 4 6 and 2 armed to setae medially 2 setae both with one seta, merus distoposteriorly with

article 3 about and laterally, twice as long as article a process, a spine a seta, carpus with a

with 2, armed distolaterally with 3 or 5 setae, apical spine and a seta, propodus posteriorly 2

with 3 4 and 4 with 4 with zone or plumose setae (fig. 5); spines setae, dactylus setules,

flagellum 5-articulated, article 1 almost three secondary unguis and little spine (fig. 13).

the otherarticles times as long as together, long Pereiopod 2 prehensile, basis and ischium

article 5 3 both with aesthetascs on articles 1 to 4, with or one seta, posterior margin of merus

with lateral of and 4 setae on the tip (fig. 6). group a spine a seta, distally

and of distal Antenna 2 reaching to the anterior margin of with a process a group setae, car-

with of pereionite 4; peduncle 5-articulated, articles 1 pal process a group setae, propodus

with and and 2 partly fused, article 5 the longest, as long posteriorly two processes two groups

and of and with as articles 3 4 together, article 1 unarmed, spines setae, dactylus 3 setules, article 2 with 1 4 3 with 2 with uneruis and setules to setae, article to 4 apex secondary two

setae, article 4 with several simple setae and 1 (fig. 14).

article 3 7 3-6 or 2 plumose setae, 5 strongly armed, Pereiopods to ambulatory, increasing

with several in distally plumose setae; flagellum 6- length, 7 shorter than 6, little difference be-

to 8-articulated, articles armed with several tween pereiopods 2 and 3 (figs. 15-19).

setae (fig. 4). Pleopod 1 smaller than pleopod 2, ovate ex-

Frontal lamina freely projecting, anterior opodite and subrectangular endopodite, both

and posterior margin about of equal size, abut- rami subequal in length and with plumose setae

the much ting on clypeus; clypeus triangular, (fig. 22). 54 - 1984 BIJDRAGEN TOT DE DIERKUNDE, (1) 55

1-12. Arubolana n. male: 1, entire 2, 3, Figs. parvioculata sp., (scale a); pereionites laterally (a); anteroclypeal region (b); 4, antenna 2, right (b); 5, antenna 1, left (e); 6, detail offlagellum ofantenna 1, left (d); 7, maxilla 1, left (c);

left sternite 8, maxilla 2, left (c); 9, mandible, (c); 10, mandible, right (c); 11, maxilliped, right (c); 12, penes on 7 (f). 56 - J. NOTENBOOM ARUBOLANA

13-21. Arubolana male: left Figs. parvioculata n. sp., 13, pereiopod 1, (scale g); 14, pereiopod 2, left (g); 15, pereiopod3, left (h); 16, pereiopod 4, left (h); 17, pereiopod5, left (h); 18, pereiopod6, left (h); 19, pereiopod 7, left (h); 20, uropod, left (h); 21, telson (g). 54 - 1984 57 BIJDRAGEN TOT DE DIERKUNDE, (1)

22-27. Arubolana male: left left detail of of Figs. parvioculata n. sp., 22, pleopod 1, (scale h); 23, pleopod2, (h); 24, apex ap- pendix masculina (i); 25, pleopod 3, left (h); 26, pleopod 4, left (h); 27, pleopod 5, right (h).

with than basal of Pleopod 2 in the male very broadly longer segment exopodite, unarm rounded exopodite, armed with plumose setae, ed and membranous (fig. 25).

blunt and 4: a group of setae with a tip broader Pleopod large 2-segmented exopodite,

distal with base on mediodistal margin; endopodite smaller segment plumose setae (a small than with 3 mediodistal of of the exopodite, apex plumose setae; ap- group setae blunt-tip

masculina shorter basal with 2 and pendix terminal, slightly type), segment plumose setae a than endopodite, apex with 3 spiniform simple seta; endopodite small, reaching to the elements, one of which being longer (figs. middle of the distal exopodal segment, un-

23-24). armed and membranous (fig. 26).

Pleopod 2 in the female basically similar to Pleopod 5: small 2-segmented exopodite, that in the male, with several plumose setae on distal segment scarcely armed with plumose the basal endopodite. setae, segment with one simple seta; en-

Pleopod 3: large 2-segmented exopodite, dopodite smaller than exopodite, unarmed and distal with membranous segment plumose setae (mediodistal (fig. 27). margin with a group of setae with blunt tip and Uropod: protopodite wedge-shaped, medio- broader basal with several base), segment distally one plumose seta, laterodistally two

and wider than plumose setae; endopodite very small, hardly simple setae; endopodite longer - 58 J. NOTENBOOM ARUBOLANA

the of naked Cora Tunnel (Lago Colony), approximate position exopodite, on apex a group setae,

12°25'13"N 69°52'10"W, 16 May 1978, ZMA coll. no. and medially 5 plumose setae and 2 spines; ex- Is. 100.648 a & b, one juvenile male (2.9 mm), holotype opodite oblong and narrow, armed on tip with a (coll. J. H. Stock and S. Weinberg). Sta. 80/17, same of lateral and median group naked setae, 24 coll. Is. locality as sta. 78/290, May 1980, ZMA no. each with L. margins a spine (fig. 20). 105.250, 14 femjiles and 9 males, topotypes (coll.

Botosaneanu and J. Notenboom).

— The is Etymology. specific name composed

of the Latin words parvus = small and oculus = Additional description. — Body (fig. 28) and alludes to the small of the animal. eye, eyes rather wide, 2.2-2.4 times as long as wide.

Maximum of both males and females Habitat. — Arubolana length parvioculata n. sp. was Coxal 7 of into 6.25 mm. on 2 to caught by means filtering water seeping plates pereionites

1 dug holes reaching the level of the water table posteroventrally pointed (fig. 29); pereionite than the 3 (Karaman-Chappuis method) in the dry bed of longer others; pereionite partly

covered 4 to 7 of the Rio Secco, Discovery Bay, Jamaica. by pereionite 2; pereionites

about the same size Pleonite 1 The sediments consisted of boulders, coarse (fig. 28). partly

and sand. The of the covered by pereionite 7; pleonites 2 to 4 almost gravel coarse temperature

as wide as water in the holes was about 26°C. The hole pereionite 7, epimera triangular.

Penes sternite 7 Telson closest the contained with on prominent to sea (15 m) water a (fig. 38).

than the chlorinity of 26580 mg/1, and could be classified trapezoidal, longer wide, narrower at

which is concave and as seawater. The water in the two other holes, posterior margin slightly

with 35 and about 25 from the had armed a few setae at m m sea, simple (fig. 28). Antenna than the chloride contents of 4848 and 5328 mg/1, 1 short, hardly longer of the head; respectively, and could be classified as mixo- posterior margin peduncle

3-articulated, articles 1 and 2 short, article 3 at haline water. This points to a large salt

1 and 2 tolerance (euryhalinity) of A. parvioculata. least as long as together (fig. 33); article The fauna found together with the cirolanids flagellum 5-articulated, 1 about 3 times

the other articles articles be considered of as as 1 can a mixture aquatic (ground- long together,

to 4 each with aesthetasc water) fauna and terrestrial (soil) fauna, cer- one elongate reaching

the of the 5 with tainly caused by disturbance of the substrate beyond tip flagellum, article a

during the digging of the holes. In addition to few long setae (fig. 34).

Antenna 2: articles 1 the cirolanids, other aquatic were blind peduncle 5-articulated,

and 2 article 5 of about the amphipods (Metaniphargus ), isopods (Micro- partly fused; same

3 and 4 cerberus), ostracods, polychaetes, and length as together (fig. 43); flagellum

soil fauna 8-articulated oligochaetes; elements were ter- (fig. 44).

restrial isopods, Collembola, pseudoscorpions, Frontal lamina broad, rectangular, anterior-

fused with the abut- and myriapods. In general, only few in- ly rostrum, posteriorly not

dividuals of this on the about 7 times as accompanying fauna were ting clypeus. Clypeus

wide found. as high, apex not freely projecting.

and in 30 Two other holes the locali- Labrum the same were dug at same clypeus plane (figs.

but closer the and ty, to sea (about 2 m). These sta- 45-46).

Mandibular blades tions contained neither cirolanids nor blind am- masticatory asym-

mandible but Microcerberus and metrical, left with ac- phipods, polychaetes were occasionally lacinia mobilis armed present. cessory spine; triangular, with 13-14 spines; incisor armed with 9-10

Arubolana imula Botosaneanu & Stock, 1979 distal of spines; palp article 2 with a group

(Figs. 28-46) about 8 setae, article 3 distally with 6-7 setae

and 2 longer terminal setae (figs. 35, 37). Material examined. — Amsterdam Expeditions to Maxilla endite armed with 3 setae the West Indian Islands, sta. 78/290, Aruba: Mangel 1 : pappose TOT DE 54 - 1984 BIJDRAGEN DIERKUNDE, (1) 59

Figs. 28-39. Arubolana imula Botosaneanu & Stock, 1979, topotypes: 28, entire animal, ￿ (scale 1); 29, pereionites, lateral,

￿ (1); 30, anteroclypeal region, ￿ (k); 31, maxilliped, left, ￿ (g); 32, maxilliped, right, ￿ (g); 33, antenna 1, right, ￿

(g); 34, detail of flagellum of antenna 1, right, ￿ (j); 35, mandible, left, ￿ (g); 36, maxilla 2, right, ￿ (h); 37, mandible,

sternite 7 maxilla right, ￿ (g); 38, penes on (j); 39, 1, right, ￿ (h). - 60 J. NOTENBOOM ARUBOLANA

left, Figs. 40-44. Arubolana imula Botosaneanu & Stock, 1979, topotypes: 40, pleopod 2, right, ￿ (scale g); 41, pleopod 2,

￿ (g); 42, detail of appendix masculina (j); 43, peduncle of antenna 2, left, ￿ (g); 44, flagellum of antenna 2, left, ￿ (g).

Median of of and 2 simple setae; exopodite with 11 spines (2 margin protopodite pleopod 1

have armed with 3 longer ones small teeth) and 1 serrate seta spines, endopodite slightly

(fig. 39). smaller than exopodite.

Maxilla 2: armed with 3 2 male: armed on me- lobe-like, apex Pleopod protopodite longer plumed setae and 2 small simple setae dian margin with 3 spines, lateral margin with

broad (fig. 36). one simple seta; exopodite rather on

Maxillipedal endite with 2 plumose setae, distal end, mediodistal margin with about 26 without coupling elements; palp 4-articulated, setae with blunt tip and broader base, remain-

1 with 1 article the about article squarish, seta, 2 the ing setae tapering to tip; endopodite largest with 1 + 4 setae, article 3 with 1 + 3 the same length as exopodite, setae without

4 the setae, article smallest with 7 setae (figs. blunt tip, appendix masculina implanted

the median 31-32). subterminally on margin, straight BIJDRAGEN TOT DE DIERKUNDE, 54 (1) - 1984 61

45-48. electron Arubolana imula Botosaneanu Figs. Scanning microscopical photographs. 45-46, & Stock, 1979, topotypes:

view of anterior. ventral view of 45, ventral clypeal region; 46, head, 47-48, Arubolana parvioculata n. sp.: 47, clypeal

anterior region; 48, head, (same magnification as 47).

in with element medio- adult specimens, a spiniform on Uropodal protopodite wedge-shaped, the one apex (figs. 41-42). distally plumose seta, laterodistally two

Pleopod 2 in the female basically the same as simple setae; endopodite longer and wider than in the armed with of naked male, endopodite densely exopodite, on tip a group setae, plumose setae (fig. 40). plumose setae laterally; exopodite oblong and

3: armed with 3 armed with naked its Pleopod protopodite spines narrow, setae on apex.

lateral on the median margin and 1 simple seta; mediodistal margin of exopodite with about 30 Habitat. — The Mangel Cora Tunnel at Lago

of the Aruba still the known setae blunt-tip type. Colony on is only locality

Pleopods 4 and 5: protopodite armed with 3 of Arubolana imula. The tunnel was first de-

and lateral median spines one seta; exopodite scribed by Wagenaar Hummelinck (1979). without blunt-tip setae. During the Amsterdam Expeditions to the West 62 - J. NOTENBOOM ARUBOLANA

Indian Habitat. — This is known Islands, the tunnel was visited a couple species only from

in anchialine habitats of times. During the first visit May 1978, a (salinity of the water about

found of in single specimen of A. imula was together that seawater) the Church and

of Wonderland Bermuda. ob- with large quantities Metaniphargus longipes caves on Divers

Stock, 1977 (hadziid Amphipoda) and Typhlatya served the animals swimming several meters

On 24 and 6 above the bottom of the cave no sp. (Decapoda, Atyidae). May lakes;

June 1980 the tunnel was visited again. This specimens were ever observed crawling over the

of hummelincki Bowman Iliffe time a few specimens Cyathura substrate. & (1983) suggest that

1982 An- Botosaneanu & Stock, (Isopoda, Arubolana aruboides is a predator capturing its

also found with food thuridea) were together more from open waters.

specimens of the cirolanid.

The substrate on the bottom of the water fill-

the tunnel consists of fine silt ing mainly very DISCUSSION and the water becomes very quickly muddy

during sampling. The largest densities of The genus Arubolana is a clearly recognizable

animals are found in places with pieces of rot- unit within the Cirolanidae owing to the first

The of the is which ting wood. temperature water ap- antenna with only 5 flagellum articles of

the first is the proximately 30°C. 2 to 3 times as long as remaining

the tunnel used for articles the second with During years was pump- together, antenna

ing industrial water and as a result the water relatively few flagellum articles, the reduced

became more and more brackish. Since 1980 maxilla 2, the slender 4-articulated maxillipedal

the used the first and tunnel is not anymore. In 1955 palp, prehensile second pereio-

chloride Wagenaar Hummelinck registrated a pods, the subterminally implanted appendix

concentration of 1340 mg/1, while in 1978 and masculina, the exopodite of pleopod 5 with few

3600 and 3782 were and the of five 1980, mg/1 measured, marginal setae, presence pleon

respectively. segments.

More information about this remarkable The three known Arubolana species differfrom

in in habitat can be found Wagenaar Hummelinck one another the following aspects:

(1979) and Botosaneanu & Stock (1979 and — General: A. parvioculata is the smallest,

has 1982). maximum length 2.9 mm, A. aruboides a

the maximum recorded length of 4.0 mm,

of largest is A. imula with a maximum length

6.25 the first slender and aruboides mm; two species are Arubolana (Bowman & Iliffe, 1983) than three times slightly more as long as wide,

Remark. — This been described A. imula is robust about 2.3 times species has as a more species

aruboides. The authors realized that wide. A. small Bermudalana as long as parvioculata possesses

Bermudalana the two might be synonymous with, or a eyes, however, other species are totally

subgenus of, Arubolana. They decided to blind.

describe close — Pleonites: in A. imula the fifth is a new genus, to Arubolana, on ac- pleonite

of differences in and the in A. count pereiopods totally encompassed by fourth, par-

pleonites. They concluded: "the differences are vioculata this pleonite is only partly encom-

believed be of value in the usually to generic passed, whereas A. aruboides has a free fifth

hence The difference between these Cirolanidae, we have proposed a new pleonite. last two

genus for the Bermuda cirolanid. We realize species is, however, small and is possibly evok-

that could be made ed of muscle contraction and however, a plausible case by varying degrees

for assigning the latter to Arubolana or for telescoping of the somites.

of — in recognizing Bermudalana as a subgenus Anteroclypeal region: A. imula the

Arubolana” (see further Discussion). frontal lamina is wide, not abutting posteriorly - 63 BIJDRAGEN TOT DE DIERKUNDE, 54 (1) 1984

on the clypeus and fused anteriorly with the probably a predator on planktonic or nektonic

A. aruboides and A. have The of in rostrum; parvioculata a organisms. salinities the waters which

and fron- the Arubolana from triangular clypeus a freely projecting species were found, range

tal A. has brackish marine. In the members of lamina; only parvioculata a freely pro- to general

the jecting clypeal apex. genusArubolana appear to have a large salt

— Third pereiopod: in A. imula this is tolerance.

undeniably ambulatory, in the other two As to the position of Arubolana within the

its this species morphology is intermediatebetween family, genus shows affinity with the

the second and the fourth in A. marine Metacirolana in pereiopods; genus (see diagnosis

be aruboides this pereiopod seems to in a more Bruce, 1981). This affinity is showed by mor-

prehensile state (also considering the armature) phological similarities concerning the

consider of the (Bowman & Iliffe, 1983, it clearly moderately developed flagella antennae,

in A. it is in the broad frontal the slender prehensile); however, parvioculata a anteriorly lamina,

more ambulatory state. maxillipedal palp, the pereiopods without flat-

— Pleopods: these are very similar in A. imula tened articles and with dactyli in which the

and A. notable is the small is minute absent parvioculata; very en- secondary unguis or (the

dopodite of the third pleopod in these two general shape of the pereiopods is similar in

species; A. aruboides differs, among others, in Arubolana and Metacirolana), and the medially

having armed endopodites of pleopods 3 and 4. produced uropodal protopodite. In addition,

Uropod: the endopodite is relatively wide in both A. parvioculata, A. aruboides and Metacirolana

A. imula and A. in A. aruboides it is anterior parvioculata; show a freely projecting margin of the

frontal laminaand of 5 relatively oblong. a lateral margin pleonite

— Telson: this is in A. imula and A- which is either linguiform partially or not at all encom-

A. aruboides; parvioculata has a trapezoidal telson, passed by the epimera of pleonite 4. Both A.

width. and Metacirolana have about the same length as The posterior parvioculata a downward

margin is concave in A. imula and A. par- projecting rounded apex of the clypeus.

vioculata, in A. aruboides it is convex. Besides, A. aruboides and Metacirolana have in

Some of the above-mentioned morphological common the setation of the endopodites of

differences in and 3 and 4. A. imula (such as the pleonites pleopods has a more

between the three Arubolana Metacirolana-like but the fron- pereiopods) species habitus, rostrum,

are considered be discriminative at tal and 5 usually to lamina, clypeus pleonite are totally

generic level within the Cirolanidae. Possibly different.

the three species have to be recognized as Although Arubolana in general shows affinity

different Nevertheless, with this is representing subgenera. Metacirolana, more strongly express-

with the have the it ed in A. and knowledge we at moment is parvioculata A. aruboides. Metacirolana

difficult to identify subgenera in Arubolana. is a taxon with cosmopolitan distribution, but

There are remarkable differences in habitat, apparently poorly represented in the Carribean

behaviour, and probably food between the (see Bruce, 1981).

three Arubolana species. A. imula lives in waters

(less than 1 m deep) of a partly artificial tunnel ZOOGEOGRAPHY in dug limestone. The species crawls over the bottom and feeds probably on organic detritus It is most likely that hypogean cirolanid species

or is a A. lives in evolved from marine scavenger. parvioculata ancestors. The family is

sediments in the mouth of intermittentriver distributed in the an mainly seas; epigean con-

near the It is excluded that this tinental almost coast. not taxa are unknown, and the

also lives in the marine interstitial. show species hypogean representatives a disjunct

A. aruboides is distribution Finally, a free-swimming species pattern. For the West Indian taxa

in waters of inland anchialine it is this is shown This deep caves, on map 1. map also 64 - J. NOTENBOOM ARUBOLANA

Distribution of Map 1. West Indian hypogean cirolanid taxa: 1, Anopsilana crenata Bowman & Franz, 1982; 2, Arubolana imula Botosaneanu Arubolana Bahalana & Stock, 1979; 3, parvioculata n. sp.; 4, geracei Carpenter, 1981; 5, Bahalana cardiopus

Notenboom, 1981; 6, Haitilana radicicola Notenboom, 1981; 7, Haitilana acanthura Notenboom, 1981; 8, Haptolana trichostoma Silva Bowman, 1966; 9, Troglocirolana cubensis (Hay, 1903), based on Naboada (1974). Arubolana aruboides

from is indicated the this of (Bowman & Iliffe, 1983), Bermuda, not on map because island is situated out its frame.

Asterisks are used to indicate more than one locality in larger areas. Arrows indicate single localities or more localities in

small a very area.

all subterranean Cirolanidae is assumed demonstrates that nearly localities are by

Botosaneanu for Arubolana imula situated in the neighbourhood of the present sea & Stock (1979)

localities of the taken in the late coasts. Exceptions are the two to have place

Cuban These Miocene/Pliocene and Notenboom taxa. are, especially Haptolana period by

inland for the Haitilana in the Cenozoic trichostoma, more cave inhabitants. (1981) species

the For explanation of this distribution pat- period. tern we can assume an active or a passive Another question is how did marine model. An active is from the colonize the littoral of the oceanic process dispersal ancestors marine littoral into the groundwater habitats island Bermuda and which mechanism acted in

the near coast. A passive model can be regres- the evolution of Arubolana aruboides from its

i.e. the sion, stranding of marine populations marine stock. Bermuda consists of a mid-ocean during geotectonic uplifts after the populations volcanic seamount capped with Pleistocene and

The adapted to mixohaline or limnic conditions. Recent, marine and eolian, limestones.

model is low stands of level This exemplified by Stock (1976, karst was formed during sea

for 1977a, b) several West Indian stygobiont corresponding to periods of Pleistocene glacia-

for taxa, example: Thermosbaenacea, in- tion (Bowman & Iliffe, 1983). It is likely that in

and hadziid evolution the golfiellid Amphipoda. An same periods or more recently, the marine

this corresponding to regression model for ancestor of A. aruboides colonized the anchialine 54 - 1984 65 BIJDRAGEN TOT DE DIERKUNDE, (1)

and of cirolanid from cave habitats. This colonization could have genus species troglobitic isopod Cuba. Int. J. Speleol., 2: 105-108, pis. 24-27. happened by dispersal, but also by regression, BOWMAN, T. E. & R. FRANZ, 1982. Anopsilana crenata, a during the sea-level falls in the Pleistocene. new troglobitic cirolanid isopod from Grand Cayman The habitat in which A. has been parvioculata Island, Caribbean sea. Proc. biol. Soc. Wash., 95

found is clearly intermediate between the (3): 522-529.

T. E. T. Bermudalana marine littoral and the inland groundwaters. BOWMAN, & M. ILIFFE, 1983. and of aruboides, a new genus species troglobitic The different salinities of the water in which A. from marine Isopoda (Cirolanidae) caves on parvioculata lives is indicative of the euryhalinity Bermuda. Proc. biol. Soc. Wash., 96 (2): 291-300. of the The small size and rather species. BROODBAKKER, N. W. & D. L. DANIELOPOL, 1982. The

elongate body shape is typical of inhabitants of chaetotaxy of Cypridacea (Crustacea, Ostracoda)

limbs: proposals for a model. interstitial biotopes. In river estuaries, such as descriptive Bijdr. Dierk., 52 (2): 103-120. the locality of A. parvioculata, sedimentation is BRUCE, N. L., 1981. Cirolanidae (Crustacea: Isopoda) of the dominant All this geological process. sug- Australia: diagnosis of Leach, Metacirolana that it is that this more likely species Neocirolana gests Nierstrasz, Hale, Anopsilana Paulian &

Deboutteville from marine and three — originated through dispersal a new genera Natatolana,

Politolana and Cartetolana. stock. Nevertheless the locality, Discovery Bay, Aust. J. mar. Freshwat. Res., 32: 945-966. in with is situated an area geotectonically in , press. "Monograph on Australian marine uplifted Plio-Pleistocene terraces, therefore also cirolanid isopods" (Brill, Leiden). has to be taken into account. 1981. Bahalana regression CARPENTER, J. H., geracei n. gen., n. sp., All three Arubolana species appear to have a troglobitic marine cirolanid isopod from Lighthouse from in San Salvador Bahamas. evolved marine ancestors relatively re- Cave, Island, Bijdr. Dierk., 51 (2): 259-267. late Cenozoic cent geological times, or P. WAGENAAR, HUMMELINCK, 1979. De grotten van de Pleistocene. It is difficult to conceive a general Nederlandse Antillen. Caves of the Netherlands model in which this evolution could have acted. Antilles. Uitg. natuurw. Studiekring Suriname, 97 is For Arubolana imula regression very plausible, (Natuurhist. Reeks, 1): 1-176. but for A. aruboides and A. parvioculata regression MONOD, TH., 1930. Contribution à l'étude des Ciro-

lanidae. Annls. Sci. nat., (Zool., 10) 13: 129-183. and/or dispersal are both possible. NOTENBOOM, 1981. Some J., new hypogean cirolanid

ACKNOWLEDGEMENTS isopod crustaceans from Haiti and Mayaguana

(Bahamas). Bijdr. Dierk., 51 (2): 313-331. I would like to thank Prof. Dr. J. H. Stock who has given RACOVITZA, E.-G., 1912. Cirolanides (première série). the continue work West Indian me opportunity to my on Archs. Zool. 10: XV- exp. gén., (5) 203-329, pis. hypogean cirolanid isopods, and Dr. L. Botosaneanu for XXVIII. useful discussions. Both have read the manuscript of this RIOJA, E., 1956. Datos sobre algunos isópodos caver- Mr. N. L. Bruce is thanked for advice paper. personal on nfcolos de la isla de Cuba. An. Inst. Biol. Univ. Cirolanidae, and Susan Parren-Gardner for reviewing the Mex., 27 (2): 437-462. English text. SILVA NABOADA, G., 1974. Sinopsis de la espeleofauna The fieldwork has been supported by grants from the Cubana. Serie 43: 43-44 espeleologica y carsológica, Beijerinck Popping Fonds (Amsterdam), the Treub (Academia de Ciencias de Cuba, Instituto de Maatschappij (Utrecht), and the Amsterdamse Univer- Geografia, Departemento de Espeleologia, La siteits Vereniging (Amsterdam). Habana).

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Received: 27 September 1983