Bijdragen lot de Dierkunde, 62 (1) 21-36 (1992)

SPB Academie Publishing bv, The Hague

Marine interstitial and Isopoda (Crustacea) from Santiago,

Cape Verde Islands

Jan H. Stock & Ronald Vonk

Institute of Taxonomie Zoology, University of Amsterdam, P.O. Box 4766, 1009AT Amsterdam,

The Netherlands

Keywords: Amphipoda, Isopoda, interstitial, Cape Verde Islands

Abstract Material and methods

Three of recorded from interstices of The material which this is based been species Amphipoda are a on paper has collected with

marine beach the island of Verde Bou-Rouch tidal on Santiago, Cape Archipela- a biophreatical pump (see Bou, 1975), on a

littoralis Psam- beach flat the island of in the Verde Ar- go: Cabogidiella n. gen., n. sp. (Bogidiellidae), on Santiago Cape

50 mogammarus spinosus n. sp. (Melitidae), and sketi chipelago,at a depth of some cm below the substrate surface,

Karaman, 1980 ().The latter, widely distributed at several places between low-tide and a zone rather high in the

species (West Indies, Canary Islands), is new to the Cape Verde mediolittoral belt. The sediments in which the lived con-

Islands. Furthermore, an isopod is described from the same lo- sisted of a mixture of gravel, coarse sand, and some silt. At the

Caecostenetroides mixtum of the the in the cality, n. sp. (Gnathostenetroididae). moment sampling, salinity was same as open

sea, but - because the beach in question is situated in the mouth

of a temporarily dry torrent which carries water only during ex-

Résumé ceptional showers - an occasional decrease in salinity is

possible.

Trois espèces d’Amphipodes sont signalées d’interstices d’une

plage marine sur l’île de Santiago, archipel du Cap-Vert:

Cabogidiella littoralis et nov. (Bogidiellidae), Psam- gen. sp. Taxonomic part

mogammarus spinosus sp. nov. (Melitidae) et Idunella sketi

1980 Karaman, (Liljeborgiidae).La dernière, une espèce large- AMPHIPODA ment répandue (Indes occidentales, îles Canaries), est nouvelle

les îles du décrit de la même pour Cap-Vert. Également localité, Family Bogidiellidae

un Caecostenetroides mixtum est Isopode, sp. nov. (Gnatho-

stenetroididae). Cabogidiella n. gen.

Introduction Diagnosis. - Bogidiellidae with 5 pairs of coxal

gills (on pereionites 2 through 6). Molar part of

the frame of In of a study on the stygofauna the mandible in reduction. Palp of first maxilla

mid-Atlanticislands, a visit was paid to two islands 2-segmented. Pleopodal exopodites 3-segmented, of the Verde The Uro- Cape Archipelago. present paper not sexually dimorphic; endopodite absent.

describes number a of malacostracan pod 1: both rami of both sexes modified into

found in interstitialwaters of a marine beach on the dagger-like structures. Rami of uropod 3 subequal

island of Santiago. Previous to our studies, no in length.

stygofaunal crustaceans were known from this The is monotypic; type-species C. littoralis

island. n. sp. 22 J.H. Stock & R. Vonk - Marine interstitial Crustacea from the Cape Verde Islands

Derivatio nominis. - The generic name is a con- Genera nrs. 7 and 8 differ from Cabogidiella in

traction of the terra typica, the Cape Verde Islands, an apomorphic, 1-segmented palp of maxilla 1 (ver-

and the of the of the and in name type-genus family sus 2-segmented), "special" pleopods (third

The inter- Bogidiellidae. specific name refers to the exopodite segment minute or absent; endopodite at

tidal habitat. least as long as first exopodite segment).

No doubt, the new genus Cabogidiella is closest

Remarks. - Withinthe family Bogidiellidae (sensu to Antillogidiella (nr. 5) and Actogidiella (nr. 6),

Stock, 1981, and Coineau & Stock, 1986), there are both endemic to the West Indian area sensu lato.

that the transformation several (sub)genera share The latter two differ (1) in having coxal gills on

of of 1 into less one or both rami uropod more or pereionites 4 through 6 only (on 2 through 6 in the

dagger-shaped structures: (1) Pseudingolfiella new genus); (2) in lacking a dagger-like modifica-

Noodt, 1965; (2) Dussartiella Ruffo, 1979; (3) Ker- tion in the rami of uropod 1 of the male (although

guelenella Ruffo, 1974; (4) Bollegidia Ruffo, 1974; those of the female are modified as in both sexes of

(5) Antillogidiella Stock, 1981; (6) Actogidiella Cabogidiella); and (3) in showing sexual dimor-

Stock, 1981; (7) Marigidiella Stock, 1981; (8) phism in pleopod 2 (none in the new genus).

Marinogidiella Karaman, 1982*; (9) Cabogidiella As is usual in the Bogidiellidae, the (sub)genera

n. gen.; and perhaps (10) Aurobogidiella Karaman, are characterized by a combination of apomorphic

1988. Most of share of and characters of rather refined these genera the same type plesiomorphic a

habitat, viz. marine intertidalor sublittoral sands. nature. In Cabogidiella, the absence of sexual

Dussartiella from freshwater Only comes a spring dimorphism in the pleopods and the high number

and Antillogidiella has been found in a brackish of coxal gills (5 pairs) are plesiomorphic, but the

well and in an anchihaline cave. modified uropod 1 in both maleand female and the

Of these reduced molar of mandible genera, nr. 1 is characterized by an apo- part the are apo-

morphic (uniramous) uropod 3. Nr. 2 has an apo- morphic.

morphic (reduced) mandible palp, a parviramous

and uropod 3, a plesiomorphic (multisegmented)

in the littoralis exopodite pleopods. Nr. 3 is, amongst other Cabogidiella n. sp.

characters, characterized by apomorphic (uniseg- (Figs. 1-2)

rami of the Nr. 4 mented) pleopods. possesses an

The - apomorphic (uniramous) uropod 1. remaining Material. All from the intertidal zone of a beach in the mouth

of a dry riverbed, genera, nrs. 5 through 10, belong to the cluster S.W. ofAchada de Santo Antonio (island of

2 Santiago, S.W. of Praia); UTM coordinates TS 2785 x around the genus Bogidiella. l6 4885; 31 Jan. 1991. Of these, nr. 10 possesses, according to Kara- Sta. 91-24: 1 1 89 in o* (holotype), Ç (allotype), paratypes, man's (1988) Fig. 1J, a dagger-shaped endopodite a bank of fine gravel at mid-tide (Zoölogisch Museum Amster- in uropod 1, but in his text (: 101) this shape is dis- dam, ZMA Coll. Nr. Amph. 108.832).

1 missed as due to previous damage. The exopodite Sta. 91-21: paratype, in a tidal pool filled with sand and

mid-tide of gravel, at (ZMA Amph. 108.835). uropod 1 in this genus is more or less plesio- 11 Sta. 91-22: paratypes, in a creek with sandy bottom, below morphic, in that it bears some distal spines. the mid-tide level (ZMA Amph. 108.833). Aurobogidiella differs moreover from Cabogidiella Sta. 91-23: 12 paratypes, near the low-tide line, in rather fine in the plesiomorphic 4-segmented exopodites of sand (ZMA Amph. 108.834).

pleopods 1 and 2 (versus 3-segmented), the absence Accompanying interstitial fauna: Caecostenetroides mixtum

of n. sp. (Isopoda), Psammogammarusspinosus n. sp., Dulzura a coxal gill on pereionite 2 (versus presence), and lobata Stock & Vonk, 1991, Idunella sketi Karaman, 1980 (Am- a less reduced mandible (with spine row between in- phipoda), and Staurocladia sp. (Hydrozoa). cisor and molar).

Description. - Small-sized species (body length

* As the date of to of publication Karaman's see Coineau paper, 1.13-1.49mm, n = 10); males tend to be slightly & Stock, 1986: 580. smaller than females. Body shape as typical of the Bijdragen tot de Dierkunde, 62 (1) - 1992 23

Fig. 1. Cabogidiellalittoralis n. gen., n. sp., paratypes: a, antenna 1, ￿ (scale A); b, antenna 2, ￿ (A); c, right mandible,￿ (D); d, left corpus mandibulae,￿ (D); e, labium, ￿ (E); f, maxilla 1, ￿ (D); g, maxilla 2, ￿ (D); h, maxilliped,￿ (D); i, tip of maxillipedal from different of palp, ￿, seen a angle (B); j, gnathopod 1, ￿ (C); k, gnathopod2, ￿ (C); 1, coxal gill and oostegite pereiopod 5,

￿ (C). Scales on Fig. 2. 24 J.H. Stock & R. Vonk - Marine interstitial Crustacea from the Cape Verde Islands

Basis with Bogidiella-group; blind, colourless. 1 long seta on posterior margin. Propo-

with 2 of size that Antenna 1 (Fig. la) spines on ventral mar- dus same as of gnathopod 1, elongate-

of 2 with gin of peduncle segment 1 ; segment 2 about 75% ovate; palmar angle spines; palmar margin length of segment 1 ; segment 3 more than 50% of setae only. length of segment 2. Accessory flagellum Pereiopods 3 (Fig. 2a) and 4 of similar morpholo-

armed. 5 2-segmented, long. Flagellum 7-segmented; long gy, very poorly Pereiopod (Fig. 2b) slight-

than aesthetascs on segments 3 through 6. ly longer pereiopod 4, poorly armed. Pereio-

Antenna 2 (Fig. lb) with short, plump gland pod 6 as long as pereiopod 5 and of similar mor- cone. Flagellum 5-segmented; 1 short aesthetasc on phology. Pereiopod 7 (Fig. 2c) longer and more segment 5. robust than pereiopod 6 and more strongly armed,

with distal end of and Mandibles (Figs, le, d): Incisor short, robust, some long setae on carpus

anterior of teeth poorly developed. Right lacinia mobilis finely some very long setae on margin propo-

dus. Claw about 60% of of denticulate; left lacinia vaguely 5- or 6-dentate. very long, length propo-

Molar reduced in size; left molar with minute seta, dus. No lentiform organs on pereiopods 3 to 7. right molar without seta. Palp 3-segmented; seg- Coxal gills on pereionites 2 through 6, ovate with ment 2 distally swollen, with 1 seta; segment 3 nar- poorly demarcated basal stalk; very small (not ex-

than 3 ventral of coxal rower segment 2, with (sub)distal setae. tending beyond margin plate) on

Labium (Fig. le) with well-developed outer pereionite 2, small (but extending beyond coxal

inner lobes almost lobes; probably represented by plate) on remaining pereionites (Fig. II). Oostegites

stretch between lobes. in distal straight outer on pereionites 2 through 5, short, linear,

Maxilla 1 (Fig. If) with 2-segmented palp; palp part armed with some 8 long setae, which are about segment 2 with 3 distal setae. Outer lobewith 7 dis- as long as oostegite (Fig. 11). tal spines; inner margin of these spines, from lateral Epimeral plates (Fig. 2d) with convex, naked to medial, armed with0-3-0-1-3-0-3 denticles. Inner ventral margin. Posteroventral corner notched, lobe with truncate distal margin, armed with 2 with 1 setule, in plates 1 and 2; rounded, without setae. setule, in plate 3.

Maxilla 3 of similar 2 (Fig. lg) with 6 setae on outer lobe and Pleopods 1 to general morphology

4 on inner lobe. (Figs. 2e-g), but decreasing in length in an-

Maxilliped (Figs, lh, i): Inner and outer plates teroposterior direction. Peduncle with2 retinacula.

inner with 2 1 with 2 short short; plate distally simple teeth; outer Exopodite segment plumose setae; plate distally with 2 simple spines. Palp segment 3 segment 2 with 2 medium-sized plumose setae; seg-

with withrow of 5 teeth and 6 medialsetae. Shape of seg- ment 3 long and slender, 2 long plumose setae.

and show ments 3 4 up differently when seen from Endopodite absent. different 4 without angles (see illustrations). Segment (dac- Uropod 1 (Fig. 2h): Peduncle ven- tylus) more or less strongly curved, distally with 3 troproximal spine and without dorsal spines; distal elements (2 long, 1 short). spines small. Exopodite much shorter than endopo-

Coxal plates small, wider than long, not over- dite, upcurved, dagger-shaped, armed with 1 setule lapping. at about60% of its length. Endopodite likewise up-

Gnathopod (Fig. Ij): Basis with 1 long seta on curved and dagger-shaped, with 1 setule slightly posterior margin. Merus with finger-shaped dis- proximad of middle of segment. toposterior projection, armed with 1 seta. Carpus Uropod 2 (Fig. 2i) normal. Peduncle with 2 distal with rounded shorter than broad, posterior projection, armed spines only. Exopodite slightly en- with 1 barbed spine and 1 barbed seta. Propodus dopodite, both with short distal spines only. elongate-ovate; 2 palmar angle spines; palmar mar- Uropod 3 (Fig. 2j): Peduncle and rami armed gin convex, with 2 long setae and some small se- with very long spines. Rami of equal length. Exopo- tules. curved. Dactylus dite usually with groupof central spines (number of

2 between and with Gnathopod (Fig. Ik) longer than gnathopod 1. spines may vary 0 4), endopodite Bijdragen tot deDierkunde, 62 (1) - 1992 25

2. littoralis Fig. Cabogidiella n. gen., n. sp., paratypes: a, pereiopod 3, ￿ (scale A); b, pereiopod 5, ￿ (A); c, pereiopod 7, ￿ (A);

d, epimeralplates 1 to 3, ￿ (A); e, pleopod 1, ￿ (F); f, pleopod 2, ￿ (F); g, pleopod3, ￿ (F); h, uropod 1, ￿ (C); i, uropod 2, ￿

(C); j, uropod 3, ￿ (F); k, telson, ￿ (B). [ex. = exopodite.] 26 J.H. Stock & R. Vonk - Marine interstitial Crustacea from the Cape Verde Islands

middle of and of with 1 spine near medial margin. ele segments 4 5 equal length, some se-

Telson distal (Fig. 2k) roughly trapezoidal; mar- tae. Flagellum 7-segmented.

almost Labrum distal gin straight; 1 or 2 long distolateral spines, as illustrated (Fig. 3d); margin

1 short spine and 2 sensory setules on lateral almost straight.

margin. Left mandible (Fig. 3e) with 3-segmented palp,

in short. Incisor Lacinia mobilis No sexual differences observed pereional, segment 3 5-dentate.

5 Molar with pleonal, or urosomal appendages. 5-dentate; pre-lacinia spines. small,

short, plumose molar seta. Right mandible(Fig. 3f)

Remarks. - number of left but lacinia with 2 toothed Although a large specimens as one, finely cusps,

is available, not a single specimen is complete: the and 4 pre-lacinia spines; molar likewise with seta.

third Labium with distinct inner lobes posterior pereiopods and the uropod are very (Fig. 3g).

Left maxilla with often lacking. In the above description a combina- 1 (Fig. 3h) slender, narrow,

armed in distal with tion is made of the appendages of several para- 2-segmented palp, part 4 types. slender spines and 1 seta. Outer lobe with 7 spines,

the medial margin of which (from lateral to medial)

with 3-3-many-l-many-1-many denticles, respec-

Family Melitidae tively. Inner lobe roughly rectangular, with 1 short

Genus Psammogammarus S. Karaman, 1955 and 4 long setae. Palp of right maxilla 1 (Fig. 3i)

with much more robust than left, 1 seta and 4 short

Psammogammarus spinosus n. sp. spines.

(Figs. 3-6) Maxilla 2 (Fig. 3j) with oblique row of 4 strong

setae on inner lobe.

Material. - Sta. 91-21:1 cr holotype, 8 paratypes (ZMA Amph. Maxilliped (Fig. 4a): Palp segment 3 bulbous;

108.828); sta. 91-22: 2 (ZMA Amph. 108.830); sta. paratypes claw long, curved. Outer lobe with 2 spines on distal

91-23: 1 9 allotype, 2 paratypes (ZMA Amph. 108.829); sta. with margin and 2 on medial margin. Inner lobe 3 91-24: 14 paratypes (ZMA Amph. 108.831). For more details small distal spine-teeth. about these stations, see above under Cabogidiellalittoralis. Gnathopod 1 (Fig. 4b) much smaller than

gnathopod 2. Coxal plate much wider than long. Description. - Body shape resembling that of Ps. Merus lobate. Carpus longer than wide, shorter stocki Vonk, 1990. Coxal plates 1 to 4 touching or than propodus. Propodus with 2 palmar angle slightly overlapping, plates 5 to 7 not touching. spines; palmar margin convex, finely denticulate, Body length (without antennae and uropods) of

with row of 8 small, partly bifid, spines. Claw adult male 2.6 mm, of adult female 2.5 mm. curved. females with Ovigerous very few (1 to 3) large eggs. Gnathopod 2 (Fig. 4d) with long, ribbon-shaped Blind. Body unpigmented. Dorsum armed with a coxal gill. Coxal plate wider than long. Merus not few setules only. Lateral head lobe (Fig. 3a) lobate, but with small distoposterior point. Carpus pronounced, rounded; antennal sinus hardly indi-

triangular. Propodus elongate-ovate. Palmar mar- cated, unnotched.Epimeral plates (Fig. 3k) without with small gin convex, finely denticulate, 7 spines ventral armature, weakly pointed. and 2 palmar angle spines. Claw thin, curved. Appendages of female: Antenna 1 (Fig. 3b) 1.7 Pereiopods 3 (Fig. 5a) and 4 similar; coxal plate mm long. Peduncle armed with setae only; pedun- wider than long; coxal gill elongate ovate, nearly as cle segment 1 > 2 > 3. Accessory flagellum about basis. All long as segments sparsely setose. as long as proximal two flagellum segments com- Pereiopod 5 (Fig. 5b) much shorter than pereio- bined, 2-segmented. Flagellum 13-segmented, aes- pod 6. Coxal plate anterolobate, with somewhat thetascs on segments 3 through 12, thin, about75% club-shaped coxal gill, smaller than coxal gill of P3. of of length corresponding flagellum segment. Posterodistal corner of basis subangular; both an- Antenna 2 (Fig. 3c) much shorter than antenna 1. terior and posterior margin of basis almost straight. Gland cone distally truncate, rather short. Pedun- Bijdragen tot de Dierkunde, 62 (1) - 1992 27

Fig. 3. Psammogammarusspinosus n. sp., paratypes: a, head, from the right, ￿ (scale G); b, antenna 1, ￿ (H); c, antenna 2, ￿ (H); d, labrum, ￿ (I); e, left mandible, ￿ (J); f, right corpus mandibulae, ￿ (J); g, labium, ￿ (I); h, left maxilla 1, ￿ (J); i, palp of right maxilla 1, ￿ (J); j, maxilla 2, ￿ (E); k, epimeral plates 1 to 3, ￿ (G). Scales on Fig. 5. 28 J.H. Stock & R. Vonk - Marine interstitial Crustacea from the Cape Verde Islands

d, Fig. 4. Psammogammarus spinosus n. sp., paratypes: a, maxilliped, ￿ (scale J); b, gnathopod 1, ￿ (J); c, gnathopod2, ￿ (G);

gnathopod2, ￿ (G). Scales on Fig. 5. Bijdragen tot deDierkunde, 62 (1) - 1992 29

5. basal of Fig. Psammogammarusspinosus n. sp., paratypes: a, pereiopod 3, ￿ (scale G); b, pereiopod 5, ￿ (H); c, part pereiopod

6, ￿ (H); d, pereiopod 7, ￿ (H); e, basis of pereiopod 7, ￿ (I); f, telson, ￿ (I). [p.s. = prepeduncularspine of uropod 3.] - 30 J.H. Stock & R. Vonk Marine interstitial Crustacea from the Cape Verde Islands

Fig. 6. Psammogammarus spinosus n. sp., paratypes: a, uropod 1, ￿ (scale I); b, uropod 2, ￿ (I); c, uropod 3, ￿ (I). Scales on Fig. 5.

Pereiopods 6 and 7 subequal in length. Pereio- sal inner spine; 2 short distodorsal outer spines. Ex- pod 6 (Fig. 5c) with equilobate, small coxal plate, opodite slightly shorter than endopodite, with 1

anterior coxal dorsal of which bearing strong seta on margin; gill spine and 4 distal spines, one very small. Margins of basis almost straight; long. Endopodite with 1 or 2 dorsal spines and 5 posterodistal lobe angular. Pereiopod 7 (Fig. 5d) distal spines, of which 2 long. with small, non-lobate, rectangular coxal plate, Uropod 2 (Fig. 6b): Peduncle with 3 distal spines. bearing strong seta on anterior margin; no coxal Exopodite slightly shorter than endopodite, with 1 gill. Basis with almost straight margins; dorsal spine and 4 distal spines. Endopodite with 2 posterodistal lobe pointed. dorsal, 2 medial, and 5 distal spines.

Oostegites (Fig. 5a) linear, on gnathopod 2 and Uropod 3 (Fig. 6c) with long, ventral, prepedun- pereiopods 3, 4, and 5; with few, long, marginal cular spine (p.s. in Fig. 5f). Peduncle with 6 long setae. distal spines. Endopodite tapering, short, about as

Pleopods 1 to 3 "ordinary". Endopodite longer long as peduncle; with 1 distal seta and 2 short, than Ramiof first exopodite. pleopod 7-segmented; medial setae. Exopodite segment 2 longer than seg- of third second and pleopods 4- to 6-segmented. ment 1 ; segment 1 armed mostly with spiniform ele-

Two denticulate retinacula on peduncle. ments, segment 2 mostly with setiform elements.

Telson almost each Uropod 1 (Fig. 6a): Peduncle with strong ven- (Fig. 5f) completely cleft; troproximal spine; 2 laterodorsal spines; 4 medio- lobe with 2 very long lateral spines in subproximal dorsal spines; very long, slightly upcurved distodor- position (sometimes these 2 spines of very unequal Bijdragen tot de Dierkunde, 62 (1) - 1992 31

length), 1 mediolateral, plumose setule, 2 very long Karaman, 1980: 425-430, Figs. I-IV.

distal spines, and 2 long, subdistal sensory setules.

Material. - Sta. 91-22: 21 specimens; sta. 91-24: 42 specimens

(for details about these stations, see under Cabogidiella lit- Appendages of male. — Pronounced sexual dimor- toralis). phism in gnathopod 2 (Fig. 4c) only: basis with 1

seta on posterior margin; propodus larger than in Remarks. — This species, originally described from

female and somewhat more swollen; palmar margin anchihaline cave waters of Bermuda, is common in

with distinct emargination just distad of the two an- interstitia of coarse sand and gravel in shallow gle spines and 2 (hardly separated) swellings in dis- waters of several places in the West Indies and in

tal part. the Canary Islands. It is new to the Cape Verde calceoli sexual No on antennae. No dimorphism Islands.

in pleopods. None of the males examined has re-

tained the third uropod.

ISOPODA

- The name (Latin, Etymology. specific spinosus Family Gnathostenetroididae

alludes to the telson spines. spiny) long Genus Caecostenetroides Fresi & Schiecke, 1968

Remarks. - Stock & Sánchez (1987) have presented Caecostenetroides mixtum n. sp. a key to the species of Psammogammarus s.l. In the (Figs. 7-9) years after 1987 two more species have been

described in the genus, viz. Ps. stocki Vonk, 1990

Material. - Sta. 91-24: a (holotype), allotype, and Ps. fluviatilis Stock, 1991. The former species 1 1 9 53 para-

types (ZMA Is. 105.513); sta. 91-21: 22 paratypes (ZMA Is. keys out in couplet 3b of the key, the latter in 105.510); sta. 91-22: 14 paratypes (ZMA Is. 105.511); sta. 91-23: couplet 2b. The new species described in the present 5 paratypes (ZMA Is. 105.512). For more details about these sta-

out in 3a, with Ps. gar- paper keys couplet together tions, see under Cabogidiellalittoralis.

thi(Barnard, 1952), but it differs from garthi in the

telson with short in - following respects: (1) spines Description. Body length (cephalic frons to distal

in basis garthi, versus very long spines spinosus; (2) margin pleotelson) 3.5 mm (female paratype) or 3.3 of 7 with tall in pereiopod distoposterior point gar- mm (male holotype). Body (Fig. 7a) almost colour-

a small in thi, versus point spinosus; (3) palmar less, eye-less. Anterolateralcorners of pereionites 1

of male 2 in emargination gnathopod deep garthi, to 6 with small spine. shallow in coxal 7 and spinosus; (4) plate triangular Antenna 1 (Fig. 7c) 5-segmented; 1 long aes-

naked in and with 1 seta garthi, rectangular strong thetásc on apex of segment 5 and 1 distolateral aes- in of basis of thetasc spinosus; (5) posterior margin gnatho- on segment 4.

1 naked in with 2 setae in Antenna pod garthi, long spinosus; 2 (Figs. 7d, e): Small 1-segmented ex-

basis of 5 with (6) pereiopod overhanging postero- opodite inserted on peduncle segment 3; flagellum distal lobe in garthi, non-overhanging in spinosus; 18- to 25-segmented.

(7) distomedial peduncular spine of uropod 1 short Labrum(Fig. 7f) rounded. Labium(Fig. 7b) with in in distal of rami garthi, long spinosus; (8) spines many subapical setae. of 1 shorter in than in uropod garthi spinosus. Mandibles (Figs. 7g, h) with heavy incisor. Left

mandible(Fig. 7g) with 3-dentatelacinia mobilis; 2

serrate and 4 smooth spines between incisor and

Family Liljeborgiidae molar; molar conical, with 3 subapical setae and

Genus Idunella Sars, 1895 tuft of setules; palp 3-segmented, segment 2 with 1

barbed, 1 smooth, and 2 smaller spines; segment 3

Idunella sketi Karaman, 1980 sickle-shaped with 10-15 small spinules on endal 32 J.H, Stock & R. Vonk - Marine interstitial Crustacea from the Cape Verde Islands

Fig. 7. Caecostenetroides mixtum n. sp. (a, ￿ paratype, 2.5 mm; d, ￿ allotype, 3.3 mm; b-c, e-h, ￿ holotype, 3.3 mm): a, body, lateral labium 1 mandible (scale K); b, (L); c, antenna (L); d, antenna 2 (L); e, peduncle of antenna 2 (L); f, labrum (L); g, left (M); h, right mandible (M). Bijdragen tot de Dierkunde, 62 (1) - 1992 33

8. 2.7 3.2 Fig. Caecostenetroides mixtum n. sp. (a-c, ￿ holotype, 3.3 mm; d, i, ￿ paratype, mm; e, ￿ paratype, mm; f, ￿ allotype,

2 1 3.3 mm; g-h, ￿ paratype, 2.5 mm): a, maxilla 1 (scale M); b, maxilla (M); c, maxilliped (L); d, pereiopod (L); e, pereiopod 2 (L);

Scales f, distal part of pereiopod 1 (M); g, pereiopod 3 (L); h, pereiopod 4 (L); i, pereiopod 5 (L). on Fig. 7. 34 J.H. Stock & R. Vonk - Marine interstitial Crustacea from the Cape Verde Islands

dite with margin and 1 strong apical spine. Right mandible with 3 plumose distalsetae, exopodite 2 se-

(Fig. 7h) with 10-12 spines between incisor and tae, 1 distal and 1 subdistal. Pleopod 4 cr (Fig. 9h)

and 3 molar; no lacinia observed. 9 with 2-segmented exopodite, bearing

Maxilla 1 (Fig. 8a): Outer lobe with 6-8 denticu- plumose distal setae; endopodite with 1 distal

late spines; inner lobe with several distal and sub- plumose setule. Pleopod 5 cr (Fig. 9i) and 9 unira-

with distal distal setae and setules, and a small, toothed dis- mous, unsegmented, 1 short plumose

tomedial element. seta.

Maxilla 2 (Fig. 8b) with 3 lobes: outer lobe with Uropod (Fig. 9j): Peduncle and rami richly se-

central lobe with 3 inner lobe about half 5, pennate spines, tose; exopodite as long as endopodite.

with 9-11 distal and mediodistal setae, one of Marsupium consisting of large, overlapping

which barbed. translucent plates, devoid of setae, attached lateral-

Maxilliped (Fig. 8c) with elongate-oval epipo- ly to pereionites 2 to 5. Genital papillae of male

dite. Endite with straight medial margin, armed (Fig. 9k) protruding ventroproximally from

with several setules and 3 coupling hooks, opposing pereionite 7.

3 hooks on the contralateral side; anterior margin No clear secondary sexual differences have been

truncate. Palp 5-segmented, segments 1 to 3 ex- observed, except for the females being somewhat

panded, segments 4 and 5 narrow. larger than the males, and of course in the pleopods

Pereiopod 1 (Figs. 8d, f): Carpus elongate- 1 and 2.

trapezoidal, ventrally with 4-5 pectinate setae and

8-12 smooth - setae. Propodus elongate-rectan- Remarks. Four species of Caecostenetroides are gular, twice as long as wide; ventral margin lined actually known: C. ischitanum Fresi & Schiecke,

with 6 conical spines and 1 long palmar angle spine, 1968; C. nipponicum Nunomura, 1975, C. rudera-

latter finely serrate on inner margin and with thin lis Stock & Vonk, 1990, and C. ascensionis Vonk & extension Palmar at tip. margin slightly convex, Stock, 1991. Caecostenetroides mixtum n. sp. is with 2 spines, one of which serrate. Dactylus with closely related to C. ruderalis, from marine inter-

3 denticulate teeth on endal margin; unguis less stices of Tenerife (Canary Islands). The most im- than half doubtthat the second male as long as dactylus. portant difference is no

Pereiopods 2 to 7 (Figs. 8e, g-i; 9a-c) subsimi- pleopod does not resemble that of C. ruderalis, but

lar. Propodus usually with 4 crooked spines on en- that of two geographically more remote species, C. dal sometimes margin, with 2, 3, or 5; presence of ascensionis and C. nipponicum (exopodite with

inner plumose seta on margin of basis variable as short distal seta, instead of a long seta; endopodite well. with Dactylus 2 subequal claws, a sigmoid dis- with bunch of distal spines, instead of one large sig- tal and smaller distal differences seta, some setules. Remaining moid spine). Other, less striking, per- setation rather irregular. tain to (1) the first antenna, which bears 2 aes-

Pleonites Two free well- in in rude (Figs. 7a, 9k): pleonites, thetascs C. mixtum, versus 1 C. ra lis; (2) developed, not enclosed by pereionite 7. the presence of anterolateralspines on the corners

Pleopods: Pleopod 1 (Fig. 9e) present in cr, lack- of the pereionites, absent in C. ruderalis; (3) ab-

in ing 9 ; large and operculiform, deeply cleft, sence of distal spiniform processes on the labium,

2 covering remaining pleopods. Pleopods cr (Fig. versus presence in C. ruderalis; (4) more post-

with medial 9f) separate, basipodite 3 setae; exopo- incisor spines, several of them naked; (5) broad, dite last with smooth of 2-segmented, segment 1 short seta; en- spines on propodal margin pereiopod 1,

2 with bundle of 3 instead of 4 endal on dopodite segment vaguely pec- spines dactylus. tinate no observed The of a second aesthetasc on antenna "setae"; longitudinal grooves presence

the along segments. Pleopods 2 9 (Fig. 9d) fused, 1 is encountered also in C. ischitanum, from the

with medioterminal operculiform, notch and 4 se- Gulf of Naples, but not in the other species. tae. Pleopod 3 cr (Fig. 9g)and 9 with 2-segmented

- The alludes exopodite and 1-segmented endopodite; endopo- Etymology. specific name, mixtum, Bijdragen tot deDierkunde, 62 (1) - 1992 35

9. Caecoslenetroides mixtum 3.2 2.7 3.3 Fig. n. sp. (a, c-d, ￿ paratype, mm; b, ￿ paratype mm; e-f, ￿ holotype mm; g-j, ￿ para- type, 2.5 mm): a, pereiopod 6 (Scale L); b, pereiopod 7 (L); c, pereiopod 7 (L); d, pleopod 2 (L); e, pleopod 1 (L); f, pleopod 2 (L);

4 7 g, pleopod 3 (L); h, pleopod (L); i, pleopod 5 (L); j, uropod (L); k, pereionite with genital papillae(pleopod 1 not shown) (K). Scales

7. on Fig. 36 J.H. Stock & R. Vonk - Marine interstitial Crustacea from the Cape Verde Islands

i to the mixture of morphological traits of various ly, Aurobogidiella,n. gen. Poljoprivreda Sumarstvo, 34(4):

species of Caecostenetroides. 93-105.

Nunomura, N., 1975. Marine Isopoda from the rocky shore of

Osaka Bay, Middle Japan, 1. Bull. Osaka Mus. nat. Hist., 29:

15-35. Acknowledgements Noodt, W., 1965. Interstitielle Amphipoden der konvergenten

Gattungen Ingolfiella und Pseudingolfiella n. gen. aus

Südamerika. Crustaceana, 9(1): 17-30. The fieldwork for the present study was executed with the aid of

Ruffo, S., 1974. Nuovi Anfipodiinterstiziali delle coste del Sud a NATO (Brussels) Collaborative Research Grant, contract Africa. Atti Ist. Veneto Sei. Lett. Arti, (CI. Sei. nat.) CRG 880011, the Treub Maatschappij (Amsterdam), and the mat.

132: 399-419. Netherlands Foundation for the Advancement of Tropical

1979. Descrizione di due nuovi anoftalmi Research (WOTRO, The Hague). We thank Mr. Kees Hazevoet, Ruffo, S., Anfipodi

dell'Iran e del Madagascar. Boll. Mus. civ. Stor. nat. Verona, 1N1A, São Jorge dos Órgãos (Cabo Verde) for his assistance on

6: 419-440. the island of Santiago, and ETI (Amsterdam) for aid in com-

1981. The and Stock, J.H., zoogeography of the puter logistics. family Bogidiellidae(Crustacea, Amphipoda),with emphasis

on the West Indian taxa. Bijdr. Dierk., 51(2): 345-374.

Stock, J.H., 1991. A new species of Psammogammarus (Am- References phipoda, Melitidae) from river alluvia in Luzon, Philippines.

Stygologia, 7(4): 227-233.

Stock, J.H. & E. Sánchez, 1987. Psammogammarus initialis n. Barnard, J.L., 1952. A new species of amphipod from Lower

a new mediolittoral interstitial California (genus Eriopisa). Pacific Sei., 6: 295-299. sp., amphipod from Tenerife. Stygologia, 3(3): 264-277. Bou, C., 1975. Les méthodes de récolte dans les eaux souter-

J.H. & R. 1990. Marine interstitial Asel- raines interstitielles. Annls. Spéléol., 29(4): 611-619. Stock, Vonk, Isopoda

lota of the superfamily Gnathostenetroidoidea. Cah. Biol, Coineau, N. & J.H. Stock, 1986. Amphipoda, Bogidiellidae.In:

31: 5-24. L. Botosaneanu (ed.), Stygofauna mundi: 574-580 (E.J. mar.,

J.H. & R. 1991. Une nouvelle de Brill, Leiden). Stock, Vonk, espèce Dulzura,

hadzioïdes connu seulement de Fresi, E. & U. Schiecke, 1968. Caecostenetroides ischitanum genre d'Amphipodes jusqu'ici

l'Indo-Pacifique, découverte aux îles du Vert At- - A Cap (Océan (Isopoda, Parastenetriidae) new genus and species from Cah. Biol. 32: 477-486. the Bay of Naples. Pubbl. Staz. zool. Napoli, 36: 427-436. lantique). mar.,

Vonk, R., 1990. Psammogammarus stocki n. sp. (Crustacea, Karaman, G.S., 1980. Revision of genus Idunella Sars with

Amphipoda, Melitidae) from beach interstitia on Tenerife. description of new species, I. Sketi, n. sp. (fam. Liljeborgii-

271-276. dae). Acta adriat., 21(2): 409-435. Bijdr. Dierk., 60(3/4):

Vonk, R. & J.H. Stock, 1991. Caecostenetroides n. Karaman, G.S., 1982. Critical remarks to the recent revisions of ascensionis

sp., a blind interstitial isopod (Asellota, Gnathostenetroi- Bogidiella-group of genera with study of some taxa (fam.

from Ascension South Atlantic. Gammaridae).Poljoprivredai Sumarstvo, 28 (3/4) ("1981"): doidea) island, Trop. Zool.,

4: 89-98. 31-57.

Karaman, G.S., 1988. Thenew genus of the family Bogidiellidae

()from coastal seawater (mesopsammon)of Ita- Received: 22 August 1991