TANTULACUS HOEGI GEN. ET SP. NOV. (TANTULOCARIDA: DEOTERTHRIDAE) FROM THE MEIOBENTHOS OF THE FAROE BANK, NORTH ATLANTIC

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1 TANTULACUS HOEGI GEN. ET SP. NOV. (TANTULOCARIDA: DEOTERTHRIDAE) FROM THE MEIOBENTHOS OF THE FAROE BANK, NORTH ATLANTIC RONY HUYS, PETER F. ANDERSEN & REINHARDT M. KRISTENSEN SARSIA Huys, RONY, PETER F. ANDERSEN & REINHARDT M. KRISTENSEN Tantulacus hoegi gen. et sp. novo (Tantulocarida: Deoterthridae) from the meiobenthos of the_.faroe Bank, North Atlantic. - Sarsia 76: Bergen. ISSN Three free-living tantuli of a new genus and species, Tantulacus hoegi, were discovered among the meiofauna from deep carbonate shell-sand on the Faroe Bank. The host.is unknown. Tantulacus is referred to the Deoterthridae on account of its larval characters. It occupies an intermediate positon between Deoterthron - Aphotocentor and the other deoterthrid genera. It can be readily distinguished from other tantulocaridans by. the,presence of a distinct rigid spine on the endopod of the second to fifth thoracopods. Some aspects of the deoterthrid stylet are discussed. T. hoegi is the fourth tantulocaridalt" described from the temporary meiobenthos. Rony Huys, Zoology Institute, State University of Gent, K.L. Ledeganckstraat 35; B-9000 Gent, Belgium, and Netherlands Institute of Ecology, Centre for Estuarine and Coastal Ecology, Vierstraat 28, 4401 EA Yerseke, The Netherlands. - Peter F. Andersen& Reinhardt M. Kristensen, Zoological Museum, Universitetsparken 15, DK-2100, Denmark. INTRODUCTION Tantulocarida utilise a wide variety of marine epibenthic crustaceans as hosts: misophrioid and harpacticoid copepods, isopods, tanaids, cumaceans, and ostracods. Although some of these fascinating ectoparasitic crustaceans were first described nearly a century ago (BONNIER 1903), it was BOXSHALL & LINCOLN'S (1987) trail-blazing account on the life cycle that aroused the interest in the group. The recent discovery of infective larvae (tantuli) in the interstitial environment of sub littoral sediments (Huys 1991) also has attracted the attention of meiobenthologists. Sorting of meiofauna from deep muddy bottoms in the western Mediterranean led to the discovery of three new genera (Huys 1989, 1991) and a preliminary survey of the meiofauna of the Antarctic Weddell Sea produced at least four new species (R. Huys own obs.). During processing of meiobenthic animals collected during the BIO FAR expedition to the Faroe Bank in Spring 1990, one of us (RMK) found three specimens of a tan tulocaridan representing a new genus and species described below. Seven species have thus far been described from northern Europe but inadequate sampling and lack of information in many other areas hinders biogeographical analyses. Most tantulocaridans (Microdajidae, Onceroxenidae) from northern Europe were Contribution No. 7 of the BIOFAR-project, Kaldbak Laboratory, FR-180 Kaldbak, Faroe Islands. discovered upon inspection of tanaid hosts collected from the Rockall Trough, the Scottish coasts and Scandinavia, although a few species were found.t\} parasitise harpacticoid copepods (Huys & Box SHALL 1988) or asellote isopods (BOXSHALL &-LIN COLN 1987). The primarily copepod-infesting.deoterthridae is perhaps the most diverse family in number of species but only one species has previously been recorded from North European waters (Huys & BOXSHALL 1988). This tantulocaridan., Bore'ltantulus kunzi Huys & BOXSHALL, was found on the harpacticoid Cylindropsyllus laevis BRADY in the Skagerrak. The new species described herein represents the second deoterthrid tantulocaridan from northern Europe and is also the first record of a sediment-inhabiting tantulus from this area. MATERIAL AND METHODS Three tantuli were found during sorting of meiofauna from the sampling site BIOFAR-627 (61 17'42" N, 08 32'18" W; depth 260 m) located near an area of natural gaseous discha~e on the Faroe Bank (North Atlantic). The bottom sample was taken during the RN Valdivia-Fahrt 95 (coordinator H. Thiel, University of Hamburg) on. 18 April 1990 with a large, anchor dredge by R.M. Kriste-nsen and H. Thiel. The sediment consists of a mixture of very fine carbonate shell-sand and basalt-sand derived from the edge of the Faroe bank. The very clean sediment contained a negligible amount of detritus, but high numbers of bacteria were encountered (presumably methano-bacteria associated with the gaseous extrusions). Accompanying meiofauna includes nematodes, harpaticoid copepods, gastrotrichs, loriciferans, and tardigrades. 287

2 The holotype is dissected on 2 slides which are deposited in The Natural History Museum, London under registration No The paratype mounted on a SEM-stub is deposited in the Zoological Museum of Copenhagen (ZMNO) under registration No. BIOFAR 627-stub 14. The Epon-embedded specimen is retained in the personal collection of one of us (RMK) for future TEM-investigation. Tantulocaridans were extracted from the sediment by osmotic fresh-water shocking and stained with Rose Bengal. The holotype tantulus was fixed in 4 % buffered formalin solution, stored in 2 % aqueous glycerine and examined as a temporary preparation in glycerine. All drawings were made under oil immersion using a Leitz Dialux 20 microscope with interference contrast. Judicious manipulation of the coverslip allowed careful examination of the detailed morphology of the thoracopods and the cephalon. After completing the description, the specimen was transferred to lactophenol mounting medium and the preparation was sealed with glyceel (Gurr, BDH Chemicals Ltd, Poole, England). The paratypes (2 specimens) were fixed in tri-aldehyde, post-fixed in osmium tetroxide and prepared for scanning electron microscopy. One specimen was dehydrated through graded acetone, critical point dried with CO 2, mounted on a stub, sputter coated with gold, and examined on a JEOL JSM-840 scanning electron microscope. The second paratype was embedded in Epon 812 for future transmission electron microscopy. The terminology of the body segmentation is adopted from HUYS (1991). TAXONOMY Tantulacus gen. n. Diagnosis. Class Tantulocarida. Family Deoterthridae. Tantulus larva comprising cephalon, thorax of 6 pedigerous somites and 1 limbless somite, and an undivided abdomen. First thoracic tergite largely concealed beneath posterior margin of dorsal cephalic shield. Cephalic shield triangular; ornamentation consisting of 4 anterior plus 7 posterior pairs of pores, surface lamellae present. Cephalic stylet curved in lateral aspect. Thoracopods 1 to 5 each with unsegmented protopod bearing a well developed medial endite. Exopod of thoracopods 1 to 5 2- segmented with 4 (legs 1-3) or 5 setae (legs 4-5). Endopod I-segmented with 1 seta (leg 1) or 1 seta plus a rigid, acutely curved spine (legs 2-5). Thoracopod 6 without distinct rami, with coupling spines on medial margin of protopod and 2 setae apically. Abdomen with transverse lamellae running around the somite. Caudal rami distinct, armed with 1 short and 2 long setae. Host unknown. Etymology. - The generic name is derived from the Latin tantulus, meaning very small, and acus, meaning needle and refers to the peculiarly shaped, rigid endopodal spine on the second to fifth thoracopods. Gender: feminine. Type and only species. Tantulacus hoegi gen. et sp. n. DESCRIPTION Tantulacus hoegi gen. et sp. n. 3A-F), the tantulus larva la-b; Holotype (Figs 1-3: based on interference contrast microscopy only) External morphology Body (Fig. la-b) comprising a cephalon covered by a dorsal shield, 6 pedigerous thoracic somites, 1 limbless thoracic somite and a I-segmented abdomen. Total body length about 150 JLm, measured from the tip of the cephalon to the posterior margin of the abdomen. Cephalon more or less triangular in dorsal view, tapering anteriorly towards the oral disc; posterior margin straight with posterolateral angles represented by slightly pronounced lobes; ventrolateral margins with minute knob-like extension anterior to posterolateral pores" Cephalic shield about 1.4 times longer than wide (70,urn x 50,urn). Integument of shield with various longitudinal surface lamellae: anterior half with 2 dorsal and 2 lateral lamellae, posterior half with 5 dorsal (1 of which middorsal) and 2 ventrolateral lamellae. The rostrum is absent. The oral disc is about 39,urn in diameter (Fig. 2C) and is positioned far anteriorly so that it is partly visible in dorsal aspect (Figs lb, 2A). The disc is lobate anteriorly and possesses a tiny filament-like structure on both sides of the central opening (Fig. 2C). Anterior to the dorsal integument of the shield are membraneous flap-like extensions (s.m.) which can sheath the anterior part of the disc when it is attached to the host (Figs la, 2B). A funnel-shaped organ (f. o. ; Fig. 2C) is present just anterior to the aperture through which the cephalic stylet is extruded; the organ has a minute pore apically and is almost completely withdrawn so that it is no longer visible in lateral aspect (Fig. 2B) There are 11 pairs of simple pores on the shield (Fig. la-b); 4 pairs in the anterior part (on both sides arranged in the typical deoterthrid L-pattern) and 7 pairs around the posterior margin of which 1 pair is located subdorsally and another one surrounds a tiny,..""ll.w'" none of the pores was covered by hyaline substance. The ventral surface of the shield lacks pores and lamellae altogethel There are no cephalic ~n'n"""'_ ages. The cephalic stylet is completely extruded in the holotype (Figs la, 2B). It is about 44 /-tm and distinctly curved in lateral view. The central aperture lies slightly anterior to the middle of the oral attachment disc and is surrounded a collar-like zone which is slightly folded over Free thoracic so mites each with distinct Fig. 1. Tantulacus hoegi gen. et sp. n. Holotype tantulus. A. Habitus, lateral view. B. Habitus, dorsa! view

3 20 )Jm A B B / / c Fig. 2. Tantulacus hoegi gen. et sp. n. Holotype tantulus. A. Cephalon, dorsal view showing internal structures (external ornamentation omitted). B. Same, lateral view [Inset showing detail of stylet apex]. C. Oral disc and associated structures, ventral [distal part of stylet omitted]. Abbreviations: b.c. = buccal capsule; b.g. = buccal gubernaculum; c.s. = cephalic stylet; f.o. = funnel-shaped organ; g.b. = glandular body; g.s. = globular structure; h.b. = hyaline band; s.m. = sheathing membrane; r.f. = remnant of funnel-shaped organ. that of first somite largely concealed beneath posterior rim of cephalic shield (Fig. la-b). Tergites lacking conspicuous surface ornamentation; those of somites 2 to 6 with posterolateral corner produced into spinous process (Fig. la). Thoracic somites I to 6 bearing a pair of reduced swimmings legs. Thoracopod I (Fig. 3A) with large I-segmented protopod, subrectangular in shape and with small medial endite bearing at least 1 minute spine. Endo- pod represented by elongate segment bearing apical seta and a spatulate process along the inner lateral margin. Exopod 2-segmented; proximal segment much wider than long, unarmed; distal segment longer than wide, with 2 distal processes each bearing a long inner seta and a short outer seta which are confluent basally. Thoracopods 2 and 3 (Fig. 3B-C) with mented pro top od bearing bulbous medial fl. Holotype tantulus. A. Thoracopod L B. Thoracopod 2. C. 'h"".rnn{,n 5. F. Thoracopod

4 armature of endite under light microscope visible as 2 spinous elements (coupling spines» Endopod represented by long segment; outer margin with two armature elements closely set in a socket, proximal one flexible and slender, distal one rigid, spiniform and acutely curved; endopodal apex transformed into gripping apparatus consisting of distal spinous process and movable, subdistal spatulate element Exopod 2-segmented; proximal segment without any armature, distal segment with 2 large setae and 2 smaller ones> Thoracopods 4 and 5 (Fig> 3D-E) similar to preceding ones except for exopodal armature consisting of 5 setae in total Thoracopod 6 (Fig> 3F) uniramous; comprising a single protopodal segment with 2 coupling spines along the inner margin and 2 long setae apically> Last thoracic somite limbless; L9 times wider than long (8)3 /lm x 15>8 /lm» Abdomen (Fig> la-b) unisegmented, L1 times longer than wide (19)1 /lm x 17>5 {Lm); surface with minute epicuticular lamellae arranged in regular pattern consisting mainly of transverse lamellae> Dorsal hind margin with two combs consisting of several fine spinules, the tips of which do not extend to the posterior margin of the caudal rami> Ventral posterior border setulose> Caudal rami distinct, almost square; armed.with 1 short and 2 long setae (Fig> la-b); longest seta inserting apically, shortest one lateral near base of caudal ramus> Internal morphology The slender cephalic stylet (cs» is medially positioned in the cephalon, its distal half protruding through the central pore of the oral attachment disc (Fig> 2A-B) > The base of the stylet is expanded laterally and dorsally but lacks well defined barbs> The posterior part of the stylet is clearly hollow and unlike previous observations the central core seems to continue as a fine duct in the distal shaft all the way to its apex> The tip of the stylet does not taper to a very fine point but shows 6 spinous processes arranged in pairs around a minute pore and decreasing in size ventrally (Fig> 2B). The cuticular guiding apparatus or buccal gubernaculum (b.g.) is discernible around the basal part of the stylet It essentially consists of a thick-walled conical structure, its lateral, ventral and dorsal margins being formed by thin, backwardly directed extensions (Fig. 2A-C). The buccal gubernaculum does not seem to have an anterior middorsal process. The buccal capsule (b.c.) (or at least part of it) is rmwp'''''tl by a chitinous tubular structure in front of the gubernaculum and encloses the middle part of the stylet. The paired stylet protractors originate anteriorlyon the lateral wings of the gubernaculum and insert posteriorly to the base of the The strongly developed protractors are broad strands which leave the stylet fully exposed dorsally even when they are in a state of maximum contraction as in the holotype (Fig. 2A» A hyaline band (h>b», probably representing a tendon, is visible at about midway of the protractors (Fig> 2A» The stylet retractors which withdraw the stylet were not observed in the holotype. Four large, globular structures (g.s.) are arranged in pairs on both sides of the stylet, occupying most of the space in the half of the cephalon. Two other structures, referred to as glandular bodies (g>b.) by Huys (1991), are found near the buccal gubernaculum, and their cretory?) ducts seem to lie in close contact with the base of the stylet. A third glandular body was discerned in the posteroventral portion of the Ion. Only the apical part of the funnel-shaped organ (f.o.) is present in the holotype and is visible outside the disc although a remnant (r.f.) of the internal part of the organ (muscle?) could be discerned dorsally to the cephalic stylet. Paired longitudinal trunk muscles are present dorsally and ventrally. It has not been possible to identify precisely the number of strands and the sites of origin and insertion of the various muscles> Remnants of extrinsic and intrinsic thoracopodal muscles were found as well Paratype (Figs 4--6). SEM observations of one of the paratypes revealed additional information on the fine structure of the oral disc, the thoracopods and the abdomen. The ventral surface of the cephalon is concave and shows 4 ventrolateral, surface lamellae which are arranged in pairs (Fig. 4A). These longitudinal membranous ridges extend onto the anterior end of the cephalon where they conceal the sheathing membrane (Fig. 4B). The innermost lamellae have a lateral incision immediately behind the oral disc, the outermost ones are longer and extend onto the posterolateral angles of the cephalic shield 4A). The midventral region of the cephalon does not show any ornamentation. Fig. 4. SEM micrographs of Tantulacus hoegi gen> et sp. n. Para type tantulus. A> Habitus, ventrolateral view. B. Oral disc showing extruded funnel-shaped organ. C Funnel-shaped organ, posterior view. D> Same, lateral view> Scale bars: A, B = 10 pm; C, D = 1 pm>

5 The aggregation of foreign particles apparently trapped in a gluey substance hinders a careful examination of the oral disc (Fig. 4B). The tiny filaments on both sides of the central aperture seem to arise from the surface of the oral disc rather than from the margin. (Fig. 4B). The pinnate ornamentation suggests a certain resemblance to genuine setae and raises the possibility that they represent vestiges of the antennules (cf. aesthetascs in adult male) or some other kind of cephalic limbs. The funnel-shaped organ is completely extruded in the paratype (Fig. 4B). It is surrounded at its base by a cylindrical structure, presumably guiding the organ during extrusion (Fig. 4B, C). The organ is constricted subdistally and shows a longitudinal wing-like extension on either lateral margin (Fig. 4C, D). The apex is modified into a discoid structure which fits in the large conical aperture (4.3,um) of the oral disc during complete withdrawal of the funnel-shaped organ. The posterolateral angles of the cephalic shield are backwardly produced into a spinous thin-walled extension bearing two simple pores and a third one showing a raised collar surrounding a tiny filament (sensillum?) (Figs 4A, SB). The protopods of all thoracopods show a distinct ornamentation consisting of dorso-ventral surface lamellae along the outer margins and numerous setules, being particularly abundant at the outer anterolateral and the inner posterolateral sufaces (Fig. SA). The exopodal setae, and to a lesser extent the endopodal ones, have conspicuous ridges composed of minute transversely connected longitudinal lamellae (Fig. SC). These ridges are found only along the posterior face of the setae, whereas the anterior face is provided with a double longitudinal row of setules. A similar setulation was also observed for the caudal rami setae, but ridges were apparently missing (Fig. 6B). The endopodal gripping apparatus (Fig. SC) consists of a rigid, spatulate spine with proximally directed denticles, and a slender seta-like element with flexible distal part. The grappling hooks on the thoracopodal endites are of the usual palmate type with three pairs of proximally directed barbs (Fig. SD). The posterior margin of the abdomen shows a series of paired membranous extensions consisting of closely set setules and covering the anterior part of the caudal rami (Fig. 6A). Two of these extensions are also discernible at the ventral hind margin (Fig. 6B). Adult male and female: unknown. Etymology. - The is dedicated to our colleague Dr Jens T. H\'Ieg, Institute of Cell and Anatomy, University of in recognition of his outstanding contributions to the biology and ultrastructure of rhizocephalan barnacles. DISCUSSION The genus Tantulacus is placed in the Deoterthridae on account of its larval characters (Huys including the unisegmented abdomen, the absence of a rostrum and the cephalic pore pattern. The cephalic pores are arranged in the configuration which was first described for Coralliotantulus coomansi Huys and represents a slight deviation from the basic deoterthrid pattern due to the presence of an extra pore at the posterolateral angle (Huys 1990b). Epicuticular lamellae represent another important aspect of tantulocaridan body ornamentation. These surface lamellae are sometimes extensively distributed all over the entire like in Aphotocentor styx Huys, though in most species they are restricted to the cephalon where they are arranged longitudinally and/or to the abdomen where the lamellae are primarily transverse. Abdominal lamellae may frequently mark the boundaries between individualised somites formerly present in a basipodellid-like ancestor with a multisegmented abdomen and may be mistaken for true segmental joints. It is possible that the alleged 2segmented condition of the abdomen in the Onceroxenidae is due to such a misinterpretation. In Tantulacus, and in most other Deoterthridae these lamellae form part of a complex network and vestiges of their original transverse arrangement remains visible in dorsal aspect only. All Deoterthridae have 2 armature elements on the endopod of the second to fifth thoracopods, but in none of the previously described genera these elements are modified. T. hoegi can therefore be readily distinguished from the other members of the family by the presence of a distal rigid on these rami. The maximum number of armature elements found on any thoracopodal exopod is five and is retained only in the Dcoterthridae. All known species of Deoterthron BRADFORD & HEWITT and Aphotocentor Huys show this number on the second to fifth thoracopods whilst all other genera described thus far in the family have 4 setae at the most. The new genus holds an intermediate because of the retention of this ancestral number Fig. 5. SEM micrographs of Tantulacus hoegi gen. et sp. n. Paratype tantulus. A. Posterolateral angle of cephalic shield, lateral view. C Endopodal gripping apparatus of ridged ornamentation of exopodal setae. D. Grappling hook of thoracopod 6. Scale bars: A = 294 B. 295

6 Fig, 6, SEM micrographs of Tantulacus hoegi gen. et sp. n. Paratype tantulus. A, Posterior thoracic somites and abdomen, dorsal view. B. Posterior part of abdomen and caudal rami, ventral view. Scale bars: A = 10 pm; B = 1 /-lm. on thoracopods 4 and 5 only. Differences in setation between individual thoracopods (2-5) are uncommon amongst tantulocaridans. In Dicrotrichura tricinta also to the Deoterthridae, the second thoracopod is different from legs 3 to 5 (Huys 1989). T. shows another possible armature formula 2-3 different from legs 4-5) and it is conceivable that other combinations will be revealed when more species become available. In general the reduction in thoracopodal armature appears in a posterior to anterior series from the fifth onwards, The first thoracopod represents then the most reduced limb of the series (except for the in which all limbs are extremely reduced), not only reductions in setation but sometimes also of the entire endopod. The new is also m 4 setation elements on the first whereas the maximum found thus far was 3 & BOXSHALL 1988; Huys 1991). The presence of Tantulocarida in marine sediments and their status as part of the temporary meiobenthos is now well established with records from the Mediterranean, the Antarctic and the 296 North Atlantic. Prior to attachment to the crustacean host tantulocaridan larvae pass through a benthic phase during which successful location and infestation of a suitable host are the prime and only requirements. Since tantuli are not equipped with functional mouthparts, it is presumed that they are non-feeding and therefore will soon start to deteriorate in the absence of a host. Several features of the internal morphology suggest that the holotype specimen was already in such a disintegrated condition at the time it was collected, probably indicating that it had not been successful in the location of a suitable host. For instance, the paired retractor muscles necessary to withdraw the stylet after penetration of the host cuticle were completely missing. With the exception of the external apical part, the entire organ was degenerated leaving only a defined remnant internally. Similarly, the musculature of the trunk somites and the thoracopods were partly deteriorated, hindering exact identification of the precise sites of origin and insertion of the respective muscles. It is unlikely that this selective breakdown of internal structures is the result of the fixation or preservation techniques employed since several other structures stylet protractors) were not yet disintegrated. The stylet of T. hoegi exhibits some interesting features, The six minute processes arranged at the apex of the stylet have not been observed before in any other tantulocaridan and this leads to the suggestion that the tip of the stylet might have been broken off (perhaps due to penetration of the host's integument) in those tantulocaridans (mostly Deoterthridae) that displayed a blunt stylet apex. The apical processes were arranged around a central pore which is connected via a thin duct with the hollow base of the stylet. This new observation suggests that at least in the Deoterthridae chemical dissolution (by glands that closely adjoin the base of the stylet) aids in the penetration of the host cuticle. Representatives of the latter family lack well-defined barbs at the posterior rim of the stylet and the stylet itself is less robust and rather delicate compared to the Microdajidae, indicating that the puncturing of the host integument is not purely mechanical (Huys 1991). It is unlikely that the hollow stylet is used to obtain host's body fluids or predigested tissues because all structures necessary to operate the stylet disintegrate immediately upon successful attachment and subsequent penetration of the host. The conical aperture through which the funnel-shaped organ penetrates is much larger than the central pore used to extrude the stylet, Huys & BOXSHALL (1988) found that the latter pore in Boreotantulus kunzi is only about 0.7 fj.m in diameter and observations of other tantuli revealed a similar size. This leads to the attractive suggestion that the funnel-shaped organ performs a role in feeding rather than in host location by using the puncture hole made by the stylet. The short tissue strand observed by BOXSHALL & LINCOLN (1987) in a female Onceroxenus curtus still attached to host cuticle might be a remnant of the funnel-shaped organ and the raised cylindrical structure coinciding with the central puncture point made in the integument might well be homologous with the proximal cylindrical structure surrounding the basal part of the funnel-shaped organ in non-attached tantuli. With a total body length in the region of 150 fj.m, T. hoegi is amongst the largest tantulocaridans discovered thus far, and is by far the largest deoterthrid known. Only Doryphallophora aselloticola (BOXSHALL & LINCOLN) and D. megacephala (LIN COLN & BOXSHALL) are of a comparable size, but both species are known as ectoparasites of deep-sea asellote isopods from the Southern Hemisphere (BOXSHALL & LINCOLN 1983; LINCOLN & BOXSHALL 1983). T. hoegi is the northernmost record of any deotherthrid and only HANSEN (1913) reported another tantulocaridan from a Northern was found on the (LILLJEBORG) GREVE, whose current distribution pattern suggests that it is a very widespread specie;; in North European waters. It is perhaps premature state that deoterthrid species display more restricted distribution patterns, but in view of their host ficity this might well be attributed to the distribution of the harpacticoid hosts which IS more limited than for asellote or tanaids. ACKNOWLEDGEMENTS Grateful thanks are due to the crew of the R/V Valdiviu during Cruise 95, to the leader of the "R",v"wua Prof. Dr H. Thiel, and to the coordinator FAR-project Dr Arne N0rrevang. Pan of this research was carried out under EEC Science Grant No. ::>1'2*0443 (RH), Erasmus Grant No, ICP-E-()()73 and Grant No, SNF of tht Danish Natural Research Council (RMK), This is communication No. 549 of d"o Centre for Estuarine and Coastal Ecology, Yersekc. REFERENCES Bonnier, J. 1903, Sur deux types nouveaux parasiles d'un Cumace et d'un ~clllz()pcjde Compte rendu h"bdomadaire des seances demie des sciences, Paris 136: Boxshall, G.A. & RJ. Lincoln Tantulocarida, a class of Crustacea eclopar3silic on other crustae,, " ans. - Journal of Crustacean 3: The life cycle of the eea). - Philosophical Transactions ciety of London. B. Biological 303. Hansen, H.J CruSTacea Malacostraca H., IV. The lorder Tanaidacea. - Danish Ingol{EApedirion 3: Huys, R Dierotrichura tricinew gen. el spec, A new tantulocaridan from the Mediterranean Bijdragen tot de Dierkunde 1990a. Campyluxiphos dineti gen, et from off Namibia and a redefinition terthridae Boxshall & Lincoln carida). - Journal of Natural 24: , 1990b. Coralliotantulus coomansi gen. et First record of a tantulocaridan (Crustacea: poda) from subtidal sands in tropical waters, - Stygologia 5: Tantulocarida (Crustacea: a Mew taxon from the temporary S.Z.N.l.: Marine 12:1-34, Huys, R. & G.A. Boxshall A,IC\\ genus and species of tantulocaridan (Crustacea: Tantulocarida) parasitic on a copepod from the Skagerrak. - Sarsia Lincoln, R.J. & G.R Boxshall Deoterthron (Crustacea: tic on a asellote from New Journal of History 17: , Accepted 10 December