Search

The taxonomy of the genus Typhlocypris Vejdovský, 1882 is reviewed. New morphological information on Typhlocypris eremita (Vejdovský, 1882), the type species of the genus, is provided, and a new reference material is presented. The generic diagnosis is emended with details derived from the developmental trajectory of the valves, from the juvenile stage A-3 to the adult. Those criteria clearly differentiate Typhlocypris from the related genus Pseudocandona Kaufmann, 1900. As here redefined, Typhlocypris is a phylogentic lineage of the subfamily Candoninae containing extant species presently living in aquatic subterranean habitats and fossil species recovered from non-marine Late Palaeogene to Neogene and Quaternary deposits in Europe and western Asia. The type species of Typhlocypris is considered a metaspecies, taxonomically treated as T. eremita (sensu lato), which includes populations resembling the newly designated reference material. The homeomorphic triangular valve shape of the Candoninae is discussed. Careful examination of the valve morphology of Typhlocypris combined with the analysis of limb traits helps to distinguish representatives of this genus from unrelated phylogenetic groups presenting similar triangularly shaped valves. It is emphasised that for a useful description of Typhlocypris taxa both transmitted light and scanning electron microscopy are necessary.

The taxonomy of the genusTyphlocyprisVejdovský, 1882 is reviewed. New morphological information onTyphlocypris eremita(Vejdovský, 1882), the type species of the genus, is provided, and a new reference material is presented. The generic diagnosis is emended with details derived from the developmental trajectory of the valves, from the juvenile stage A-3 to the adult. Those criteria clearly differentiateTyphlocyprisfrom the related genusPseudocandonaKaufmann, 1900. As here redefined,Typhlocyprisis a phylogentic lineage of the subfamily Candoninae containing extant species presently living in aquatic subterranean habitats and fossil species recovered from non-marine Late Palaeogene to Neogene and Quaternary deposits in Europe and western Asia. The type species ofTyphlocyprisis considered a metaspecies, taxonomically treated asT. eremita(sensu lato), which includes populations resembling the newly designated reference material. The homeomorphic triangular valve shape of the Candoninae is discussed. Careful examination of the valve morphology ofTyphlocypriscombined with the analysis of limb traits helps to distinguish representatives of this genus from unrelated phylogenetic groups presenting similar triangularly shaped valves. It is emphasised that for a useful description ofTyphlocypristaxa both transmitted light and scanning electron microscopy are necessary.

For several groups of Crustacea (especially Remipedia, Malacostraca, and Ostracoda) it has been repeatedly suggested that the antennula (first antenna) is serially homologous with the post-antennular limbs, particularly with regard to the existence of an endopodite and an exopodite. This opinion is critically reviewed and, based on arguments derived from comparative morphology, developmental biology, and phylogeny of various groups belonging to the Arthropoda, ultimately refuted. Available evidence indicates that crustacean antennules are primitively single axis limbs and the use of a terminology derived from a biramous limb, as used in some publications, is both unjustified and potentially misleading. Pour plusieurs groupes de Crustaces (en particulier les Remipedes, les Malacostraces et les Ostracodes), il a ete suggere a plusieurs reprises que l'antennule (premiere antenne) est homologue serielle des appendices post-antennulaires, en particulier par rapport a l'existence d'un endopodite et d'un exopodite. Cette opinion est analysee de facon critique a partir d'arguments provenant de la morphologie comparative, de la biologie du developpement et de la phylogenie de divers groupes d'Arthropodes, et est finalement refutee. Les elements disponibles indiquent avec evidence que les antennules de crustaces sont primitivement des appendices a axe simple et l'usage d'une terminologie derivee d'un appendice birame, observe dans certaines publications, est a la fois injustifie et peut potentiellement induire des erreurs.

The morphology and systematic affinities of Danielopolina sp. cf. D. kornickeri from Christmas Island, an isolated seamount in the Indian Ocean, are reassessed with the aid of new material including a juvenile male. The species is formally described as Danielopolina (Humphreysella) baltanasi sp. n., which places the species in a separate subgenus to Danielopolina (Danielopolina) kornickeri from northwest Australia, the only other member of the genus in the Indian Ocean. In addition, the only deep-sea member of the genus, D. carolynae from the mid-Atlantic, a putative colonizer of seamounts, belongs to the subgenus Danielopolina. These findings compound theories on the distribution and dispersal of anchialine faunas. A coherent programme of molecular phylogenetic research and historical biogeographical analysis is needed to further enquiry into the enigmatic distribution of the anchialine faunas of both isolated sea mounts and epicontinental waters. Owing to the scarcity of anchialine fauna and the difficulty of access of their habitat, a global effort will be required to assemble the required specimens. La morphologie et les affinites systematiques de Danielopolina sp. cf. D. kornickeri de l'ile Christmas, un mont sous-marin isole de l'ocean Indien, sont re-evaluees grâce a du materiel nouveau dont un mâle juvenile. L'espece est officiellement decrite comme Danielopolina (Humphreysella) baltanasi sp. n., qui la place dans un sous-genre distinct de Danielopolina (Danielopolina) kornickeri du nord-ouest de l'Australie, le seul autre membre du genre dans l'ocean Indien. De plus, le seul autre membre profond du genre, D. carolynae de la zone medio-Atlantique, que l'on suppose coloniser les monts-marins, appartient au sous-genre Danielopolina. Ces decouvertes compliquent les theories sur la repartition et la dispersion des faunes anchihalines. Un programme coherent de recherche sur la phylogenie moleculaire et l'analyse biogeographique historique sera necessaire pour eclaircir ulterieurement la repartition enigmatique des faunes anchihalines a la fois des monts sous-marins isoles et des eaux epicontinentales. En raison de la rarete de la faune anchihaline et de la difficulte d'acces a son habitat, un effort global sera necessaire afin de rassembler les specimens requis.

[The morphology and the systematic affinities of a unique juvenile specimen (post embryonic stage 1) of the ostracode, Danielopolina (family Thaumatocyprididae) are described. It was found in an anchialine cave of Christmas Island, an isolated seamount, and this is the second record of a Danielopolina species in the Indian Ocean. A comparative study of this individual with those belonging to the other 11 Danielopolina species suggests closer morphological affinities to the Australian species, D. kornickeri. In addition, our study allows the separation of the species of Danielopolina into the two new subgenera, Danielopolina and Humphreysella. Tabular keys are provided for the identification of the species belonging to these subgenera. La morphologie et les affinites systematiques d'un specimen juvenile unique (1er stade post-embryonnaire) d'un ostracode appartenant au genre Danielopolina (famille des Thaumatocyprididae) sont decrites. Cet ostracode a ete trouve dans une grotte anchialine de l'ile Christmas, un mont sous-marin isole, et c'est la seconde espece de Danielopolina rencontree dans l'ocean Indien. Une etude comparee de cet exemplaire et des 11 especes du genre Danielopolina suggere des affinites morphologiques plus etroites avec l'espece australienne D. kornickeri. De plus, notre etude a permis de separer les especes de ce genre en deux sous-genres nouveaux, Danielopolina et Humphreysella. Des cles d'identification des especes de ces sous-genres sont presentees., The morphology and the systematic affinities of a unique juvenile specimen (post embryonic stage 1) of the ostracode, Danielopolina (family Thaumatocyprididae) are described. It was found in an anchialine cave of Christmas Island, an isolated seamount, and this is the second record of a Danielopolina species in the Indian Ocean. A comparative study of this individual with those belonging to the other 11 Danielopolina species suggests closer morphological affinities to the Australian species, D. kornickeri. In addition, our study allows the separation of the species of Danielopolina into the two new subgenera, Danielopolina and Humphreysella. Tabular keys are provided for the identification of the species belonging to these subgenera. La morphologie et les affinites systematiques d'un specimen juvenile unique (1er stade post-embryonnaire) d'un ostracode appartenant au genre Danielopolina (famille des Thaumatocyprididae) sont decrites. Cet ostracode a ete trouve dans une grotte anchialine de l'ile Christmas, un mont sous-marin isole, et c'est la seconde espece de Danielopolina rencontree dans l'ocean Indien. Une etude comparee de cet exemplaire et des 11 especes du genre Danielopolina suggere des affinites morphologiques plus etroites avec l'espece australienne D. kornickeri. De plus, notre etude a permis de separer les especes de ce genre en deux sous-genres nouveaux, Danielopolina et Humphreysella. Des cles d'identification des especes de ces sous-genres sont presentees.]

The genus Danielopolina is reported from an isolated seamount, Christmas Island, Indian Ocean, where it is known, for the first time, in sympatry with a Procaridid Type of anchialine community. We explain the significance of the juxtaposition in this geographical and geological context and explore the role of active and passive dispersal in the colonization of remote seamount islands.

Pseudocandona sywulai sp. nov. (Ostracoda, Candonidae) collected in the cave Ðuderina, Croatia, is described and illustrated. The new species belongs to the eremita-species group of the genus Pseudocandona Kaufmann and can be distinguished from its congeners belonging to this group mainly by the shape and size of the carapace as well as by the chaetotaxy of the second antenna. It resembles P. eremita (Vejdovský, 1880) sensu lato very closely. A comparative morphological analysis of the species belonging to this group is presented also.

Cryptocandona phreaticola(Kiefer & Klie, 1927) and C. leruthi (Klie, 1936) are redecribed on the basis of type specimens, which allows (1) to present their morphology in detail, (2) to compare both species, and (3) to emphasize differential diagnostic characters of these species within the genus. They appear to be similar to each other and to come close to C. kieferi (Klie, 1938). Known data on the distribution and ecology of both redescribed species are also briefly summarized.

Cryptocandona brehmi (Klie, 1934) was collected from a cave in Japan; it differs markedly from the European Cryptocandona species colonizing subsurface waters. The redescription of the type material of this species allows to detail its peculiar morphological characteristics and to define its phylogenetic position within the genus Cryptocandona. C. brehmi displays closer phylogenetic affinities with the epigean species C.reducta (Alm, 1914), widely distributed in Europe. Both species form a lineage which appears more primitive than the other representatives of Cryptocandona. C. brehmi could belong to a psychrophilous fauna which spread from Europe toward eastern Asia during the Pleistocene.

During a 13 month project Stenasellus virei boui Magniez, 1968, living in the alluvial sediments of the Nert stream (near Saint Girons, Ariege), were sampled monthly in an area of 30 m2 at depths of 0.6 and 1.0 m. Isopods were found over the whole area at low frequencies: 91% of the samples contained 1-5 specimens and a total of 140 individuals was caught. After each sampling series, the sites were baited and re-sampled the next day. The isopods aggregated rapidly (up to 148 specimens/sample) around the bait, especially in interstitial areas with high permeability, and more than 2,000 additional individuals were caught with this technique. The experiment documents that S. virei boui is represented in the field by an unexpectedly large perennial population, even in superficial sediments. The animals actively react to chemical cues, moving rapidly through the interstitial space. The data also point out that the interstitial habitat and the isopods that are adapted to live within it, together build a complex ecological system. Lors d'une etude poursuivie pendant treize mois, Stenasellus virei boui Magniez, 1968, qui vit dans les sediments alluviaux du Nert (pres de Saint-Girons, Ariege), a fait l'objet de prelevements mensuels sur une aire de 30 m2, a 0,6 m et 1,0 m de profondeur. Cet Isopode a ete recolte sur la totalite de l'aire prospectee mais avec une frequence peu elevee: 91% des prelevements contenaient 1 a 5 specimens et un total de 140 individus ont ete recoltes. Apres chaque serie de prelevements, les sites etudies ont ete appates puis preleves a nouveau le jour suivant. Les Isopodes se rassemblaient rapidement autour des appats (jusqu'a 148 individus par site), essentiellement dans les zones a permeabilite elevee. Plus de 2000 individus additionnels ont ete captures par cette technique. Les donnees obtenues montrent que S. virei boui peut former des populations abondantes dans des sediments relativements superficiels; les animaux repondent activement aux informations chimiques en se deplacant rapidement dans les espaces interstitiels. Ainsi est suggere le fait que l'habitat interstitiel et les Isopodes qui lui sont adaptes forment un systeme ecologique plus complexe qu'on ne le pensait.

One of the persistent themes of subterranean biology during this century was the inventory of the aquatic fauna on a large geographic scale. At the beginning of the century Racovitza (1913) proposed to create, for this purpose, an interna tional organization called "Biospeologica". In a period of more than 40 years, hundreds of caves were explored on several continents and the faunistic results have been reported in many publications. Soon it became apparent that subter ranean waters are widely inhabited by old, endemic species, which have their closer relatives in the marine environment. Racovitza, in a metaphorical way, pointed out that caves, being filled with numerous "living fossils", could be considered as a kind of natural museums. The attraction for the discovery of hypogean "living fossils" and the search for the explanation of their historical origin was pursued by several generations of naturalists. It also captivated the interest of Jan H. Stock, as we shall briefly review below. By the middle of this century, biologists noted that not only caves with fresh water habitats are ecologically and biogeographically highly interesting for the knowledge of subterranean biodiversity, a situation already well documented by the "Biospeologica" contributors. Also other environments, however, like the porous sediments in coastal marine areas and along their inland valleys, are rich in endemic species. Furthermore, it was recently discovered that marine caves opening into sub-aerial and/or submarine areas, harbour numerous "living fossils" as well. Jan Stock, at the beginning of his career as a carcinologist, studied mainly copepods and amphipods (Wagner, this issue). His first publications on ground