Jan H. Stock

Some remarkable distribution patterns in stygobiont Amphipoda

Vicariant distribution patterns in stygobiont amphipod genera can be explained by plate tectonic effects (opening of the Atlantic) and by Tethyan events. Consequently these must be ‘old’ genera. Many stygobionts have congeneric relatives in shallow marine waters. The occurrence of old genera on ‘young’ islands seems to indicate that the young islands must have existed as shallow banks or seamounts in the period when the Atlantic started to open, and before the disruption of the Tethys Sea.

Sur Quelques Copépodes Associés Aux Invertébrés Des Côtes Du Roussillon

Systematic researches undertaken during several short visits to Banyuls, France (Departement des Pyrenees Orientales), have procured 33 species of Copepoda associated with Invertebrata, of which 2 belong to the Harpacticoida, 30 to the Cyclopoida and 1 to the Caligoida. Seven species (numbers 2, 6, 7, 13, 16, 21, 28 of the preceding list) are new to science; of these two had to be referred to new genera. Moreover, six species are new to the Mediterranean (numbers 1, 12, 23, 24, 25, 27) and fifteen are already described species parasiting new hosts (numbers 1, 3, 4, 5, 8, 9, 10, 11, 12, 18, 22, 23, 27, 30, 32, 33).

The freshwater Amphipoda of the Falkland Islands

All four species of freshwater amphipods recorded in the literature from the Falkland Islands were found again during a recent expedition. Hyalella curvispina Shoemaker has been previously recorded, but under several incorrect names. Hyalella neonoma nom. nov. is proposed for the preoccupied name H. patagonica, the commonest species in our collections. Falklandella obtusa Schellenberg and F. cuspidata Schellenberg are completely redescribed, and the latter is removed to a new genus, Praefalklandella. According to their external morphology, the last two genera belong to the Crangonyctoidea, but the calceoli discovered on both antennae of the male of Praefalklandella are surprisingly of the ‘gammarid’ type not the ‘crangonyctid’ type.

Terrestrial Amphipoda (Talitridae) from Ascension and Saint Helena (South Central Atlantic)

Three species of Talitridae have been found well above sea-level (335–853 m) of the islands of Ascension and St Helena in the South Central Atlantic: (1) Platorchestia platensis (Kroyer, 1845), collected on Ascension only, represented by a morphologically and ecologically aberrant morph, provisionally called P. platensis f. monodi (Mateus et al., 1986); (2) Talitriator insularis nov. sp., collected on both islands, and closely related to T. cylindripes K. H. Barnard, 1940 from South Africa; (3) Talitroides alluaudi (Chevreux, 1896), likewise found on both islands, undoubtedly accidentally introduced with vegetation as in many other areas of the world. Remarks are provided on Floresorchestia and on Platorchestia joi nom. nov. (pro P. crassicornis (Derzhavin, 1937), a preoccupied name).

Biogeographic synthesis of the insular groundwater faunas of the (sub) tropical Atlantic.

Anchihaline habitats occur most frequently in subsiding areas. Typically, they are populated by ancestors of marine origin. These ancestral forms have a much wider distribution in the open sea, thus their hypogean descendents occur in phenetically similar populations on various islands. On the contrary, on rising islands, marine ancestors stranded during the uplift and got isolated in brackish or fresh ground waters, giving rise to phenetic and genetic isolates in very restricted areas. They belong to old genera with a large ditribution (amphi-Atlantic or Tethyan) The stygofaunas of both rising and subsiding areas thus originated in the sea, but contrary to the often uttered suggestions, not in the deep-sea. Phenetic resemblance between deep-sea and anchihaline taxa may indicate common ancestry, but then it must be shallow-water ancestry for both, simply because no deep-sea species survived the two oxygen-crises in the early and mid-Tertiary.

Cases of hyperassociation in the Copepoda (Herpyllobiidae and Nereicolidae)

SummaryFour new and one unidentified species of parasitic Copepoda have been found on three species of Polychaeta Polynoidae, inducing galls on hard corals (Stylasterina and Octocorallia) in the bathyal zone of the southern Indian and Pacific Oceans. This is the first case of hyperassociation recorded in the Copepoda. ac]19841115

A new genus and species of Talitridae (Amphipoda) from a cave in Terceira, Azores

A new genus and species of terrestrial talitrid amphipod (land-hopper), Macarorchestia martini, was discovered in a cave on Terceira in the Azores archipelago. The only cave adaptation of the animal appears to be the small size of its eyes.

Two new amphipod crustaceans of the genus Bahadzia from ‘blue holes’ in the Bahamas and some remarks on the origin of the insular stygofaunas of the Atlantic

Bahadzia setimana sp. nov. from South Andros, and B. obliqua sp. nov. from Cat Island, both in the Bahamas, are described. The recently described genus Bahadzia now contains five closely related taxa, each apparently confined to a single island or isolated group of islands, in a restricted area of the West Indies, ranging from Haiti in the south to the northern Bahamas. The present discoveries show not only that low-salinity groundwaters of the West Indies have a marked degree of insular endemism, but that the high-salinity anchihaline habitats possess endemics in certain groups as well. Current models which seek to explain the evolution of stygobionts on Atlantic Islands are reviewed critically and the most likely synthesis is provided.

Deep-water Pycnogonida of the INCAL, BIOGAS, GEOMANCHE and SAFARI cruises

Ten species of deep-water Pycnogonida are recorded, mainly from the north-eastern Atlantic Basin. Of particular interest are Ascorhynchus abyssi Sars (new to the British Isles), Colossendeis arcuata A. Milne Edwards (northernmost record in European waters), C. bicinc0ta Schimkewitsch (third Atlantic record, depth range increased), C. macerrima Wilson (new records from the English Channel), Nymphon laterospinum Stock (new to the Indian Ocean), Pallenopsis (Bathypallenopsis) oscitans (Hoek) (new to the English Channel and bathymetrical range extension), P. (B.) tritonis Hoek (extension of depth range), P. (B.) tydemani caraibica Stock (second European record, now found at the entrance of the English Channel), and Anoplodactylus arnaudae Stock (range extended to the Rockall Trench).

Copepods associated with reef corals: a comparison between the Atlantic and the Pacific

Endoparasitic copepods are very numerous in Indo-West Pacific corals. In West Indian corals they were thought to be absent, but recent studies have shown that a varied endoparasitic copepod fauna exists as well. Striking is the taxonomic composition of the coral-inhabiting copepods: In the Indo-Wcst Pacific Lichomolgidae and Xarifiidae are the dominant families, both are absent in the West Indies. On the other hand, Corallovexiidae and Asterocheridae dominate in the West Indies; the former family is absent and the latter is apparently rare and not very diversified in the Indo-Wcst Pacific.