Denise Bellan-Santini

Relationship between populations of amphipods and pollution

Abstract The composition and distribution of the amphipods inhabiting rocky environments in the French Mediterranean coast have been studied over the past 18 yr with particular emphasis upon pollution. The results from 203 quantitative samples, each consisting of 400 cm2 area were analysed as to species, number of specimens, partial dominance, Shannon-Weaver and Margalef Index of diversity and similarity index of Sanders. Included were 35 species of gammarids and 4 species of caprellids which were represented by over 90 000 individuals. An inverse relationship was found to exist between the richness of the population and the degree of pollution. No caracteristic group of species was linked to areas affected by pollution, but certain species were excluded by more severe pollution whereas the number of specimens of some other species increased, a certain balance between two preferential groups as indicated.

Biodiversity in the ecosystem of the Portuguese continental shelf: distributional ecology and the role of benthic amphipods

The biodiversity and distributional ecology of amphipod crustaceans were analysed from benthic surveys in 1985 and 1986 along the coast of Portugal, from the Tagus canyon to the coast of Minho, in order to determine their role in the ecosystem of the Portuguese continental self. In samples obtained from different types of substrate between 18 and 545 m, we identified 113 species belonging to 51 genera of 24 families. Seventeen of these species were new records for the Portuguese coast. The relative frequencies and number of individuals of all species were analysed. The genus Ampelisca clearly dominated the group of the most frequent and abundant species, which also exhibited a large range of vertical distribution. Most of the 113 species were found only down to 150 m depth, corresponding roughly to the lower limit of the continental shelf. Fifteen species exhibited clear bathyal traits, being consistently found deeper than 100 m, especially in the Tagus canyon and the upper zone of the continental slope. The most frequent and abundant species were found predominatly or in large numbers in medium to fine sand bottoms. This type of substrate also contained the highest number of species. The granulometric structure of the habitat could constitute the most important factor controlling both biodiversity and development of large amphipod populations, since oxygen level, water exchange, number of available shelters, and probably the quantity and quality of nutritional resources all vary as a function of substrate texture. Because of their dominance in both frequency and abundance, several Ampelisca species may constitute an important food source for many secondary consumers of the shelf sediments, especially for demersal fishes.

Illustrated Key to Ampelisca Species from the North-Eastern Atlantic

The genus Ampelisca comprises more than 150 species and is one of the more important benthic genus of marine amphipods. New species are regularly added (Barnard & Agard 1986; Bellan-Santini & Marques, 1986; Goeke, 1987). Ampelisca are found from the intertidal zone to abyssal depths but most of them live on the continental shelf. In spite of many studies, it is often difficult to distinguish some species which are morphologically similar. In the last ten years, twenty-two species have been described from the north-eastern Atlantic (BellanSantini & Kaim-Malka, 1977; Bellan-Santini & Dauvin, 1981, 1986; Dauvin & Bellan-Santini, 1982, 1985; Bellan-Santini & Marques, 1986). Materials come from MNHN of Paris collection, collected by Chevreux (1894–1924) (Dauvin & Bellan-Santini, 1985, 1986) and specimens collected during the last 25 years. All these new species are described from the Atlantic coast from northern Brittany to the Sahara and from the Mediterranean Sea.

The Benthic Amphipod Fauna of the Azores (Portugal): an Up-To-Date Annotated List of Species, and Some Biogeographic Considerations

The Azores archipelago, located in the middle north Atlantic region, is biogeographically very interesting. With regard to the benthic amphipod fauna there are only few studies that concern the Azores, although species inventory and distributional ecology are relatively well known for the Portuguese continental coast (0 to 700 m). Actually, the knowledge of benthic amphipods from the Azores is limited to the results of two oceanographical expeditions, that took place in the first half of this century, and to data provided by some relatively recent papers and several other sporadic references. Moreover, this knowledge is mainly or exclusively taxonomic. Benthic amphipod dispersal capability is small compared to that of molluscs, decapods or fishes. They have direct development and a reduced swimming capability, and their migrations, both nictemeral and horizontal, cannot compensate these features. This limited dispersal capability determines a clear endemic tendency, and a reduced probability of global fauna mixtures. Therefore, amphipods constitute a fine biological material for biogeographic studies. In order to provide a tool for biogeographical comparisons, the available data on the Azores amphipod fauna were compiled. A review of the available literature and the study of several collections from the Azores, sampled during 1988 and 1989 at the islands of S. Miguel and Faial, provided a list of 122 species from 29 families. Thirty species were identified from the study of the S. Miguel and Faial collections, of which 15 (50%) are new records for the Azores, which emphasizes the existing lack of knowledge. One Ampithoe species might be new, and will be further studied, although it will be necessary to collect more specimens. Additionally, some available ecological data for each species arc given in the present paper.

Amphipoda of the hydrothermal vents along the mid-Atlantic Ridge

During the FARA programme, hydrothermal sites were discovered and studied on the mid-Atlantic Ridge. Amphipods were collected during Alvin dives at two sites: Lucky Strike and Snake Pit. Four new species are described: Gitanopsis alvina, Bouvierella curtirama, Luckia striki and Steleuthera ecoprophycea, one of which requires the new genus Luckia. No Lysiannassoidea on Pardaliscidae have been collected at the Atlantic sites although together they represent more than 99% of collections made at vent localities in the East Pacific. This difference is discussed together with the different trophic groups characteristic of hydrothermal vents.

An overview of the amphipod genus Haploops (Ampeliscidae)

Available data concerning the taxonomy, biology, ecology and biogeography of the genus Haploops is presented. The genus, represented by 15 valid species, is typically associated with deep and cold waters. Haploops is confined to the Arctic, north Atlantic and north Pacific Oceans with the exception of two Tasmanian species. Phyletic relationships show four principal groups of species, but there is no clear correlation between these groups and their biogeographical distribution. The biology of Haploops is typical of the biology of a cold-water amphipod. The distribution and the biology of Haploops is contrasted with that of Ampelisca , another genus of the family Ampeliscidae.

Ampeliscidae (Amphipoda) from iceland with a description of a new species (Contribution to the BIOICE research programme)

This work presents the study of an Ampeliscidae collection sampled during the BIOICE-programme around Iceland. Ampeliscids were present at 164 stations with 4467 individuals. Sixteen species were identified: nine Ampelisca, three Byblis and four Haploops. A new species, Ampelisca islandica n.sp., is described. It is very close to Ampelisca odontoplax Sars, 1895 and is characterized by an elevated posteriorly pointed dorsal carina on urosome segment 1 the posterior edge of which overreaches urosome 2, and by having the outer ramus of uropod 2 with a long subterminal spine. The data established the vertical distributions of four species: the lower bathyal limit for three species and the upper bathyal limit for two species. The most abundant species were Byblis gaimardi, B. minuticornis, Ampelisca macrocephala, A. aequicornis, and A. uncinata. The ampeliscids can be classified in five groups in relation to bathymetry: (1) species from the continental shelf and the upper part of the continental slope to 800 m...

Ampeliscidae (Amphipoda) from the Bay of Biscay

ABSTRACT Recent collections from the southern part of the Bay of Biscay furnished an interesting collection of Ampeliscidae. Eighteen species were identified, among them 3 species new to science, Ampelisca parabyblisoides, Ampelisca sorbei, and Haploops gascogni, and 3 species new for this area, Ampelisca declivitatis Mills, 1967, and Haploops similis Stephensen, 1925, previously known from the northwestern Atlantic waters, and Ampelisca pusilla Sars, 1891, previously found on the coast of Norway. The presence of Ampelisca anomala Sars, 1883, in the Bay of Biscay was confirmed. We discuss here the geographical and bathymetric distribution of the Ampeliscidae from the Bay of Biscay, and their relationships with the species from Atlantic shallow and deep-sea areas.

Stenothoidae (Crustacea: Amphipoda) of hydrothermal vents and surroundings on the Mid‐Atlantic Ridge, Azores Triple Junction zone

Four new species of Stenothoidae were collected from the Azores Triple Junction zone during different French cruises on the Mid‐Atlantic Ridge. One of the species belongs to the genus Torometopa (T. saldanhae) and is the first record of this genus in the Atlantic Ocean. The three other species belong to the genus Stenothoe (S. divae, S. marvela, and S. menezgweni). It is not possible to determine from morphological and ecological characters whether these amphipod species are endemic to hydrothermal systems or are bathyal species that may be found away from vent sites.

Rhachotropis species (Crustacea: Amphipoda: Eusiridae) of hydrothermal vents and surroundings on the Mid‐Atlantic Ridge, Azores Triple Junction zone

Three new species of Rhachotropis were collected from the Azores Triple Junction zone during three cruises on the Mid‐Atlantic Ridge, by three sediment traps deployed on or near vent sites Lucky Strike (37°17′N, 32°16′W, 1686 m depth) and Rainbow (36°14′N, 33°54′W, 2250 m depth). A key of the Atlantic Rhachotropis is proposed.